B. H. Hahn

The levels of evidence supporting the recommendations (A-C) are defined at the end of the "Major Recommendations" field.

Renal Biopsy and Histology

The Task Force Panel recommended that all patients with clinical evidence of active lupus nephritis (LN), previously untreated, undergo renal biopsy (unless strongly contraindicated) so that glomerular disease can be classified by current International Society of Nephrology/Renal Pathology Society (ISN/RPS) classification (level C evidence) (see Table 1 in the original guideline document for ISN/RPS classification of LN). In addition, disease can be evaluated for activity and chronicity and for tubular and vascular changes. Finally, biopsies may identify additional or alternative causes of renal disease, such as tubular necrosis related to medications, hypovolemia, or hypotension. Biopsy is most highly recommended in patients with the characteristics indicated in the following table.

Table. Indications for Renal Biopsy in Patients with Systemic Lupus Erythematosus

	Level of Evidence
Increasing serum creatinine without compelling alternative causes (such as sepsis, hypovolemia, or medication)	C
Confirmed proteinuria of ≥1.0 gm per 24 hours (either 24-hour urine specimens or spot protein/creatinine ratios are acceptable)	C
Combinations of the following, assuming the findings are confirmed in at least two tests done within a short period of time and in the absence of alternative causes: Proteinuria ≥0.5 gm per 24 hours plus hematuria, defined as ≥5 RBCs per hpf Proteinuria ≥0.5 gm per 24 hours plus cellular casts	C

RBCs = red blood cells; hpf = high-power field.

The Task Force Panel recommended that treatment be based in large part on the classification of type of LN by these ISN/RPS criteria. As a result, the following recommendations are presented according to the histologic classification of nephritis. The Task Force Panel agreed that class I (minimal mesangial immune deposits on immunofluorescence with normal light microscopy) and class II (mesangial hypercellularity or matrix expansion on light microscopy with immune deposits confined to mesangium on immunofluorescence) generally do not require immunosuppressive treatment (level C evidence). In general, patients with class III (subendothelial immune deposits and proliferative changes in <50% of glomeruli) and class IV (subendothelial deposits and proliferative glomerular changes involving ≥50% of glomeruli) require aggressive therapy with glucocorticoids and immunosuppressive agents. Class V (subepithelial immune deposits and membranous thickening of glomerular capillaries) when combined with class III or IV should be treated in the same manner as class III or IV. Class V alone ("pure membranous LN") may be approached somewhat differently, as indicated below under "Recommendations for Induction of Improvement in Patients with Class V 'Pure Membranous' LN". Histologic class VI (sclerosis of ≥90% of glomeruli) generally requires preparation for renal replacement therapy rather than immunosuppression. The designations "A" and "C" indicate whether active or chronic changes are present; the higher the chronicity the less likely that the nephritis will respond to immunosuppression. However, A or C classifications were not included in the entry criteria for clinical trials in LN published to date, and therefore they are not considered in the recommendations.

Adjunctive Treatments

The Task Force Panel recommended that all systemic lupus erythematosus (SLE) patients with nephritis be treated with a background of hydroxychloroquine (HCQ; level C evidence), unless there is a contraindication.

All LN patients with proteinuria ≥0.5 gm per 24 hours (or equivalent by protein/creatinine ratios on spot urine samples) should have blockade of the renin–angiotensin system, which drives intraglomerular pressure (level A evidence for nondiabetic chronic renal disease). Treatment with either angiotensin-converting enzyme (ACE) inhibitors or angiotensin receptor blockers (ARBs) reduces proteinuria by approximately 30%, and significantly delays doubling of serum creatinine and progression to end-stage renal disease in patients with nondiabetic chronic renal disease. These classes of medications are contraindicated in pregnancy. The use of combination ACE inhibitors/ARB therapies is controversial. ACE inhibitors or ARB treatments are superior to calcium-channel blockers and diuretics alone in preserving renal function in chronic kidney disease.

The Task Force Panel recommended that careful attention be paid to control of hypertension, with a target of ≤130/80 mm Hg (level A evidence for nondiabetic chronic renal disease). The Task Force Panel also recommended that statin therapy be introduced in patients with low-density lipoprotein cholesterol >100 mg/dl (level C evidence). Note that a glomerular filtration rate <60 ml/minute/1.73 m² (equivalent to a serum creatinine level >1.5 mg/dl or 133 µmoles/liter) is a risk factor for accelerated atherosclerosis. SLE itself is also an independent risk factor for accelerated atherosclerosis.

Finally, the Task Force Panel recommended that women of child-bearing potential with active or prior LN receive counseling regarding pregnancy risks conferred by the disease and its treatments (level C evidence).

Recommendations for Induction of Improvement in Patients with ISN Class III/IV Lupus Glomerulonephritis

The Task Force Panel recommended mycophenolate mofetil (MMF) (2–3 gm total daily orally) or intravenous (IV) cyclophosphamide (CYC) along with glucocorticoids (level A evidence) (see Figure 2 in the original guideline document). MMF and CYC are considered equivalent based on recent high-quality studies, a meta-analysis, and expert opinion. Long-term studies with MMF are not as abundant as those with CYC; data show good results for induction therapy with MMF of 3 gm total dose daily for 6 months, followed by maintenance with lower doses of MMF for 3 years. MMF has been similar in efficacy in all races studied to date (whites, Asians, African Americans, and Latin/Hispanic Americans). The Aspreva Lupus Management Study (ALMS) trial comparing response rates of LN to MMF plus glucocorticoids showed similar improvement in whites, Asians, and other races (primarily African Americans and Hispanics). However, The Task Force Panel voted that Asians compared to non-Asians might require lower doses of MMF for similar efficacy (level C evidence). Therefore, the physician might aim for 3 gm per day total daily highest dose in non-Asians and 2 gm per day in Asians. There is evidence that African Americans and Hispanics with LN respond less well to IV CYC than do patients of white or Asian races. MMF/mycophenolic acid (MPA) may be an initial choice more likely to induce improvement in patients who are African American or Hispanic.

