Department of Nephrology, Key Laboratory for the Prevention and Treatment of Chronic Kidney Disease of Chongqing, Chongqing Clinical Research Center of Kidney and Urology Diseases, Xinqiao Hospital, Army Medical University, (Third Military Medical University), Chongqing, 400037, China.
Int Urol Nephrol. 2023 Nov;55(11):2925-2933. doi: 10.1007/s11255-023-03579-0. Epub 2023 Apr 3.
The value of monoclonal protein (M-protein) in antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) patients with renal involvement has not been investigated.
We analyzed AAV patients with renal involvement from 2013 to 2019 in our center. Patients with immunofixation electrophoresis were divided into M-protein positive group and M-protein negative group. The clinicopathological features and outcomes of the two groups were compared.
Ninety-one AAV patients with renal involvement were enrolled for analysis, and 16 patients (17.6%) had a positive test for M-protein. Compared with M-protein negative patients, M-protein positive patients had lower hemoglobin (77.6 vs 88.4 g/L, p = 0.016), mean corpuscular hemoglobin concentration (313 vs 323 g/L, p = 0.002),serum albumin (29.4 vs 32.5 g/L, p = 0.026) and complement 3 (C3) (0.66 vs 0.81 g/L, p = 0.047), while higher platelets (252 vs 201 10/L, p = 0.048) and incidence of pulmonary infection (62.5% vs 33.3%, p = 0.029). However, renal pathological features between the two groups had no significant difference. In addition, during a median follow-up of 33 months, Kaplan-Meier survival analysis showed that, compared with M-protein negative patients, M-protein positive patients had a higher risk of all-cause mortality (log-rank test, p = 0.028), especially for patients who were not dialysis-dependent at the time of admission (log-rank test, p = 0.012).
Our results indicate that M-protein is associated with different clinicopathological features and increased all-cause mortality in AAV patients with renal involvement. Testing M-protein and rigorous diagnosing of the significance of the presence of M-protein may be helpful for assessing the survival of AAV patients with renal involvement.
抗中性粒细胞胞浆抗体（ANCA）相关性血管炎（AAV）合并肾损害患者的单克隆蛋白（M 蛋白）的价值尚未得到研究。
我们分析了 2013 年至 2019 年期间在我中心就诊的合并肾损害的 AAV 患者。对免疫固定电泳患者进行 M 蛋白阳性组和 M 蛋白阴性组的分组。比较两组的临床病理特征和结局。
共纳入 91 例合并肾损害的 AAV 患者进行分析，其中 16 例（17.6%）M 蛋白检测阳性。与 M 蛋白阴性患者相比，M 蛋白阳性患者的血红蛋白（77.6 与 88.4 g/L，p=0.016）、平均红细胞血红蛋白浓度（313 与 323 g/L，p=0.002）、血清白蛋白（29.4 与 32.5 g/L，p=0.026）和补体 3（C3）（0.66 与 0.81 g/L，p=0.047）较低，血小板（252 与 201×10/L，p=0.048）和肺部感染发生率（62.5%与 33.3%，p=0.029）较高。然而，两组患者的肾脏病理特征无显著差异。此外，中位随访 33 个月后，Kaplan-Meier 生存分析显示，与 M 蛋白阴性患者相比，M 蛋白阳性患者的全因死亡率更高（对数秩检验，p=0.028），尤其是入院时无需透析的患者（对数秩检验，p=0.012）。
我们的研究结果表明，M 蛋白与 AAV 合并肾损害患者的不同临床病理特征和全因死亡率增加有关。检测 M 蛋白并严格诊断 M 蛋白存在的意义，可能有助于评估 AAV 合并肾损害患者的生存情况。
