Predictive Value Of Serum IL-6,TNF-α And D-dimer In Children With Mycoplasma Pneumoniae Pneumonia

Objective By observing the change of IL-6,TNF-α,D-dimer in the serum of children with different severity of Mycoplasma pneumoniae pneumonia and looking for the clinical cut-off value between the common and severe cases,we can judge and evaluate accordingly the possibility of the common Mycoplasma pneumoniae pneumonia developing into severe ones,provide clues and evidence for early diagnosis of severe cases,get an early chance of detection,diagnosis and treatment,and eventually avoid the occurrence of serious complications.Method Take the children who were diagnosed as Mycoplasma pneumoniae pneumonia with fever,cough and other symptoms in the third pediatric ward of the Yan’an University Affiliated Hospital from December 2017 to December 2019 as research objects.Combined with the diagnostic criteria of severe mycoplasma pneumoniae pneumonia in the consensus of experts,a total of 88 cases were included,including 43 cases in the severe group.45 cases were randomly selected into the general group according to the two-color ball method.The two groups of children’s age,gender and WBC,CRP,IL-6,TNF-α,D-dimer related indicators were compared by single factor analysis,and the statistically significant indicators were further analyzed by binary logistic regression analysis.Then,further draw the ROC curve of the obtained independent related risk factors,and analyze the cut-off value and diagnostic value of various indicators for diagnosing severe Mycoplasma pneumoniae pneumonia.Result 1.Comparison of general conditions: After independent sample Chi-square test and t test,there was no statistically significant difference in gender composition ratio and age between severe group and ordinary group(P> 0.05).2.Univariate analysis of various laboratory indicators: After independent sample t-test(or approximate t-test),the difference in WBC,CRP,IL-6,TNF-α,D-dimer levels bewteen severe and mild groups is statistically significant(P <0.05).3.Binary Logistic Regression Analysis: The above 7 indicators(including gender,age,WBC,CRP,IL-6,TNF-α,D-dimer)were analyzed by single factor analysis and there are 5 indicators,such as WBC,CRP,The levels of IL-6,TNF-α,and D-dimer in the severe group significantly different from the general group.After the colinearity test,the existence of multicollinearity was excluded.Logistic regression analysis was performed on the five indicators(WBC,CRP,IL-6,TNF-α,and D-dimer),and finally four indicators(including CRP,IL-6,TNF-α,D-dimer)were Incorporated the best regression equation.The equation is: Logit(P)=(-21.75)+ 0.14X1 + 0.28X2 + 0.46X3 + 3.70X4.By comparing the consistency of the regression model with the actual diagnosis results,it is found that the diagnostic accuracy of the equation is 93.2%.4.Results of ROC curve of each independent risk factor: By performing ROC curve analysis of each independent risk factor,the diagnostic value of the above 4 independent risk factor indicators are as follows: CRP sensitivity is 0.77,specificity is 0.80,area under the curve is 0.84 and the diagnostic cut-off value is 32.35.IL-6 sensitivity is 0.79,specificity is 0.76,area under the curve is 0.75,and diagnostic cut-off value is 25.02.TNF-α sensitivity is 0.86,specificity is 0.87,area under the curve is 0.88 and the diagnosis cut-off value is 30.35.The D-dimer sensitivity is 0.86,the specificity is 0.82,the area under the curve is 0.90 and the diagnostic cut-off value is 2.82.Conclusion1.CRP,IL-6,TNF-α,D-dimer are independent risk factors for severe mycoplasma pneumoniae pneumonia.2.When each independent risk factor exceeds the "diagnostic cut-off value",that is,CRP>32.35,IL-6>25.02,TNF-α >30.35,D-dimer>2.82,the risk of commen MPP developing into severe MPP increases and the higher the value of each indicator,the heavier the disease.3.By comparing the results of ROC curves of 4 independent risk factors,it was found that compared with CRP,IL-6 has higher diagnostic sensitivity and lower specificity,TNF-α has higher diagnostic sensitivity and specificity.The sensitivity of D-dimer is equivalent to TNF-α,but the specificity is slightly lower.In terms of overall diagnostic value,D-dimer>TNF-α>CRP>IL-6,D-dimer is an ideal predictor for judging the severity of MPP.