The exact suggested dose of MMF varied based on the clinical scenario: for those with class III/IV without cellular crescents and for those with proteinuria and a stable creatinine for whom a renal biopsy sample cannot be obtained, both 2 gm and 3 gm total daily doses were acceptable to the Task Force Panel, while a dose of 3 gm daily was favored for those with class III/IV and crescents and for those with proteinuria and a recent significant rise in creatinine.

Some evidence suggests that MPA and enteric-coated mycophenolate sodium are less likely than MMF to cause nausea and diarrhea, but this is controversial, and the exact equivalency of the preparations is not firmly established. The Core Expert Panel recommended that MMF and MPA are likely to be equivalent in inducing improvement of LN, with 1,440–2,160 mg total daily dose of MPA roughly equivalent to 2,000–3,000 mg total daily dose of MMF. Some investigators have suggested that serum levels of MPA, the active metabolite of MMF, should be measured at the trough or peak (1 hour after a dose), and treatment of SLE should be guided by these levels. However, there are not enough data at this time to make recommendations for monitoring of drug levels.

There are two regimens of IV CYC recommended by the Task Force Panel: 1) low-dose "Euro-Lupus" CYC (500 mg IV once every 2 weeks for a total of 6 doses), followed by maintenance therapy with daily oral azathioprine (AZA) or daily oral MMF (level B evidence), and 2) high-dose CYC (500–1,000 mg/m² IV once a month for 6 doses), followed by maintenance treatment with MMF or AZA (level A evidence) (see Figure 2 in the original guideline document). If CYC is being considered for treatment, the Core Expert Panel recommended IV CYC at the low "Euro-Lupus" dose for white patients with Western European or Southern European racial/ethnic backgrounds (level B evidence). In European study patients, the low- and high-dose regimens were equivalent in efficacy, and serious infections were less frequent with the lower doses. The low- and high-dose regimens have not been compared in nonwhite racial groups. Ten years of followup comparing low- and high-dose regimens showed similar rates of LN flares, end-stage renal disease, and doubling of the serum creatinine.

Pulse IV glucocorticoids (500–1,000 mg methylprednisolone daily for 3 doses) in combination with immunosuppressive therapy is recommended by the Task Force Panel, followed by daily oral glucocorticoids (0.5–1 mg/kg/day), followed by a taper to the minimal amount necessary to control disease (level C evidence). There are insufficient data to recommend a specific steroid taper because the nephritis and extrarenal manifestations vary from patient to patient. There was no consensus reached regarding the use of monthly IV methylprednisolone with monthly IV CYC.

Although AZA has been used to treat LN, the Task Force Panel did not recommend it as one of the first choices for induction therapy.

The panel recommends that most patients be followed for 6 months after initiation of induction treatment with either CYC or MMF before making major changes in treatment other than alteration of glucocorticoid doses, unless there is clear evidence of worsening at 3 months (50% or more worsening of proteinuria or serum creatinine; level A evidence).

Fertility issues are often a concern for young SLE patients with nephritis. In a discussion, the Task Force Panel recommended that MMF was preferable to CYC for patients who express a major concern with fertility preservation, since high-dose CYC can cause permanent infertility in both women and men (level A evidence of gonadal toxicity). Six months of high-dose IV CYC was associated with approximately 10% sustained infertility in young women, and higher rates in older women. If 6 months of CYC were followed by quarterly doses, there was a higher rate of infertility. The Task Force Panel did not reach a consensus on the use of leuprolide in patients with SLE receiving CYC as a means to preserve fertility. They also noted that MMF is teratogenic (class D in US Food and Drug Administration [FDA] ranking). Therefore, the physician should be sure that a patient is not pregnant before prescribing MMF or MPA, and the medications should be stopped for at least 6 weeks before pregnancy is attempted.

Recommendations for Induction of Improvement in Patients with Class IV or IV/V Plus Cellular Crescents

The Task Force Panel recommended either CYC or MMF for induction of improvement in this type of LN (level C evidence), along with IV pulses of high-dose glucocorticoid and initiation of oral glucocorticoids at the higher-range dosage, 1 mg/kg/day orally (see Figure 2 in the original guideline document). For the purpose of these recommendations statements, the presence of any crescents on a renal biopsy sample was considered crescentic LN. Until recently, experts have favored high-dose IV CYC for treatment of LN with cellular crescents. In general, the presence of crescents indicates a poorer prognosis, even with appropriate treatment. Further recommendations for a pregnant patient with crescentic glomerulonephritis are provided in the section on "Treatment of LN in Patients Who Are Pregnant," below.

Recommendations for Induction of Improvement in Patients with Class V "Pure Membranous" LN

The Task Force Panel recommends that patients with pure class V LN and with nephrotic range proteinuria be started on prednisone (0.5 mg/kg/day) plus MMF 2–3 gm total daily dose (level A evidence) (see Figure 3 in the original guideline document).

Other therapies for membranous LN have been reported; however, the Task Force Panel did not reach consensus on a recommendation regarding those therapies.

Recommendations for Maintaining Improvement in Patients Who Respond to Induction Therapy

The Task Force Panel recommended that either AZA or MMF be used for maintenance therapy (level A evidence) (see Figure 2 in the original guideline document). The Task Force Panel did not vote on the rate of medication taper during the maintenance phase; to date, there are no adequate data to inform the physician regarding how rapidly AZA or MMF can be tapered or withdrawn.

Recommendations for Changing Therapies in Patients Who Do Not Respond Adequately to Induction Therapy

In patients who fail to respond after 6 months of treatment (based on the treating physician's clinical impression) with glucocorticoids plus MMF or CYC, the Task Force Panel recommends a switch of the immunosuppressive agent from either CYC to MMF, or from MMF to CYC, with these changes accompanied by IV pulses of glucocorticoids for 3 days (level C evidence) (see Figure 2 in the original guideline document). For CYC, either low dose or high dose can be used in white individuals, as discussed above in the section on "Recommendations for Induction of Improvement in Patients with ISN Class III/IV Lupus Glomerulonephritis," above. Evidence to support these opinions is not as strong as evidence for the efficacy of initial induction therapy. The panel also voted that in some cases rituximab can be used in patients whose nephritis fails to improve or worsens after 6 months of one induction therapy, or after the patient has failed both CYC and MMF treatments (level C evidence). The Task Force Panel did not reach consensus regarding the use of calcineurin inhibitors in this setting; however, there is evidence for their efficacy as an induction agent and in refractory disease.

