TITLE:
Antigen-Specific Antibody Profiles in TB-Exposed and Infected Patients: A Cohort Study from Pakistan
AUTHORS:
Hina Farzana, Natasha Anwar
KEYWORDS:
M. tuberculosis (M. tb), MMIA, Antibody Response
JOURNAL NAME:
Journal of Tuberculosis Research,
Vol.12 No.4,
November
25,
2024
ABSTRACT: Background: Circulating antibodies against specific M. tuberculosis (M. tb) antigens offer promising diagnostic biomarkers and an appealing alternative due to their ease of application, cost-effectiveness, and relatively non-invasive nature. This study aimed to quantify and characterize the IgG antibody response against a panel of eight Mycobacterium tuberculosis (M. tb) antigens in TB-exposed and infected patients. The overarching hypothesis was that the IgG profiles and median fluorescence intensity (MFI) against each M. tb antigen could potentially differentiate between pulmonary, extrapulmonary, index contacts and healthy controls in a high TB burden setting. Methods: A multiplex microbead immunoassay (MMIA) was used to measure the serological response in 524 blood samples against eight M. tb antigens namely Rv-3881, Ag85-a, Ag85-b, Ag85-c, P-38, HspX, CFP-10 and MPT-32, with antibody concentrations determined using MFI and antigen’s cut off was established to determine the percentage of patients with positive antibody response for each antigen. Diagnostic accuracy of panel antigens was determined through ROC (Receiver operating characteristic) curve analysis and AUC (area under the curve) with 95% CI by using SPSS version 22. Results: ROC analysis demonstrated that all eight TB antigens in the panel are suitable for diagnosing TB infection in endemic areas, with an AUC ranging from 0.996 to 0.999 (p Conclusions: The M. tb antigen-specific IgG antibody profiles, with established cutoffs, could be incorporated into current immunological tests to enable rapid and accurate diagnosis and differentiation of TB infection types in TB endemic settings.