Predictive value of HIT-antibodies detection for new thrombosis in heparin-induced thrombocytopenia / 中华检验医学杂志

ABSTRACT

Objective To investigate the predictive value of HIT-antibodies(HIT-Ab) detection for new thrombus in suspected Heparin-Induced thrombocytopenia (HIT). Methods Retrospective cohort study. 472 suspected HIT patients were collected from July 2016 to November 2018, and all subjects under-went a 4Ts score and were sent for HIT-Ab tests. According to the results of HIT-Ab, there were four groups412 cases of negative HIT-Ab (0-0.9 U/ml), 45 cases of weak-positive HIT-Ab (1.0-4.9 U/ml), 12 cases of moderate-positive HIT-Ab (5.0-15.9 U/ml), and 3 cases of strong-positive HIT-Ab (≥16.0 U/ml) respective-ly. Ultrasound or CT examination was used to confirm new thrombosis as a standard to evaluate the value of HIT-Ab for predicting new thrombus. The diagnostic efficacy of HIT-Ab for HIT was evaluated in clinically confirmed HIT. Results The incidence rates of new thrombus in each group were 15.8％ in Negative HIT-Ab group (62/412), 48.9％in Weak-positiveHIT-Ab group (22/45), 75.0％in Moderate-positive HIT-Ab group (9/12), and100％in Strong-positive HIT-Ab group (3/3)(P<0.00). When HIT-Ab≥1.0 U/ml, the speci-ficity for diagnosing new thrombus was 93.0％, the sensitivity was 34.2％, the negative predictive value (NPV) was 84.2％, and the positive predictive value (PPV) was 56.5％. The diagnostic rates of HIT in each group werenegative 0％(0/412), weak-positive 62.2％(28/45), moderate-positive (12/12) and strong-positive (3/3) were 100％. When HIT-Ab≥ 1.0 U/ml, the specificity for HIT diagnosis was 96.0％, the sensitivity was 100％, NPV was 100％, and PPV was 71.5％. Conclusions In suspected HIT patients, the incidence of new thrombosis increases with the elevated HIT-Ab level. HIT-Ab detection can be used as a crucial tool for new thrombosis prediction and HIT diagnosis in suspected HIT patients. Clinicians can develop treatment strategies based on HIT-Ab levels.