Validity of the Oxford classification of IgA nephropathy in children

In 2009, the Oxford classification of IgA nephropathy was published. However, its validity has not been fully examined in children. This study aimed to assess this system in an independent large-scale cohort of children. We analyzed 161 consecutive children with newly diagnosed IgA nephropathy from 1977 to 1989 retrospectively. We examined the ability of each variable in the Oxford classification as a predictor of renal outcome defined as a parts per thousand yen stage III chronic kidney disease (CKD) (estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73 m(2)) using Cox regression analysis. The mean mesangial score, and ratios of segmental glomerulosclerosis, endocapillary hypercellularity, tubular atrophy, and crescents were 0.49, 0.8%, 13.1%, 3.3%, and 9.2% respectively. Seven cases reached a parts per thousand yen stage III CKD. In univariate analyses, mesangial hypercellularity score, endocapillary hypercellularity, tubular atrophy, and crescents were significant predictors of renal outcome. In a multivariate analysis, only mesangial hypercellularity score, tubular atrophy, and crescents were significant though, depending on models. Segmental glomerulosclerosis was not a significant predictor of renal outcome. Although the significance of crescents was not addressed in the Oxford classification, crescents were important predictors of outcome. The Oxford classification appears to be valid for predicting renal outcome in children.