Mycophenolate Mofetil for IgA Nephropathy

IgA nephropathy (IgAN) is the commonest primary glomerulonephritis worldwide. In Hong Kong, IgAN accounts for approximately 30% of all primary glomerular diseases, and a significant proportion of young patients (\< 50 years of age) on dialysis therapy are sufferers of primary IgAN. To date, no specific therapeutic agent has been consistently shown to halt the progression of IgAN to end-stage renal failure, particularly in patients with persistent significant proteinuria and the presence of chronic tubulointerstitial inflammation on kidney biopsy. In recent years, angiotensin-converting enzyme inhibitors (ACEI) have been found capable of significantly reducing proteinuria in some IgAN patients, while others, particularly those with the ACE DD genotype, showed either absent or unsatisfactory response to angiotensin blockade. Mycophenolate mofetil (MMF) is a marketed immunosuppressive drug which acts by releasing mycophenolic acid (MPA) to inhibit the de novo pathway of purine synthesis, and hence is relatively selective for lymphocytes. Apart from being efficacious for the prophylaxis of renal allograft rejection and for the induction of remission in severe lupus nephritis, MMF has been anecdotally reported to avert progression to allograft failure in recurrent IgAN of the transplanted kidney. Data on the clinical efficacy of MMF in the treatment of primary IgAN, however, is lacking. In the current proposal, we aim to study the clinical efficacy of MMF in patients with biopsy-proven IgAN and clinically significant proteinuria despite angiotensin blockade. Patients will be followed up for at least 5 years to track any survival difference between groups.