Current management of lupus nephritis: popular misconceptions

The management of lupus nephritis is typified by popular misconceptions: that there is a 'standard of care', that treatment has well-defined aims and that the optimum length of treatment is established. In reality, however, uncertainties still exist and the evidence base remains weak. Until recently, initial therapy for class IV lupus nephritis typically involved intravenous cyclophosphamide, yet although cyclophosphamide is superior to azathioprine in improving renal function, it is not superior in terms of mortality. In fact, recent studies show mycophenolate mofetil to be superior to cyclophosphamide in terms of response rate and safety profile and at least as effective as other immunosuppressants. The role of steroids is unclear. Clearly, no standard of care exists in lupus nephritis. The Euro-Lupus Nephritis Trial found that treatment response at six months, in terms of reduced serum creatinine and proteinuria, was the best predictor of long-term renal outcome. Proteinuria, however, can take a long time to reach baseline levels, and normalization of urine is not the same as loss of histological disease activity. Response to treatment thus is not the same as disease remission. Although treatment should aim to reduce the risk of end-stage renal disease and death, control of proteinuria and prevention of flares are also important. Patients who have nephritic flares are almost seven times as likely to progress to end-stage renal disease compared with those who do not. Regimens involving maintenance phases have been developed, but uncertainty remains about the risk of flares and how they can be predicted. The optimum duration of treatment has yet to be determined.