Flanigan T P
Miriam Hospital, Providence, Rhode Island.
Am J Trop Med Hyg. 1994;50(5 Suppl):29-35.
Cryptosporidium parvum is an ubiquitous protozoan parasite that infects the gastrointestinal track, leading to enteritis. The course of the disease is closely linked to the immunocompetence of the host. In patients with human immunodeficiency virus (HIV) infections, the CD4 cell count is the best marker of the ability of the immune system to clear Cryptosporidium infection at the mucosal surface. In HIV seropositive persons who have cleared Cryptosporidium infection, levels of specific anti-Cryptosporidium secretory IgA are elevated compared with persons with acquired immunodeficiency syndrome (AIDS) and chronic cryptosporidiosis. In contrast, anti-Cryptosporidium serum antibody responses are much greater in persons with AIDS and chronic Cryptosporidium infection. Secretory antibody is also effective in neutralizing Cryptosporidium infection in vitro. Secretory IgA may be responsible for recovery from infection or may only be a marker for an effective immune response at the mucosal surface. Specific defeats in secretory antibody responses in patients with AIDS and cryptosporidiosis may be overcome with the development of murine or human monoclonal antibodies for oral immunotherapy.
微小隐孢子虫是一种普遍存在的原生动物寄生虫，可感染胃肠道，导致肠炎。疾病进程与宿主的免疫能力密切相关。在人类免疫缺陷病毒（HIV）感染患者中，CD4细胞计数是免疫系统在黏膜表面清除隐孢子虫感染能力的最佳标志物。在已清除隐孢子虫感染的HIV血清阳性者中，特异性抗隐孢子虫分泌型IgA水平比获得性免疫缺陷综合征（AIDS）和慢性隐孢子虫病患者更高。相比之下，AIDS和慢性隐孢子虫感染患者的抗隐孢子虫血清抗体反应要强得多。分泌型抗体在体外也能有效中和隐孢子虫感染。分泌型IgA可能是感染恢复的原因，或者可能只是黏膜表面有效免疫反应的一个标志物。随着用于口服免疫治疗的鼠源或人源单克隆抗体的开发，AIDS和隐孢子虫病患者分泌型抗体反应的特异性缺陷可能会被克服。