There is evidence in open-label trials that LN may respond to rituximab treatment. Prospective, randomized, placebo-controlled trials did not show a significant difference between rituximab and placebo (on a background of MMF and glucocorticoids) after 1 year of treatment.

Evidence to support the use of cyclosporine or tacrolimus in LN is from open trials and recent prospective clinical trials; additional prospective trials are in progress. In a recent prospective trial, tacrolimus was equivalent to high-dose IV CYC in inducing complete and partial remissions of LN over a 6-month period. In another 4-year–long prospective trial, cyclosporine was similar to AZA in preventing renal flares in patients receiving maintenance therapy.

If nephritis is worsening in patients treated for 3 months with glucocorticoids plus CYC or MMF, the Task Force Panel recommended that the clinician can choose any of the alternative treatments discussed (level C evidence). Although combinations of MMF and calcineurin inhibitors and of rituximab and MMF are being studied and might be considered for those who have failed the recommended induction therapies, data are not robust enough at this time to include them for voting scenarios.

The FDA has approved belimumab for use in seropositive patients with SLE who have active disease in spite of prior therapies.

Identification of Vascular Disease in Patients with SLE and Renal Abnormalities

Several types of vascular involvement can occur in renal tissue of SLE, including vasculitis, fibrinoid necrosis with narrowing of small arteries/arterioles ("bland" vasculopathy), thrombotic microangiopathy, and renal vein thrombosis. In general, vasculitis is treated similarly to the more common forms of LN discussed above. Bland vasculopathy is highly associated with hypertension; it is not clear which comes first, SLE or hypertension. Thrombotic microangiopathy can be associated with a thrombotic thrombocytopenia–like picture. The Task Force Panel recommended that thrombotic microangiopathy be treated primarily with plasma exchange therapy (level C evidence)

Treatment of LN in Patients Who Are Pregnant

The Task Force Panel recommended several approaches for management of LN in women who are pregnant (all level C evidence) (see Figure 4 in the original guideline document). In patients with prior LN but no current evidence of systemic or renal disease activity, no nephritis medications are necessary. Patients with mild systemic activity may be treated with HCQ; this probably reduces activity of SLE during pregnancy. If clinically active nephritis is present, or there is substantial extrarenal disease activity, the clinician may prescribe glucocorticoids at doses necessary to control disease activity, and if necessary AZA can be added. High-dose glucocorticoid therapy in patients with SLE is associated with a high risk of maternal complications such as hypertension and diabetes mellitus. MMF, CYC, and methotrexate should be avoided because they are teratogenic in humans. Although AZA is listed as pregnancy category D in Micromedex, cross-sectional studies have shown that the risk of fetal abnormalities is low. The dose of AZA should not exceed 2 mg/kg in a pregnant woman. For patients with a persistently active nephritis with documented or suspected class III or IV with crescents, consideration of delivery after 28 weeks for a viable fetus is recommended.

Monitoring Activity of LN

Recommendations for monitoring LN are shown in the following table, and result from votes of the Task Force Panel (level C evidence).

Table. Recommended Monitoring of Lupus Nephritis*

	Blood Pressure	Urinalysis	Protein/Creatinine Ratio	Serum Creatinine	C3/C4 Levels	Anti-DNA
Active nephritis at onset of treatment	1	1	1	1	2†	3
Previous active nephritis, none currently	3	3	3	3	3	6
Pregnant with active GN at onset of treatment	1	1	1	1	1	1
Pregnant with previous nephritis, none currently	1	1	3	3	3	3
No prior or current nephritis	3	6	6	6	6	6

*Values are the monthly intervals suggested as the minimum frequency at which the indicated laboratory tests should be measured in the systemic lupus erythematosus scenarios shown in the left-hand column. GN = glomerulonephritis.
†Opinion of authors based on a study published after the Task Force Panel had voted.

Definitions:

Level of Evidence

• Level of Evidence A: Data derived from multiple randomized clinical trials
• Level of Evidence B: Data derived from a single randomized trial, or nonrandomized studies
• Level of Evidence C: Only consensus opinion of experts, case studies, or standard-of-care

The levels of evidence supporting the recommendations (A-C) are defined at the end of the "Major Recommendations" field.

Renal Biopsy and Histology

The Task Force Panel recommended that all patients with clinical evidence of active lupus nephritis (LN), previously untreated, undergo renal biopsy (unless strongly contraindicated) so that glomerular disease can be classified by current International Society of Nephrology/Renal Pathology Society (ISN/RPS) classification (level C evidence) (see Table 1 in the original guideline document for ISN/RPS classification of LN). In addition, disease can be evaluated for activity and chronicity and for tubular and vascular changes. Finally, biopsies may identify additional or alternative causes of renal disease, such as tubular necrosis related to medications, hypovolemia, or hypotension. Biopsy is most highly recommended in patients with the characteristics indicated in the following table.

Table. Indications for Renal Biopsy in Patients with Systemic Lupus Erythematosus

	Level of Evidence
Increasing serum creatinine without compelling alternative causes (such as sepsis, hypovolemia, or medication)	C
Confirmed proteinuria of ≥1.0 gm per 24 hours (either 24-hour urine specimens or spot protein/creatinine ratios are acceptable)	C
Combinations of the following, assuming the findings are confirmed in at least two tests done within a short period of time and in the absence of alternative causes: Proteinuria ≥0.5 gm per 24 hours plus hematuria, defined as ≥5 RBCs per hpf Proteinuria ≥0.5 gm per 24 hours plus cellular casts	C

RBCs = red blood cells; hpf = high-power field.

