OBJECTIVETo investigate cytokine level in bronchoalveolar lavage fluid (BALF) in children with refractory Mycoplasma pneumoniae pneumonia (RMPP) and the effects of methylprednisolone on RMPP.

METHODSixty cases with RMPP and 20 cases with bronchial foreign body with no respiratory tract infection as control group hospitalized in Department of Pulmonary Diseases, the Children's Hospital Affiliated to Medical School of Zhejiang University from February 2012 to February 2013 were enrolled. The RMPP patients were divided into two groups randomly (30 cases in each). Steroid group were given methylprednisolone 2 mg/(kg·d) intravenously for 3 days, and the cases in non steroid group were not given steroid therapy. Patients whose fever relieved after steroid treatment were classified as defervesced group while the others were classified as non defervesced group. Each patient was examined with fiberoptic bronchoscopy and bronchoalveolar lavage 3 days after admission and cytokine level in BALF of each patient was detected.

RESULT(1) In steroid group, the proportion of patients whose fever disappeared within 3 days after steroid therapy was 9/30 cases (30%), and in non steroid group no one responded within 3 days after medication, showing statistically significant difference (χ² = 14.073, P=0.002), at the same time, the duration of cough in steroid group was significantly shorter than that in non steroid group (5.1 d vs. 7.0 d, t=-2.276, P=0.027). The total fever time of steroid group was 4.7 days, which as compaired with non steroid group (6.7 days) was shorter, but the difference was not significant (t=-1.351, P=0.134). (2) IL-1 β, IL-4, IL-6, IL-8, IL-10, IFN-γ in BALF of steroid group and non steroid group were both significantly higher than that of control group. But the same comparison between steroid group and non steroid group showed no significant difference. (3) In steroid group, IL-2 and IL-8 in BALF of patient whose fever disappeared after steroid therapy were both significantly lower than that of patients who still had fever (t=2.771, 2.054, P=0.010, 0.049) , but no significant difference was found between the two groups in BALF IL-1 β, IL-4, IL-6, IL-10, IFN-γ levels (P>0.05).

CONCLUSION(1) Three days of 2 mg/(kg·d) methylprednisolone therapy had the antipyretic effect in children with RMPP, and could shorten the length of cough. (2) Incresed BALF IL-1 β, IL-4, IL-6, IL-8, IL-10, IFN-γ levels were observed in RMPP and high level of BALF IL-2 and IL-8 might have some relevance with persistent fever of RMPP in children.