Wang Xin, Yu Xiao-Juan, Wang Su-Xia, Zhou Fu-de, Zhao Ming-Hui
Renal Division, Department of Medicine, Peking University First Hospital, Beijing, China.
Peking-Tsinghua Center for Life Sciences, Beijing, China.
Ren Fail. 2024 Dec;46(1):2283587. doi: 10.1080/0886022X.2023.2283587. Epub 2024 Feb 19.
Light-chain proximal tubulopathy (LCPT) is a rare disease characterized by the accumulation of monoclonal light chains within proximal tubular cells. This study aimed to investigate the clinical characteristics of LCPT from a single Chinese nephrology referral center. Patients with kidney biopsy-proven isolated LCPT between 2016 and 2022 at Peking University First Hospital were retrospectively included. Clinical data, kidney pathological type, treatment, and prognosis were analyzed. Nineteen patients were enrolled, the mean age at diagnosis was 57 ± 11 and the sex ratio was 6/13 (female/male). Mean proteinuria was 2.44 ± 1.89 g/24 hr and the mean estimated glomerular filtration rate (eGFR) at the point of biopsy was 59.640 ± 27.449 ml/min/1.73 m. κ-restriction (84%) was dominant among LCPTs. An abnormal free light chain ratio was observed in 86% of the patients. Proximal tubulopathy with cytoplasmic inclusions accounted for the majority (53%), followed by tubulopathy associated with interstitial inflammation reaction (26%), proximal tubulopathy without cytoplasmic inclusions (16%), and proximal tubulopathy with lysosomal indigestion/constipation (5%). One patient presented with acute kidney injury and 16 patients presented with chronic kidney disease. Regarding follow-up, patients received bortezomib-based or R-CHOP chemotherapy or supportive treatment only. The mean follow-up time was 22 ± 16 months, and the mean eGFR was 63.098 ± 27.439 ml/min/1.73 m at the end of follow-up. These patients showed improved or stable kidney function. This is the first case series report of LCPT in four different pathological types in northern China. Clone-targeted chemotherapy may help preserve the kidney function in these patients.
轻链近端肾小管病（LCPT）是一种罕见疾病，其特征为单克隆轻链在近端肾小管细胞内蓄积。本研究旨在从中国一家单一的肾脏病转诊中心调查LCPT的临床特征。回顾性纳入了2016年至2022年期间于北京大学第一医院经肾活检证实为孤立性LCPT的患者。分析了临床资料、肾脏病理类型、治疗及预后情况。共纳入19例患者，诊断时的平均年龄为57±11岁，男女比例为6/13（女性/男性）。平均蛋白尿为2.44±1.89 g/24小时，活检时的平均估计肾小球滤过率（eGFR）为59.640±27.449 ml/min/1.73 m²。κ型限制（84%）在LCPT中占主导。86%的患者观察到游离轻链比例异常。伴有胞质内包涵体的近端肾小管病占大多数（53%），其次是与间质炎症反应相关的肾小管病（26%）、无胞质内包涵体的近端肾小管病（16%）以及伴有溶酶体消化/便秘的近端肾小管病（5%）。1例患者出现急性肾损伤，16例患者出现慢性肾脏病。关于随访，患者接受了以硼替佐米为基础的化疗或R-CHOP化疗或仅接受支持治疗。平均随访时间为22±16个月，随访结束时的平均eGFR为63.098±27.439 ml/min/1.73 m²。这些患者的肾功能显示改善或稳定。这是中国北方关于四种不同病理类型LCPT的首个病例系列报告。针对克隆的化疗可能有助于保护这些患者的肾功能。
