Treatment of severe IgA nephropathy in children.

We treated ten children with severe IgA nephropathy (IgAN) [proteinuria greater than 1 g/day, hypertension, renal insufficiency, segmental sclerosis, crescent formation and/or glomerular basement membrane (GBM) deposition of IgA] with prednisone and azathioprine for 1 year. Following the year of therapy, seven of the ten children underwent a repeat kidney biopsy. All biopsies were scored for activity (percentage of glomeruli demonstrating crescent formation, degree of mesangial proliferation and interstitial infiltrate; maximum score = 9) and chronicity (percentage of glomeruli demonstrating fibrous crescents, segmental sclerosis, global sclerosis, and degree of tubular atrophy and interstitial fibrosis; maximum score = 12). After 1 year of therapy, the protein excretion of all the children decreased significantly (P less than 0.01) from 4,052 +/- 3,190 mg/day to 1,692 +/- 1,634 mg/day. The activity score decreased significantly (P less than 0.01) from 4.35 +/- 0.94 prior to therapy to 2.28 +/- 0.75 after therapy while the chronicity score was unchanged (5.42 +/- 1.7 vs 5.85 +/- 2.0). The percentage of glomeruli demonstrating cellular crescents decreased (P less than 0.05) from 21.2 +/- 21.7% prior to therapy to 0.94 +/- 2.4% after therapy. Mesangial deposition of IgA persisted but GBM deposition of IgA was less prominent after therapy. During the follow-up period (mean 2.6 years, range 9 months-7.5 years), one child required brief retreatment for biopsy-confirmed recurrence of active disease, two children have developed renal insufficiency due to progressive scarring in the absence of inflammation, while the remaining seven are stable. We suggest that treatment with prednisone and azathioprine may be beneficial in children with severe IgAN and that a controlled clinical trial is warranted.