Predictive Value of Risk Factors for Chronic Idiopathic Thrombocytopenic Purpura in Patients with Acute Type of Disease

Abstract

Background: Immune thrombocytopenic purpura (ITP) is an autoimmune disease in which autoantibodies react with platelet surface antigens and results in mild to severe thrombocytopenia due to decreased platelet count or inhibition of platelet production. Given the relatively high prevalence of ITP among children and the lack of standard diagnostic testing for the diagnosis of chronic disease, this study evaluated the predictive value of risk factors for chronic ITP in hospitalized patients. Methods: This prospective cohort study was performed on 65 children with ITP who referred to Ali Asghar and Rasool Akram hospitals in Tehran, Iran during the years 2017 and 2018. Relationships between different risk factors including age of diagnosis, gender, white cell count, primary platelet count, Mean platelet volume (MPV) , history and type of previous patient infection, FCG gene mutation, and type of FCG mutation with chronic disease incidence were investigated using multiple logistic regression model. Results: Of 65 patients, 31 (47.69%) were male and 34 (52.31%) were included in the study. 28 patients (43.08%) had acute ITP and 37 (56.92%) had chronic ITP. Frequency of FCG gene mutation in patients with chronic and acute type ITP was 16.36% and 7.27%, respectively (p = 0.51). No association was found between the history of previous infection and its type with the chronic incidence of ITP. Multiple Logistic regression model showed that 3 factors including absolute number of lymphocytes, age of diagnosis and primary WBC count were directly linked to chronic ITP. Furthermore, 3 factors of platelet, sex and MPV were indirectly related to chronic ITP. In addition, absolute number of lymphocytes, age of diagnosis and primary WBC count were significantly associated with chronic ITP. The ROC analysis showed that the cut off rate of these factors was 0.31. Further analysis of these risk factors in comparison with the gold standard demonstrated that the diagnostic sensitivity and specificity of these risk factors for chronic ITP were 73.08% and their specificity was 88.57%, indicating the high importance and predictive power of these risk factors. Conclusion: According to the results of the current study, evaluation of 6 major risk factors including absolute lymphocyte count, age at diagnosis, sex, MPV level, platelet level at diagnosis and primary WBC count for the identification of chronic ITP is recommended before IVIG treatment. Of course, more comprehensive studies can definitely lead to more comprehensive models. Funding Statement: The authors stated: Not applicable. Declaration of Interests: The authors declare that they have no competing interests. Ethics Approval Statement: The children participated in the study with the full parental consent, ensuring that all children's information was kept confidential. The project was initially approved by the Ethics Committee of Iran University of Medical Sciences with code IR.IUMS.FDM.REC. 1396.29265