Cerebral venous sinus thrombosis associated with SRA-negative heparin-induced thrombocytopenia: case report.

Background: There are very few documented reports in literature of cerebral venous sinus thrombosis (CVST) caused by immune-mediated heparin-induced thrombocytopenia (HIT). Further, there are very few reports of false negative serotonin release assays (SRAs) when testing for immune-mediated HIT.

Case Presentation: We present a case of a 60- year-old male with recent unfractionated heparin administration for venous thromboembolism prophylaxis, an elevated 4T score of 5 and acute CVST in which immune-mediated HIT was suspected.

Platelets from 13-lined ground squirrels are resistant to cold storage lesions.

During torpor in a 13-lined ground squirrel heart rate and blood flow decrease, increasing the risk of blood clot formation. In response, cells involved in clotting called platelets are sequestered in the liver, stored in the cold for months, and released back into circulation upon arousal. This is in contrast to non-hibernating mammals, including humans, in which chilled platelets undergo cold storage lesions and phagocytosis, leading to rapid clearance from circulation post-transfusion.

Off-the-shelf cryopreserved platelets for the detection of HIT and VITT antibodies.

Heparin-induced thrombocytopenia (HIT) is suspected much more often than it is confirmed. Technically simple platelet factor 4 (PF4)-polyanion enzyme-linked immunosorbent assays (ELISAs) are sensitive but nonspecific. In contrast, accurate functional tests such as the serotonin release assay, heparin-induced platelet activation assay, and PF4-dependent P-selectin expression assay require fresh platelets and have complex assay end points, limiting their availability to specialized reference laboratories.