Objective:To investigate changes of CD4+T/CD8+T ratio in children with mycoplasma pneumoniae pneumonia(MPP)at different ages and to predict outcome.Methods:A total of 150 children aged 1～12 with MPP admitted to The Second People's Hospital of Hefei from March 2021 to September 2023 were selected as study group,and were divided into improved group(n=112)and deteriorated group(n=38)according to clinical outcomes after treatment.According to age,patients were divided into in-fant group(≤3 years old)38 cases,preschool group(4～6 years old)57 cases,school age group(>6 years old)55 cases.General information,biochemical test indicators and other related data were collected,CD4+T/CD8+T was calculated,and statistical analysis was performed by SPSS23.0 software.Through univariate and multifactor Logistics regression analysis,changes of CD4+T/CD8+T and other indicators in MPP children of different ages were compared,and independent factors affecting outcome of MPP children were screened.ROC curve was used to analyze efficacy of selected independent influencing factors in predicting outcome of MPP children of different ages.Log-binomial model was used to analyze risk effect of age on CD4+T/CD8+T and different outcomes in MPP children.Dose-response relationship between CD4+T/CD8+T and risk of disease progression in MPP children was analyzed by Logistic regression model combined with restricted cubic spline(RCS)model.P<0.05 was statistically significant.Results:CRP,IgA,IgG,IgM and CD8+T were the highest in infant group,followed by preschool group,the lowest in school-age group(P<0.05),CD4+T and CD4+T/CD8+T were the lowest in infant group,followed by preschool group,and the highest in school-age group(P<0.05).MPP children with≤3 years old accounted for the lowest proportion of improvement(18.76%)and the worst improvement,followed by MPP children with 4～6 years old,MPP children with>6 years old accounted for the highest proportion of improvement(43.75%),and the best im-provement(P<0.001).Improvement of children with disease course≤7 days was significantly better than disease course>7 days(P<0.001).CRP,DD,ESR,LDH,IgA,IgG,IgM and CD8+T levels in children with MPP deterioration were significantly higher than children with MPP improvement(P<0.001),and CD4+T and CD4+T/CD8+T levels were significantly lower than children with MPP im-provement(P<0.001).Multi-factor Logistics regression analysis showed that age,IgA,IgG,IgM and CD4+T/CD8+T were independent influencing factors for outcome of MPP children(P<0.05).ROC curve analysis showed that when cut-off value was 1.50,AUC of CD4+T/CD8+T to predict outcome of MPP children was 0.86(95%CI:0.75～0.94),sensitivity and specificity were 83.76%and 84.60%,respectively.Log-binomial model showed that MPP children with CD4+T/CD8+T≤1.50%had the highest risk of worsening out-come.Risk scores before and after adjustment were 2.05(1.41～3.75),2.07(1.46～3.88)and 2.14(1.50～4.02)times of those in im-provement group.School-age children with CD4+T/CD8+T>1.50%had the lowest risk of worsening,and risk before and after adjust-ment was 1.07(1.00～1.87),1.13(1.04～1.98),1.18(1.07～2.01)times higher than improved group.RCS model analysis of relation-ship between CD4+T/CD8+T and different outcomes in MPP children showed that regardless of whether confounders were adjusted,CD4+T/CD8+T was negatively correlated with outcome of MPP children.Conclusion:CD4+T/CD8+T in MPP children of different ages is significantly different.CD4+T/CD8+T is the lowest in infant group,followed by preschool group,and the highest in school-age group.CD4+T/CD8+T in children with worsening MPP is significantly lower than improved MPP,and CD4+T/CD8+T is negatively correlated with outcome of MPP children,which has certain value in predicting outcome of MPP children.

Objective:To investigate changes of CD4+T/CD8+T ratio in children with mycoplasma pneumoniae pneumonia(MPP)at different ages and to predict outcome.Methods:A total of 150 children aged 1～12 with MPP admitted to The Second People's Hospital of Hefei from March 2021 to September 2023 were selected as study group,and were divided into improved group(n=112)and deteriorated group(n=38)according to clinical outcomes after treatment.According to age,patients were divided into in-fant group(≤3 years old)38 cases,preschool group(4～6 years old)57 cases,school age group(>6 years old)55 cases.General information,biochemical test indicators and other related data were collected,CD4+T/CD8+T was calculated,and statistical analysis was performed by SPSS23.0 software.Through univariate and multifactor Logistics regression analysis,changes of CD4+T/CD8+T and other indicators in MPP children of different ages were compared,and independent factors affecting outcome of MPP children were screened.ROC curve was used to analyze efficacy of selected independent influencing factors in predicting outcome of MPP children of different ages.Log-binomial model was used to analyze risk effect of age on CD4+T/CD8+T and different outcomes in MPP children.Dose-response relationship between CD4+T/CD8+T and risk of disease progression in MPP children was analyzed by Logistic regression model combined with restricted cubic spline(RCS)model.P<0.05 was statistically significant.Results:CRP,IgA,IgG,IgM and CD8+T were the highest in infant group,followed by preschool group,the lowest in school-age group(P<0.05),CD4+T and CD4+T/CD8+T were the lowest in infant group,followed by preschool group,and the highest in school-age group(P<0.05).MPP children with≤3 years old accounted for the lowest proportion of improvement(18.76%)and the worst improvement,followed by MPP children with 4～6 years old,MPP children with>6 years old accounted for the highest proportion of improvement(43.75%),and the best im-provement(P<0.001).Improvement of children with disease course≤7 days was significantly better than disease course>7 days(P<0.001).CRP,DD,ESR,LDH,IgA,IgG,IgM and CD8+T levels in children with MPP deterioration were significantly higher than children with MPP improvement(P<0.001),and CD4+T and CD4+T/CD8+T levels were significantly lower than children with MPP im-provement(P<0.001).Multi-factor Logistics regression analysis showed that age,IgA,IgG,IgM and CD4+T/CD8+T were independent influencing factors for outcome of MPP children(P<0.05).ROC curve analysis showed that when cut-off value was 1.50,AUC of CD4+T/CD8+T to predict outcome of MPP children was 0.86(95%CI:0.75～0.94),sensitivity and specificity were 83.76%and 84.60%,respectively.Log-binomial model showed that MPP children with CD4+T/CD8+T≤1.50%had the highest risk of worsening out-come.Risk scores before and after adjustment were 2.05(1.41～3.75),2.07(1.46～3.88)and 2.14(1.50～4.02)times of those in im-provement group.School-age children with CD4+T/CD8+T>1.50%had the lowest risk of worsening,and risk before and after adjust-ment was 1.07(1.00～1.87),1.13(1.04～1.98),1.18(1.07～2.01)times higher than improved group.RCS model analysis of relation-ship between CD4+T/CD8+T and different outcomes in MPP children showed that regardless of whether confounders were adjusted,CD4+T/CD8+T was negatively correlated with outcome of MPP children.Conclusion:CD4+T/CD8+T in MPP children of different ages is significantly different.CD4+T/CD8+T is the lowest in infant group,followed by preschool group,and the highest in school-age group.CD4+T/CD8+T in children with worsening MPP is significantly lower than improved MPP,and CD4+T/CD8+T is negatively correlated with outcome of MPP children,which has certain value in predicting outcome of MPP children.