Abstract: ObjectiveTo investigate the relationships among serum free light chains (FLCs) and clinical indicators and renal pathological changes of  diabetic nephropathy (DN). MethodsForty DN patients and 40 nonDN patients were enrolled. The participants were divided into experiment and control group，but chronic inflammatory disease was exclued. Serum creatinine， urinary protein， hsCRP and Hcy were observed. The λFLC  and  κFLC were detected by indirect immunofluorescence. Furthermore， we observed the renal pathological changes by light microscope. The λFLC  and κFLC were determined through ELISA. Univariate analysis was used to examine the relationships between FLCs and clinical indicators and renal pathological changes of DN. ResultsThe experiment group had higher hsCPR and Hcy level than the control group (P<0.05). The levels of cFLC (The sum of λFLC  and κFLC)  in the experiment group were higher compared with the control group (P<0.05). The Hcy and hsCRP were positively correlated with combined free light chain(cFLC) (P<0.05). The scores of tubulointerstitial lesions showed positive correlations (P<0.05) with cFLC， but negatively correlated with eGFR (P<0.05). ConclusionThe level of cFLC could be a predictor of the risk of mortality (especially cardiovascular disease caused) of DN patients and the progression of  DN.

Key words: diabetic nephropathies, immunoglobulin light chains, cardiovascular diseases, death, risk factors