Light Chain Restriction in Proximal Tubules—Implications for Light Chain Proximal Tubulopathy

Frontiers in Medicine

article

Christoph Daniel¹  Monika Klewer¹  Anke Büttner²  Fulvia Ferrazzi¹  Simone Bertz¹  Kerstin Amann¹  Maike Büttner-Herold¹  Nathalie Krieglstein¹  Teresa Chuva⁴  Kaija Minuth¹  Frederick Pfister¹ 

[1] Department of Nephropathology, Institute of Pathology, Friedrich-Alexander-University Erlangen-Nuremberg;School of Psychology, College of Life and Environmental Sciences, University of Birmingham;Institute of Pathology, Friedrich-Alexander-University Erlangen-Nuremberg;Department of Nephrology, Portuguese Institute of Oncology

关键词: renal tubule;    light chain restriction;    monoclonal gammopathies of renal significance;    tubular crystals;    cast nephropathy;   

DOI  :  10.3389/fmed.2022.723758

学科分类：社会科学、人文和艺术（综合）

来源: Frontiers

【 摘 要 】

Monoclonal gammopathy (MG) causes various nephropathies, which may suffice for cytoreductive therapy even in the absence of diagnostic criteria for multiple myeloma or B-cell non-Hodgkin lymphoma. The aim of this study was to better understand the significance of light chain (LC) restriction or crystals (LC-R/C) in proximal tubules in the spectrum of LC-induced nephropathies. A consecutive cohort of 320 renal specimens with a history of B-cell dyscrasia was characterized. Special attention was paid to immunohistochemical LC restriction in proximal tubules, tubular crystals or constipation, and ultrastructural findings. Complementary cell culture experiments were performed to assess the role of LC concentrations in generating LC restriction. Light chain restriction or crystals in proximal tubules was found in a quarter of analyzed cases (81/316) and was associated with another LC-induced disease in 70.4% (57/81), especially LC cast-nephropathy (cast-NP) and interstitial myeloma infiltration. LC restriction without significant signs of acute tubular injury was observed in 11.1% (9/81). LC-R/C was not associated with inferior renal function compared to the remainder of cases, when cases with accompanying cast-NP were excluded. Besides crystals, cloudy lysosomes were significantly associated with LC-R/C on an ultrastructural level. In summary, LC-R/C is frequent and strongly associated with cast-NP, possibly indicating that a high load of clonal LC is responsible for this phenomenon, supported by the observation that LC restriction can artificially be generated in cell culture. This and the lack of significant tubular injury in a subgroup imply that in part LC-R/C is a tubular trafficking phenomenon rather than an independent disease process.

【 授权许可】

CC BY