Validity of the Oxford classification of IgA nephropathy in children

Abstract

Background: 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.

Methods: 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 ≥ stage III chronic kidney disease (CKD) (estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m(2)) using Cox regression analysis.

Results: 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 ≥ 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.

Conclusions: The Oxford classification appears to be valid for predicting renal outcome in children.