ObjectiveTo investigate the clinical significance of KL-6 and LDH level changes in children with viral pneumonia.Methods82 children with viral pneumonia admitted in our hospital from January 2015 to December 2016 were selected as subjects and divided into two groups according to the characteristics of viral pneumonia and severe pneumonia diagnostic criteria:severe group(35 cases)and mild group(47 cases),and 30 healthy children of similar age and sex were selected as control group.Serum LDH levels were measured by rate method before and after treatment,and the levels of KL-6 were measured by enzyme-linked immunosorbent assay (ELISA).The clinical symptom were scored and the correlation between KL-6 level and clinical symptoms were compared.The children of two groups were treated with Ribavirin and Recombinant Interferon,the disappeared time of their cough,wheezing,rales and fever were recorded and the datas were used to made the correlation analysis.ResultsThe levels of serum KL-6 in the severe group and the mild group were significantly higher than that in the control group before treatment,and severe group was significantly higher than that of the mild group,and the differences were statistically significant(P＜0.05).After treatment,the levels of serum KL-6 in the severe group and the mild group were compared,and the difference was not statistically significant(P＞0.05),but it was significantly higher than that of the control group,the differences were statistically significant(P＜0.05).Before treatment,the serum LDH levels of the severe group and mild group were significantly higher than that of the control group,while the mild group was significantly higher than that of the control group,the differences were statistically significant(P＜0.05).After treatment,the serum LDH levels of severe group and the mild group were compared,and the difference was not statistically significant(P＞0.05),but it was significantly lower than that of the control group,the differences were statistically significant(P＜0.05).The score of clinical symptoms in the severe group was significantly higher than in the mild group,and the disappeared time of cough,wheezing,rales and fever in the severe group were significantly higher than those in the mild group,the differences were statistically significant(P＜0.05).The level of KL-6 was positively correlated with the clinical symptom score,cough,wheezing,rale and fever disappearance time (P＜0.05).ConclusionSerum KL-6 level can be used as an effective index for evaluating the severity and prognosis of viral pneumonia in children,and the level of LDH can also be used to reflect the degree of disease change.