The Task Force Panel recommended that treatment be based in large part on the classification of type of LN by these ISN/RPS criteria. As a result, the following recommendations are presented according to the histologic classification of nephritis. The Task Force Panel agreed that class I (minimal mesangial immune deposits on immunofluorescence with normal light microscopy) and class II (mesangial hypercellularity or matrix expansion on light microscopy with immune deposits confined to mesangium on immunofluorescence) generally do not require immunosuppressive treatment (level C evidence). In general, patients with class III (subendothelial immune deposits and proliferative changes in <50% of glomeruli) and class IV (subendothelial deposits and proliferative glomerular changes involving ≥50% of glomeruli) require aggressive therapy with glucocorticoids and immunosuppressive agents. Class V (subepithelial immune deposits and membranous thickening of glomerular capillaries) when combined with class III or IV should be treated in the same manner as class III or IV. Class V alone ("pure membranous LN") may be approached somewhat differently, as indicated below under "Recommendations for Induction of Improvement in Patients with Class V 'Pure Membranous' LN". Histologic class VI (sclerosis of ≥90% of glomeruli) generally requires preparation for renal replacement therapy rather than immunosuppression. The designations "A" and "C" indicate whether active or chronic changes are present; the higher the chronicity the less likely that the nephritis will respond to immunosuppression. However, A or C classifications were not included in the entry criteria for clinical trials in LN published to date, and therefore they are not considered in the recommendations.

Adjunctive Treatments

The Task Force Panel recommended that all systemic lupus erythematosus (SLE) patients with nephritis be treated with a background of hydroxychloroquine (HCQ; level C evidence), unless there is a contraindication.

All LN patients with proteinuria ≥0.5 gm per 24 hours (or equivalent by protein/creatinine ratios on spot urine samples) should have blockade of the renin–angiotensin system, which drives intraglomerular pressure (level A evidence for nondiabetic chronic renal disease). Treatment with either angiotensin-converting enzyme (ACE) inhibitors or angiotensin receptor blockers (ARBs) reduces proteinuria by approximately 30%, and significantly delays doubling of serum creatinine and progression to end-stage renal disease in patients with nondiabetic chronic renal disease. These classes of medications are contraindicated in pregnancy. The use of combination ACE inhibitors/ARB therapies is controversial. ACE inhibitors or ARB treatments are superior to calcium-channel blockers and diuretics alone in preserving renal function in chronic kidney disease.

The Task Force Panel recommended that careful attention be paid to control of hypertension, with a target of ≤130/80 mm Hg (level A evidence for nondiabetic chronic renal disease). The Task Force Panel also recommended that statin therapy be introduced in patients with low-density lipoprotein cholesterol >100 mg/dl (level C evidence). Note that a glomerular filtration rate <60 ml/minute/1.73 m² (equivalent to a serum creatinine level >1.5 mg/dl or 133 µmoles/liter) is a risk factor for accelerated atherosclerosis. SLE itself is also an independent risk factor for accelerated atherosclerosis.

Finally, the Task Force Panel recommended that women of child-bearing potential with active or prior LN receive counseling regarding pregnancy risks conferred by the disease and its treatments (level C evidence).

Recommendations for Induction of Improvement in Patients with ISN Class III/IV Lupus Glomerulonephritis

The Task Force Panel recommended mycophenolate mofetil (MMF) (2–3 gm total daily orally) or intravenous (IV) cyclophosphamide (CYC) along with glucocorticoids (level A evidence) (see Figure 2 in the original guideline document). MMF and CYC are considered equivalent based on recent high-quality studies, a meta-analysis, and expert opinion. Long-term studies with MMF are not as abundant as those with CYC; data show good results for induction therapy with MMF of 3 gm total dose daily for 6 months, followed by maintenance with lower doses of MMF for 3 years. MMF has been similar in efficacy in all races studied to date (whites, Asians, African Americans, and Latin/Hispanic Americans). The Aspreva Lupus Management Study (ALMS) trial comparing response rates of LN to MMF plus glucocorticoids showed similar improvement in whites, Asians, and other races (primarily African Americans and Hispanics). However, The Task Force Panel voted that Asians compared to non-Asians might require lower doses of MMF for similar efficacy (level C evidence). Therefore, the physician might aim for 3 gm per day total daily highest dose in non-Asians and 2 gm per day in Asians. There is evidence that African Americans and Hispanics with LN respond less well to IV CYC than do patients of white or Asian races. MMF/mycophenolic acid (MPA) may be an initial choice more likely to induce improvement in patients who are African American or Hispanic.

The exact suggested dose of MMF varied based on the clinical scenario: for those with class III/IV without cellular crescents and for those with proteinuria and a stable creatinine for whom a renal biopsy sample cannot be obtained, both 2 gm and 3 gm total daily doses were acceptable to the Task Force Panel, while a dose of 3 gm daily was favored for those with class III/IV and crescents and for those with proteinuria and a recent significant rise in creatinine.

Some evidence suggests that MPA and enteric-coated mycophenolate sodium are less likely than MMF to cause nausea and diarrhea, but this is controversial, and the exact equivalency of the preparations is not firmly established. The Core Expert Panel recommended that MMF and MPA are likely to be equivalent in inducing improvement of LN, with 1,440–2,160 mg total daily dose of MPA roughly equivalent to 2,000–3,000 mg total daily dose of MMF. Some investigators have suggested that serum levels of MPA, the active metabolite of MMF, should be measured at the trough or peak (1 hour after a dose), and treatment of SLE should be guided by these levels. However, there are not enough data at this time to make recommendations for monitoring of drug levels.

There are two regimens of IV CYC recommended by the Task Force Panel: 1) low-dose "Euro-Lupus" CYC (500 mg IV once every 2 weeks for a total of 6 doses), followed by maintenance therapy with daily oral azathioprine (AZA) or daily oral MMF (level B evidence), and 2) high-dose CYC (500–1,000 mg/m² IV once a month for 6 doses), followed by maintenance treatment with MMF or AZA (level A evidence) (see Figure 2 in the original guideline document). If CYC is being considered for treatment, the Core Expert Panel recommended IV CYC at the low "Euro-Lupus" dose for white patients with Western European or Southern European racial/ethnic backgrounds (level B evidence). In European study patients, the low- and high-dose regimens were equivalent in efficacy, and serious infections were less frequent with the lower doses. The low- and high-dose regimens have not been compared in nonwhite racial groups. Ten years of followup comparing low- and high-dose regimens showed similar rates of LN flares, end-stage renal disease, and doubling of the serum creatinine.

