Interpretation of serial interferon-gamma test results to measure new tuberculosis infection among household contacts in Zambia and South Africa.
Interpretation of serial interferon-gamma test results to measure new tuberculosis infection among household contacts in Zambia and South Africa.
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DOI：
10.1186/s12879-020-05483-9
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发表时间：
2020-10-15
影响因子：
3.7
通讯作者：
Floyd S
中科院分区：
文献类型：
--
作者：
Sloot R;Shanaube K;Claassens M;Telisinghe L;Schaap A;Godfrey-Faussett P;Ayles H;Floyd S
已提出更严格的QuantiFERON-TB Gold In-Tube（QFT）转换（从阴性到阳性）定义，以更明确地检测近期结核病（TB）感染。我们探讨了替代转换定义，以帮助解释系列QFT结果，并在一项大型队列研究中估计结核感染的发病率。我们使用了来自年龄≥15岁的结核病家庭接触者的QFT系列结果，这些结果在基线和两次随访访视（2006-2011年）期间收集，作为赞比亚和南非（SA）24个社区队列研究的一部分。将使用制造商定义（干扰素-γ（IFN-g）< 0.35至≥0.35，“def 1”）的转化率与更严格的定义（IFN-g < 0.2至≥0.7 IU/ml，“def 2”; IFN-g < 0.2至≥1.05 IU/ml，“def 3”; IFN-g < 0.2至≥1.4 IU/ml，“def 4”）进行比较。采用Poisson回归进行分析。赞比亚有1 365人，南非有822人获得了量化宽松测试结果。在HIV阴性个体中，使用def 1的QFT转换率为27.4/100人年（CI：22.9-32.6），使用def 2的QFT转换率为19.0/100人年（CI：15.2-23.7），使用def 3的QFT转换率为14.7/100人年（CI：11.5-18.8），使用def 4的QFT转换率为12.0/100人年（CI：9.2-15.7）。在赞比亚和南非，def 1-def 4之间的相对差异相似。使用def 1，在包括这两个国家的分析中，与HIV阴性相比，如果HIV阳性而未接受抗逆转录病毒治疗，则转换的可能性较小（aRR = 0.7，95%CI = 0.4-0.9）。使用def 2-4发现了相同的关联方向。即使采用最严格的定义，也发现高转换率，表明这些社区结核病患者的家庭接触者中结核病感染率很高。由于缺乏参考标准，使用不同QFT转换阈值的灵敏度和特异性之间的权衡仍然未知。然而，我们确定了一个适当的定义可能属于的边界，我们最严格的定义无疑具有高度的特异性。
A more stringent QuantiFERON-TB Gold In-Tube (QFT) conversion (from negative to positive) definition has been proposed to allow more definite detection of recent tuberculosis (TB) infection. We explored alternative conversion definitions to assist the interpretation of serial QFT results and estimate incidence of TB infection in a large cohort study. We used QFT serial results from TB household contacts aged ≥15 years, collected at baseline and during two follow-up visits (2006–2011) as part of a cohort study in 24 communities in Zambia and South Africa (SA). Conversion rates using the manufacturers’ definition (interferon-gamma (IFN-g) < 0.35 to ≥0.35, ‘def1’) were compared with stricter definitions (IFN-g < 0.2 to ≥0.7 IU/ml, ‘def2’; IFN-g < 0.2 to ≥1.05 IU/ml, ‘def3’; IFN-g < 0.2 to ≥1.4 IU/ml, ‘def4’). Poisson regression was used for analysis. One thousand three hundred sixty-five individuals in Zambia and 822 in SA had QFT results available. Among HIV-negative individuals, the QFT conversion rate was 27.4 per 100 person-years (CI:22.9–32.6) using def1, 19.0 using def2 (CI:15.2–23.7), 14.7 using def3 (CI:11.5–18.8), and 12.0 using def4 (CI:9.2–15.7). Relative differences across def1-def4 were similar in Zambia and SA. Using def1, conversion was less likely if HIV positive not on antiretroviral treatment compared to HIV negative (aRR = 0.7, 95%CI = 0.4–0.9), in analysis including both countries. The same direction of associations were found using def 2–4. High conversion rates were found even with the strictest definition, indicating high incidence of TB infection among household contacts of TB patients in these communities. The trade-off between sensitivity and specificity using different thresholds of QFT conversion remains unknown due to the absence of a reference standard. However, we identified boundaries within which an appropriate definition might fall, and our strictest definition plausibly has high specificity.