R: IgG deposition in IgA nephropathy patients

Dear Editor-in-Chief, I read with great interest the recently published article by Nasri H. entitled “IgG deposition in IgA nephropathy patients” in the esteemed Journal of Renal Injury Prevention. In this study on 114 biopsies of IgA nephropathy (IgAN) patients they found no significant association of IgG deposits with age. There was no correlation of IgG deposit with four morphologic variables of Oxford classification (1). At this study, I would like to point out a few points. Recently, Wada et al. conducted a study on 57 IgAN patients who divided into two groups: IgA+IgG deposition (IgA-IgG) group and IgA deposition alone (IgA) group. They found, proteinuria was greater in the IgA-IgG group than the IgA group. Capillary wall IgA deposits were noted more frequently in the IgA-IgG group than the IgA group. They concluded that mesangial IgG deposition is associated with more severe clinical features in patients with IgAN (2). Previously Yoshimura et al. suggested that capillary IgA deposition is closely linked to clinical and histologic activities of IgAN and is considered to be an important factor responsible for the progression of the disease, possibly through crescent formation (3). However, this aspect of IgAN needs more test to investigate the potential clinical significance of immunostaining data, especially with regards to Oxford classification.