Fabiano Rafaela Cabral Gonçalves, de Almeida Araújo Stanley, Bambirra Eduardo Alves, Oliveira Eduardo Araújo, Simões E Silva Ana Cristina, Pinheiro Sérgio Veloso Brant
Division of Clinical Nephrology, Clinics Hospital, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.
Division of Renal Pathology, Clinics Hospital, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.
Pediatr Nephrol. 2017 Jul;32(7):1211-1220. doi: 10.1007/s00467-017-3610-y. Epub 2017 Feb 23.
Data on the risk factors for chronic kidney disease in children with immunoglobulin A nephropathy (IgAN) are scarce. This study was aimed at investigating whether glomerular C4d immunostaining is a prognostic marker in pediatric IgAN.
In this retrospective cohort study, 47 patients with IgAN biopsied from 1982 to 2010 were evaluated. Immunohistochemistry for C4d was performed in all cases. For analysis, patients were grouped according to positivity or not for C4d in the mesangial area. Primary outcome was a decline in baseline estimated glomerular filtration rate (eGFR) by 50% or more.
Median follow-up was 8.3 years. Median renal survival was 13.7 years and the probability of a 50% decline in eGFR was 13% over 10 years. Nine children exhibited the primary outcome and 4 developed end-stage renal disease (ESRD). Compared with C4d-negative patients (n = 37), C4d-positive patients (n = 10) presented higher baseline proteinuria (1.66 ± 0.68 vs 0.47 ± 0.19 g/day/1.73 m2, p < 0.001), a progressive decline in eGFR (−10.04 ± 19.38 vs 1.70 ± 18.51 ml/min/1.73 m2/year; p = 0.045), and more frequently achieved the primary outcome (50.0 vs 10.8%, p = 0.013), and ESRD (30.0 vs 2.7%, p = 0.026). No difference was observed in Oxford classification variables. Baseline proteinuria, endocapillary hypercellularity and mesangial C4d deposition were associated with primary outcome in univariate analysis. Proteinuria and mesangial C4d deposition at baseline independently predicted the decline in eGFR. Renal survival was significantly reduced in C4d-positive patients (8.6 vs 15.1 years in C4d-negative patients, p < 0.001).
In this exclusively pediatric cohort, positivity for C4d in the mesangial area was an independent predictor of renal function deterioration in IgAN.
关于免疫球蛋白A肾病（IgAN）患儿慢性肾病危险因素的数据很少。本研究旨在调查肾小球C4d免疫染色是否为儿童IgAN的预后标志物。
在这项回顾性队列研究中，对1982年至2010年期间接受活检的47例IgAN患者进行了评估。所有病例均进行了C4d免疫组织化学检测。为了进行分析，根据系膜区C4d阳性与否对患者进行分组。主要结局是基线估计肾小球滤过率（eGFR）下降50%或更多。
中位随访时间为8.3年。中位肾脏生存期为13.7年，10年内eGFR下降50%的概率为13%。9名儿童出现了主要结局，4名发展为终末期肾病（ESRD）。与C4d阴性患者（n = 37）相比，C4d阳性患者（n = 10）的基线蛋白尿更高（1.66±0.68 vs 0.47±0.19 g/天/1.73 m2，p < 0.001），eGFR呈进行性下降（-10.04±19.38 vs 1.70±18.51 ml/分钟/1.73 m2/年；p = 0.045），更频繁地达到主要结局（50.0 vs 10.8%，p = 0.013）和ESRD（30.0 vs 2.7%，p = 0.026）。牛津分类变量未观察到差异。在单因素分析中，基线蛋白尿、毛细血管内细胞增多和系膜C4d沉积与主要结局相关。基线时的蛋白尿和系膜C4d沉积独立预测eGFR下降。C4d阳性患者的肾脏生存期显著缩短（C4d阴性患者为8.6年，C4d阳性患者为15.1年，p < 0.001）。
在这个全为儿童的队列中，系膜区C4d阳性是IgAN肾功能恶化的独立预测因素。
