Changes Of Serum CRP,D Dimer,Serum Ferritin And IL-18 Levels In Children With Mycoplasma Pneumonia And Their Clinical Significance

Objective: To investigate the changes of CRP、 D-dimer,ferritin and IL-18 levels in children that diagnosed as Mycoplasma pneumoniae pneumonia and their clinical significance.Methods: In this study,69 cases diagnosed as mycoplasma pneumoniae pneumonia in the first affiliated hospital of Shihezi university school of medicine,from October 2019 to October 2020,were incorporated in this study.They were divided into severe MPP group and mild MPP group according to the illness severity.And children treated as non-Mycoplasma pneumoniae pneumonia during the same period were taken as control group.Basic clinical information were collected.serum D-dimer,ferritin and IL-18 levels were tested respectively by immunofluorescence assay,chemiluminescence method,enzyme linked immunosorbent assay.And related infectious and biochemical indicators were collected,including the WBC,CRP and PCT and LDH.The levels of serum D-dimer,ferritin and IL-18 in the mild MPP,severe MPP and control group were compared,the correlation between the indicators were analyzed,and the ROC curve analysis of the indicators in the diagnosis of SMPP was conducted to further clarify the role of D-dimer,ferritin and IL-18 in the early recognition and disease assessment of Mycoplasma pneumoniae pneumonia,so as to guide clinical diagnosis and treatment.Results:1.There was no significant difference in age and gender between mild group,case group and control group(P > 0.05);The levels of D-dimer and FER in MPP mild and severe groups were both significantly higher than those in the control group(P<0.001);The levels of D-dimer and FER in severe MPP group were significantly higher than those in mild MPP group(P<0.001);The levels of PCT and LDH in mild and severe MPP groups were significantly higher than those in control group(P<0.001),but there was no significant difference in PCT and LDH levels between mild MPP group and severe MPP group(P >0.05);There was statistical significance in the level of IL-18 among the three groups(P < 0.05),but no statistical significance in the level of WBC among the three groups(P > 0.05).2.Correlation analysis of various indicators : CRP was positively correlated with D-dimer,PCT and FER in MPP children(p<0.05),the correlation between CRP and FER was 0.41,which is higher among the three.D-dimer was positively correlated with LDH and FER(p<0.05),and the correlation coefficient was 0.53,wchich is at the highest level among those indicators.There was no correlation between PCT and FER and LDH(>0.05).3.Using CRP,D-dimer,PCT,LDH and FER level as test variables and MPP severe(1=MPP severe group,0=control group as effect variables,the ROC curve indicated that the area under the curve of D-dimer and FER wans the largest,among which,the cut-off value of D-dimer was 0.95,the sensitivity was 86.67%,the specificity was 93.75%,and the AUC was 0.940(CI:0.881-0.998).The cut-off value of FER was123.65,the sensitivity was 93.33%,the specificity was 76.56%,and the AUC was 0.940(CI:0.805-0.975).Conclusion:1.Blood levels of CRP,D-dimer,ferritin,PCT and LDH are of great significance in the diagnosis of severe MPP.2.In MPP children,there is a positive correlation among CRP,D-dimer and ferritin levels,and D-dimer has the strongest correlation with ferritin levels,which can be used for the early diagnosis of MPP and the evaluation of severe MPP.3.Among the related indicators in children with severe MPP,the area under the curve of D-dimer and ferritin was the largest,and had the highest value in the diagnosis and evaluation of severe MPP.3.IL-18 level may play an auxiliary role the diagnosis and disease assessment of MPP,which needs to be further confirmed by large sample and multi-center studies.