Abstract: 【Abstract】Objective To investigate the serum growth differentiation factor-15 (GDF-15) level in patients with different types of renal diseases and its correlation with renal function. Methods We recruited 122 patients with different types of nephropathy treated in the Department of Nephrology, Shandong Provincial Hospital from December 2019 to August 2020 in this study, and 15 healthy people from physical examination center as the control group. Serum GDF-15 was detected by ELISA. Clinical data and laboratory parameters were collected, and analyzed in association with serum GDF-15 and other factors. Results Serum GDF-15
was significantly higher in patients with diabetic nephropathy than that in control group (t=6.522, P＜0.001), IgA nephropathy (t=4.322, P=0.004) and lupus nephritis patients (t=3.884, P=0.001). Serum GDF-15 was significantly higher in multiple myeloma patients than in control group (t=5.678, P＜0.001), IgA nephropathy (t=4.532, P=0.004) and lupus nephritis patients (t=4.244, P=0.008). Age (r=0.395, P<0.001), abnormal immunofixation electrophoresis (r=0.251, P=0.003), blood glucose (r=0.205, P= 0.016), CRP (r=0.178, P=0.038), free light chain ratio (r=0.324, P<0.001), and MM (r=0.225, P=0.008) were positively correlated with serum GDF-15 level. Linear regression analysis showed that serum GDF-15 level was significantly associated with age (β= 0.395, P<0.001), elevated CRP (β=0.175, P=0.040), MM (β=0.192, P=0.025), abnormal immunofixation electrophoresis (β=0.251, P=0.003), and abnormal free light chain ratio (β=0.299, P<0.001). Conclusions Serum GDF-15 level varied in different renal diseases and was correlated with age, blood glucose, CRP,MM, free light chain ratio and abnormal immunofixation electrophoresis. Serum GDF-15 level is a useful index reflecting the extent of kidney injury.

Key words: Growth differentiation factor- 15, Renal diseases, Immunofixation electrophoresis, Free light chain