Intravenous Immunoglobulin (IVIG) use in HIT and efficacy of early IVIG compared to standard of care treatment.

BACKGROUND

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

METHODS

We performed a retrospective chart review across the Allegheny Health Network (2015-2025). We described clinical characteristics and outcomes among all HIT patients who received IVIG (n=29). We also compared early IVIG recipients (n=24) to 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 of 16 - 35 ×109/L) and thrombosis was present at diagnosis in 75.8% of patients. Platelet recovery was achieved in 93.1% at a median of 6 days (IQR 3 - 9 Days) days from first dose of IVIG administration, with 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; HR 2.15, 95%CI 1.09-4.26, p=0.028). Higher platelet nadir predicted faster recovery (HR 2.247 per 10 × 109/L, p < 0.001). No significant differences in thrombosis, bleeding, or mortality were observed.

CONCLUSIONS

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