Intravenous immunoglobulin use in heparin-induced thrombocytopenia and efficacy of early intravenous immunoglobulin compared with standard-of-care treatment.

Abstract

Background: Heparin-induced thrombocytopenia (HIT) is an immune-mediated prothrombotic complication of heparin exposure. Intravenous immunoglobulin (IVIG) has been proposed as adjunctive therapy for refractory or autoimmune HIT. Real-world utilization patterns and the impact of early administration on clinical outcomes remain unclear.

Objectives: To describe real-world utilization of IVIG in HIT over a 10-year period, and to compare platelet recovery and clinical outcomes between patients receiving early early IVIG (within 3 days of diagnosis) and those receiving standard of care alone.

Methods: We conducted a retrospective chart review across hospitals within the Allegheny Health Network (2015-2025). We described the clinical characteristics and outcomes of all HIT patients who received IVIG (n = 29). We also compared early IVIG recipients (n = 24) with controls (n = 129) using 1:2 propensity score matching. The primary outcome was time to platelet recovery, analyzed using Kaplan-Meier estimation and Cox proportional hazards regression.

Results: IVIG was used in a cohort of patients with a median platelet count nadir of 26 × 10⁹/L (IQR, 16-35), and thrombosis was present at diagnosis in 75.8%. Platelet recovery was achieved in 93.1% of patients, with a median time of 6 days (IQR, 3-9) after the first IVIG dose and a favorable safety profile. Early IVIG (within 3 days of HIT diagnosis) was associated with significantly faster platelet recovery in the matched cohort (median, 3 vs 5 days; hazard ratio, 2.15; 95% CI, 1.09-4.26; P = .028). A higher platelet nadir predicted faster recovery (hazard ratio, 2.247 per 10 × 10⁹/L; P < .001). No significant differences in thrombosis, bleeding, or mortality were observed.

Conclusion: At our institution, IVIG use for HIT was limited to severely ill patients with a high thrombotic burden. Early IVIG administration accelerated platelet recovery compared with standard-of-care alone. Prospective multicenter studies are needed to confirm these findings.