Effectivity of in-house developed sandwich ELISA for antigen detection in resource constraint settings

Abstract

Introduction: Around 26% of World’s Tuberculosis (TB) cases are in India. In resource constrained settings, it is difficult to use diagnostic tests like nucleic acid amplification technique and mycobacterial culture due to their complexity and expensiveness.Developing an assay using polyclonal antibody may help to solve this problem. On the basis of that we worked to detect tubercular antigen developing Sandwich ELISA from the serum of tuberculosis patients. Materials & Methods: For the study 50 cases, 50 disease controls, 30 healthy control subjects were taken. Commercially available reagents were used for the development of Sandwich ELISA. The data was statistically analyzed with the help of software SPSS version 16.0. Results: Our effectively developed test had 82% area under the ROC curve. 81% (n=35) patients of PTB cases with non-HIV infection detected by our Sandwich ELISA and 57% cases with the co-infection of HIV-TB. Developed test had 70.91% positive predictive value and 75.56% negative predictive value. Conclusion: We successfully developed Sandwich ELISA for tubercular antigen detection. To increase the sensitivity and specificity of the Sandwich ELISA, as per the WHO guidelines, further work is needed.