Batool Aisha, Chaudhry Shahzad, Javaid Ayesha, Kenney Ashley
Internal Medicine, Columbia St. Mary Hospital, Milwaukee, USA.
Family Medicine, Advocate Aurora Healthcare, Milwaukee, USA.
Cureus. 2023 Sep 18;15(9):e45453. doi: 10.7759/cureus.45453. eCollection 2023 Sep.
Heparin-induced thrombocytopenia (HIT) is a commonly encountered condition, especially in inpatient settings, and is often attributed to high mortality and prolonged hospital stays. A rare entity, autoimmune heparin-induced thrombocytopenia (aHIT) refers to a condition in which antiplatelet factor-4 (PF4) antibodies activate platelets even in the absence of heparin. Our patient presented 12 days after transcatheter aortic valve replacement (TAVR) with altered mental status and severe thrombocytopenia. Further work-up revealed acute thromboembolic cerebrovascular accident (CVA),and the HIT antibody was positive. He was started on intravenous argatroban infusion with poor response. Platelet factor-4 antibodies were positive as well, and he was started on intravenous immunoglobulins (IVIG) therapy resulting in platelet recovery. This case is a reminder to consider autoimmune HIT, especially when platelet count fails to improve with conventional therapy.
肝素诱导的血小板减少症（HIT）是一种常见病症，尤其在住院患者中，常被认为与高死亡率和延长住院时间有关。一种罕见的自身免疫性肝素诱导的血小板减少症（aHIT）是指即使在没有肝素的情况下，抗血小板因子4（PF4）抗体也能激活血小板的病症。我们的患者在经导管主动脉瓣置换术（TAVR）后12天出现精神状态改变和严重血小板减少。进一步检查发现急性血栓栓塞性脑血管意外（CVA），且HIT抗体呈阳性。开始静脉输注阿加曲班，但反应不佳。血小板因子4抗体也呈阳性，于是开始静脉注射免疫球蛋白（IVIG）治疗，血小板得以恢复。该病例提醒我们要考虑自身免疫性HIT，尤其是在常规治疗后血小板计数未能改善的情况下。
