Galai N, Margolick J B, Astemborski J, Vlahov D
Department of Epidemiology, The Johns Hopkins School of Hygiene and Public Health, Baltimore, Maryland, USA.
Clin Immunol Immunopathol. 1996 May;79(2):134-41. doi: 10.1006/clin.1996.0060.
Prior studies, based on populations of homosexual men, have shown that during HIV infection, levels of total circulating T-cells (CD3+ lymphocytes) remain constant for long periods of time after seroconversion. This suggested homeostatic phenomenon was observed to break down about 18 months prior to AIDS diagnosis with a quick loss of T-cells. The objective of this study was to determine whether (a) total T-cells are maintained at a constant level for long periods of time among HIV-infected injection drug users (IDUs) and (b) total T-cells decline before AIDS onset in this risk group and, if so, by how long. The design and setting was prospective follow-up, with semiannual clinic visits, of 646 HIV-infected IDUs who participate in the ALIVE study (Baltimore, MD). Among AIDS cases, T-cell levels remained quite stable at about 1500 cells/microl up to approximately 24 months prior to AIDS. However, a steep decline in CD3+ cell levels began approximately 24 months prior to AIDS diagnosis and was -17.5% per 6 months in the last 18 months before AIDS. Among seropositive IDUs without AIDS, a gradual decline of less than -4% per 6 months was observed. These trends remained virtually unchanged after accounting for current injection drug use, smoking, and HIV-related medications. IDUs, like homosexual men, exhibited T-cell homeostasis following HIV infection, as well as failure of this homeostasis about 2 years before AIDS. Although the mechanisms for the maintenance and later failure of the homeostasis of T-lymphocytes are not well understood, the observation has a potentially important prognostic value as well as biological interest.
此前基于男同性恋人群开展的研究表明，在感染艾滋病毒期间，血清转化后很长一段时间内，循环总T细胞（CD3 +淋巴细胞）水平保持恒定。这种稳态现象在艾滋病诊断前约18个月被观察到出现破坏，T细胞迅速减少。本研究的目的是确定：（a）在感染艾滋病毒的注射吸毒者（IDU）中，总T细胞是否能长时间维持在恒定水平；（b）在这个风险群体中，总T细胞在艾滋病发病前是否会下降，如果会，提前多久下降。研究设计和背景是对参与ALIVE研究（马里兰州巴尔的摩）的646名感染艾滋病毒的注射吸毒者进行前瞻性随访，每半年进行一次门诊检查。在艾滋病病例中，直至艾滋病发病前约24个月，T细胞水平一直相当稳定，约为1500个细胞/微升。然而，CD3 +细胞水平在艾滋病诊断前约24个月开始急剧下降，在艾滋病发病前的最后18个月中，每6个月下降17.5%。在未患艾滋病的血清阳性注射吸毒者中，观察到每6个月逐渐下降不到4%。在考虑了当前的注射吸毒情况、吸烟和与艾滋病毒相关的药物治疗因素后，这些趋势基本保持不变。与男同性恋者一样，注射吸毒者在感染艾滋病毒后也表现出T细胞稳态，以及在艾滋病发病前约2年出现这种稳态的破坏。尽管T淋巴细胞稳态维持及后期破坏的机制尚不完全清楚，但这一观察结果具有潜在的重要预后价值和生物学意义。
