Arterial Thrombosis in Patients with Primary Immune Thrombocytopenia: A Nationwide Study

Objective: Primary immune thrombocytopenia (pITP) is an acquired bleeding disorder involving decreased numbers of platelets due to platelet destruction or impaired production. The clinical presentation of pITP can be multifaceted and thrombotic events may rarely manifest. Thrombosis can develop with treatment or during the untreated period. The primary objective of this study was to examine the frequency of arterial thromboembolic events (ATEs) in patients with pITP. We also aimed to evaluate the risk factors in these patients and the effect of ITP treatments on ATEs. Materials and Methods: The study was designed as a retrospective multicenter study conducted under the guidance of the Turkish Society of Hematology’s Scientific Subcommittee on Hemostasis-Thrombosis. Patients over the age of 18 with pITP who subsequently developed ATE while undergoing follow-up for pITP were evaluated. Results: A total of 2,178 patients with pITP were screened and 37 patients (1.7%) were observed to have developed ATE. The mean age was 62 years. Fifteen (40.5%) of the patients who developed ATEs were not receiving pITP treatment at the time of thromboembolism. Among the patients receiving pITP treatment at the time of the ATE, 9 (24.3%) were receiving eltrombopag and 10 (27%) were receiving corticosteroids. Compared to patients who did not develop ATEs, multivariate analysis revealed that the presence of hypertension, comorbidity, and history of venous thromboembolism statistically significantly increased the risk of developing ATEs (p=0.008, p=0.018, and p=0.038, respectively). Conclusion: The risk of ATEs may increase in pITP patients both during and without treatment. It is important to inquire thoroughly about the presence of comorbidities, atherosclerotic risk factors, hypertension, and history of thrombosis in these patients at the initiation of treatment. Correctable risk factors should be addressed to minimize the number of risk factors present. The treatment of pITP must be individualized, including consideration of age-related disorders.