LETTER TO THE EDITOR Comment on: Clinical, Histopathological and Immunofluorescent Findings of IgA Nephropathy

We read with interest the recently published article by Tipu et al. entitled “Clinical, histopathological and immunofluorescent findings of IgA nephropathy”, in the esteemed Iranian Journal of Immunology (1). The study described frequency of different clinical, histopathological and immunofluorescent characteristics of IgA nephropathy. The authors should be applauded for their findings; however, we would like to remind a few points about IgA nephropathy (IgAN). After popularization of Oxford classification of IgAN on July 2009 (2), it is necessary to describe the morphologic lesions in the cadre of this classification. Thus, it is indispensable to change the morphologic lesions of table 2 of the mentioned work, according to the MEST variables. In the materials and methods section, the authors stated that, specimen for immunofluorescence, stained for antibodies of IgA, IgG, IgM, C3, C4 and fibrinogen. However, the definition of IgAN requires the presence of IgA deposits which were graded ≥ 2+ and the absence of C1q deposition (2,3). Hence, the specimens for C1q antibody must be stained and its strict negative, brightness should be stated in the paper as an important part of definition of IgAN following ≥ 2+ brightness of IgA antibody deposits (1-5). Since IgAN has various morphologic features, it is indispensable to rule out the lupus nephritis. While in the later, there is a prominent deposit of C1q. As the authors also mentioned, IgA nephropathy (IgAN) is very common form of primary glomerulonephritis and occurs worldwide (4-9) and the disease may have distinct morphologic and clinical presentation in different regions (1). Therefore these kinds of studies are crucial in our region to further understand the presentations of immunoglobulin A nephropathy.