Monoclonal Ig crystalline nephropathies are rare lesions resulting from precipitation of monoclonal Igs in the kidney as crystalline inclusions. They can be categorized into lesions with predominant intracellular crystals (light chain [LC] proximal tubulopathy, LC crystal-storing histiocytosis, and LC crystalline podocytopathy) and lesions with predominant extracellular crystals (crystalglobulin-induced nephropathy and crystalline variant of LC cast nephropathy). The majority of these lesions are associated with low tumor burden lymphoproliferative disorders, with the exception of crystalline variant of LC cast nephropathy. Extrarenal involvement (e.g., skin and cornea) is frequent. Kidney biopsy is the cornerstone for diagnosis, which often requires electron microscopy and antigen retrieval. A thorough hematologic workup and evaluation of extrarenal involvement is mandatory for management. Treatment of these lesions is with clone-directed therapy, with the goal of achieving hematologic very good partial response or complete response, which preserves or improves kidney function. and studies, animal models, and novel sequencing techniques have been invaluable tools to understand the pathogenesis of LC proximal tubulopathy and can be used to increase our limited knowledge of the pathogenesis of the other monoclonal Ig crystalline nephropathies. This review provides an update on the pathology, renal and hematologic characteristics, extrarenal manifestations, prognosis, treatment, and pathogenesis of monoclonal Ig crystalline nephropathies.

中文翻译：

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单克隆免疫球蛋白结晶性肾病


单克隆 Ig 结晶性肾病是罕见的病变，是由于单克隆 Ig 在肾脏中以结晶包涵体形式沉淀而引起的。它们可分为以细胞内晶体为主的病变（轻链 [LC] 近端肾小管病、LC 晶体储存组织细胞增多症和 LC 结晶性足细胞病）和以细胞外晶体为主的病变（晶球蛋白诱导性肾病和 LC 管型肾病的晶体变体）。这些病变中的大多数与低肿瘤负荷淋巴增殖性疾病相关，但 LC 管型肾病的结晶变体除外。肾外受累（例如皮肤和角膜）很常见。肾活检是诊断的基石，通常需要电子显微镜和抗原修复。对于治疗来说，必须进行彻底的血液学检查和肾外受累评估。这些病变的治疗采用克隆定向治疗，目标是实现血液学非常好的部分缓解或完全缓解，从而保留或改善肾功能。研究、动物模型和新型测序技术是了解 LC 近端肾小管病发病机制的宝贵工具，可用于增加我们对其他单克隆 Ig 结晶性肾病发病机制的有限了解。本综述提供了单克隆 Ig 结晶性肾病的病理学、肾脏和血液学特征、肾外表现、预后、治疗和发病机制的最新信息。