RESUMO
INTRODUCTION: During hemodialysis (HD) the interaction of the blood with the dialyzer triggers both an inflammatory reaction and an activation of the coagulation cascade. An accepted parameter to quantify the extent of coagulation activation during HD is not available. This study aims to evaluate its amplitude, comparing dialyzers made of different polysulfone polymers, by measuring D-dimers in the filter-rinsing fluids (Frf) and to test whether Frf D-dimers are suitable candidate markers to assess contact coagulation activation during HD. METHODS: In a prospective, cross-over study 41 hemodialysis patients were randomly allocated to nine HD sessions with three types of polysulfone membranes: Filter A: Poliflux®RevaclearMAX; Filter B: Helixone®Fx80, Filter C: Polyflux®H210. FINDINGS: A total of 117 HD sessions were studied. The mean (SD) filter (Frf) D-dimers were 0.19 µg/L (0.56) for Filter A; 0.66 µg/L (2.81) for Filter B; 0.33 µg/L (1.13) for Filter C. Significant differences were found: A vs. B (P < 0.01), A vs. C (P = 0.01); B vs. C not significant. A large between-patient variability of D-dimer filter levels was found. D-Dimers in blood showed a similar trend but differences were not significant. DISCUSSION: The contact activation of coagulation during HD may also vary among filters made up with similar polysulfones. D-dimer in the filter rinsing fluid but not in the blood can be considered a candidate marker for the evaluation of thrombogenicity during HD. Further studies are needed to elucidate the mechanism(s) and to confirm the usefulness of filter rinsing fluid D-Dimers as a clotting activation marker during HD.
