Study on the significance of cytokine in bronchoalveolar lavage fluid in children with refractory mycoplasma pneumoniae pneumonia and the correlation with serum C reactive protein

Abstract

Objective To explore the levels and clinical significance of MCP-4, IL-25, TNF-α and CysLTR-1 in bronchoalveolar lavage fluid(BALF)of children with refractory mycoplasma pneumoniae pneumonia(RMPP)and their correlation with serum C-reactive protein(CRP). Methods One hundred and nine children diagnosed as RMPP who underwent fiberoptic bronchoscopy in acute stage(course of disease within 2 weeks)were selected as the experimental group.According to the manifestations of mucosa, secretions and lumen under bronchoscope, the patients were divided into RMPP1 group(68 cases of severe pathological injury under bronchoscope)and RMPP2 group(41 cases of mild pathological injury under bronchoscope). They were divided into RMPP1 wheezing group(20 cases), RMPP1 non- wheezing group(48 cases), RMPP2 wheezing group(15 cases)and RMPP2 non-wheezing group(26 cases).15 children with non-mycoplasma pneumoniae pneumonia(NMPP)and non-wheezing lobar pneumonia in the same period were selected as control group 1.At the same time, 15 children without pneumonia underwent bronchial foreign body(FB)removal as control group 2.The levels of MCP-4, IL-25, TNF-α and CysLTR-1 in BALF of children in experimental group were determined by double antibody sandwich ELISA.Serum CRP, D dimer(DD), ALT and peripheral blood neutrophil percentage(N%)were also detected. Results (1)The levels of CRP, DD, ALT and N% in RMPP1 group with severe bronchoscopic manifestations were higher than those in RMPP2 group with relatively mild bronchoscopic manifestations(all P 0.05). (3)CRP was positively correlated with IL-25, MCP-4 and TNF-a(all P<0.05), but not with CysLTR-1. Conclusion (1)Clinical laboratory indicators such as CRP, DD, ALT and N% can assist in early identification of RMPP.The higher the above indicators, the more serious performance of RMPP under microscope.(2)Cytokines MCP-4, IL-25, CysLTR-1 and TNF-α all participate in the pathogenesis of RMPP, and may play an important role in the occurrence of wheezing and development of asthma in children induced by MP infection.(3)Serum CRP levels were positively correlated with the levels of IL-25, MCP-4 and TNF-α in BALF of RMPP wheezing children.Both MCP-4 and IL-25 selectively affected Th2-induced Th2 cells.CRP is associated with IL-25 and MCP-4 who mediated immune inflammation injury.It is speculated that CRP may also cause Th2-mediated immune inflammation injury by affecting Th2 cells. Key words: Refractory mycoplasma pneumoniae pneumonia; Electronic fiberoptic bronchoscope; Cell factor; C-reactive protein; Children