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.

Bronchoalveolar Lavage Fluid ; chemistry ; Bronchoscopy ; Child ; Cytokines ; chemistry ; Fever ; Humans ; Methylprednisolone ; therapeutic use ; Mycoplasma pneumoniae ; Pneumonia, Mycoplasma ; drug therapy

Objective:To explore potential predictors of refractory Mycoplasma pneumoniae pneumonia (RMPP) in early stage. Methods:The prospective multicenter study was conducted in Zhejiang, China from May 1 st, 2019 to January 31 st, 2020. A total of 1 428 patients with fever >48 hours to <120 hours were studied. Their clinical data and oral pharyngeal swab samples were collected; Mycoplasma pneumoniae DNA in pharyngeal swab specimens was detected. Patients with positive Mycoplasma pneumoniae DNA results underwent a series of tests, including chest X-ray, complete blood count, C-reactive protein, lactate dehydrogenase (LDH), and procalcitonin. According to the occurrence of RMPP, the patients were divided into two groups, RMPP group and general Mycoplasma pneumoniae pneumonia (GMPP) group. Measurement data between the 2 groups were compared using Mann-Whitney U test. Logistic regression analyses were used to examine the associations between clinical data and RMPP. Receiver operating characteristic (ROC) curves were used to analyse the power of the markers for predicting RMPP. Results:A total of 1 428 patients finished the study, with 801 boys and 627 girls, aged 4.3 (2.7, 6.3) years. Mycoplasma pneumoniae DNA was positive in 534 cases (37.4%), of whom 446 cases (83.5%) were diagnosed with Mycoplasma pneumoniae pneumonia, including 251 boys and 195 girls, aged 5.2 (3.3, 6.9) years. Macrolides-resistant variation was positive in 410 cases (91.9%). Fifty-five cases were with RMPP, 391 cases with GMPP. The peak body temperature before the first visit and LDH levels in RMPP patients were higher than that in GMPP patients (39.6 (39.1, 40.0) vs. 39.2 (38.9, 39.7) ℃, 333 (279, 392) vs. 311 (259, 359) U/L, both P<0.05). Logistic regression showed the prediction probability π=exp (-29.7+0.667×Peak body temperature (℃)+0.004×LDH (U/L))/(1+exp (-29.7+0.667×Peak body temperature (℃)+0.004 × LDH (U/L))), the cut-off value to predict RMPP was 0.12, with a consensus of probability forecast of 0.89, sensitivity of 0.89, and specificity of 0.67; and the area under ROC curve was 0.682 (95% CI 0.593-0.771, P<0.01). Conclusion:In MPP patients with fever over 48 to <120 hours, a prediction probability π of RMPP can be calculated based on the peak body temperature and LDH level before the first visit, which can facilitate early identification of RMPP.