Comparison of clinical characteristics and inflammatory cytokines between hypoxemic and non-hypoxemic human adenovirus 55 pneumonia

Background: Human adenovirus (HAdV) can cause severe community-acquired pneumonia, but there are few studies on the associated cytokine patterns. The purpose of this study was to analyze the relationship between inflammatory cytokine and severity of adenovirus pneumonia. Methods: This was a prospective observational study. We evaluated pneumonia patients admitted to the Armed Forces Capital Hospital in Korea. On admission, blood samples were acquired from patients who showed signs of pneumonia. HAdV infection was diagnosed using Real-Q RV detection Kit, and types of HAdV were confirmed by nucleotide blast analysis. We used enzyme-linked immunosorbent assays (ELISAs) to quantify the serum levels of cytokines [interleukin (IL)-6, IL-8, tumor necrosis factor (TNF)-α, γ-interferon (IFN-γ), and IL-10]. We evaluated clinical characteristics and cytokine patterns. Results: Of 74 pneumonia patients, respiratory specimens from 43 tested positive for HAdV-55, and the other 31 tested negatives. The length of hospital stay was significantly longer in the HAdV group. The serum concentrations of IL-6, IL-8, IL-10, and IFN-γ were all significantly higher in the HAdV group. Of the 43 HAdV pneumonia patients, 6 evidenced PaO2/FiO2 (PF) ratio <300, and 37 did not. Compared to the non-hypoxemic group, the hypoxemic group showed significantly lower lymphocyte and monocyte counts, and increased IL-6 and IFN-γ concentrations. Logistic regression analysis showed that the IL-6, IL- 10, and IFN-γ were significantly associated with hypoxemia in the HAdV group. The IL-6, and IFN-γ levels correlated significantly with the PF ratio. Conclusions: We found that the levels IL-6, IL-10, and IFN-γ were significantly associated with hypoxemia in patients with HAdV-55 pneumonia.