凝血过程干预对结核发病及抗结核治疗的影响

Tuberculosis (TB) is a global health emergency. Epidemiological finding that transmission of primary drug resistance is the main cause of high resistance of tuberculosis in China requires urgently for novel strategies to reduce the generation and transmission of drug resistance. Granuloma-targeted host-directed therapy (HDT) allows for the repurpose of existing drugs as adjunctive therapies to aid in treatment and prevention of TB. Our preliminary study based on statistical analysis of pathological samples, radiological data, hematological and biochemical parameters revealed a close correlation of the activation of coagulation pathway with severity of pathological lesions, eg. the area of caseous necrosis, the grade of fibro-encapsulation and the bacteria counts from sputum of active TB patients. Retrospective clinical observations indicate that the anti-platelet and anti-fibrotic drug, bromelain, improves the effects of first-line anti-TB drugs on several re-treated cases. Based on these findings, we will investigate the influence of expression and activation of anti-coagulation factors, including PROC, RGS18, TFPI, etc. on granuloma pathogenesis, caseous necrosis, fibro-encapsulation, and the adjunctive effect on anti-TB treatment, using the model of zebra fish with Mycobacterium marinum infection. This animal model resembles well with TB infections in humans with a heterogeneous, but well-organized, and dynamic accumulation of immune cells in granuloma, with caseous inner parts and a fibrous wall when mature. With retrospective and prospective clinical study, we will further investigate the association of the changes of coagulation-anticoagulation activities with the progress and severity of tuberculosis, and evaluate the adjunctive effects of the anti-coagulation drugs, eg. aspirin and bromelain, on anti-TB treatment. Our study will help us to understand the pathogenesis of tuberculosis, and may provide new way to anti-fibrotic TB HDT research.

结核病是严重危害人类健康的全球公共卫生问题，耐药菌的传播，更令结核病疫情雪上加霜。由于新药研发滞后、周期长，调节宿主免疫反应，以期提高现有药物作用的 host-directed therapy (HDT) 成为结核病研究的新热点。我们前期临床标本观察及数据分析发现，外源性凝血途径活化与结核肉芽肿坏死、纤维化包裹及病人痰菌量密切相关；少量病例回顾性分析发现抗凝血、抗纤维化药物有助于难治性结核病人的治疗。在此基础上，本课题将利用海分枝杆菌感染斑马鱼等模式动物实验结合体外细胞模型，进一步研究干预凝血过程的PROC、RGS18、TFPI等关键的抗凝血因子表达及活性对肉芽肿形成、坏死、纤维化包裹、药物杀菌作用等的影响；结合回顾性和小样本前瞻性临床研究，分析凝血功能变化与结核病情的相关性，以及抗凝血药物对抗结核治疗效果的影响。本课题将有助于阐明结核病理发生机制，并为难治性结核HDT辅助治疗提供新思路。

结核病发病的机制尚不完全清楚。本项目基于前期体外细胞模型及临床病理标本和影像数据分析的研究基础，提出凝血相关因子和血小板可能在结核病理发生中起关键作用。项目研究发现，结核病人外周血的凝血相关指标在病人尚无排菌的感染早期即与肉芽肿坏死面积、纤维化包裹、空洞相关；在痰菌阳性的病人，凝血相关指标也与病人空洞发生和痰菌量相关。糖尿病合并结核病人病情较重，可能是由于糖尿病合并结核病人外周血高糖水平造成血小板和凝血系统预激活状态有关；男女性在结核发病和病情严重程度上的年龄相关的差异，也可能是由于年龄相关的性激素水平变化影响基础水平、或结核菌感染后凝血相关因子的差异造成。活动性结核病人外周血中血小板-中性粒细胞复合物比率明显增加，在结核菌感染的动物模型上证明，血小板通过抑制呼吸爆发和自由基产生，抑制髓系细胞的杀菌作用，但对肺部免疫细胞群数量和抗分枝杆菌的T细胞反应无影响。凝血和血小板抑制对结核病尤其是难治性结核病的辅助治疗作用还待后续基于临床实验的证据。