Department of Nephrology, University of Medicine and Pharmacy "Carol Davila", Bucharest, Romania.
Department of Nephrology, "Dr. Carol Davila" Teaching Hospital of Nephrology, Bucharest, Romania.
Ren Fail. 2024 Dec;46(1):2313179. doi: 10.1080/0886022X.2024.2313179. Epub 2024 Feb 15.
The clinical significance of mesangial immunoglobulin (Ig) M deposition in IgA nephropathy (IgAN) has been less explored and remains a topic of debate. Therefore, our study aimed to investigate the prognostic value of mesangial IgM deposition in a long-term follow-up cohort of IgAN patients.
A unicentric retrospective study was conducted on 93 consecutive IgAN patients (median age 41 years, 68% male, eGFR 48.7 mL/min, proteinuria 1.1 g/g) from 2010 to 2015. They were followed until end-stage kidney disease (ESKD), death, or until the end of the study in January 2021, with a median follow-up of 7 years. An independent pathologist evaluated the IgM immunofluorescence pattern, Oxford MEST-C score, and transmission electron microscopy (TEM) lesions following a comprehensive protocol.
In our cohort, 70% had mesangial IgM-positive deposits, while 30% were IgM-negative. Both groups were similar in age, sex, prevalence of arterial hypertension, Charlson comorbidity scores, kidney function (eGFR and proteinuria), pathology findings (Oxford MEST-C score, IgG and C3 immune deposition), and TEM analysis. Treatment with RASI and immunosuppression, and death rates were also comparable. However, 37% of IgM-positive patients progressed to ESKD, significantly higher than the 11% in the IgM-negative group. Univariate and multivariate Cox proportional hazards regression analyses identified lower eGFR, higher Oxford MEST-C score, and mesangial IgM deposits as independent factors associated with shorter kidney survival.
Our study highlights mesangial IgM deposition as a potential risk factor for ESKD in patients with advanced IgAN, laying a foundation for further research in this area.
系膜区免疫球蛋白 M（IgM）沉积在 IgA 肾病（IgAN）中的临床意义尚未得到充分探索，仍然存在争议。因此，我们的研究旨在探讨 IgAN 患者长期随访队列中系膜 IgM 沉积的预后价值。
我们对 2010 年至 2015 年期间的 93 例连续的 IgAN 患者（中位年龄 41 岁，68%为男性，eGFR 为 48.7 mL/min，蛋白尿为 1.1 g/g）进行了单中心回顾性研究。他们随访至终末期肾病（ESKD）、死亡或 2021 年 1 月研究结束，中位随访时间为 7 年。一位独立的病理学家按照综合方案评估 IgM 免疫荧光模式、牛津 MEST-C 评分和透射电镜（TEM）病变。
在我们的队列中，70%的患者系膜区有 IgM 阳性沉积，而 30%的患者为 IgM 阴性。两组在年龄、性别、动脉高血压患病率、Charlson 合并症评分、肾功能（eGFR 和蛋白尿）、病理发现（牛津 MEST-C 评分、IgG 和 C3 免疫沉积）和 TEM 分析方面相似。RASI 和免疫抑制治疗以及死亡率也相似。然而，37%的 IgM 阳性患者进展为 ESKD，显著高于 IgM 阴性组的 11%。单因素和多因素 Cox 比例风险回归分析确定较低的 eGFR、较高的牛津 MEST-C 评分和系膜 IgM 沉积是与肾脏生存时间缩短相关的独立因素。
我们的研究强调系膜 IgM 沉积是 IgAN 患者进展为 ESKD 的潜在危险因素，为该领域的进一步研究奠定了基础。
