Background: Reversal of active glomerular lesions after immunosuppressive treatment in patients with IgA nephropathy (IgAN) and their association with prognosis have not been well established.
Methods: Sixty patients with IgAN who received repeat biopsies after immunosuppressive treatment were recruited. Reversal of renal pathological lesions was evaluated between the first and second biopsy. The end-point was defined as a 30% reduction in estimated glomerular filtration rate (eGFR) or end-stage renal disease after the second biopsy.
Results: Active glomerular lesions, i.e. endocapillary hypercellularity (E), crescents (C) and necrosis (N) were markedly decreased at the second biopsy after immunosuppressive therapy (36.7 vs. 8.3%, p < 0.001; 85.0 vs. 25.0%, p < 0.001; and 51.7 vs. 3.3%, p < 0.001). Patients with E, C or N at the first biopsy but reversed at the second biopsy showed significantly decreased median levels of proteinuria and hematuria. Such clinical changes were not observed in those with active lesions at both biopsies. After a median follow-up of 32 months, 25.0% of patients reached the end-point. Repeat biopsy confirmed that only tubular atrophy/interstitial fibrosis was associated with the renal outcome.
Conclusions: Active glomerular lesions can be reversed by immunosuppressive treatment in patients with IgAN. The reversal is accompanied by improvement in proteinuria and hematuria. The reversal of these lesions during the disease process may explain the lack of significant correlation of these lesions with clinical outcomes in the present study as well as in previous evaluation studies of the Oxford classification of IgAN.