The investigators study the efficacy and safety of tacrolimus in the treatment of membranous nephritis secondary to systemic lupus erythematosus.

Glomerulonephritis is one of the major disease manifestations of systemic lupus erythematosus (SLE). The treatment of membranous (type V) lupus nephritis, a subset that carries a high morbidity, remains unsatisfactory. Recent studies suggest that immunosuppressive therapy targeted against the calcineurin pathway of T-helper cells, for example, tacrolimus, may be effective in the treatment of primary membranous nephropathy. The investigators plan to conduct an open-label single-arm study of the efficacy and safety of tacrolimus in the treatment of membranous nephropathy secondary to SLE. Twenty patients with biopsy-proven membranous nephropathy secondary to SLE will be recruited. They will be treated with oral prednisolone and tacrolimus for 6 months, followed by 6 months of maintenance steroids alone. Proteinuria, renal function, clinical and serologic lupus activity will be monitored. Complete remission is defined as 24-hour urinary protein excretion to less than 0.5 gm/day. This study will explore the potential role of tacrolimus in the treatment of membranous lupus nephritis, which is usually resistant to conventional therapy.

Inclusion Criteria:

• Fulfill the revised American College of Rheumatology criteria for SLE
• Have biopsy-proven membranous nephropathy secondary to SLE
• Nephrotic syndrome with proteinuria (> 3 g/day) and serum albumin < 30 g/dl, with or without active urinary sediments despite steroid therapy (with or without cytotoxic agents)
• Age over 18 with informed consent
• Female patients of child-bearing age and male patients who agree to maintain effective birth control practice during the study

Exclusion Criteria:

• Patient with abnormal liver function tests
• Patient with hepatitis B surface antigen or who is hepatitis C antibody positive
• Patient who is diabetic
• Patient who is receiving non-steroidal anti-inflammatory drugs (NSAIDs) or other agents known to influence urinary protein excretion
• Patient is allergic or intolerant to macrolide antibiotics or tacrolimus