IDO in respiratory distress patients

Data linked to the proposed publication: Diagnostic accuracy of Kynurenine to tryptophan ratio in peripheral blood to distinguish Tuberculosis from COVID-19, PCP or CAP.

Tuberculosis (TB) kills almost as many people annually as COVID-19 killed in 2020, yet remains challenging to diagnose. The kynurenine (kyn)/tryptophan (trp) ratio, an indicator of indoleamine 2,3-dioxygenase activity, is of interest as a host biomarker of respiratory distress. We calculated the diagnostic potential of the kyn/trp ratio to distinguish TB from COVID-19, community-acquired pneumonia (CAP), Pneumocystis pneumonia (PCP) and non-communicable lung disease. We measured the kyn/trp ratio by ELISA on peripheral blood along with C-reactive protein (CRP) values as a comparator assay of the host immune response. An elevated kyn/trp ratio was seen in individuals with TB, COVID-19, CAP and PCP but not in those with non-communicable diseases. Individuals with TB had the highest kyn/trp ratio. At a cut-off value of 0.165, the kyn/trp ratio was able to differentiate individuals with TB disease from healthy control subjects with a sensitivity of 72.5%, specificity of 100.0%, positive predictive value (PPV) of 100.0% and negative predictive value (NPV) of 93.9%, and from patients with other aetiologies of respiratory distress with a sensitivity of 72.5%, specificity of 74.8%, PPV of 40.5% and NPV of 92.0%. The kyn/trp ratio performed better than CRP for distinguishing TB disease from other respiratory illnesses with the area under the receiver operating curve of 0.76 compared with 0.61. The kyn/trp ratio can be used as an adjunctive blood-based diagnostic test for TB.

与所提议出版物相关联的数据：外周血中犬尿氨酸与色氨酸比值在鉴别结核病与COVID-19、社区获得性肺炎（CAP）或肺孢子虫肺炎（PCP）中的诊断准确性。
结核病（TB）每年造成的死亡人数与2020年COVID-19死亡人数相近，但其诊断仍具挑战性。犬尿氨酸（kyn）/色氨酸（trp）比值，作为犬尿氨酸2,3-双加氧酶活性的指标，作为宿主呼吸窘迫的生物标志物而受到关注。我们计算了犬尿氨酸/色氨酸比值在区分结核病与COVID-19、社区获得性肺炎（CAP）、肺孢子虫肺炎（PCP）和非传染性肺部疾病中的诊断潜力。我们通过ELISA在外周血中测量了犬尿氨酸/色氨酸比值，并将其与C反应蛋白（CRP）值作为宿主免疫反应的对照检测进行比较。在结核病、COVID-19、CAP和PCP患者中观察到升高的犬尿氨酸/色氨酸比值，而在非传染性疾病患者中则没有观察到。结核病患者具有最高的犬尿氨酸/色氨酸比值。在0.165的截断值下，犬尿氨酸/色氨酸比值能够以72.5%的灵敏度、100.0%的特异性、100.0%的阳性预测值（PPV）和93.9%的阴性预测值（NPV）将患有结核病的人群与健康对照组区分开来，并且以72.5%的灵敏度、74.8%的特异性、40.5%的PPV和92.0%的NPV将患有其他呼吸窘迫病因的患者区分开来。与C反应蛋白相比，犬尿氨酸/色氨酸比值在区分结核病与其他呼吸系统疾病方面表现更佳，其受试者工作特征曲线下面积为0.76，而C反应蛋白的面积为0.61。犬尿氨酸/色氨酸比值可以作为结核病的辅助血液诊断检测方法。