动物与人的机体免疫性,尤其是 T 细胞承担的细胞免疫性,随着年龄的增长而降低。相反,机体感染性疾病、新生物和自身免疫疾病的发生率则明显增高。不少学者指出,这类变化可能是机体高龄时担负抗感染、抗肿瘤或防止自身免疫疾病的监视系统出了故障,因而免疫机能降低或紊乱所致。为 Animal and human immunity, especially T cells bear the cellular immunity, with age and decreased. On the contrary, the incidence of infectious diseases, neoplasms and autoimmune diseases was significantly increased. Many scholars have pointed out that such changes may be due to the failure of the monitoring system that is responsible for anti-infective, anti-tumor or autoimmune diseases in the elderly when the body is in advanced form, thus resulting in the reduction or disruption of immune function. for