T-SPOT.TB in the diagnosis of tuberculous peritonitis

Abstract

To evaluate the value of T-SPOT.TB in the diagnosis of tuberculous peritonitis (TBP). A total of 50 patients with clinically suspected TBP admitted from August 2011 to July 2012 from the Third Xiangya Hospital were enrolled in this prospective cohort study. Peripheral blood T-SPOT.TB, purified protein derivatives of tuberculin (PPD) skin test, serum tuberculosis antibody (TB-Ab) and ascitic adenosine deaminase (ADA) were measured in the 50 patients and we compared the diagnostic value of the 4 methods. According to the standard of diagnosis of TBP and grouping, 24 patients were diagnosed with TBP, 17 non-TBP and 9 undiagnosed in the end. The sensitivity of T-SPOT.TB for the diagnosis of TBP was 91.7% (22/24), with statistical significance when compared with PPD skin test 37.5% (9/24), serum TB-Ab 16.7% (4/24), and ascitic ADA 36.4% (8/22) (P<0.01). The specificity of T-SPOT.TB for the identification of non-TBP was 76.5% (13/17), without statistical significance when compared with PPD skin test 70.0% (7/10), serum TB-Ab 78.6% (11/14), and ascitic ADA 100% (14/14) (P>0.05). The positive prediction value of T-SPOT.TB for the diagnosis of TBP was 84.6% (22/26), without statistical significance when compared with PPD skin test 75.0% (9/12), serum TB-Ab 57.1% (4/7), and ascitic ADA 100%(8/8) (P>0.05). The negative prediction value of T-SPOT.TB for the identification of non-TBP was 86.7% (13/15), with statistical significance when compared with PPD skin test 31.8% (7/22), serum TB-Ab 35.5% (11/31), and ascitic ADA 50.0% (14/28) (P<0.05). Peripheral blood T-SPOT.TB for the diagnosis of TBP is highly sensitive, which is better than PPD skin test, serum TB-Ab, and ascitic ADA. T-SPOT.TB has an important reference for diagnosing suspected TBP quickly and accurately.