Comparison Of Quantiferon TB-Gold (QFT-G) With Tuberculin Skin (TST) Testing In Serpiginous Choroiditis In An Indian population

Subijay Sinha

Purpose: To ascertain correlation between Quantiferon and Tuberculin skin test (Positive >10mm) in Serpiginous Choroiditis which is presumed to have tuberculous involvement. Both the tests aim to detect latent tuberculosis infection

Methods: We performed both the tests in fifty patients with serpiginous choroiditis. .Twelve had previously received anti tubercular therapy (ATD). Physician opinion was sought for initiation of ATD who tested positive for either of the two tests.

Results: 30 (60%) tested positive with QFT-G, and 28 (56%) tested positive with TST. Only 15 (30%) tested positive with both.ATD was initiated in 5 patients (10%).

Conclusions: No correlation could be established between the two tests in patients with serpiginous choroiditis. The Quantiferon test which was approved for diagnosing Mycobacterium tuberculosis infection, including latent tuberculosis infection failed to correlate with the more prevalent Tuberculin skin testing in a tuberculous endemic population where BCG vaccination is routinely used for immunization.