Combined treatment with renin-angiotensin system blockers and polyunsaturated fatty acids in proteinuric IgA nephropathy: a randomized controlled trial.

BACKGROUND: Currently, several therapeutic protocols exist for IgA nephropathy (IgAN); results in slowing the progression to end-stage renal disease (ESRD) are variable, but approximately 30-40% of patients require replacement therapy (dialysis or renal transplantation) by 20 years from the onset. The adverse effects brought by the chronic assumption of drugs can be a potential limit. Actually, the most used therapies for IgAN are renin-angiotensin system blockers (RASB), glucocorticoids and immunosuppressive agents. Trials with polyunsaturated fatty acids (PUFA) in IgAN have been done since the first successful attempt by Hamazaki in 1984, resulting in alternate answers, but no trials have ever been done testing the efficacy of combined therapy with RASB and PUFA.

METHODS: We tested the effect of a 6-month course of PUFA (3 grams/day) in a group of 30 patients with biopsy-proven IgAN and proteinuria already treated with RASB randomized to receive PUFA supplementation or to continue their standard therapy. The primary end-point was the percent reduction of proteinuria from the baseline. Secondary end-points were modifications in glomerular filtration rate (GFR), blood pressure, serum triglycerides and erythrocyturia.

RESULTS: At the end of the 6-month trial, the percent reduction of proteinuria was 72.9% in the PUFA group and 11.3% in the RASB group (P < 0.001). A reduction of >or=50% of baseline proteinuria was achieved in 80.0% of PUFA patients and 20.0% of RASB patients (P = 0.002). Erythrocyturia was significantly lower in the PUFA group (P = 0.031). No significant changes in renal function, blood pressure and triglycerides were observed.

CONCLUSIONS: PUFA associated with RASB reduced proteinuria in patients with IgAN more than RASB alone.