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

Am J Clin Pathol. 1999 May;111(5):700-6. doi: 10.1093/ajcp/111.5.700.


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.

MeSH terms

  • Carbon Radioisotopes
  • Clinical Laboratory Techniques*
  • Decision Support Techniques*
  • Enzyme-Linked Immunosorbent Assay / methods*
  • Heparin / adverse effects*
  • Heparin / metabolism
  • Humans
  • Platelet Aggregation
  • Platelet Factor 4 / metabolism
  • Predictive Value of Tests
  • Sensitivity and Specificity
  • Serotonin / metabolism
  • Thrombocytopenia / chemically induced*
  • Thrombocytopenia / diagnosis*
  • Thrombocytopenia / metabolism


  • Carbon Radioisotopes
  • Serotonin
  • Platelet Factor 4
  • Heparin