Distribution and expression of IL-17 and related cytokines in children with Mycoplasma pneumoniae pneumonia

抄録

The pathogenesis of Mycoplasma pneumoniae pneumonia (MPP), especially the local immune responses of the lungs, is poorly understood. In this study, we used FCM (Flow Cytometry) to analyze IL-17 and related cytokines in plasma and bronchoalveolar lavage fluid (BALF) samples from 18 patients with general MPP (GMPP) and 30 patients with refractory MPP (RMPP). The levels of IL-1Ra, IL-6, IL-8, IL-17 and TNF-α were significantly elevated in the BALF of MPP children compared with the plasma (P<0.01). The plasma IL-6 levels in the children with RMPP were higher than those in the children with GMPP (P<0.05), but the IL-17 levels showed the opposite trend (P<0.05). The children with RMPP had significantly higher BALF levels of IL-8, IL-17 and TNF-α than the children with GMPP (P<0.05), and the elevated levels of IL-17 correlated with the focal size of the lung lesions (P<0.05). The elevated levels of IL-17 and related cytokines in the BALF could suggest that the local inflammatory response should be distinguished from the systemic inflammatory response in children with MPP. RMPP might involve aggravated inflammatory progression at the site of infection. The level of IL-17 might correlate with the extent and severity of the lung lesions in MPP.