Herzmann Christian, Ernst Martin, Lange Christoph, Stenger Steffen, Kaufmann Stefan H E, Reiling Norbert, Schaberg Tom, van der Merwe Lize, Maertzdorf Jeroen
Center for Clinical Studies, Research Center Borstel, Borstel, Germany.
Division of Clinical Infectious Diseases, Research Center Borstel, Borstel, Germany.
PLoS One. 2017 Nov 10;12(11):e0187882. doi: 10.1371/journal.pone.0187882. eCollection 2017.
Blood based Interferon-(IFN)-γ release assays (IGRAs) have a poor predictive value for the development of tuberculosis. This study aimed to investigate the correlation between IGRAs and pulmonary immune responses in tuberculosis contacts in Germany.
IGRAs were performed on bronchoalveolar lavage (BAL) cells and peripheral blood from close healthy contacts of patients with culturally confirmed tuberculosis. Cellular BAL composition was determined by flow cytometry. BAL cells were co-cultured with three strains of Mycobacterium tuberculosis (Mtb) and Mtb derived antigens including Purified Protein Derivative (PPD), 6 kD Early Secretory Antigenic Target (ESAT-6) and 10 kD Culture Filtrate Protein (CFP-10). Levels of 29 cytokines and chemokines were analyzed in the supernatants by multiplex assay. Associations and effects were examined using linear mixed-effects models.
There were wide variations of inter-individual cytokine levels in BAL cell culture supernatants. Mycobacterial infection and stimulation with PPD showed a clear induction of several macrophage and lymphocyte associated cytokines, reflecting activation of these cell types. No robust correlation between cytokine patterns and blood IGRA status of the donor was observed, except for slightly higher Interleukin-2 (IL-2) responses in BAL cells from IGRA-positive donors upon mycobacterial infection compared to cells from IGRA-negative donors. Stronger correlations were observed when cytokine patterns were stratified according to BAL IGRA status. BAL cells from donors with BAL IGRA-positive responses produced significantly more IFN-γ and IL-2 upon PPD stimulation and mycobacterial infection than cells from BAL IGRA-negative individuals. Correlations between BAL composition and basal cytokine release from unstimulated cells were suggestive of pre-activated lymphocytes but impaired macrophage activity in BAL IGRA-positive donors, in contrast to BAL IGRA-negative donors.
In vitro BAL cell cytokine responses to M. tuberculosis antigens or infection do not reflect blood IGRA status but do correlate with stronger cellular responses in BAL IGRA-positive donors. The cytokine patterns observed suggest a pre-activated state of lymphocytes and suppressed macrophage responsiveness in BAL cells from BAL IGRA-positive individuals.
基于血液的干扰素-γ（IFN-γ）释放试验（IGRAs）对结核病发生的预测价值较差。本研究旨在调查德国结核病接触者中IGRAs与肺部免疫反应之间的相关性。
对经培养确诊的结核病患者的密切健康接触者的支气管肺泡灌洗（BAL）细胞和外周血进行IGRAs检测。通过流式细胞术确定BAL细胞组成。将BAL细胞与三株结核分枝杆菌（Mtb）以及Mtb衍生抗原（包括纯化蛋白衍生物（PPD）、6kD早期分泌抗原靶标（ESAT-6）和10kD培养滤液蛋白（CFP-10））共培养。通过多重检测分析上清液中29种细胞因子和趋化因子的水平。使用线性混合效应模型检查相关性和效应。
BAL细胞培养上清液中个体间细胞因子水平存在广泛差异。分枝杆菌感染和PPD刺激显示出几种与巨噬细胞和淋巴细胞相关的细胞因子明显诱导，反映了这些细胞类型的激活。除了在分枝杆菌感染后，IGRA阳性供体的BAL细胞中白细胞介素-2（IL-2）反应略高于IGRA阴性供体的细胞外，未观察到细胞因子模式与供体血液IGRA状态之间有显著相关性。当根据BAL IGRA状态对细胞因子模式进行分层时，观察到更强的相关性。与BAL IGRA阴性个体的细胞相比，BAL IGRA阳性反应供体的BAL细胞在PPD刺激和分枝杆菌感染后产生的IFN-γ和IL-2明显更多。BAL组成与未刺激细胞的基础细胞因子释放之间的相关性提示BAL IGRA阳性供体中存在预激活的淋巴细胞，但巨噬细胞活性受损，这与BAL IGRA阴性供体相反。
体外BAL细胞对结核分枝杆菌抗原或感染的细胞因子反应不反映血液IGRA状态，但与BAL IGRA阳性供体中更强的细胞反应相关。观察到的细胞因子模式表明BAL IGRA阳性个体的BAL细胞中淋巴细胞处于预激活状态，巨噬细胞反应性受到抑制。
