Heparin-induced thrombocytopenia in paediatric patients - a review of the literature and a new case treated with danaparoid sodium

The immunological form of heparin-induced thrombocytopenia (HIT) is a poten tially life-threatening adverse reaction of heparin medication. It is media ted by multimolecular complexes consisting of platelet factor 4 (PF4)-hepar in-IgG which bind to platelets via platelet Fc gamma receptors. Cross-linki ng of multiple Fc gamma receptors results in platelet activation, platelet aggregation and enhanced thrombin generation with. a increasing risk of dev eloping new thrombosis. In children, data on MIT are sparse. This review of the literature reports on 8 children aged 3 months to 15 years and 14 newb orns suffering from HIT. Additionally, we report one new case treated with danaparoid sodium. Thrombotic complications were venous (n = 12) and arteri al (n = 15). The children received heparin either for a spontaneous thrombo tic event, for severe cardiac diseases or to maintain patency of intravascu lar catheters which are used for nutrition, blood sampling, and for applica tion of medication. After diagnosis of HIT they were further anticoagulated with aspirin, warfarin, danaparoid sodium, lepirudin or low molecular weig ht heparin. Conclusion Although HIT is less frequently reported in newborns and childre n, paediatricians should be aware of HIT in childhood as a potential compli cation of heparin application. The widespread practice of flushing catheter s with heparin should also be debated in view of the risk of triggering the primary immune-response of HIT. In 1999, treatment options for further par enteral anticoagulation of HIT patients are danaparoid sodium (a low-molecu lar weight heparinoid) and lepirudin (a direct thrombin inhibitor).