Amdahl B M, Rubins J B, Daley C L, Gilks C F, Hopewell P C, Janoff E N
Department of Medicine, Veterans Affairs Medical Center, USA.
Am J Respir Crit Care Med. 1995 Dec;152(6 Pt 1):2000-4. doi: 10.1164/ajrccm.152.6.8520768.
Human immunodeficiency virus (HIV) infection is associated with a significantly increased incidence of pneumococcal pneumonia and concomitant bacteremia. We hypothesized that the predisposition of HIV-infected patients to invasive pneumococcal infection may be related, in part, to an impaired immune response to the pneumococcal antigen pneumolysin (PLY) because PLY facilitates bacterial invasion. We measured serum anti-PLY antibodies in two separate populations of HIV-infected and HIV-seronegative controls, using both an enzyme-linked immunosorbent assay method and a functional assay of antibody inhibition of PLY-induced hemolysis and cytotoxicity. HIV-infected patients in the United States had significantly lower titers of anti-PLY antibodies by both methods than did seronegative control subjects. Moreover, HIV-infected patients in Kenya who later developed pneumococcal bacteremia also had significantly lower anti-PLY antibody levels at baseline compared with seronegative control subjects. We conclude that lower baseline levels of antibodies to PLY are associated with the higher incidence of bacteremic pneumococcal infections among HIV-infected patients.
人类免疫缺陷病毒（HIV）感染与肺炎球菌肺炎及并发菌血症的发病率显著增加有关。我们推测，HIV感染患者易发生侵袭性肺炎球菌感染，部分原因可能是对肺炎球菌抗原肺炎溶血素（PLY）的免疫反应受损，因为PLY有助于细菌入侵。我们使用酶联免疫吸附测定法和抗体抑制PLY诱导的溶血及细胞毒性的功能测定法，在两组分别为HIV感染和HIV血清阴性对照人群中检测血清抗PLY抗体。通过这两种方法，美国的HIV感染患者的抗PLY抗体滴度均显著低于血清阴性对照受试者。此外，与血清阴性对照受试者相比，肯尼亚后来发生肺炎球菌菌血症的HIV感染患者在基线时的抗PLY抗体水平也显著较低。我们得出结论，HIV感染患者中抗PLY抗体的较低基线水平与菌血性肺炎球菌感染的较高发病率相关。
