Bottom line: Sensitivity and specificity of SRA is reported up to 100% and 97%, respectively, for UFH- and LMWH-treated patients. Many studies regarding a clinical suspicion of HIT, use SRA as the ‘gold standard’ for diagnosis.
Summary: Tardy, B. Experts’ opinion or the serotonin release assay as a gold standard for the diagnosis of heparin-induced thrombocytopenia (HIT)? Journal of thrombosis and haemostasis 2011 vol:9 iss:8 pg:1667 -1669.
See Table 1. Reported and revisited specificity and sensitivity of 4Ts score and immunoassays in five studies (p. 1668)
Heparin-induced thrombocytopenia is a troublesome adverse drug reaction, commonly believed to be caused by platelet-activating antibodies reactive against complexes between heparin and chemokines, most often but not always platelet factor 4. HIT is a challenge to clinically diagnose, as the cardinal clinical features of HIT, thrombocytopenia and thromboembolism in the setting of a proximate heparin exposure, are common findings among hospitalized patients for whom other conceivable explanations exist.