Autoimmune Heparin-Induced Thrombocytopenia: Treatment Obstacles and Challenging Length of Stay

Abstract

Patient: Male, 55Final Diagnosis: Auto-immune heparin thrombocytopenia -Treatment obstacles and challenging length of staySymptoms: Thrombocytopenia • thrombosisMedication: —Clinical Procedure: IVIGSpecialty: HematologyObjective:Unusual clinical courseBackground:Autoimmune heparin-induced thrombocytopenia (aHIT) refers to a condition, in which antiplatelet factor-4 (PF4) antibodies activate platelets even in the absence of heparin (heparin independent platelet activation). This is a severe hypercoagulable state triggering massive thrombin storm needing additional therapies and aggressive anticoagulation apart from stopping heparin. Thrombocytopenia in these cases seems to be very severe and prolonged compared to classic HIT and poses additional clinical challenges in terms of anticoagulation management. Recently, direct oral anticoagulants (DOACs) seem to be an attractive option in the management of HIT as an alternative to vitamin K antagonists (VKA).Case Report:We describe a case of a 55-year African American male who presented with pleuritic chest pain and was found to have worsening kidney disease. Clinical and electrocardiogram findings suggested uremic pericarditis, and dialysis was warranted. After 5 days of exposure to heparin flushes during dialysis, the patient developed thrombocytopenia, and subsequently HIT was diagnosed. Argatroban was started initially, however, his platelets count continued to drop, and he developed acute deep venous thrombosis of the right lower leg. IVIG (intravenous immunoglobulin) was started and his platelet count started to improve after several days. The patient was discharged on Eliquis and his platelet count returned to normal levels after 3 months.Conclusions:This case emphasizes the challenge managing HIT, a condition that has a high rate of complications. Several studies have reported platelet recovery with IV immunoglobulin when standard therapies fail. Recent evidence also supports the safety and efficacy of DOACs in offering a simplified way of managing these patients, especially in outpatient settings.

Intravenous Immune Globulin (IVIG) for Treatment of Autoimmune Heparin-Induced Thrombocytopenia: A Systematic Review

“…8,14-16,23-30,33-41 Even though 6 patients did not have a favorable platelet increase by 5 days after their initial IVIG administration, the platelet count continued to rise in all but 1 patient. 14,23,26,28,37,41 This patient was lost to platelet monitoring 5 days past the administration of IVIG. 14 For all patients, after IVIG administration, the median time for a change in platelet count of at least 50 × 10 9 /L was 3 days.…”

“…35,39 Around the time that HIT was diagnosed, 87.5% (n = 21/24) of patients had a venous thrombus. 8,14-16,23-30,33,34,36,37,40,41 Three patients had both arterial and venous thromboses at HIT diagnosis. 8,23,34 DIC was reported in 5 patients.…”

“…14,28,41 The data for these patients are included in Tables 2 and 3. 8,14-16,23-30,33-41 Data in Table 2 include age, sex, patient type, initial anticoagulant used, new thrombosis and bleeding complications at HIT diagnosis, 4T score, immunoassay OD, activation assay results, aHIT variant (delayed, flush-induced, fondaparinux-associated, persistent, spontaneous), anticoagulant for HIT treatment, and platelet nadir. Data in Table 3 include platelet nadir, IVIG dose(s), weight used to calculate dose (when available), product used (when available), post-IVIG platelet recovery (defined as an increase in platelets by at least 50 × 10 9 /L), thrombosis after IVIG administration, and highest platelet count post-IVIG.…”

“…14,16,23-30 In all, 92% of patients (n = 22/24) had an immunoassay completed (median OD = 2.75; range = 1.69 to 3.83). 14,15,23-30,33-41 Although 2 patients had an OD <2 and 2 patients did not report an immunoassay, all patients reviewed, except those from Huang et al 27 (OD = 3.68), had a positive activation assay (most of them used SRA). 8,14-16,23-30,33-41 Autoimmune HIT was confirmed in 9 patients by the use of SRA (reported positive SRA results at 0 IU/mL UFH or use of the PEA assay).…”

“…In all, 50% of patients (n = 12) received at least 1 g/kg/d of IVIG for 2 consecutive days (CDs; for their initial dose), 8,14,15,24,25,28,33,35-37,40 including 1 patient who received 1 g/kg/d for 5 days. 28 Other common doses administered included 0.5 g/kg/d ×4 CDs (n = 3) 24,28,29 and 0.4 g/kg/d ×5 CDs (n = 2).…”