Reviewer response for version 1

Objective An ELISA test was performed to detect antibody response in the serum of pulmonary tuberculosis (PTB) patients with confirmed acid-fast bacilli (AFB) in sputum along with healthy controls using the in-house prepared antigen of Mycobacterium tuberculosis (MTB) H37Rv strain sonicated soluble extract. Methods The present study has recruited participants with AFB sputum smear positivity (N = 652) and healthy controls (N= 251). Serum samples of both groups were subjected to antibody analysis by ELISA. The evaluation of diagnostic specificity was based on a positive score represented by titers above the cut–off value. Statistical analysis was performed. Results A significant antibody response was (P value < 0.0001) observed in PTB sputum smear-positive patients as compared to healthy controls. We found that 577 PTB patients show positive antibody responses against the prepared sonicated antigen. Antibody detection by using the ELISA method has revealed 88.50% sensitivity and 97.61% specificity. Conclusion This immunological test could be much more efficient to detect antibody response in PTB sputum smear-positive patients. Further, the test may be useful in smear-negative cases of TB and those with latent infection.