Background: The efficacy and proper doses of steroid pulse therapy in patients with immunoglobulin A nephropathy (IgAN) have not been established. We therefore investigated the effects of methylprednisolone (MP) pulse therapy in patients with histologically active IgAN and established renal impairment at the time of treatment.
Methods: We assessed 22 patients (8 males, 14 females) with established renal impairment (Stage 3, 4 or 5 CKD; median eGFR, 34.05 ml/min/1.73 m2) and active IgAN (median histological Grade 3). All patients had been maintained on an angiotensin receptor blocker or an angiotensinconverting enzyme inhibitor. Patients were treated with 500 mg intravenous MP every 2 weeks for 6 months to improve or stabilize renal function. The efficacy of MP pulse therapy was analyzed by comparing the slopes of the eGFR (ml/min/1.73 m2) and log transformed urine albumin/creatinine ratios (mg/g) before, during, and after treatment using linear regression coefficients.
Results: All patients completed the planned 6 months of MP pulse therapy. Linear regression analysis showed improvements in the monthly decline of eGFR in 16 of 22 patients (73%) after treatment. The rate of eGFR decline in the before treatment period differed significantly from that in the after treatment period (-0.931 ± 0.871 vs 0.141 ± 0.998, p = 0.007). Patients with initial eGFR ≥ 30 ml/min/1.73 m2 showed significantly improved 10-month dialysisfree renal survival after MP pulse therapy (p = 0.040). In contrast, there was no improvement in urinary albumin to creatinine ratio (p = NS). MP pulse therapy was well tolerated, except for one patient with facial flushing and palpitation. There were no other serious adverse events during the study period.
Conclusions: MP 500 mg every 2 weeks for 6 months was safe and effective in patients with IgAN and preexisting renal dysfunction.