TREATMENT

All patients with proteinuria, irrespective of the histologic class, should be treated with ACE inhibitors or ARBs. Hypertension should be strictly controlled. Hyperlipidemia should also be treated if present, which may require the use of a statin drug. The use of nonsteroidal antiinflammatory drugs should be assessed and, if present, limited. Prolonged or unprotected exposure to sunlight should be rigorously avoided because it can trigger lupus fares.

Pharmacologic immunosuppression is often not required for class I or II disease. In contrast, in class III or class IV disease, there is a higher risk for progressive loss of kidney function that mandates more aggressive treatment. The two drugs best studied for induction therapy are pulse cyclophosphamide and mycophenolate. Either one is initiated in conjunction with high-dose corticosteroids. The preponderance of data from clinical trials suggests that the two regimens are equivalent in achieving remission, usually at rates of 60% to 80%. Maintenance of remission can be obtained with mycophenolate or azathioprine.

The treatment of membranous (class V) LN is controversial. All patients should receive treatment for proteinuria. Immunosuppressive regimens involving corticosteroids in conjunction with cyclophosphamide, cyclosporine, or mycophenolate have all been tried with varying results. It appears that combination regimens are superior to corticosteroids alone.

PROGNOSIS

The overall survival of patients with LN has improved over the last half century, with 5-year survival rates increasing from 50% in the 1940s and 1950s to more than 90% since the 1990s. Nevertheless, disease-wide outcomes remain unsatisfactory. Nearly 50% of patients treated for LN will eventually have relapse of their symptoms. In addition, a significant number of patients will be unable to tolerate treatment, suffer serious adverse events from immunosuppression, or have disease that is refractory to therapy. End-stage renal disease (ESRD) eventually occurs in 10% to 15% of patients.

Once a patient progresses to ESRD, the systemic manifestations of SLE will often abate over a period of months, perhaps because the loss of nephrons eliminates an important source of autoantigens. Kidney transplant is a viable option with generally excellent outcomes. Recurrence of LN in the allograft develops in less than 10% of cases and very rarely causes allograft loss.