Evaluation Of The Diagnostic Value Of Enzyme-Linked Immunosorbent Assay In Mycoplasma Pneumonia In Adults

Objectives: According to the results of M.pneumoniae antibody with passive particle agglutination(PA),in this paper we investigate the diagnostic value of the MP-IgM qualitative results and MP-IgG quantitative results in M.pneumoniae pneumonia in adults with enzyme-linked immunosorbent assay(ELISA).Methods: The patients of MPP and NMP group were 162 and 228 adults respectively,and all of them were from respiratory ward of Shengjing hospital,China medical university.Venous blood was collected 2 ml at admission and on the 7th day after admission.162 healthy cases came from the medical center without respiratory tract infection signs within 6 months.M.pneumoniae antibodies in serum were detected with PA and ELISA.We selected the patients with ELISA MP-IgM negative during the hospitalization in MPP(n=110,specimen=220),NMP group(n=227,specimen=454),and the controls with MP-IgM negative(n=162,specimen=162)as research objects,and based on the results with PA we analysed the correlation between the concentration of MP-IgG in ELISA and the titers in PA,consequently initially explored the possible concentration of MP-IgG as a reference for diagnosis of M.pneumoniae infection.In order to further explore the MP-IgG concentration changing of the bi-serum in acute phase of M.pneumoniae infection in ELISA as the criteria of M.pneumoniae exact diagnosis,We chooseded the patients with seroconversion or increased antibody titers(≥4)in PA method and solitary ELISA MP-IgG positive during the hospitalization in MPP(n=92)as research objects.Results: According to the reference standard of M.pneumoniae pneumonia with PA,the concentration of MP-IgG in ELISA was equal to or greater than 92.16 RU/ml which could be considered as the reference standard for solitary MP-IgG positive patients,and the diagnostic sensitivity and specificity were 34.57% and 94.74% respectively.And if we used the combination MP-IgM positive but MP-IgG lower than 92.16 RU/ml andMP-IgG equal to or greater than 92.16 RU/ml as the reference standard of M.pneumoniae pneumonia,the diagnostic sensitivity and specificity were 40.12% and94.29% individually.Based on the definite diagnostic criteria with PA in patients with M.pneumoniae pneumonia,the ELISA MP-IgG concentration increasing times was equal or greater than 1.48 during 7 days and the concentration of MP-IgG after 7 days is ≥92.16 RU/ml,which could be used as a diagnostic standard of M.pneumoniae infection for solitary IgG positive patients;However,it was ≤1.53 times and the concentration of MP-IgG < 92.16RU/ml after 7 days.,which could basically rule out M.pneumoniae infection.Conclusions: Combination MP-IgM qualitative results and MP-IgG quantitative results with ELISA were great significance to the diagnosis of M.pneumoniae pneumonia in adults.