Pulse IV glucocorticoids (500–1,000 mg methylprednisolone daily for 3 doses) in combination with immunosuppressive therapy is recommended by the Task Force Panel, followed by daily oral glucocorticoids (0.5–1 mg/kg/day), followed by a taper to the minimal amount necessary to control disease (level C evidence). There are insufficient data to recommend a specific steroid taper because the nephritis and extrarenal manifestations vary from patient to patient. There was no consensus reached regarding the use of monthly IV methylprednisolone with monthly IV CYC.

Although AZA has been used to treat LN, the Task Force Panel did not recommend it as one of the first choices for induction therapy.

The panel recommends that most patients be followed for 6 months after initiation of induction treatment with either CYC or MMF before making major changes in treatment other than alteration of glucocorticoid doses, unless there is clear evidence of worsening at 3 months (50% or more worsening of proteinuria or serum creatinine; level A evidence).

Fertility issues are often a concern for young SLE patients with nephritis. In a discussion, the Task Force Panel recommended that MMF was preferable to CYC for patients who express a major concern with fertility preservation, since high-dose CYC can cause permanent infertility in both women and men (level A evidence of gonadal toxicity). Six months of high-dose IV CYC was associated with approximately 10% sustained infertility in young women, and higher rates in older women. If 6 months of CYC were followed by quarterly doses, there was a higher rate of infertility. The Task Force Panel did not reach a consensus on the use of leuprolide in patients with SLE receiving CYC as a means to preserve fertility. They also noted that MMF is teratogenic (class D in US Food and Drug Administration [FDA] ranking). Therefore, the physician should be sure that a patient is not pregnant before prescribing MMF or MPA, and the medications should be stopped for at least 6 weeks before pregnancy is attempted.

Recommendations for Induction of Improvement in Patients with Class IV or IV/V Plus Cellular Crescents

The Task Force Panel recommended either CYC or MMF for induction of improvement in this type of LN (level C evidence), along with IV pulses of high-dose glucocorticoid and initiation of oral glucocorticoids at the higher-range dosage, 1 mg/kg/day orally (see Figure 2 in the original guideline document). For the purpose of these recommendations statements, the presence of any crescents on a renal biopsy sample was considered crescentic LN. Until recently, experts have favored high-dose IV CYC for treatment of LN with cellular crescents. In general, the presence of crescents indicates a poorer prognosis, even with appropriate treatment. Further recommendations for a pregnant patient with crescentic glomerulonephritis are provided in the section on "Treatment of LN in Patients Who Are Pregnant," below.

Recommendations for Induction of Improvement in Patients with Class V "Pure Membranous" LN

The Task Force Panel recommends that patients with pure class V LN and with nephrotic range proteinuria be started on prednisone (0.5 mg/kg/day) plus MMF 2–3 gm total daily dose (level A evidence) (see Figure 3 in the original guideline document).

Other therapies for membranous LN have been reported; however, the Task Force Panel did not reach consensus on a recommendation regarding those therapies.

Recommendations for Maintaining Improvement in Patients Who Respond to Induction Therapy

The Task Force Panel recommended that either AZA or MMF be used for maintenance therapy (level A evidence) (see Figure 2 in the original guideline document). The Task Force Panel did not vote on the rate of medication taper during the maintenance phase; to date, there are no adequate data to inform the physician regarding how rapidly AZA or MMF can be tapered or withdrawn.

Recommendations for Changing Therapies in Patients Who Do Not Respond Adequately to Induction Therapy

In patients who fail to respond after 6 months of treatment (based on the treating physician's clinical impression) with glucocorticoids plus MMF or CYC, the Task Force Panel recommends a switch of the immunosuppressive agent from either CYC to MMF, or from MMF to CYC, with these changes accompanied by IV pulses of glucocorticoids for 3 days (level C evidence) (see Figure 2 in the original guideline document). For CYC, either low dose or high dose can be used in white individuals, as discussed above in the section on "Recommendations for Induction of Improvement in Patients with ISN Class III/IV Lupus Glomerulonephritis," above. Evidence to support these opinions is not as strong as evidence for the efficacy of initial induction therapy. The panel also voted that in some cases rituximab can be used in patients whose nephritis fails to improve or worsens after 6 months of one induction therapy, or after the patient has failed both CYC and MMF treatments (level C evidence). The Task Force Panel did not reach consensus regarding the use of calcineurin inhibitors in this setting; however, there is evidence for their efficacy as an induction agent and in refractory disease.

There is evidence in open-label trials that LN may respond to rituximab treatment. Prospective, randomized, placebo-controlled trials did not show a significant difference between rituximab and placebo (on a background of MMF and glucocorticoids) after 1 year of treatment.

Evidence to support the use of cyclosporine or tacrolimus in LN is from open trials and recent prospective clinical trials; additional prospective trials are in progress. In a recent prospective trial, tacrolimus was equivalent to high-dose IV CYC in inducing complete and partial remissions of LN over a 6-month period. In another 4-year–long prospective trial, cyclosporine was similar to AZA in preventing renal flares in patients receiving maintenance therapy.

If nephritis is worsening in patients treated for 3 months with glucocorticoids plus CYC or MMF, the Task Force Panel recommended that the clinician can choose any of the alternative treatments discussed (level C evidence). Although combinations of MMF and calcineurin inhibitors and of rituximab and MMF are being studied and might be considered for those who have failed the recommended induction therapies, data are not robust enough at this time to include them for voting scenarios.

The FDA has approved belimumab for use in seropositive patients with SLE who have active disease in spite of prior therapies.

Identification of Vascular Disease in Patients with SLE and Renal Abnormalities

Several types of vascular involvement can occur in renal tissue of SLE, including vasculitis, fibrinoid necrosis with narrowing of small arteries/arterioles ("bland" vasculopathy), thrombotic microangiopathy, and renal vein thrombosis. In general, vasculitis is treated similarly to the more common forms of LN discussed above. Bland vasculopathy is highly associated with hypertension; it is not clear which comes first, SLE or hypertension. Thrombotic microangiopathy can be associated with a thrombotic thrombocytopenia–like picture. The Task Force Panel recommended that thrombotic microangiopathy be treated primarily with plasma exchange therapy (level C evidence)

Treatment of LN in Patients Who Are Pregnant

The Task Force Panel recommended several approaches for management of LN in women who are pregnant (all level C evidence) (see Figure 4 in the original guideline document). In patients with prior LN but no current evidence of systemic or renal disease activity, no nephritis medications are necessary. Patients with mild systemic activity may be treated with HCQ; this probably reduces activity of SLE during pregnancy. If clinically active nephritis is present, or there is substantial extrarenal disease activity, the clinician may prescribe glucocorticoids at doses necessary to control disease activity, and if necessary AZA can be added. High-dose glucocorticoid therapy in patients with SLE is associated with a high risk of maternal complications such as hypertension and diabetes mellitus. MMF, CYC, and methotrexate should be avoided because they are teratogenic in humans. Although AZA is listed as pregnancy category D in Micromedex, cross-sectional studies have shown that the risk of fetal abnormalities is low. The dose of AZA should not exceed 2 mg/kg in a pregnant woman. For patients with a persistently active nephritis with documented or suspected class III or IV with crescents, consideration of delivery after 28 weeks for a viable fetus is recommended.

