Study On Detection Of Lymphocyte Subsets In Serum And Bronchoalveolar Lavage Fluid Of Refractory Mycoplasma Pneumoniae Pneumonia In Children

ObjetiveThis study of refractory Mycoplasma pneumoniae pneumonia(refractory Mycoplasma pneumoniae pneumonia,RMPP)in children with peripheral blood and Bronchoalveolar lavage fluid(Bronchoalveolar lavage fluid,BALF)tested lymphocyte subgroup,further explore the correlation between various indexes of lymphocyte subsets and the severity of disease in children with RMPP.It provides a new method for the early diagnosis and treatment of RMPP,which is of great significance for guiding clinical diagnosis and treatment and reducing the burden on the families of children.MethodsThis study included 32 children with RMPP who were hospitalized in Shenyang Children’s Hospital from October 1,2018 to December 30,2020 and required bronchoscopy and bronchoalveolar lavage(BAL).There were 61 children in the general MPP group treated with bronchoalveolar lavage.General clinical data such as age,gender,fever time,hospitalization days and pleural effusion were recorded.Serum C-reactive protein(CRP),lactic dehydrogenase(LDH)and Ferritin(FER)levels were recorded.In the refractory group,2ml of peripheral blood was collected in the acute phase(within 2 weeks of disease course),and bronchoalveolar lavage fluid(BALF)was collected at the same time during bronchoscopy to detect the lymphocyte subsets CD3~+,CD4~+,CD8~+,CD4~+/CD8~+,CD19~+and CD56~+levels;2ml of peripheral blood was collected in the acute phase of children in the general group,and the levels of peripheral blood lymphocyte subsets CD3~+,CD4~+,CD8~+,CD4~+/CD8~+,CD19~+,CD56~+were detected.All data were statistically analyzed using SPSS22.0 software.Measurement data that obeyed the normal distribution were expressed as mean±standard deviation(?±),and t-test was used for comparison between groups.The measurement data that does not conform to the normal distribution are represented by the median and interquartile range[M(P25,P75)].The Wilcoxon rank sum test is used for comparison between groups,and the Wilcoxon signed rank sum test is used for comparison within groups.The ROC curve was used to evaluate the specific detection indicators for children with RMPP,and the best cut-off value was found by the Youden index method.P<0.05 is statistically significant.Results1.The age of onset of children in the RMPP group was significantly higher than that in the ordinary MPP group,and the difference was statistically significant(P<0.05).2.There was no difference in gender between the RMPP group and the ordinary MPP group,and the difference was not statistically significant(P>0.05).3.The incidence of pleural effusion in the RMPP group was significantly higher than that in the ordinary MPP group,and the fever time and hospital stay were significantly longer than that in the ordinary MPP group,the differences were statistically significant(P>0.05).4.The acute phase CRP,LDH and FER of children in RMPP group were significantly higher than those in ordinary MPP group,and the differences were statistically significant(P<0.05).5.There was no significant difference in the percentages of peripheral blood lymphocyte subsets CD3+,CD4+,CD8+,CD19+,CD56+between children in RMPP group and ordinary MPP group(P>0.05).6.The absolute count of CD3~+,CD4~+,CD4~+/CD8~+and CD19~+in peripheral blood lymphocyte subsets in RMPP group was significantly lower than that in normal MPP group,while the absolute count of CD56~+was significantly higher than that in MPP group,and the difference was statistically significant(P<0.05).The area under the curve of CD3~+,CD4~+,CD19~+,CD4~+/CD8~+is above 0.8,and the diagnostic value is high.The area under the CD4~+curve is 0.916,which has the greatest predictive and diagnostic value,and the best cutoff value is 716.03/u L.7.The CD4~+/CD8~+of alveolar lavage fluid of children in RMPP group was significantly lower than that of peripheral blood,and the difference was statistically significant(P<0.05).Conclusions1.The levels of CRP,LDH and FER in peripheral blood are correlated with the severity of MPP,which has important guiding significance for the evaluation of the condition of children with RMPP.2.The expression of absolute count of CD3~+,CD4~+,CD4~+/CD8~+and CD19~+in peripheral blood lymphocyte subsets of children in the RMPP group was significantly decreased,while the absolute count of CD56~+was significantly increased,suggesting the presence of immune dysfunction.With the aggravation of the disease,the immune dysfunction was more obvious,which has guiding significance for the immunoregulatory treatment of children.When the absolute count of CD4+is lower than 716.03 pcs/u L,it indicates that the child is very likely to progress to RMPP.3.The CD4~+/CD8~+in bronchoalveolar lavage fluid was significantly lower than that in peripheral blood in children with RMPP,indicating that bronchoalveolar lavage fluid had higher diagnostic efficacy than peripheral blood.