Serological diagnosis for active tuberculosis in Malaysian population: Comparison of four protein candidate

ObjectiveTo asses the ability of 4 types of Mtb proteins-ESAT6, SCWP, MAN and Ag85 to serve as indicator for active tuberculosis among Malaysian population.MethodsSera from 90 individuals, 60 from confirmed pulmonary tuberculosis patients and 30 healthy PPD negative individuals were tested for presence of anti-IgG and anti IgA by ELISA assay.ResultMean concentration of IgG and IgA were higher in patients compared to healthy Positivity of the ELISA test were calculated, taking the cut off value at mean +2 SD of healthy sera. The sensitivity of the ELISA IgA assay for ESAT 6, SCWP, MAN and Ag85 were 81.1%, 83.3%, 11.7% and 53.3% respectively. The sensitivity of the ELISA IgG asay for ESAT 6, SCWP, MAN and Ag85 were 71.0%, 71.0%, 71.0% and 21.0% respectively.ConclusionDetectionof IgA against SCWP promised a good indicator for active tuberculosis infection among Malaysian.