Impact of Intravenous Immunoglobulin (IVIG) on Venous Thromboembolism/Pulmonary Embolism in Immune Thrombocytopenic Purpura- an NIS 2020 Database Analysis

Background: The current study probed into the interplay between intravenous immunoglobulin administration and immune thrombocytopenic purpura on risk for venous thromboembolism (VTE) and pulmonary embolism (PE). Both ITP and IVIG have been independently reported to be associated with an increased risk for thrombosis. We aimed to investigate how IVIG administration influences the incidence of VTE/PE in the setting of ITP and to clarify if IVIG modulates the thrombotic risk inherent to ITP.

Methods: We conducted a retrospective analysis of the NIS database 2020 with an International Classification of Diseases (ICD)-10 diagnosis code for ITP, comorbidities, risk factors for VTE/PE along with the proportion of patients receiving IVIG and a diagnosis of VTE/PE. All statistical analyses were done by using STATA version SE18.0. The multivariate regression analysis was done after adjusting for demographic variables and comorbidities to estimate the adjusted odds ratio (aOR) of developing VTE/PE in those suffering from ITP that received IVIG

Results: There were 56,530 hospitalizations with a diagnosis of ITP. The median patient age was 58.9 (95% CI 58.3-59.5), and 56.55% of the patients were females. 26.9% of the patients have a Charlson Comorbidity Index (CCI) score of 0, while 16.5% scored 1 and 13.55% scored 2; 43.05% scored 3. The proportion of the patients who had IVIG out of the 56,530 hospitalizations for ITP is 4265.605 of the 56,530 who suffered VTE/PE. In this regard, a subgroup analysis among patients with ITP receiving IVIG was performed after adjusting for age, gender, race, CCI, and the risk factors of VTE/PE such as smoking, oral contraceptive intake, obesity, history of thrombosis, thrombophilia, cancer, myeloproliferative neoplasms, fracture, COPD, and varicose veins using multivariate regression analysis. This revealed that ITP patients who received IVIG had significantly decreased odds of developing VTE/PE with an aOR of 0.23 (95% CI of 0.05-0.91, p=0.037). This lowering of the thrombotic events in IVIG recipients may indicate a protective effect of IVIG in ITP.

Conclusion: Despite the intrinsic prothrombotic state associated with ITP, our results showed that intravenous immunoglobulin therapy in ITP was associated with a significantly reduced odds of VTE/PE. This would indicate that IVIG could reduce some of the thrombotic risks associated with ITP. These results are encouraging and need replication on larger prospective studies to clearly elucidate the mechanisms behind such an observed protective effect.