Monitoring Activity of LN

Recommendations for monitoring LN are shown in the following table, and result from votes of the Task Force Panel (level C evidence).

Table. Recommended Monitoring of Lupus Nephritis*

	Blood Pressure	Urinalysis	Protein/Creatinine Ratio	Serum Creatinine	C3/C4 Levels	Anti-DNA
Active nephritis at onset of treatment	1	1	1	1	2†	3
Previous active nephritis, none currently	3	3	3	3	3	6
Pregnant with active GN at onset of treatment	1	1	1	1	1	1
Pregnant with previous nephritis, none currently	1	1	3	3	3	3
No prior or current nephritis	3	6	6	6	6	6

*Values are the monthly intervals suggested as the minimum frequency at which the indicated laboratory tests should be measured in the systemic lupus erythematosus scenarios shown in the left-hand column. GN = glomerulonephritis.
†Opinion of authors based on a study published after the Task Force Panel had voted.

Definitions:

Level of Evidence

• Level of Evidence A: Data derived from multiple randomized clinical trials
• Level of Evidence B: Data derived from a single randomized trial, or nonrandomized studies
• Level of Evidence C: Only consensus opinion of experts, case studies, or standard-of-care

The levels of evidence supporting the recommendations (A-C) are defined at the end of the "Major Recommendations" field.

Renal Biopsy and Histology

The Task Force Panel recommended that all patients with clinical evidence of active lupus nephritis (LN), previously untreated, undergo renal biopsy (unless strongly contraindicated) so that glomerular disease can be classified by current International Society of Nephrology/Renal Pathology Society (ISN/RPS) classification (level C evidence) (see Table 1 in the original guideline document for ISN/RPS classification of LN). In addition, disease can be evaluated for activity and chronicity and for tubular and vascular changes. Finally, biopsies may identify additional or alternative causes of renal disease, such as tubular necrosis related to medications, hypovolemia, or hypotension. Biopsy is most highly recommended in patients with the characteristics indicated in the following table.

Table. Indications for Renal Biopsy in Patients with Systemic Lupus Erythematosus

	Level of Evidence
Increasing serum creatinine without compelling alternative causes (such as sepsis, hypovolemia, or medication)	C
Confirmed proteinuria of ≥1.0 gm per 24 hours (either 24-hour urine specimens or spot protein/creatinine ratios are acceptable)	C
Combinations of the following, assuming the findings are confirmed in at least two tests done within a short period of time and in the absence of alternative causes: Proteinuria ≥0.5 gm per 24 hours plus hematuria, defined as ≥5 RBCs per hpf Proteinuria ≥0.5 gm per 24 hours plus cellular casts	C

RBCs = red blood cells; hpf = high-power field.

The Task Force Panel recommended that treatment be based in large part on the classification of type of LN by these ISN/RPS criteria. As a result, the following recommendations are presented according to the histologic classification of nephritis. The Task Force Panel agreed that class I (minimal mesangial immune deposits on immunofluorescence with normal light microscopy) and class II (mesangial hypercellularity or matrix expansion on light microscopy with immune deposits confined to mesangium on immunofluorescence) generally do not require immunosuppressive treatment (level C evidence). In general, patients with class III (subendothelial immune deposits and proliferative changes in <50% of glomeruli) and class IV (subendothelial deposits and proliferative glomerular changes involving ≥50% of glomeruli) require aggressive therapy with glucocorticoids and immunosuppressive agents. Class V (subepithelial immune deposits and membranous thickening of glomerular capillaries) when combined with class III or IV should be treated in the same manner as class III or IV. Class V alone ("pure membranous LN") may be approached somewhat differently, as indicated below under "Recommendations for Induction of Improvement in Patients with Class V 'Pure Membranous' LN". Histologic class VI (sclerosis of ≥90% of glomeruli) generally requires preparation for renal replacement therapy rather than immunosuppression. The designations "A" and "C" indicate whether active or chronic changes are present; the higher the chronicity the less likely that the nephritis will respond to immunosuppression. However, A or C classifications were not included in the entry criteria for clinical trials in LN published to date, and therefore they are not considered in the recommendations.

Adjunctive Treatments

The Task Force Panel recommended that all systemic lupus erythematosus (SLE) patients with nephritis be treated with a background of hydroxychloroquine (HCQ; level C evidence), unless there is a contraindication.

All LN patients with proteinuria ≥0.5 gm per 24 hours (or equivalent by protein/creatinine ratios on spot urine samples) should have blockade of the renin–angiotensin system, which drives intraglomerular pressure (level A evidence for nondiabetic chronic renal disease). Treatment with either angiotensin-converting enzyme (ACE) inhibitors or angiotensin receptor blockers (ARBs) reduces proteinuria by approximately 30%, and significantly delays doubling of serum creatinine and progression to end-stage renal disease in patients with nondiabetic chronic renal disease. These classes of medications are contraindicated in pregnancy. The use of combination ACE inhibitors/ARB therapies is controversial. ACE inhibitors or ARB treatments are superior to calcium-channel blockers and diuretics alone in preserving renal function in chronic kidney disease.

