[The incidence of heparin-induced thrombocytopenia and positivity of antibody in patients treated with heparin preparations].

ABSTRACT

OBJECTIVES: To investigate the incidence of the heparin-induced thrombocytopenia (HIT) and positivity of anti-heparin/platelet factor 4 complex antibody (HIT-antibody) in inpatients treated with heparin preparations. METHODS: A total of 197 consecutive patients, including 120 men and 77 women, who were treated with unfractioned heparin (UFH) or low molecular weight heparin (LMWH), were enrolled in this study. HIT-antibody was detected by enzyme-linked immunosorbent assay (ELISA). All patients were classified into subgroups based on "4Ts" (Pretest Clinical Scoring System) and types of underlying disorders. The incidence of HIT and positivity of HIT-antibody among different groups were analyzed. RESULTS: The overall incidence of HIT was 3.0% (6/197), and the positivity of HIT antibody was 12.2% (24/197). The positivity of HIT-antibody was 10.1% (18/178), 7.7% (1/13) and 83.3% (5/6) in low, moderate and high HIT probability group respectively. There were significant differences of HIT positivity and mean level of HIT-antibody between the high HIT probability group and the low or moderate HIT probability group (P = 0.000). Both the incidence of HIT and positivity of HIT-antibody were higher in surgical patients than in medical patients (5.8% vs 0.9%, P = 0.047 and 19.8% vs 6.3%, P = 0.004). CONCLUSIONS: The incidence of HIT and positivity of HIT-antibody were 3.0% and 12.2% respectively, both of which were related with the types of disorders. Detection of HIT-antibody has a better applicable value in patients with high HIT probability.