Yuko Shima1, Koichi Nakanishi2, Hironobu Mukaiyama1, Yu Tanaka1, Takuzo Wada1, Ryojiro Tanaka3, Hiroshi Kaito3, Kandai Nozu4, Mayumi Sako5, Kazumoto Iijima4, Norishige Yoshikawa6. 1. Department of Pediatrics, Wakayama Medical University, Wakayama City, Wakayama, Japan. 2. Department of Pediatrics, Child Health and Welfare (Pediatrics), Graduate School of Medicine, University of the Ryukyus, 207 Uehara Nishihara-cho, Nakagami-gun, Okinawa, 903-0125, Japan. knakanis@med.u-ryukyu.ac.jp. 3. Department of Nephrology, Hyogo Prefectural Kobe Children's Hospital, Kobe, Hyogo, Japan. 4. Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Hyogo, Japan. 5. Division for Clinical Trials, Clinical Research Center, National Center for Child Health and Development, Tokyo, Japan. 6. Clinical Research Center, Takatsuki General Hospital, Takatsuki City, Osaka, Japan.
Abstract
BACKGROUND: IgA nephropathy (IgAN) is characterized by predominant mesangial IgA deposition. Some patients with IgAN demonstrate IgA deposition in glomerular peripheral capillaries (cap-IgA). The clinicopathological significance of cap-IgA remains incompletely investigated in children. METHODS: We retrospectively analyzed 503 consecutive cases of biopsy-proven childhood IgAN between July 1976 and June 2013 to compare clinical and pathological features between IgAN patients with and without cap-IgA. RESULTS: Among the 503 patients, 30 (6.0%) had cap-IgA. We found significant differences in proteinuria (2.0 vs. 0.5 g/day/m2, p < 0.0001), time from onset to kidney biopsy (2.2 vs. 8.3 months, p < 0.0001), and rate of proteinuria remission after treatment (23.3% vs. 48.0%, p = 0.007) between both groups. Pathological analysis revealed significant differences in M1 (83.3% vs. 56.0%, p = 0.002), ratio of subendothelial electron dense deposits (EDDs, 58.6% vs. 16.5%, p < 0.0001) and subepithelial EDDs (48.3% vs. 16.5%, p = 0.0001), and glomerular basement membrane (GBM) lysis (58.6% vs. 27.1%, p = 0.0006) between both groups. More than half of cap-IgA patients (17/30, 56.7%), whereas only 26.2% of non-cap-IgA patients (124/473), were treated with immunosuppressive treatments. Six of 30 cases (20%) with cap-IgA reached glomerular filtration rate (GFR) categories G3a-G5 (estimated GFR < 60 ml/min/1.73 m2) at most recent observation (mean observation period: 7.0 ± 4.0 years). According to Kaplan-Meier analysis, patients with cap-IgA had significantly lower kidney survival curves than non-cap-IgA patients (72.8% vs. 97.2% at 10 years, p < 0.0001). CONCLUSIONS: Cap-IgA is associated with acute inflammation with GBM changes, resulting in refractory heavier proteinuria. Cap-IgA may represent a poor prognostic factor.
BACKGROUND: IgA nephropathy (IgAN) is characterized by predominant mesangial IgA deposition. Some patients with IgAN demonstrate IgA deposition in glomerular peripheral capillaries (cap-IgA). The clinicopathological significance of cap-IgA remains incompletely investigated in children. METHODS: We retrospectively analyzed 503 consecutive cases of biopsy-proven childhood IgAN between July 1976 and June 2013 to compare clinical and pathological features between IgAN patients with and without cap-IgA. RESULTS: Among the 503 patients, 30 (6.0%) had cap-IgA. We found significant differences in proteinuria (2.0 vs. 0.5 g/day/m2, p < 0.0001), time from onset to kidney biopsy (2.2 vs. 8.3 months, p < 0.0001), and rate of proteinuria remission after treatment (23.3% vs. 48.0%, p = 0.007) between both groups. Pathological analysis revealed significant differences in M1 (83.3% vs. 56.0%, p = 0.002), ratio of subendothelial electron dense deposits (EDDs, 58.6% vs. 16.5%, p < 0.0001) and subepithelial EDDs (48.3% vs. 16.5%, p = 0.0001), and glomerular basement membrane (GBM) lysis (58.6% vs. 27.1%, p = 0.0006) between both groups. More than half of cap-IgA patients (17/30, 56.7%), whereas only 26.2% of non-cap-IgA patients (124/473), were treated with immunosuppressive treatments. Six of 30 cases (20%) with cap-IgA reached glomerular filtration rate (GFR) categories G3a-G5 (estimated GFR < 60 ml/min/1.73 m2) at most recent observation (mean observation period: 7.0 ± 4.0 years). According to Kaplan-Meier analysis, patients with cap-IgA had significantly lower kidney survival curves than non-cap-IgA patients (72.8% vs. 97.2% at 10 years, p < 0.0001). CONCLUSIONS: Cap-IgA is associated with acute inflammation with GBM changes, resulting in refractory heavier proteinuria. Cap-IgA may represent a poor prognostic factor.
Entities:
Keywords:
Capillary IgA deposition; Children; Electron dense deposits; IgAN; Immunofluorescence; Kidney failure; School screening programs
Authors: Mark Haas; Jacobien C Verhave; Zhi-Hong Liu; Charles E Alpers; Jonathan Barratt; Jan U Becker; Daniel Cattran; H Terence Cook; Rosanna Coppo; John Feehally; Antonello Pani; Agnieszka Perkowska-Ptasinska; Ian S D Roberts; Maria Fernanda Soares; Hernan Trimarchi; Suxia Wang; Yukio Yuzawa; Hong Zhang; Stéphan Troyanov; Ritsuko Katafuchi Journal: J Am Soc Nephrol Date: 2016-09-09 Impact factor: 10.121
Authors: Anthony S Alvarado; Nicole K Andeen; Sergey Brodsky; Alice Hinton; Tibor Nadasdy; Charles E Alpers; Christopher Blosser; Behzad Najafian; Brad H Rovin Journal: Nephrol Dial Transplant Date: 2018-07-01 Impact factor: 5.992
Authors: George J Schwartz; Alvaro Muñoz; Michael F Schneider; Robert H Mak; Frederick Kaskel; Bradley A Warady; Susan L Furth Journal: J Am Soc Nephrol Date: 2009-01-21 Impact factor: 10.121