The Task Force Panel recommended that careful attention be paid to control of hypertension, with a target of ≤130/80 mm Hg (level A evidence for nondiabetic chronic renal disease). The Task Force Panel also recommended that statin therapy be introduced in patients with low-density lipoprotein cholesterol >100 mg/dl (level C evidence). Note that a glomerular filtration rate <60 ml/minute/1.73 m² (equivalent to a serum creatinine level >1.5 mg/dl or 133 µmoles/liter) is a risk factor for accelerated atherosclerosis. SLE itself is also an independent risk factor for accelerated atherosclerosis.

Finally, the Task Force Panel recommended that women of child-bearing potential with active or prior LN receive counseling regarding pregnancy risks conferred by the disease and its treatments (level C evidence).

Recommendations for Induction of Improvement in Patients with ISN Class III/IV Lupus Glomerulonephritis

The Task Force Panel recommended mycophenolate mofetil (MMF) (2–3 gm total daily orally) or intravenous (IV) cyclophosphamide (CYC) along with glucocorticoids (level A evidence) (see Figure 2 in the original guideline document). MMF and CYC are considered equivalent based on recent high-quality studies, a meta-analysis, and expert opinion. Long-term studies with MMF are not as abundant as those with CYC; data show good results for induction therapy with MMF of 3 gm total dose daily for 6 months, followed by maintenance with lower doses of MMF for 3 years. MMF has been similar in efficacy in all races studied to date (whites, Asians, African Americans, and Latin/Hispanic Americans). The Aspreva Lupus Management Study (ALMS) trial comparing response rates of LN to MMF plus glucocorticoids showed similar improvement in whites, Asians, and other races (primarily African Americans and Hispanics). However, The Task Force Panel voted that Asians compared to non-Asians might require lower doses of MMF for similar efficacy (level C evidence). Therefore, the physician might aim for 3 gm per day total daily highest dose in non-Asians and 2 gm per day in Asians. There is evidence that African Americans and Hispanics with LN respond less well to IV CYC than do patients of white or Asian races. MMF/mycophenolic acid (MPA) may be an initial choice more likely to induce improvement in patients who are African American or Hispanic.

The exact suggested dose of MMF varied based on the clinical scenario: for those with class III/IV without cellular crescents and for those with proteinuria and a stable creatinine for whom a renal biopsy sample cannot be obtained, both 2 gm and 3 gm total daily doses were acceptable to the Task Force Panel, while a dose of 3 gm daily was favored for those with class III/IV and crescents and for those with proteinuria and a recent significant rise in creatinine.

Some evidence suggests that MPA and enteric-coated mycophenolate sodium are less likely than MMF to cause nausea and diarrhea, but this is controversial, and the exact equivalency of the preparations is not firmly established. The Core Expert Panel recommended that MMF and MPA are likely to be equivalent in inducing improvement of LN, with 1,440–2,160 mg total daily dose of MPA roughly equivalent to 2,000–3,000 mg total daily dose of MMF. Some investigators have suggested that serum levels of MPA, the active metabolite of MMF, should be measured at the trough or peak (1 hour after a dose), and treatment of SLE should be guided by these levels. However, there are not enough data at this time to make recommendations for monitoring of drug levels.

There are two regimens of IV CYC recommended by the Task Force Panel: 1) low-dose "Euro-Lupus" CYC (500 mg IV once every 2 weeks for a total of 6 doses), followed by maintenance therapy with daily oral azathioprine (AZA) or daily oral MMF (level B evidence), and 2) high-dose CYC (500–1,000 mg/m² IV once a month for 6 doses), followed by maintenance treatment with MMF or AZA (level A evidence) (see Figure 2 in the original guideline document). If CYC is being considered for treatment, the Core Expert Panel recommended IV CYC at the low "Euro-Lupus" dose for white patients with Western European or Southern European racial/ethnic backgrounds (level B evidence). In European study patients, the low- and high-dose regimens were equivalent in efficacy, and serious infections were less frequent with the lower doses. The low- and high-dose regimens have not been compared in nonwhite racial groups. Ten years of followup comparing low- and high-dose regimens showed similar rates of LN flares, end-stage renal disease, and doubling of the serum creatinine.

Pulse IV glucocorticoids (500–1,000 mg methylprednisolone daily for 3 doses) in combination with immunosuppressive therapy is recommended by the Task Force Panel, followed by daily oral glucocorticoids (0.5–1 mg/kg/day), followed by a taper to the minimal amount necessary to control disease (level C evidence). There are insufficient data to recommend a specific steroid taper because the nephritis and extrarenal manifestations vary from patient to patient. There was no consensus reached regarding the use of monthly IV methylprednisolone with monthly IV CYC.

Although AZA has been used to treat LN, the Task Force Panel did not recommend it as one of the first choices for induction therapy.

The panel recommends that most patients be followed for 6 months after initiation of induction treatment with either CYC or MMF before making major changes in treatment other than alteration of glucocorticoid doses, unless there is clear evidence of worsening at 3 months (50% or more worsening of proteinuria or serum creatinine; level A evidence).

Fertility issues are often a concern for young SLE patients with nephritis. In a discussion, the Task Force Panel recommended that MMF was preferable to CYC for patients who express a major concern with fertility preservation, since high-dose CYC can cause permanent infertility in both women and men (level A evidence of gonadal toxicity). Six months of high-dose IV CYC was associated with approximately 10% sustained infertility in young women, and higher rates in older women. If 6 months of CYC were followed by quarterly doses, there was a higher rate of infertility. The Task Force Panel did not reach a consensus on the use of leuprolide in patients with SLE receiving CYC as a means to preserve fertility. They also noted that MMF is teratogenic (class D in US Food and Drug Administration [FDA] ranking). Therefore, the physician should be sure that a patient is not pregnant before prescribing MMF or MPA, and the medications should be stopped for at least 6 weeks before pregnancy is attempted.

Recommendations for Induction of Improvement in Patients with Class IV or IV/V Plus Cellular Crescents

The Task Force Panel recommended either CYC or MMF for induction of improvement in this type of LN (level C evidence), along with IV pulses of high-dose glucocorticoid and initiation of oral glucocorticoids at the higher-range dosage, 1 mg/kg/day orally (see Figure 2 in the original guideline document). For the purpose of these recommendations statements, the presence of any crescents on a renal biopsy sample was considered crescentic LN. Until recently, experts have favored high-dose IV CYC for treatment of LN with cellular crescents. In general, the presence of crescents indicates a poorer prognosis, even with appropriate treatment. Further recommendations for a pregnant patient with crescentic glomerulonephritis are provided in the section on "Treatment of LN in Patients Who Are Pregnant," below.

