Progressive Presentation of Type 2 Heparin-Induced Thrombocytopenia (HIT-2) in ESRD: An Illustrative Case Report

Heparin-induced thrombocytopenia (HIT) is a well known side effect of heparin therapy. Type-1 HIT is a non-immune response that is relatively common in patients exposed to heparin. It is often transient, rarely deadly, and resolves quickly after heparin is withdrawn. Type-2 HIT is a more severe form of the syndrome that is immune-mediated and associated with systemic arterial and/or venous thrombosis. HIT commonly develops within fourteen days of initial heparin exposure, but delayed-onset cases are becoming increasingly reported. HIT can also develop in patients who have previously been exposed to heparin without subsequent development of the syndrome. We present a case of HIT-2 in a patient with ESRD who had been receiving unfractionated heparin therapy for a large proportion of the previous 7 months without development of thrombocytopenia. This case underscores the importance of continuous monitoring for HIT even after the patient has been receiving heparin treatment either periodically or continuously for extended periods of time.