Comparison of Available Purified-protein Derivative (PPD) Tuberculin Skin Test (TST) Antigen Solutions in Detecting Latent Tuberculosis Infection in India

This study was terminated effective 12/23/2021

This study is conducted by the Cohort for Tuberculosis Research by the Indo-US Medical Partnership (C-TRIUMPH) under the Regional Prospective Observational Research for Tuberculosis (RePORT) Network, an international TB consortium. 

Given the worldwide shortage of PPD TST antigen solutions, it is important to establish the sensitivity of the commercially available SPAN diagnostic TST when compared products used in international settings.  This study aims to establish whether the SPAN diagnostic product is bioequivalent to PPDs that are produced and used outside of India. This study will also compare the tuberculin results with the two different generations of the interferon gamma release assay (QuantiFERON TB-Gold, or QGIT). 

Our hypothesis is that SPAN diagnostic PPD will be bioequivalent  (having the equivalent ability to detect latent tuberculosis infection) to internationally produced PPDs, and that our comparison will produce timely information on the performance of the 4th generation IGRA among cohorts of interest in the Indian population.

This study will compare the immunogenicity of PPD TST prepared by SPAN diagnostics/Arkray Healthcare and Statens Serum Institut (SSI) among key populations from a group of TB cohort studies in India. Study participants would be recruited from IRB-approved studies that are recruiting the household contacts of index TB cases. An additional blood specimen (in addition to those collected by the parent study) will be collected for testing the 4th generation of the QGIT diagnostic test for latent TB Infection.