Recommendations for Induction of Improvement in Patients with Class V "Pure Membranous" LN

The Task Force Panel recommends that patients with pure class V LN and with nephrotic range proteinuria be started on prednisone (0.5 mg/kg/day) plus MMF 2–3 gm total daily dose (level A evidence) (see Figure 3 in the original guideline document).

Other therapies for membranous LN have been reported; however, the Task Force Panel did not reach consensus on a recommendation regarding those therapies.

Recommendations for Maintaining Improvement in Patients Who Respond to Induction Therapy

The Task Force Panel recommended that either AZA or MMF be used for maintenance therapy (level A evidence) (see Figure 2 in the original guideline document). The Task Force Panel did not vote on the rate of medication taper during the maintenance phase; to date, there are no adequate data to inform the physician regarding how rapidly AZA or MMF can be tapered or withdrawn.

Recommendations for Changing Therapies in Patients Who Do Not Respond Adequately to Induction Therapy

In patients who fail to respond after 6 months of treatment (based on the treating physician's clinical impression) with glucocorticoids plus MMF or CYC, the Task Force Panel recommends a switch of the immunosuppressive agent from either CYC to MMF, or from MMF to CYC, with these changes accompanied by IV pulses of glucocorticoids for 3 days (level C evidence) (see Figure 2 in the original guideline document). For CYC, either low dose or high dose can be used in white individuals, as discussed above in the section on "Recommendations for Induction of Improvement in Patients with ISN Class III/IV Lupus Glomerulonephritis," above. Evidence to support these opinions is not as strong as evidence for the efficacy of initial induction therapy. The panel also voted that in some cases rituximab can be used in patients whose nephritis fails to improve or worsens after 6 months of one induction therapy, or after the patient has failed both CYC and MMF treatments (level C evidence). The Task Force Panel did not reach consensus regarding the use of calcineurin inhibitors in this setting; however, there is evidence for their efficacy as an induction agent and in refractory disease.

There is evidence in open-label trials that LN may respond to rituximab treatment. Prospective, randomized, placebo-controlled trials did not show a significant difference between rituximab and placebo (on a background of MMF and glucocorticoids) after 1 year of treatment.

Evidence to support the use of cyclosporine or tacrolimus in LN is from open trials and recent prospective clinical trials; additional prospective trials are in progress. In a recent prospective trial, tacrolimus was equivalent to high-dose IV CYC in inducing complete and partial remissions of LN over a 6-month period. In another 4-year–long prospective trial, cyclosporine was similar to AZA in preventing renal flares in patients receiving maintenance therapy.

If nephritis is worsening in patients treated for 3 months with glucocorticoids plus CYC or MMF, the Task Force Panel recommended that the clinician can choose any of the alternative treatments discussed (level C evidence). Although combinations of MMF and calcineurin inhibitors and of rituximab and MMF are being studied and might be considered for those who have failed the recommended induction therapies, data are not robust enough at this time to include them for voting scenarios.

The FDA has approved belimumab for use in seropositive patients with SLE who have active disease in spite of prior therapies.

Identification of Vascular Disease in Patients with SLE and Renal Abnormalities

Several types of vascular involvement can occur in renal tissue of SLE, including vasculitis, fibrinoid necrosis with narrowing of small arteries/arterioles ("bland" vasculopathy), thrombotic microangiopathy, and renal vein thrombosis. In general, vasculitis is treated similarly to the more common forms of LN discussed above. Bland vasculopathy is highly associated with hypertension; it is not clear which comes first, SLE or hypertension. Thrombotic microangiopathy can be associated with a thrombotic thrombocytopenia–like picture. The Task Force Panel recommended that thrombotic microangiopathy be treated primarily with plasma exchange therapy (level C evidence)

Treatment of LN in Patients Who Are Pregnant

The Task Force Panel recommended several approaches for management of LN in women who are pregnant (all level C evidence) (see Figure 4 in the original guideline document). In patients with prior LN but no current evidence of systemic or renal disease activity, no nephritis medications are necessary. Patients with mild systemic activity may be treated with HCQ; this probably reduces activity of SLE during pregnancy. If clinically active nephritis is present, or there is substantial extrarenal disease activity, the clinician may prescribe glucocorticoids at doses necessary to control disease activity, and if necessary AZA can be added. High-dose glucocorticoid therapy in patients with SLE is associated with a high risk of maternal complications such as hypertension and diabetes mellitus. MMF, CYC, and methotrexate should be avoided because they are teratogenic in humans. Although AZA is listed as pregnancy category D in Micromedex, cross-sectional studies have shown that the risk of fetal abnormalities is low. The dose of AZA should not exceed 2 mg/kg in a pregnant woman. For patients with a persistently active nephritis with documented or suspected class III or IV with crescents, consideration of delivery after 28 weeks for a viable fetus is recommended.

Monitoring Activity of LN

Recommendations for monitoring LN are shown in the following table, and result from votes of the Task Force Panel (level C evidence).

Table. Recommended Monitoring of Lupus Nephritis*

	Blood Pressure	Urinalysis	Protein/Creatinine Ratio	Serum Creatinine	C3/C4 Levels	Anti-DNA
Active nephritis at onset of treatment	1	1	1	1	2†	3
Previous active nephritis, none currently	3	3	3	3	3	6
Pregnant with active GN at onset of treatment	1	1	1	1	1	1
Pregnant with previous nephritis, none currently	1	1	3	3	3	3
No prior or current nephritis	3	6	6	6	6	6

*Values are the monthly intervals suggested as the minimum frequency at which the indicated laboratory tests should be measured in the systemic lupus erythematosus scenarios shown in the left-hand column. GN = glomerulonephritis.
†Opinion of authors based on a study published after the Task Force Panel had voted.

Definitions:

Level of Evidence

• Level of Evidence A: Data derived from multiple randomized clinical trials
• Level of Evidence B: Data derived from a single randomized trial, or nonrandomized studies
• Level of Evidence C: Only consensus opinion of experts, case studies, or standard-of-care