Reactivation of CMV Infection in Immunocompetent Patients Under Severe Stress

Background. Human herpes viruses establish lifelong latency after primary infection and may reactivate in immunosuppressed patients causing significant morbidity and mortality. In immunocompetent patients, although reactivation may occur disease development is deterred by the competent host immune response. Recent studies indicate that approximately one third of CMV seropositive immunocompetent ICU patients present with CMV reactivation associated with poor outcome, potentially secondary to the stress incurred. CMV reactivation among immunocompetent critically ill children has not been assessed. Study Hypothesis: Identifiable risk factors associated with CMV reactivation exist and may be used for future assessment of antiviral prophylaxis administration. Aim: Primary aim is to identify risk factors associated with CMV reactivation and poor outcome in immunocompetent children and adults under severe stress. Whether CMV reactivation occurs in critically ill children and its clinical implications remains to be determined. Secondary aim is to study the role of cellular signaling pathways of inflammation and specific adaptive immunity during this process. Work packages: A multicenter observational prospective study will be conducted among CMV seropositive pediatric and adult ICU patients. Patient clinical progress, laboratory findings, management, and complications will be recorded during the 28 days following ICU admission. Salivary free cortisol levels, plasma catecholamines, and serum cytokines levels will be measured to assess stress. CMV reactivation will be evaluated weekly by detecting CMV-DNA in peripheral blood and bronchial wash samples with real-time PCR. In a patient subsample, the nuclear factor κB and intracellular GC receptor will be measured in peripheral blood monocytes to study cellular signaling pathways of inflammation. The adaptive immune response to CMV infection following in vitro viral polypeptide stimulation will be prospectively examined in a subset of patients. Expected Results: The study will provide original data on critically ill children. Further knowledge regarding risk factors associated with CMV reactivation and poor outcome will be accumulated. Novel information regarding the role of cellular inflammation and specific adaptive immune responses during CMV reactivation will be gathered.