[Efficacy of steroid pulse therapy in patients with IgA nephropathy and impaired renal function]

In the current study, we evaluated the efficacy of methylprednisolone (MP) pulse therapy in IgA nephropathy (IgAN) patients with established renal function impairment.

We retrospectively analyzed the effect of MP pulse therapy in patients with histologically active IgAN (8 males, 12 females) whose estimated glomerular filtration rate was less than 60 mL/min/1.73 m2 (33.4 +/- 13.1, mean +/- SD). The efficacy of the MP pulse therapy was analyzed by calculating the regression coefficients (dL/mg/month) from the slopes of the 1/serum creatinine (Cr), urine protein/creatinine ratio (g/g x Cr), and the estimated interval from the pulse therapy to dialysis (that is, for Cr to reach 8 mg/dL, as calculated from the slope of 1/Cr) or the actual interval.

All patients showed improved regression coefficients (-0.0214 +/- 0.00166 vs. 0.00236 +/- 0.00895, 1 year before vs. after treatment, p < 0.01). The severity of proteinuria decreased significantly from a mean urine protein/creatinine ratio of 2.9 +/- 1.7 before therapy to 1.1 +/- 0.8 (p < 0.01) at 6 months and 0.8 +/- 0.7(p < 0.01) at 12 months after therapy. Although 7 patients underwent dialysis, the average interval from pulse therapy to dialysis was prolonged from an estimated interval of 1.1 +/- 0.9 years to an actual interval of 4.1 +/- 3.5 years. Six patients showed positive regression coefficients at the last observation (4.1 +/- 3.0 years after therapy). The remaining 7 patients who had not undergone dialysis also showed prolongation of the estimated interval from pulse therapy to dialysis of 5.9 +/- 5.1 years before pulse therapy to 25.7 +/- 20.6 years at the final observation (4.9 +/- 3.5 years after therapy). No serious side effects were observed in any of the patients.

MP pulse therapy can slow the progression of renal deterioration in patients with active IgAN, even in those patients in whom renal function impairment has set in.