The following is a summary of “Heparin-induced thrombocytopenia with very high antibody titer is associated with slower platelet recovery and higher risk of thrombosis,” published in the July 2024 issue of Hematology by Mukherjee et al.

Heparin-induced thrombocytopenia (HIT) involves antibodies against the platelet factor 4 (PF4)-heparin complex, with higher antibody levels measured by increased optical density (OD) in an enzyme-linked immunosorbent assay (ELISA) test.

Researchers conducted a retrospective study investigating the link between OD in a HIT-ELISA and the levels of antibodies targeting the PF4-heparin complex.

They studied 116 patients with HIT to assess how heparin–PF4 OD affected platelet recovery time, vascular thrombosis, and in-hospital mortality. Based on the heparin–PF4 OD, patients were categorized into three cohorts: cohort 1 had OD values between 2 and 2.4, cohort 2 had OD values between 2.4 and 2.8, and Cohort 3 had OD values above 2.8.

The results showed that a higher OD titer was linked to a significantly longer time to platelet recovery, comparing cohorts 1 and 2 (HR = 0.599, P=0.0221) and cohorts 1 and 3 (HR = 0.515, P=0.0014). The increased risk of thrombosis was observed (79.4%—cohort 3 vs. 53.8%—cohort 2 vs. 46.1%—cohort 1, P=0.04), but no impact on mortality (2.62—alive vs. 2.65—deceased, P=0.7432).

Investigators concluded that higher OD levels in the HIT ELISA correlated with slower platelet recovery and increased thrombosis risk, but further prospective studies are needed to confirm the impact of heparin-PF4 OD on patient outcomes.

Source: link.springer.com/article/10.1007/s12185-024-03811-2