Division of Immunology, Department of Pathology, Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Cape Town, South Africa.
Department of Statistical Sciences, University of Cape Town, Cape Town, South Africa.
Front Immunol. 2018 Oct 25;9:2438. doi: 10.3389/fimmu.2018.02438. eCollection 2018.
Identifying a blood circulating cellular biomarker that can be used to assess severity of disease and predict the time to culture conversion (TCC) in patients with multidrug resistant tuberculosis (MDR-TB) would facilitate monitoring response to treatment and may be of value in the design of future drug trials. We report on the frequency of blood Ki67HLA-DR CD4+ T regulatory (Treg) cells in predicting microbiological outcome before initiating second-line treatment for MDR-TB. Fifty-one patients with MDR-TB were enrolled and followed over 18 months; a subset of patients was sputum culture (SC) negative at baseline ( = 9). SC positive patients were divided into two groups, based on median TCC: rapid responders (≤71 days TCC; = 21) and slow responders (>71 days TCC; = 21). Whole blood at baseline, months 2 and 6 was stimulated with M tuberculosis (Mtb) antigens and Treg cells were then identified as CD3CD4CD25FoxP3CD127CD69 and further delineated as Ki67HLA-DR Treg. The frequency of these cells was significantly enlarged at baseline in SC positive relative to SC negative and smear positive relative to smear negative patients and in those with lung cavitation. This difference was further supported by unsupervised hierarchical clustering showing a significant grouping at baseline of total and early differentiated memory Treg cells in slow responders. Conversely, there was a clustering of a lower proportion of Treg cells and activated IFNγ-expressing T cells at baseline in the rapid responders. Examining changes over time revealed a more gradual reduction of Treg cells in slow responders relative to rapid responders to treatment. Receiver operating curve analysis showed that baseline Mtb-stimulated Ki67HLA-DR Treg cells could predict the TCC of MDR-TB treatment response with 81.2% sensitivity and 85% specificity (AUC of 0.87, < 0.0001), but this was not the case after 2 months of treatment. In conclusion, our data show that the frequency of a highly defined Mtb-stimulated blood Treg cell population at baseline can discriminate MDR-TB disease severity and predict time to culture clearance.
鉴定一种可用于评估耐多药结核病（MDR-TB）患者疾病严重程度和预测培养转换时间（TCC）的循环细胞生物标志物，将有助于监测治疗反应，并且可能对未来药物试验的设计具有价值。我们报告了 Ki67HLA-DR CD4+T 调节性（Treg）细胞在启动二线治疗 MDR-TB 之前预测微生物学结果的频率。51 例 MDR-TB 患者入组并随访 18 个月；亚组患者基线时痰培养（SC）阴性（=9）。根据中位 TCC 将 SC 阳性患者分为两组：快速反应者（TCC≤71 天；=21）和缓慢反应者（TCC>71 天；=21）。基线、2 个月和 6 个月时用 M tuberculosis（Mtb）抗原刺激全血，然后鉴定 Treg 细胞为 CD3CD4CD25FoxP3CD127CD69，并进一步划分为 Ki67HLA-DR Treg。与 SC 阴性和涂片阳性患者相比，SC 阳性患者的这些细胞在基线时明显增多，与有空洞形成的患者相比也是如此。非监督层次聚类进一步支持了这一差异，显示在缓慢反应者中，总早期分化记忆 Treg 细胞在基线时存在显著分组。相反，在快速反应者中，基线时 Treg 细胞和激活的 IFNγ表达 T 细胞的比例较低。观察随时间的变化表明，与快速反应者相比，缓慢反应者在治疗过程中 Treg 细胞的减少更为缓慢。接受者操作特征曲线分析显示，基线时 Mtb 刺激的 Ki67HLA-DR Treg 细胞可预测 MDR-TB 治疗反应的 TCC，敏感性为 81.2%，特异性为 85%（AUC 为 0.87，<0.0001），但在治疗 2 个月后则不然。总之，我们的数据表明，基线时高度定义的 Mtb 刺激的血液 Treg 细胞群的频率可以区分 MDR-TB 疾病的严重程度，并预测培养清除的时间。
