Diagnostic value of serum Mp1p antigen detection for Talaromyces marneffei infection in acquired immune deficiency syndrome patients

Objective To explore the diagnostic value of Talaromyces marneffei (T.marneffei)-specific mannose glycoprotein Mp1p antigen for T. marneffei infection in acquired immune deficiency syndrome (AIDS) patients. Methods All cases were recruited in this study from January 2012 to June 2015 in Guangzhou No.8 People′s Hospital, including 184 AIDS patients with T. marneffei infection confirmatively diagnosed by culture, and 205 controls including 176 AIDS patients without T. marneffei infection and 29 health controls. Double antibody sandwich enzyme linked immunosorbent assay and fluoroimmunoassay combined with double-antibody sandwich were both utilized to detect serum Mp1p antigen levels, and their sensitivity and specificity for diagnosing T. marneffei infection in patients with AIDS were analyzed. χ2 test and t test were used for statistical analysis. Results The ratio of males to females and age of the study group were both comparable to those of the control group (χ2=0.019, P=0.889; t=1.810, P=0.07, respecitvley). The sensitivities of double antibody sandwich enzyme linked immunosorbent assay and fluoroimmunoassay combined with double-antibody sandwich were 82.07%(151/184) and 83.15%(153/184), respectively (χ2=0.076, P=0.783). The specificities were 93.17%(191/205) and 92.68%(190/205), respectively (χ2=0.037, P=0.847). The accuracy values were 87.92%(342/389) and 88.17%(343/389), respectively (χ2=0.012, P=0.912). The false positive rates were 6.83%(14/205) and 7.32%(15/205), respectively. The false negative rates were 17.93%(33/184) and 16.85%(31/184), respectively (χ2=0.049, P=0.829). The positive predictive values were 91.52%(151/165) and 91.07%(153/168), respectively (χ2=0.021, P=0.886). The negative predictive values were 85.27%(191/224) and 85.97%(190/221), respectively (χ2=0.045, P=0.832). The Kappa values were 0.83 and 0.80, respectively. Conclusion Detection of serum Mp1p antigen of T. marneffei possesses high specificity and sensitivity, which may be utilized for rapid and early diagnosis of T. marneffei infection in patients with AIDS. Key words: Acquired immunodeficiency syndrome; Talaromyces marneffei; Mannoprotein Mp1p; Serological diagnosis