Autoimmune heparin-induced thrombocytopenia and venous limb gangrene after aortic dissection repair: in vitro and in vivo effects of intravenous immunoglobulin
Research article published in Transfusion (2019)
Abstract
BACKGROUND: Heparin-induced thrombocytopenia (HIT) is a prothrombotic disorder characterized by heparin-dependent antibodies that activate platelets (PLTs) via PLT FcγIIa receptors. "Autoimmune" HIT (aHIT) indicates a HIT subset where thrombocytopenia progresses or persists despite stopping heparin; aHIT sera activate PLTs strongly even in the absence of heparin (heparin-independent PLT-activating properties). Affected patients are at risk of severe complications, including dual macro- and microvascular thrombosis leading to venous limb gangrene. High-dose intravenous immunoglobulin (IVIG) offers an approach to interrupt heparin-independent PLT-activating effects of aHIT antibodies. CASE REPORT: A 78-year-old male who underwent cardiopulmonary bypass for aortic dissection developed aHIT, disseminated intravascular coagulation, and deep vein thrombosis; progression to venous limb gangrene occurred during partial thromboplastin time (PTT)-adjusted bivalirudin infusion (underdosing from "PTT confounding"). Thrombocytopenia recovered with high-dose IVIG, although the PLT count increase began only after the third dose of a 5-day IVIG regimen (0.4 g/kg/day × 5 days). We reviewed case reports and case series of IVIG for treating HIT, focusing on various IVIG dosing regimens used. RESULTS: Patient serum-induced PLT activation was inhibited in vitro by IVIG in a dose-dependent fashion; inhibition of PLT activation by IVIG was much more marked in the absence of heparin versus the presence of heparin (0.2 U/mL). Our literature review indicated 1 g/kg × 2 IVIG dosing as most common for treating HIT, usually associated with rapid PLT count recovery. CONCLUSION: Our clinical and laboratory observations support dose-dependent efficacy of IVIG for decreasing PLT activation and thus correcting thrombocytopenia in aHIT. Our case experience and literature review suggests dosing of 1 g/kg IVIG × 2 for patients with severe aHIT.
Abstract sourced from PubMed (NCBI) for the cited record. See the original publication for the authoritative version.
Resumen
Peer-reviewed clinical and outcomes research relevant to anticoagulation, leech therapy, and microsurgical flap management. Indexed in PubMed and verified against the NCBI record.
Por qué esto importa para la hirudoterapia
Este informe de caso con revisión de la literatura asociada describe a un hombre de 78 años que desarrolló trombocitopenia inducida por heparina autoinmune (aHIT) con coagulación intravascular diseminada (CID), trombosis venosa profunda y gangrena de extremidad venosa tras la reparación de disección aórtica; la trombocitopenia se recuperó con inmunoglobulina intravenosa de dosis alta, las pruebas in vitro mostraron que la inmunoglobulina intravenosa inhibió la activación plaquetaria de forma dependiente de la dosis (más sin heparina), y los autores sugieren una dosis de 1 g/kg x 2 para la aHIT grave. Es pertinente para la hirudoterapia porque la gangrena del paciente progresó durante el bivalirudin ajustado por PTT (un inhibidor directo de la trombina en la misma clase mecanística que el anticoagulante derivado de lombriz hirudina), ilustrando tanto el atractivo como los peligros de la dosificación de la inhibición directa de la trombina. Como un solo caso más revisión narrativa, los hallazgos son generadores de hipótesis en lugar de definitivos, el efecto de la inmunoglobulina intravenosa in vitro necesita confirmación controlada, y nada de esto atañe a la terapia con lombrices en sí misma.
Citación
Autoimmune heparin-induced thrombocytopenia and venous limb gangrene after aortic dissection repair: in vitro and in vivo effects of intravenous immunoglobulin.
Arcinas et al. · Transfusion, 2019
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Añadido a la biblioteca ASH: May 28, 2026 · Última actualización del sitio: June 18, 2026