Lu Zhao1, Liang Peng1, Danyi Yang1, Shi Chen1, Zhixin Lan1, Xuejing Zhu1, Shuguang Yuan1, Guochun Chen1, Yu Liu1, Hong Liu2. 1. Department of Nephrology, The Second Xiangya Hospital of Central South University, Changsha, Hunan, China; Hunan Key Laboratory of Kidney Disease and Blood Purification, Changsha, Hunan, China. 2. Department of Nephrology, The Second Xiangya Hospital of Central South University, Changsha, Hunan, China; Hunan Key Laboratory of Kidney Disease and Blood Purification, Changsha, Hunan, China. Electronic address: liuhong618@csu.edu.cn.
Abstract
BACKGROUND: Immunoglobulin A nephropathy (IgAN nephropathy, IgAN) is named for the renal pathological features of IgA-dominant immunoglobulin deposition. IgA deposits, however, may also occur in other diseases, from liver disease and inflammation to chronic infections and tumors. Now increasing studies have suggested that galactose-deficient IgA1 (Gd-IgA1) plays a critical role in the pathogenesis of IgAN. This study aims to investigate whether the Gd-IgA1-specific antibody KM55 contributes to differentiating primary IgAN from other diseases with IgA deposits. METHODS: In this retrospective study, we enrolled 100 Chinese patients with IgA deposits in renal biopsies, including IgAN(n = 40), IgAN with hepatitis B virus antigen deposits(n = 14), IgA vasculitis(n = 16), lupus nephritis(n = 11), incidental IgA deposits(n = 13) and negative controls(n = 6). Double immunostaining of Gd-IgA1 and IgA was performed in all biopsies. RESULTS: There were similar patterns of Gd-IgA1 deposition in primary IgAN, IgA vasculitis, and IgAN with hepatitis B virus antigen deposits. Gd-IgA1 staining could also be seen in patients with lupus nephritis and incidental IgA deposits, but the intensity was significantly lower than IgAN, and the optimal cutoff was 2+ staining for differential diagnosis. Every increase in KM55 staining intensity of 1+ was associated with an increase in the odds of primary IgAN (OR: 4.399; 95% CI: 1.725-11.216). CONCLUSIONS: Immunostaining for Gd-IgA1 by KM55 is not specific for IgA nephropathy, but weak or negative staining may favor incidental IgA deposits.
BACKGROUND:Immunoglobulin A nephropathy (IgAN nephropathy, IgAN) is named for the renal pathological features of IgA-dominant immunoglobulin deposition. IgA deposits, however, may also occur in other diseases, from liver disease and inflammation to chronic infections and tumors. Now increasing studies have suggested that galactose-deficientIgA1 (Gd-IgA1) plays a critical role in the pathogenesis of IgAN. This study aims to investigate whether the Gd-IgA1-specific antibody KM55 contributes to differentiating primary IgAN from other diseases with IgA deposits. METHODS: In this retrospective study, we enrolled 100 Chinese patients with IgA deposits in renal biopsies, including IgAN(n = 40), IgAN with hepatitis B virus antigen deposits(n = 14), IgA vasculitis(n = 16), lupus nephritis(n = 11), incidental IgA deposits(n = 13) and negative controls(n = 6). Double immunostaining of Gd-IgA1 and IgA was performed in all biopsies. RESULTS: There were similar patterns of Gd-IgA1 deposition in primary IgAN, IgA vasculitis, and IgAN with hepatitis B virus antigen deposits. Gd-IgA1 staining could also be seen in patients with lupus nephritis and incidental IgA deposits, but the intensity was significantly lower than IgAN, and the optimal cutoff was 2+ staining for differential diagnosis. Every increase in KM55 staining intensity of 1+ was associated with an increase in the odds of primary IgAN (OR: 4.399; 95% CI: 1.725-11.216). CONCLUSIONS: Immunostaining for Gd-IgA1 by KM55 is not specific for IgA nephropathy, but weak or negative staining may favor incidental IgA deposits.
Authors: M Colleen Hastings; Dana V Rizk; Krzysztof Kiryluk; Raoul Nelson; Rima S Zahr; Jan Novak; Robert J Wyatt Journal: Pediatr Nephrol Date: 2021-04-05 Impact factor: 3.651