Predicting renal outcomes in immunoglobulin A vasculitis nephritis; from ISKDC classification to Oxford MEST-C classification

Abstract

Immunoglobulin A vasculitis nephritis (IgAVN) or Henoch-Schönlein purpura nephritis (HSPN) is the most common type of secondary IgA nephropathy (IgAN), particularly in children. Overall, its prognosis is good, but in a significant number of cases, it does lead to chronic kidney disease (CKD) and end-stage renal disease (ESRD). Various classifications exist to predict the long-term outcome of kidney disease in these diseases, but none is universally accepted. We searched PubMed, Web of Science Embase, EBSCO, Scopus and directory of open access journals (DOAJ) with keywords of Henoch-Schönlein purpura nephritis, immunoglobulin A vasculitis nephritis, immunoglobulin A nephropathy, IgA vasculitis, extracapillary proliferation, IgA nephropathy, leukocytoclastic vasculitis, endstage renal disease, Oxford classification, crescent and childhood IgA vasculitis. IgAVN in children presents most often with crescents and endocapillary proliferation, with relapsing and remitting course clinically. Due to morphological resemblance of IgAVN and IgAN, the Oxford MEST-C scores could be applied for determining the long-term outcomes in the former disease. A critical concern in applying Oxford classification for IgAVN is that limited number of children with IgAVN exists in any one center and also a relatively short period of follow-up. Hence, further work in this regard is necessary. Preliminary evidence suggests that Oxford MEST-C classification is valid in predicting long-term kidney outcomes in children with IgAVN and the classification can also be used in adults. However, further, large scale, multicenter, international collaborative studies are needed to address the unmet issues.