Validating the Oxford Classification of IgA Nephropathy

[摘要] The evolution of patients with IgA nephropathy (IgAN) varies greatly, and predictive tools are needed to assess confidently the risk for progression. Although in many studies clinical risk factors such as hypertension and proteinuria have consistently been linked to outcome, the independent value of pathology remains debated. Pathologists have developed a number of classifications over the years, at times with seemingly conflicting results. In 2009, the International IgA Nephropathy Network Group, working in collaboration with the Renal Pathology Society, proposed a set of four predictive renal biopsy findings independent of clinical assessment, the MEST score (M, mesangial hypercellularity; E, endocapillary proliferation; S, segmental glomerulosclerosis/adhesion; T, tubular atrophy/interstitial fibrosis) (1,2). This study differed from previous classification by using a stepwise methodology initially considering all plausible variables, subsequently eliminating those with poor reproducibility, avoiding highly collinear biopsy findings, testing their univariate predictive value and, finally, adjusting for clinical risk factors of progression. It also simultaneously considered two important, albeit different, outcomes: The rate of renal function decline and the survival from a 50% reduction of renal function or renal failure. Despite this meticulous approach, certain limitations were unavoidable. Its retrospective design and uncontrolled treatment allocation could have influenced the results. Validation of the Oxford classification has been carried out in children as well as adults (3,4). Verification is necessary because premature implementation of biased conclusions can harm patients and mislead future research.

[学科分类] 泌尿医学

[关键词] Bone marrow necrosis;Sickle cell disease;Hyperhemolysis syndrome