Association between renal outcome and the number of steroid pulse therapies after tonsillectomy in patients with IgA nephropathy.

backgroundTonsillectomy performed on patients with Immunoglobulin A glomerulonephritis (IgAN) improved the clinical remission rate as defined by urinary protein. But the number of times steroid pulse therapies (SP) should be administered remained poorly understood.

methodMulticenter, observational, retrospective cohort study at four hospitals in the Tokyo metropolitan area between March 1981 and December 2013. We divided patients into two groups: those treated with SP three times and those treated without SP or with SP only once or twice, and we analyzed standard Cox proportional hazard model unadjusted and adjusted the confounding covariates to estimate the hazard ratio for the primary outcome, the 30% estimated decline in glomerular filtration rate, in four models: model 1, unadjusted; model 2, adjusted for age, sex, body mass index, estimated glomerular filtration rate, biopsy year, proteinuria, hematuria, Japanese historical grade, systolic blood pressure, smoking history, and diabetes as a comorbidity; model 3, adjusted for propensity score, which was estimated by multiple logistic regressions; model 4, multilevel mixed-effects parametric survival models, whose facilities comprise the second level.

resultsPatients that received three times SP therapy were significantly associated with better renal outcome compared with patients with less number of SP therapy (HR 0.66; 95% CI 0.37-1.17 in model 1, 0.40 (0.20-0.78) in model 2, 0.46 (0.25-0.88) in model 3, 0.36 (0.18-0.71) in model 4).

conclusionsFor treatment of IgAN, SP administered three times after tonsillectomy was associated with better renal prognosis compared with SP administered only once or twice.