Complete remission within 2 years predicts a good prognosis after methylprednisolone pulse therapy in patients with IgA nephropathy

Background: Pozzi et al. reported the effectiveness of steroid pulse therapy (Pozzi's regimen) in IgA nephropathy (IgAN). The present study was performed to clarify the predictive factors for IgAN patients treated with Pozzi's regimen. Methods: One hundred nine IgAN patients treated by Pozzi's regimen were observed for up to 112.6 (median 39.7) months, and remission of proteinuria (PR) and disappearance of urinary abnormalities [complete remission (CR)] after Pozzi's regimen were analyzed. Predictive factors for the glomerular filtration rate (GFR) slopes for up to 5 years were analyzed among 81 patients who were observed for at least 2 years. The outcome of a 50 % increase in sCr was compared between the CR and non-CR groups within 2 years. Results: Cumulative PR and CR rates increased rapidly until 2 years (54.5 and 46.8 % at 2 years), and then slowly but steadily up to 6 years (72.8 and 66.4 % at 6 years). Baseline characteristics of the CR and non-CR groups within 2 years were similar except for proteinuria. GFR slope was steeper in the non-CR group than in the CR group (-2.44 ± 5.12 vs. -0.32 ± 3.34 ml/min/1.73 m ²/year). On multivariate analysis, sex and CR within 2 years were associated with GFR slope. Kaplan-Meier analysis demonstrated a better survival rate in CR group patients without a 50 % increase in sCr (p = 0.024). Conclusions: Among IgAN patients treated with Pozzi's regimen, CR within 2 years predicts a good prognosis.