Heparin-induced thrombocytopenia: An update for the COVID-19 era

Abstract

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Accelerated heparin-induced thrombocytopenia in a COVID-19 patient; a case report with literature review

“…HIT is a rare complication of heparin treatment that develops due to the production of autoantibodies (immunoglobulin G) against heparin exposure, more specifically, against PF4/heparin complexes. This leads to platelet activation and initiates the coagulation cascade that results in systemic clot formation and platelet depletion, which can further complicate the COVID-19 condition [ 10 ]. The factors associated with an increased risk are extracorporeal membrane oxygenation, surgery, hemodialysis, UFH, or low molecular-weight heparin (LMWH) [ 14 ].…”

“…HIT incidence is 0.2–0.45% in the general population, which increases to 2.7% in critically ill patients [ 10 , 16 ]. Meanwhile, the exact prevalence of HIT in COVID-19 is currently unknown, and the literature is conflicting regarding this aspect [ 10 ]. Some studies have reported a low prevalence, while others have reported a high prevalence [ 13 ].…”

“…Other functional assays that can be used to confirm the diagnosis include the heparin-induced platelet aggregation assay and SRA. However, in cases with high 4Ts scores, confirmatory tests are not required [ 10 ].…”

“…Meanwhile, the immediate cessation of heparin and switching to an alternative agent is the mainstay of management in HIT. In most patients, this results in platelet count normalization within seven days [ 10 ]. However, switching to other anticoagulants is difficult as they can increase the risk of bleeding, are more expensive, and are hard to monitor [ 21 ].…”

“…These patients frequently require anticoagulation medication, such as heparin, for thromboprophylaxis [ 8 , 9 ]. Heparin-induced thrombocytopenia (HIT) is a rare and dangerous immune-mediated complication of heparin treatment that results from the production of antibodies against platelet factor 4 (PF4)/heparin complexes [ 10 ]. It is associated with an increased risk of thrombosis and a decreased platelet count.…”