Abstract

Objective: To compare tuberculin skin test (TST) with T-Spot for diagnosis of active tuberculosis (TB) as well as latent tuberculosis infection (LTBI).
Methodology: This study was conducted at Department of Immunology, Islamabad diagnostic Center, Islamabad from January to December 2018. Blood Samples of 126 individuals for T SPOT and same patients were inoculated with PPD (Mantoux test).
Results: Among 126 participants, 64 (50.8%) were male and 62 (49.2%) were female. T-Spot. was positive in 52 (41.0%) while PPD was positive in 13 (10%). Furthermore, 25 (19.84%) T-Spot. TB test was positive for male while tuberculin skin test was positive in 6 (4.7%) male. T-Spot. was positive in 27 (21.4%) female while PPD was positive in 7 (5.5%). Additionally, one (0.79%) patient each of males and females was also found to be intermediate positive for PPD, which was clearly positive for T-Spot. TB test.
Conclusion: T-Spot. was much more sensitive and specific in all age groups and different clinical conditions including immune-compromised individuals. Skin test has limitation especially for older age groups but in T-Spot. is unaffected by age and provides excellent agreement.

Key words: Tuberclosis, IGRA, T Spot,tuberclin skin test