Treatment of membranous lupus nephritis

Systemic lupus erythematosus is associated with renal involvement in almost 50–80% of cases. Although proliferative lupus nephritis is the most common form, isolated membranous lupus nephritis (MLN or class V lupus nephritis) accounts for 11–20% of cases while mixed proliferative and MLN (Class III + V/IV + V) can be seen in another 21–30%. MLN can present as either sub-nephrotic or nephrotic proteinuria with or without microscopic hematuria or renal dysfunction. These patients are at high risk of cardiovascular and cerebrovascular complications due to thrombotic tendency, dyslipidemia and hypertension. Uniform evidence regarding prognostic factors, outcome and therapy of MLN are still elusive. Systematic analysis of several studies have shown that sustained nephrotic proteinuria, failure to achieve complete remission and associated proliferative lesions denotes poor prognosis. In general, the long term renal survival rate is 50–90%, while end stage renal disease occurs in 12–22% cases. Transformation to proliferative nephritis is also well known, thus a close follow up is warranted in all pure MLN cases. Those with persistent nephrotic proteinuria, renal dysfunction and mixed histology should be treated aggressively with immunosuppressive agent while less severe cases can be managed with adjunctive therapies.