LIGHT CHAIN PROXIMAL TUBULOPATHY: A CASE STUDY AND LITERATURE REVIEW

Changda Lin, Jiequn Zhang, Yun Zhang, Shuhan Shi, Yueting Li, Jinhai Chen^* 

Department of Nephrology, The Second Affiliated Hospital of Fujian Medical University, Quanzhou, Fujian, 362000, China

Proximal tubulopathy caused by monoclonal light chains is divided into the following types: renal tubular injury and renal tubular necrosis associated with light chains, light chain-associated tubulointerstitial nephritis, light chain-associated proximal tubulopathy, and light chain cast nephropathy. Light chain proximal tubulopathy (LCPT) is a rare disease and related to plasma cell dyscrasias, characterized by light chain deposits in the proximal tubular cells, with or without crystal formation. The male patient aged 62 years old had hypertension in this study. The light microscopy results showed that no deposits were found in the glomerular mesangium, subepithelial and subendothelial regions. Lambda chains were observed, and Kappa light chain deposits were not observed under the fluorescence microscope. The electron microscopy findings showed that electron-dense deposits were not found in mesangial cells, hyperplastic matrix, mesangial and subendothelial regions. LCPT (without crystal formation)-the induced renal tubulointerstitial injury was 30%. In conclusion, This is a rare case of combined LCPT with monoclonal gammopathy of renal significance (MGRS), in which diagnosis was based on clinical manifestations and serum and urine immunofixation electrophoresis.