Positive Epstein-Barr virus detection and mortality in respiratory failure patients admitted to the intensive care unit.

BACKGROUND: Epstein-Barr virus (EBV) infection may induce immune suppression in several ways, which may influence the proper host response to other pathogens and lead to a bad outcome of critically ill patients.

METHODS: This was a single-center, retrospective, observational study. All patients admitted to an ICU because of respiratory failure were included. EBV detection from lower respiratory tract (LRT) and serum samples were routinely performed.

RESULTS: Twenty-eight consecutive cases who were admitted to the ICU at high-risk for an infection or clinical signs of an infection were included in our study. Among the 28 patients, 15 were LRT-positive for EBV (53.6%), and 8 were seropositive for EBV (28.6%). Among the LRT EBV-positive patients, pneumonia was the main indication for ICU admission (93.3%), and in LRT EBV-negative patients, acute exacerbation of COPD (AECOPD) was another indication for ICU admission (46.2%). The CD3+ T cell count (especially the CD3+CD8+ T cell count) was lower than the normal range in LRT- and serum EBV-positive patients; these count were in the normal range in EBV-negative patients. The ICU mortality was 32.1% for all patients. The mortality rate was significantly higher in patients who were seropositive for EBV than seronegative patients (62.5% vs 20.0%). No differences were shown between any outcome parameters for LRT EBV-positive and -negative patients.

CONCLUSIONS: This study showed that EBV DNA is detected in LRT and serum samples of a significant number of ICU patients with respiratory failure, and seropositivity for EBV was associated with mortality. This finding maybe correlated with a low CD3+CD8+ T cell count.