PT - JOURNAL ARTICLE AU - T. Oni AU - J. Patel AU - H.P. Gideon AU - R. Seldon AU - K. Wood AU - Y. Hlombe AU - K.A. Wilkinson AU - M.X. Rangaka AU - M. Mendelson AU - R.J. Wilkinson TI - Enhanced diagnosis of HIV-1-associated tuberculosis by relating T-SPOT.<em>TB</em> and CD4 counts AID - 10.1183/09031936.00171509 DP - 2010 Sep 01 TA - European Respiratory Journal PG - 594--600 VI - 36 IP - 3 4099 - http://erj.ersjournals.com/content/36/3/594.short 4100 - http://erj.ersjournals.com/content/36/3/594.full SO - Eur Respir J2010 Sep 01; 36 AB - The sensitivity of the tuberculin skin test is impaired in HIV-1-infected persons. Enzyme-linked immunospot-based detection of immune sensitisation may be less affected. Furthermore, the quantitative response can be related to the CD4 count, potentially improving specificity for active disease. The T-SPOT.TB assay was performed on HIV-1-infected participants, 85 with active tuberculosis (TB) and 81 healthy patients (non-TB). The ratio of the sum of the 6-kDa early secretory antigenic target and culture filtrate protein 10 response to the CD4 count (spot-forming cell (SFC)/CD4) was calculated. Using the manufacturer's guidelines, active TB was diagnosed with 76% sensitivity and 53% specificity. Using an SFC/CD4 ratio of 0.12, sensitivity (80%) and specificity (62%) improved. The quantitative T-cell response increased with increasing smear-positivity in the active TB group (p = 0.0008). In the non-TB group, the proportion of persons scored positive by T-SPOT.TB assay was lower in the group with a CD4 count of &lt;200 cells·mm−3 (p = 0.029). The ratio of the summed T-cell response to CD4 count improved the diagnostic accuracy of the T-SPOT.TB assay in HIV-1-infected persons, and a ratio of SFC/CD4 of &gt;0.12 should prompt investigation for active disease. A strong association between the degree of sputum positivity and T-SPOT.TB score was found. The sensitivity of the T-SPOT.TB assay in active disease may be less impaired by advanced immunosuppression.