Corticosteroids and Azathioprine Versus Corticosteroids Alone in IgA Nephropathy: a Randomized Controlled Trial.

In 1999, we published a multicenter, randomized, controlled trial, which compared a 6-month steroid course with supportive therapy in 86 patients with IgAN. After 5 years of follow-up, the risk of a 50% increase in plasma creatinine from baseline was significantly lower in the treated patients; proteinuria also decreased. However, the effect of steroids seemed to diminish over time. The difference in renal survival was particularly striking up till the third year, but then remained constant. We hypothesised that a six-month course of steroid therapy is not enough to ensure a stable remission, and a more aggressive treatment may be required to obtain long-term better results. At this regard, some studies of combined treatment with corticosteroids and azathioprine found that treatment was effective in preserving renal function and in reducing proteinuria. However, these studies did not clarify whether azathioprine added further benefit to steroids in the long term. We conducted a randomised controlled trial to assess the utility of low-dose azathioprine added to steroids in adult IgAN patients.