Optical density values correlate with the clinical probability of heparin induced thrombocytopenia

Heparin induced thrombocytopenia is a clinicopathologic syndrome that may result in severe thrombotic sequelae without prompt diagnosis and treatment. A clinical scoring system to assess the pre-test probability of heparin-induced thrombocytopenia, the 4 T's, has been reported to correlate with the serotonin release assay.

We performed a single-center, retrospective study correlating the 4 T's score with the commercial heparin-PF4 ELISA.

One hundred forty four cases were identified. The pre-test probability scores were: low probability 45.8%, moderate probability 41.0% and high probability 13.2%. The median optical density was 0.148, 0.223 and 0.470 for low probability, moderate probability and high probability, respectively (P < 0.0005). The frequencies of obtaining an optical density>1.00 for these probability scores were 1.5%, 6.8%, and 36.8%, respectively (P < 0.0005).

Heparin-PF4 ELISA optical density values increase with increasing probability of heparin induced thrombocytopenia.