Serum Midkine Is Related to NYHA Class and Cystatin C in Heart Transplant Recipients

Heart transplantation is now the established method of therapy for end-stage heart failure, with significantly improved outcomes over recent years. However, an increasingly prevalent complication in this population is that chronic kidney disease appears to be generally associated with subclinical inflammation. Midkine is a heparin-binding growth factor with various functions ranging from cell growth and survival to angiogenensis, repair, and inflammation. Recently, serum midkine has been reported to be a novel marker of cardiac events in heart failure patients. The aim of this study was to assess midkine concentration in 134 heart transplant recipients in relation to kidney function and New York Heart Association (NYHA) class. Heart transplant recipients had significantly higher serum creatinine, urea, cholesterol, triglycerides, fasting glucose, white blood cell count, and serum midkine, and lower estimated glomerular filtration rate than the control group. Serum midkine levels rose together with advancing NYHA class. Serum midkine was related to kidney function, NT-proBNP, transferrin, and prednisone dose. Cystatin C and NT-proBNP class turn out to be predictors of midkine in heart transplant recipients. Midkine levels are dependent on heart and kidney function, and might also represent a surrogate marker of subclinical inflammation.