The Immunomodulatory Influence of Cytomegalovirus Infection on Pediatric Patients with Immune Thrombocytopenic Purpura

Abstract

SUMMARY I mmune thrombocytopenia (ITP) in children is usually a short self-limiting disease with favorable prognosis characterized by increased platelet destruction and decreased platelet number. However, the condition can become chronic in 5% to 30% of affected children (Cuker and Cines, 2010; Elalfy et al., 2010; Imbach et al., 2006; Kuhne et al., 2003). It may be triggered by viral infection as many reports documenting the relationship of viral infections with ITP. CMV infection may result in severe, refractory ITP. Treatment with steroids was shown to worsen the course of CMV-associated ITP. A cross sectional prospective study included 31 patients with acute and persistent ITP recruited from the regular attendants of the pediatrics hematology clinic, Pediatric Hospital, Ain Shams University from November 2016 to January 2017 with the following aims:  To evaluate CMV positivity prevalence among acute and persistent ITP patients.  To assess the effect of CMV infection on the course of ITP and to evaluate the effect of CMV positivity on the INF gamma and its input on bleeding manifestations and outcome in patients with ITP. All patients were subjected to detailed history and physical examination including age, sex, age at diagnosis, clinical presentation suggestive of viral infection e.g. pneumonitis, hepatitis, petechial rashes, mononucleosis-like syndrome, bleeding signs and type of bleeding using ITP SMOG score and any organomegaly. Furthermore, Treatment lines and outcome including initial response after 1st line or more than one line when needed and duration of response were included in the study. CMV serology was done for each acute and persistent ITP patient. CMV IgG avidity was assessed in CMV IgM positive cases and IFN gamma was measured by flow cytometry for each acute and persistent ITP patient. Then the differences between positive and negative cases was evaluated according to blood picture, ITP (SMOG score), treatment and response of treatment. Our study results show that the incidence rate of CMV IgM positive in acute and persistent ITP patients was 22.7 %. In addition, all the studied acute and persistent ITP patients showed CMV IgG positivity and all CMV IgM positive cases showed high CMV IgG avidity. High IFN gamma levels were observed in all the studied acute and persistent ITP patients compared to control group (P<0.01). CMV IgM positive cases did not differ from CMV IgM negative cases in terms of age, gender, history of viral illness, clinical presentation, SMOG score, blood picture, platelet count at the time of diagnosis.