Clinical Infection Medicine, Department of Translational Medicine, Lund University, Malmö.
Department of Infectious Diseases, Skåne University Hospital, Malmö/Lund, Sweden.
AIDS. 2022 Jul 15;36(9):1245-1253. doi: 10.1097/QAD.0000000000003235. Epub 2022 Jun 1.
: The aim of this study was to assess the performance of kynurenine/tryptophan ratio for tuberculosis (TB) case-finding among antiretroviral therapy (ART)-naive people with HIV (PWH), and to investigate other factors associated with kynurenine/tryptophan ratio in this population.
: A nested case--control study based on a cohort of 812 ambulatory PWH in the Oromia region, Ethiopia.
: At enrolment, all participants submitted sputum samples for bacteriological TB investigations. Concentrations of kynurenine and tryptophan in plasma were quantified using liquid chromatography-mass spectrometry. Receiver operator characteristic curves were constructed to assess diagnostic performance (area under the curve; AUC) for kynurenine, tryptophan, and kynurenine/tryptophan ratio. Sensitivity, specificity, and predictive values were calculated. Kynurenine/tryptophan ratios were correlated to plasma levels of nine inflammation mediators, plasma HIV RNA levels, CD4 + cell count, BMI, and mid-upper arm circumference (MUAC).
: We included 124 individuals with HIV-TB coinfection (HIV+/TB+) and 125 with HIV mono-infection (HIV+/TB-). Tryptophan levels were lower in HIV+/TB+ than in HIV+/TB- (median 19.5 vs. 29.8 μmol/l, P < 0.01), while kynurenine levels were similar between these groups (median 2.95 vs. 2.94 μmol/l, P = 0.62). Median kynurenine/tryptophan ratio was 0.15 in HIV+/TB+, significantly higher compared with HIV+/TB- (0.11; P < 0.01), with AUC 0.70 for TB detection. Kynurenine/tryptophan ratio was positively correlated to plasma HIV RNA levels, IP-10, IL-18, and IL-27, and negatively correlated to CD4 + cell count, BMI, and MUAC (all P < 0.01).
: Among ART-naive PWH, kynurenine/tryptophan ratio has modest potential for TB discrimination, limiting its utility for TB case-finding in this population.
本研究旨在评估犬尿氨酸/色氨酸比值在抗逆转录病毒治疗（ART）初治 HIV 感染者（PWH）中用于结核病（TB）筛查的性能，并探讨该人群中与犬尿氨酸/色氨酸比值相关的其他因素。
基于埃塞俄比亚奥罗米亚地区 812 名门诊 PWH 的队列进行的嵌套病例对照研究。
在入组时，所有参与者均提交了用于细菌学 TB 调查的痰样本。使用液相色谱-质谱法定量血浆中犬尿氨酸和色氨酸的浓度。构建受试者工作特征曲线以评估犬尿氨酸、色氨酸和犬尿氨酸/色氨酸比值的诊断性能（曲线下面积；AUC）。计算了灵敏度、特异性和预测值。将犬尿氨酸/色氨酸比值与血浆中 9 种炎症介质、血浆 HIV RNA 水平、CD4+细胞计数、BMI 和中上臂围（MUAC）进行相关性分析。
我们纳入了 124 名 HIV-TB 合并感染（HIV+/TB+）和 125 名 HIV 单一感染（HIV+/TB-）的个体。与 HIV+/TB-相比，HIV+/TB+中的色氨酸水平较低（中位数 19.5 对 29.8μmol/L，P<0.01），而两组间犬尿氨酸水平相似（中位数 2.95 对 2.94μmol/L，P=0.62）。HIV+/TB+的犬尿氨酸/色氨酸比值中位数为 0.15，明显高于 HIV+/TB-（0.11；P<0.01），用于检测 TB 的 AUC 为 0.70。犬尿氨酸/色氨酸比值与血浆 HIV RNA 水平、IP-10、IL-18 和 IL-27 呈正相关，与 CD4+细胞计数、BMI 和 MUAC 呈负相关（均 P<0.01）。
在 ART 初治 PWH 中，犬尿氨酸/色氨酸比值对 TB 有一定的鉴别能力，限制了其在该人群中用于 TB 筛查的应用。
