Faculty of Health Sciences, Institute of Infectious Diseases and Molecular Medicine, University of Cape Town, Observatory 7925, Cape Town, South Africa.
Eur Respir J. 2010 Sep;36(3):594-600. doi: 10.1183/09031936.00171509. Epub 2010 Jan 14.
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 <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 >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.
结核菌素皮肤试验在 HIV-1 感染者中的敏感性降低。酶联免疫斑点法检测免疫致敏的效果可能影响较小。此外，定量反应可与 CD4 计数相关，从而提高对活动性疾病的特异性。对 HIV-1 感染者进行 T-SPOT.TB 检测，85 例活动性结核病（TB）患者和 81 例健康患者（非 TB）。计算 6-kDa 早期分泌抗原靶和培养滤液蛋白 10 反应的总和与 CD4 计数（斑点形成细胞（SFC）/CD4）的比值。根据制造商的指南，诊断活动性 TB 的敏感性为 76%，特异性为 53%。使用 SFC/CD4 比值为 0.12，可提高敏感性（80%）和特异性（62%）。定量 T 细胞反应随着活性 TB 组中涂片阳性的增加而增加（p=0.0008）。在非 TB 组中，T-SPOT.TB 检测评分阳性的患者比例在 CD4 计数<200 个细胞·mm(-3)的组中较低（p=0.029）。T 细胞反应总和与 CD4 计数的比值提高了 T-SPOT.TB 检测在 HIV-1 感染者中的诊断准确性，SFC/CD4 比值>0.12 应提示对活动性疾病进行调查。还发现痰阳性程度与 T-SPOT.TB 评分之间存在很强的相关性。T-SPOT.TB 检测在活动性疾病中的敏感性可能受严重免疫抑制的影响较小。
