Can CMV reactivation be a biomarker of persistent inflammation, immunosuppression, and catabolism syndrome?

Persistent Inflammation, Immunosuppression, and Catabolism Syndrome (PICS) is a multifactorial condition characterized by prolonged inflammation, immune dysfunction, and muscle wasting that occurs in some critically ill patients after they have recovered from their acute illness [1] [2]. Cytomegalovirus (CMV) reactivation is a common viral infection observed in critically ill patients and has been associated with immune dysregulation [3] [4]. This study aims to investigate the incidence of CMV reactivation in critical patients who have developed PICS. This is a data-based, observational, and cohort study. All patients with CMV reactivation admitted to the ICU between January 01, 2018, and May 01, 2023, were reviewed and those with PICS were analyzed. CMV reactivation was defined as CMV DNA ≥1000 copies/ml in tracheal samples. PICS was assessed using established clinical criteria, including inflammation and muscle wasting markers, at regular intervals during the ICU stay. The patient population was analyzed in two groups: CMV-reactivated PICS patients and CMV-non-reactivated PICS patients. During the study period, CMV reactivation was detected in 85.5% of all PICS patients. The results showed that the CMV-positive group had significantly higher APACHE-II scores at ICU admission and a higher prevalence of diabetes mellitus and cancer. According to the multivariate logistic regression model for CMV reactivation, APACHE-II score, steroid use, and the presence of thrombocytopenia were identified as significant variables. Additionally, the CMV-positive group was found to have a higher mortality rate. The incidence of CMV reactivation is very high in patients with PICS, and this condition appears to be associated with worse outcomes. Comorbidities such as steroid use, cancer, and diabetes mellitus are considered risk factors. Our findings suggest that CMV testing should be considered in patients suspected of having PICS. Understanding the relationship between CMV reactivation and PICS could pave the way for potential biomarker-based diagnostic and therapeutic approaches, enabling early identification and intervention for individuals at risk. Further prospective studies are needed to elucidate CMV reactivation's precise mechanisms and clinical implications in these complex syndromes.