Decision analysis for use of platelet aggregation test, carbon 14-serotonin release assay, and heparin-platelet factor 4 enzyme-linked immunosorbent assay for diagnosis of heparin-induced thrombocytopenia.
The value of the platelet aggregation test, carbon 14-labeled serotonin release assay (SRA), and heparin-platelet factor 4 enzyme-linked immunosorbent assay (H-PF4 ELISA) for the diagnosis of heparin-induced thrombocytopenia was evaluated by studying blood samples from 100 patients with suspected heparin-induced thrombocytopenia, and categorized into 4 clinical groups: unlikely (n = 22), possible (34), probable (36), and definite (8) thrombocytopenia. Results of the platelet aggregation test were positive in 40 of 44 patients with probable or definite heparin-induced thrombocytopenia (sensitivity 91%) and in 5 of 22 unlikely to have heparin-induced thrombocytopenia (specificity 77%). The SRA exhibited sensitivity of 88% and negative predictive value of 81%, close to those values for the platelet aggregation test; specificity and positive predictive value were 100%. The sensitivity of the heparin-PF4 ELISA was 97%, with specificity 86%, and a positive correlation was recorded between the level of antibodies to H-PF4 and clinical score (P = 0.66). When ELISA was used with the platelet aggregation test or SRA, positive predictive value and specificity were 100% when both tests yielded positive results, and negative predictive value was 100% when both tests yielded negative results. A biologic flow chart was designed that presented a choice based on the results of the platelet aggregation test or SRA in association with ELISA, and enabled more accurate and specific identification of heparin-induced thrombocytopenia.
Pouplard
C
C
Laboratoire d'Hématologie-Hémostase, Hôpital Trousseau, Tours, France.
Amiral
J
J
Borg
J Y
JY
Laporte-Simitsidis
S
S
Delahousse
B
B
Gruel
Y
Y
D002250:Carbon Radioisotopes; D019411:Clinical Laboratory Techniques; D003661:Decision Support Techniques; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D006493:Heparin / Q000009:adverse effects* / Q000378:metabolism; D006801:Humans; D010974:Platelet Aggregation; D010978:Platelet Factor 4 / Q000378:metabolism; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity; D012701:Serotonin / Q000378:metabolism; D013921:Thrombocytopenia / Q000139:chemically induced* / Q000175:diagnosis* / Q000378:metabolism
D002250:Carbon Radioisotopes; D012701:Serotonin; D010978:Platelet Factor 4; D006493:Heparin