Defective monocyte oxidative burst predicts infection in alcoholic hepatitis and is associated with reduced expression of NADPH oxidase
Defective monocyte oxidative burst predicts infection in alcoholic hepatitis and is associated with reduced expression of NADPH oxidase
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DOI：
10.1136/gutjnl-2015-310378
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发表时间：
2017-03-01
期刊：
影响因子：
24.5
通讯作者：
Thursz, Mark R.
中科院分区：
文献类型：
--
作者：
Vergis, Nikhil;Khamri, Wafa;Thursz, Mark R.
目的 为了解释酒精性肝炎对严重感染的易感性增加，我们评估了单核细胞的吞噬功能、相关信号通路的异常及其可逆性，以及吞噬细胞缺陷是否可以预测随后的感染。设计使用CD14单克隆抗体从42例严重酒精性肝炎患者的血液样本中鉴定单核细胞。使用流式细胞术、发光测定法和细菌杀灭测定法离体测量吞噬作用和单核细胞氧化爆发（MOB）。缺陷与随后感染的发展有关。使用蛋白质印迹和 PCR 研究细胞内信号通路。评估了干扰素-γ（IFN-γ）在逆转吞噬细胞缺陷方面的治疗潜力。配对纵向样本用于评估体内泼尼松龙治疗的效果。结果酒精性肝炎患者的MOB、超氧化物的产生和对大肠杆菌的细菌杀灭作用显着受损。治疗前 MOB 预测两周内感染的发展，其敏感性和特异性均优于现有的临床标志物。因此，有缺陷的 MOB 与 28 天和 90 天的死亡相关。酒精性肝炎患者的烟酰胺腺嘌呤二核苷酸磷酸 (NADPH) 氧化酶 gp91phox 亚基的表达降低，表明 MOB 缺陷。单核细胞对 IFN-γ 刺激具有抵抗力，并显示出高水平的细胞因子信号传导负调节因子、细胞因子信号传导抑制因子 1。 MOB 不受 7 天体内泼尼松龙治疗的影响。结论 酒精性肝炎中单核细胞氧化爆发和细菌杀灭作用受损，而吞噬作用对细菌的摄取得以保留。 MOB 缺陷与这些患者中 NADPH 氧化酶表达降低有关，并可预测感染和死亡的发生。
Objective In order to explain the increased susceptibility to serious infection in alcoholic hepatitis, we evaluated monocyte phagocytosis, aberrations of associated signalling pathways and their reversibility, and whether phagocytic defects could predict subsequent infection.Design Monocytes were identified from blood samples of 42 patients with severe alcoholic hepatitis using monoclonal antibody to CD14. Phagocytosis and monocyte oxidative burst (MOB) were measured ex vivo using flow cytometry, luminometry and bacterial killing assays. Defects were related to the subsequent development of infection. Intracellular signalling pathways were investigated using western blotting and PCR. Interferon-gamma (IFN-gamma) was evaluated for its therapeutic potential in reversing phagocytic defects. Paired longitudinal samples were used to evaluate the effect of in vivo prednisolone therapy.Results MOB, production of superoxide and bacterial killing in response to Escherichia coli were markedly impaired in patients with alcoholic hepatitis. Pretreatment MOB predicted development of infection within two weeks with sensitivity and specificity that were superior to available clinical markers. Accordingly, defective MOB was associated with death at 28 and 90 days. Expression of the gp91phox subunit of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase was reduced in patients with alcoholic hepatitis demonstrating defective MOB. Monocytes were refractory to IFN-gamma stimulation and showed high levels of a negative regulator of cytokine signalling, suppressor of cytokine signalling-1. MOB was unaffected by 7 days in vivo prednisolone therapy.Conclusions Monocyte oxidative burst and bacterial killing is impaired in alcoholic hepatitis while bacterial uptake by phagocytosis is preserved. Defective MOB is associated with reduced expression of NADPH oxidase in these patients and predicts the development of infection and death.