title: Evaluation of circuit and AV fistula clotting and detection of anti-PF4/heparin complex antibodies in hemodialysis patients suspected of having heparin-induced thrombocytopenia.
abstract: A retrospective study was performed to elucidate the characteristics of heparin-induced thrombocytopenia (HIT) in newly treated hemodialysis (HD) patients who essentially required anticoagulation with unfractionated heparin (UFH). Seventy-eight patients suspected of having HIT within 3 months of starting HD with UFH were selected for this study. Their platelet counts were routinely followed, and anti-PF4/heparin complex antibodies (HIT antibodies) were measured with enzyme-linked immunosorbent assay (ELISA) until the titer became negative. The characteristics of thrombocytopenia were a platelet count of ≤150 × 10(9)/L and/or decrease of ≥30% and as caused by the intermittent use (3 times/a week) of UFH during HD. Fifty-five patients showed unexpected clotting in the extracorporeal circuit and/or arteriovenous fistula (AVF) thrombosis, while 23 patients had neither of these complications. The patients were classified into HD-related and non-HD-related thrombus groups. The impact of various combinations of the 3 clinical factors (thrombocytopenia, timing, and HD-related thrombus) and the results of ELISA as a laboratory factor were examined. A combination of 2 platelet factors (thrombocytopenia and timing) and ELISA positivity did not reveal the presence of HIT, while a combination of the 3 clinical factors and a positive ELISA improved the accuracy of HIT diagnosis. The findings on the 4-factor combination were supported by high rates of seroconversion in a serotonin release assay. Combining appropriate clinical factors and a positive ELISA may lead to the proper management of HD patients suspected of having HIT. In conclusion, while HD patients showed a drop of ≤150 × 10(9)/L or ≥30% on days 7 to 30, unexpected clotting in the circuit and/or AVF thrombosis was considered as a sign of HIT development.
authors.affiliation: Hyogo Prefectural Awaji Hospital, Sumoto, Hyogo, Japan. tak-matsuo@deluxe.ocn.ne.jp
authors.forename: Takefumi
authors.initials: T
authors.lastname: Matsuo
authors.forename: Keiko
authors.initials: K
authors.lastname: Wanaka
authors.forename: Jeanine M
authors.initials: JM
authors.lastname: Walenga
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000714:Anastomosis, Surgical; D000925:Anticoagulants / Q000008:administration & dosage / Q000009:adverse effects*; D001323:Autoantibodies / Q000097:blood*; D005260:Female; D006493:Heparin / Q000008:administration & dosage / Q000009:adverse effects*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010976:Platelet Count; D010978:Platelet Factor 4; D006435:Renal Dialysis; D012189:Retrospective Studies; D013921:Thrombocytopenia / Q000097:blood / Q000139:chemically induced / Q000150:complications; D013927:Thrombosis / Q000097:blood / Q000209:etiology; D013997:Time Factors
chemical_list: D000925:Anticoagulants; D001323:Autoantibodies; D010978:Platelet Factor 4; D006493:Heparin