Clinical significance of mycoplasma pneumoniae-DNA load detection in alveolar lavage fluid of children with refractory mycoplasma pneumoniae pneumonia / 中国小儿急救医学

ABSTRACT

Objective:To investigate the clinical significance of mycoplasm pneumoniae-DNA(MP-DNA) load detected in bronchoalveolar lavage fluid of children with refractory mycoplasma pneumoniae pneumonia(RMPP) in the assessment of the condition.Methods:A total number of 98 hospitalized children with RMPP diagnosed in the Department of Pediatric Respiratory of Shengjing Hospital of China Medical University from May to November in 2018 were selected as the subjects.Bronchoscopy was performed on each subject and the alveolar lavage fluid was collected to detect the MP-DNA load quantitatively.According to the test results, all children were divided into three groups high-load group(>10 6/ml, 28 cases), medium-load group(10 3 to 10 6/ml, 54 cases), and low-load group(≤10 3/ml, 16 cases). The clinical manifestations, relevant laboratory data, imaging data, and bronchoscopy findings of the children in different load groups were compared. Results:Compared with the low-load group and medium-load groups, the level of C-reactive protein was the highest in the high-load group with statistical significance( P<0.05). The difference of lactate dehydrogenase levels among the three groups was statistically significant( P=0.001). The positive incidences of nodular protuberances, mucosal erosion and necrosis, bronchial inflammatory stenosis and mucus plugs occlusion in the high-load group were 35.7%, 32.1% and 64.3%, respectively, which were significantly higher than those in the medium-load group(13.0%, 5.6%, 38.95) and low-load group(0, 0, 12.5%), and the differences were statistically significant( P<0.05). The imaging manifestation of large areas consolidation/lung atelectasis and pleural effusion in the high-load group were 100% and 60.7%, respectively, which were significantly higher than those in the medium-load group(61.1%, 27.8%)and low-load group(25.0%, 12.5%), and the differences were statistically significant( P<0.05). Compared with the low-load group and medium-load group, the hospitalization days was the longest in the high-load group, and the fever clearance time after the application of macroclides was also the longest( P<0.05). Conclusion:The MP-DNA load of children with RMPP is closely related with the clinical features.The clinical manifestations of children with higher DNA-load are more serious.The level of local MP-DNA load can guide clinicians to use drugs rationally, better predicting the outcome of the disease.