IgA nephropathy with severe chronic renal failure: a randomized controlled trial of corticosteroids and azathioprine.

Background: Therapeutic nihilism is common in IgA nephropathy (IgAN) and renal insufficiency.

Methods: In a randomized controlled trial comparing steroids alone or combined with azathioprine in 253 IgAN patients, we used a separate randomization list for patients with creatinine >2.0 mg/dL. Twenty patients (group 1) were randomized to 3 intravenous pulses of methylprednisolone 1 g at months 1, 3 and 5, and oral prednisone 0.5 mg/kg every other day plus azathioprine 1.5 mg/kg/day for 6 months, followed by oral prednisone 0.2 mg/kg every other day plus azathioprine 50 mg/day for a further 6 months; 26 patients (group 2) received steroids alone. The primary outcome was renal survival (50% increase in plasma creatinine from baseline); secondary outcomes were proteinuria over time and adverse events.

Results: Six-year renal survival was not different between the 2 groups (50% vs. 57%; log-rank p=0.34). Median proteinuria decreased during follow-up in the whole population (from 2.45 g/day [interquartile range (IQR) 1.50-3.78] to 1.09 g/day [IQR 0.56- 2.46]; p<0.001), with no between-group difference. Multivariate predictors associated with renal survival were sex of patient, proteinuria during follow-up, number of antihypertensive drugs, angiotensin-converting enzyme inhibitors and treatment including azathioprine. Six patients in group 1 (30%) and 4 in group 2 (15%) did not complete the therapy, because of side effects (p=0.406).

Conclusions: Six-year renal survival was similar in the 2 groups. At Cox analysis the addition of azathioprine may be slightly more effective than corticosteroids alone in patients with chronic renal insufficiency, although with an increase of side effects.