Altered cytokine levels in bronchoalveolar lavage fluids from patients with mycoplasma pneumonia infection

Many reports have demonstrated that Mycoplasma pneumonia (M. pneumoniae) infection may cause the release of multiple cytokines into sputum or serum samples. However, studies focusing on bronchoalveolar lavage fluid (BALF) samples are scarce. The aim of this study was to identify the cytokines associated with M. pneumoniae infection, and explore the possible factors affecting their secretion during acute lower respiratory tract infection. 60 children with confirmed M. pneumoniae infection complicated with atelectasis, according to chest X-ray or CT scan data, and 20 children with confirmed foreign bodies in the airways (control group) were enrolled. Bronchoalveolar lavage (BAL) samples were obtained by flexible bronchoscopy, and assessed for the presence of interleukin (IL)-1β, IL-2, IL-4, IL-6, IL-8, IL-10, IL-12, tumor necrosis factor (TNF)-α, and interferon (IFN)-γ. Interestingly, IL-1β, IL-2, IL-4, IL-6, IL-8, IL-10, and IFN-γ amounts were increased in M. pneumonia infected children compared with the control group. Multiple univariate analyses of variance and multiple linear regressions showed that fever during bronchoscopy markedly affected IL-1β, IL-4, IL-10 and IFN-γ concentrations. In conclusion, IL-1β, IL-2, IL-4, IL-6, IL-8, IL-10 and IFN-γ levels were increased in BALF from patients with M. pneumonia. Increased levels of secreted IL-1β, IL-4, IL-10 and IFN-γ were associated with fever in these patients.