Comment on: Association of Proteinuria with Various Clinical Findings and Morphologic Variables of Oxford Classification in Immunoglobulin A Nephropathy Patients.

DEAR EDITOR,

I read with great interest, an interesting article by Nasri et al., entitled “association of proteinuria with various clinical findings and morphologic variables of oxford classification in immunoglobulin A nephropathy (IgAN) patients” that was published in the esteemed international journal of preventive medicine. In an observational study on 114 patients with IgAN, they found a positive association between the proportion of crescentic fibrous formation and amount of proteinuria. They also found that Nephrotic syndrome as a definition had also a positive association with the proportion of crescent formation. They suggested the prognostic value of crescent due to its association with proteinuria, and secondly they implied the importance of treatment of proteinuria to prevent progression of IgAN.[1] On this study, I would like to point out a few notes. Newly, the Oxford classification is a novel classification for IgAN, and was developed by the renal pathology society and the working group of the international IgAN network, and it clinical validity has been proven in various studies.[234] This group defined four pathologic features that were more associated with the progression of kidney disease, including: Mesangial hypercellularity, the presence of endocapillary proliferation, segmental glomerulosclerosis/adhesion, and fourthly the severity of tubular atrophy/interstitial fibrosis.[34] In fact, this classification offers a histopathologic grading system that is associated with renal disease consequences and by itself it is independent on clinical features. This classification also exhibits an improved capacity to predict the outcome of patients with IgAN.[234] All four morphologic variables of the Oxford classification have high reproducibility.[345] However, this classification doesn’t include extracapillary proliferation, and base on the results of the Oxford classification, extracapillary proliferation is not associated with renal disease outcome,[56789] meanwhile various investigations, have suggested that crescents have prognostic implication.[678910] The study of Nasri et al. further supports the importance of extracapillary crescentic proliferation due to its association with the degree of proteinuria.[1] Therefore, we suggest further studies to investigate the prognostic implication of extracapillary proliferation in larger studies, and to examine the interesting findings by Nasri and other investigators in this field. Finally, I should note that the oxford classification is not driven from a large number of patients (n = 265 patients).[7]