American Society of Hirudotherapy

Refractory autoimmune heparin-induced thrombocytopenia following cardiac surgery

Research article published in Journal of thrombosis and haemostasis : JTH (2025)

Last Updated: June 18, 2026Reviewed by: ASH Editorial Board
Research article — evidence reviewArticle reference
Evidence: Case reportDrug DevelopmentZlamal et al. · Journal of thrombosis and haemostasis : JTH, 2025

Abstract

Autoimmune heparin-induced thrombocytopenia (aHIT) is a severe subtype of heparin-induced thrombocytopenia characterized by persistent thrombocytopenia and prothrombotic condition, even though anticoagulation with heparin has been discontinued. Here, we report on a patient with a previous history of aHIT where reexposure to heparin during cardiac surgery resulted in recurrent aHIT with pulmonary embolism. Alternative anticoagulants, as well as high-dose intravenous immunoglobulin, were ineffective, and only multiple cycles of therapeutic plasma exchange restored platelet counts and prevented further thrombosis progression. The therapy was guided by an ex vivo model of antiplatelet factor 4 (PF4)-mediated thrombosis that showed accurate performance in predicting the clinical outcome. Most importantly, the ability to induce thrombus formation was mainly caused by anti-PF4 (heparin-independent) antibodies. Our paper provides the first description of recurrent aHIT with translational evidence that pathogenic heparin-independent anti-PF4 antibodies can be specifically targeted by therapeutic plasma exchange, emphasizing the clinical use in refractory cases of aHIT.

Abstract sourced from PubMed (NCBI) for the cited record. See the original publication for the authoritative version.

Publication typeCase ReportsJournal Article
Indexed MeSH termsHumansAnticoagulantsAutoantibodiesCardiac Surgical ProceduresHeparinImmunoglobulins, IntravenousPlasma ExchangePlatelet CountPlatelet Factor 4Pulmonary EmbolismPurpura, Thrombocytopenic, IdiopathicRecurrence

Summary

Peer-reviewed research on anticoagulant and antithrombotic agents relevant to leech-derived compounds and thrombosis management. Indexed in PubMed and verified against the NCBI record.

Why This Matters for Hirudotherapy

This case report describes a patient with autoimmune heparin-induced thrombocytopenia (aHIT) whose disease recurred with pulmonary embolism after heparin re-exposure during cardiac surgery; alternative anticoagulants and high-dose IVIG failed, and only repeated therapeutic plasma exchange restored platelet counts, with an ex vivo anti-PF4 thrombosis model accurately predicting the outcome. For ASH it is relevant as a reminder that heparin itself can trigger a dangerous prothrombotic immune reaction, which is part of the rationale for interest in non-heparin and naturally derived anticoagulant strategies, including leech-secretome molecules that act through heparin-independent pathways. Caveat: this is a single-patient case report, not a controlled study; it makes no claim about hirudotherapy and provides no evidence that any leech-derived agent treats aHIT, so it informs the clinical problem space only.

Citation

Refractory autoimmune heparin-induced thrombocytopenia following cardiac surgery.

Zlamal et al. · Journal of thrombosis and haemostasis : JTH, 2025

Added to ASH library: May 28, 2026 · Site last updated: June 18, 2026

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