Efficacy and safety of 'rescue therapy' with mycophenolate mofetil in resistant primary glomerulonephritis--a multicenter study.

BACKGROUND: Studies of mycophenolate mofetil (MMF) in primary glomerulonephritis have varied in their inclusion criteria, regimen and follow-up compromising assessments of efficacy and optimal dose. METHOD: This multicentre study analysed the safety and efficacy of MMF monotherapy in a large cohort with primary glomerulonephritis that was resistant to other conventional therapies. A total of 98 patients with biopsy-proven primary glomerulonephritis resistant to other drugs received MMF monotherapy for 1 year. Primary outcome measures were urinary protein excretion and the number of patients with complete or partial remission of proteinuria. Secondary analyses were time to remission and changes in the slope of creatinine clearance. RESULTS: Fifty-four percent of the patients achieved either complete or partial remission of proteinuria with no significant differences between glomerulonephritis types. Median (range) dose of MMF was 2 g/day (1.5-2 g/day) Mean (SD) treatment time to remission was 141.5 (+/-61.1) days with no significant differences between glomerulonephritis types. Serum albumin increased (P<0.01), whereas proteinuria (P<0.01) serum LDL-cholesterol (P<0.01) and mean blood pressure (P<0.05) decreased post-treatment. No significant changes were observed in glomerular filtration rate (GFR), serum creatinine or slopes of GFR. The reduction of urinary protein excretion was significantly higher in patients with basal nephrotic proteinuria and preserved renal function; it did not arise from an increased dose of angiotensin-converting enzyme inhibitors or angiotensin II receptor antagonists, since, among responders, mean blood pressure significantly decreased and the number of anti-hypertensive drugs could be reduced. CONCLUSIONS: MMF monotherapy causes a moderate decrease in proteinuria in >50% of the patients who do not have other treatment options. The response to therapy is largely influenced by a preserved renal function and requires sustained MMF treatment.