Clinical and prognostic usefulness of soluble urokinase plasminogen activator receptor in hemodialysis patients

PURPOSE: Considering its prognostic usefulness and the relationship with chronic kidney disease, we analyzed the clinical utility of soluble urokinase plasminogen activator receptor (suPAR) in end-stage renal disease patients undergoing hemodialysis treatment. We focused on the association between suPAR levels and clinical outcomes, especially those related to cardiovascular events and mortality as well as the effect of hemodialysis on the protein levels. METHODS: We enrolled 64 patients. Blood samples for laboratory tests were collected before and after the midweek hemodialysis. The concentration of suPAR was assessed using suPARNostic ELISA, ViroGates. RESULTS: Spearman rank analyses showed a positive association between suPAR and creatinine, cystatin C, galectin 3, N-terminal prohormone of brain natriuretic peptide and troponin T (p < 0.05). In ROC analysis, the suPAR concentration equal to 11.5 ng/mL was established to be the cutoff value for the prediction of mortality in the analyzed patients. Simultaneous analysis of creatinine and suPAR increased the predictive value of the latter—the area under curve increased to 0.84 (95% CI 0.70–0.94, p < 0.0001). Logistic regression analysis revealed that increase in the suPAR level was associated with the increase in odds ratio for death by 1.3 (95% CI 1.1–1.6, χ(2) = 8.2, p = 0.004). In multivariable analysis, the prediction power of suPAR appeared to be stronger after including creatinine (p = 0.0005). CONCLUSIONS: Elevated suPAR levels provide independent information on mortality risk in patients undergoing hemodialysis. The protein appears not to cross the dialysis membrane; thus, blood collection before the second hemodialysis session seems to give reliable information on the suPAR level for clinical interpretation.