严重感染与免疫应答

Severe infections and immune responses

人体免疫系统在抗感染方面起着非常重要的作用 ,但它具有双重性。恰当的免疫应答能抵卸病原体入侵 ,促进组织修复。不恰当的免疫应答可引发广泛的自身组织破坏、多重感染、多器官功能衰竭 ,导致死亡。促炎症细胞因子与抗炎症细胞因子之间相互平衡才能有助于维持内环境稳定。早年的研究过多地以动物实验结果为依据 ,加以引伸 ,认识上陷于片面性。上世纪 90年代中期 ,对严重感染进行抗炎症细胞因子治疗的多项、跨国、多中心的大规模临床试验 ,以失败告终。近年的研究提示 ,严重感染时 ,促炎症细胞因子应答与抗炎症细胞因子应答可以交替改变。若一成不变地套用某种既定的用药方案 ,以干预人体免疫性 ,很可能引起不恰当的免疫应答。当今治疗性干预倾向于下调过度炎症反应 ,遏制组织自身破坏 ,但随之而引发的更为持久的免疫抑制或者无变应性状态 ,同样可以导致惨重后果。这方面的教训深刻 。

Human immune system plays an important role in the defence of human body against infection. The mechanism is charaterized by the destroy of pathogens and, as a dual-edged sword, harming the host that results in multi-organ function failure and even the death of the host. The balance is controlled by the function of inflammation factors versus anti-inflammation cytokines. Early studies were mostly carried out in animals that failed to explain the real pictures in vivo. Many nulti-national and multi-center clinical tests on severe infections by anti-inflammation cytokine therapy in 1990s were not successful. In recent years studies showed that over-treatment to down-regulate immune respone inhibited the destroy of host tissues but, the long-term immune inhibition also made the patients more suceptable to infections. This paper reviewed the experience in this field.