PB0688 - Comparative Studies on Bovine and Porcine Unfractionated Heparin in Antibody Mediated Thrombocytopenia in Platelet Aggregation Studies

Background: Heparin induce thrombocytopenia (HIT) is a rare complication that may occur in patients treated with heparin, where heparin triggers a reaction that causes the blood to aggregate instead of preventing clots. HIT is caused by the formation of immunoglobulin G antibodies directed against heparin and platelet factor 4 (PF4) complexes. The binding causes platelet activation which releases PF4 and further enhances thrombin generation and platelet activation. Heparin-induced platelet aggregation (HIPA) evaluates platelet aggregation through conventional light transmission aggregometry, where aggregation of the donor’s platelets indicates antibodies to the heparin–PF4 complex. Shortages of porcine mucosal heparin and cultural preferences have prompted the resourcing of heparin from alternate sources, including bovine tissue. Heparin in the United States is currently derived from porcine mucosal tissue; however, bovine heparin is used in Southeast Asian countries

Aims: The purpose of this study was to observe and compare the effects of multiple batches of heparins from porcine and bovine origin in HIPA.

Methods: 30 batches of porcine and bovine mucosal heparin were obtained and re-constituted in saline to obtain a stock solution of 10 mg/mL. Further dilutions were made from 1 mg/mL to 10 ug/mL. Platelet rich plasma and platelet poor plasma was prepared from healthy volunteer blood. Normal donor platelets and serum from a patient positive for the heparin antibody were incubated with varying concentrations of heparin and the aggregation response was monitored for 20 minutes using a PAP-8 platelet aggregometer. Studies were repeated three times in eight donors. Statistical analysis was performed through one-way ANOVA using SigmaPlot.

Results: Heparin samples were able to aggregate in the HIPA assays.

Conclusion(s): No major differences were noted in the aggregation profiles of the bovine and porcine heparin samples, which aggregated at similar levels These results suggest that bovine and porcine heparin produce comparable responses in the antibody mediated aggregation of platelets.