Spijkerman I J, Koot M, Prins M, Keet I P, van den Hoek A J, Miedema F, Coutinho R A
Department of Public Health and Environment, Municipal Health Service, Amsterdam, The Netherlands.
AIDS. 1995 Sep;9(9):1085-92. doi: 10.1097/00002030-199509000-00016.
To study the prevalence, incidence and predictive value for progression to AIDS of the HIV-1 syncytium-inducing (SI) phenotype in HIV-infected injecting drug users (IDU) compared with HIV-infected homosexual men.
Two prospective cohort studies on HIV-1 infection among IDU and homosexual men.
HIV-infected IDU (n = 225) and homosexual men (n = 366) without AIDS were studied from March 1989 through December 1993. Data on laboratory markers, including the presence of SI variants, demographics, behavioural characteristics and clinical events were collected at every visit.
At baseline, SI variants were detected in 4% of IDU and 17% of homosexual men. During the study period 18 IDU and 68 homosexual men switched from non-SI to SI phenotype (4-year cumulative incidence, 14.6 and 28.4%, respectively) before AIDS diagnosis. Among participants with a documented date of HIV infection the cumulative incidence of SI was lower among IDU than homosexual men (4-year cumulative incidence, 6.2 and 20.7%, respectively). At AIDS diagnosis, 21% of all AIDS cases among IDU had the SI phenotype compared with 54% among homosexual men. In both risk groups an accelerated CD4 decline was found after the non-SI-to-SI switch. The SI phenotype appeared to be a predictor of AIDS (multivariate relative hazard, 5.33), independent of CD4 cell count and p24 antigen at baseline. In the multivariate time-dependent analysis, the relative hazard of SI phenotype decreased considerably, which is consistent with the hypothesis that the effect of SI phenotype on progression to AIDS is mediated by CD4 cell count.
The SI phenotype is associated with accelerated CD4 decline and progression to AIDS in both risk groups. The remarkable lower prevalence and incidence of the SI phenotype among IDU may implicate a difference in pathogenesis and natural history of HIV infection linked to transmission group.
与感染HIV的同性恋男性相比，研究HIV感染的注射吸毒者（IDU）中HIV-1合胞体诱导（SI）表型的流行率、发病率及进展为艾滋病的预测价值。
两项关于IDU和同性恋男性中HIV-1感染的前瞻性队列研究。
1989年3月至1993年12月，对未患艾滋病的HIV感染IDU（n = 225）和同性恋男性（n = 366）进行研究。每次随访时收集实验室指标数据，包括SI变异体的存在情况、人口统计学、行为特征和临床事件。
基线时，4%的IDU和17%的同性恋男性检测到SI变异体。在研究期间，18名IDU和68名同性恋男性在艾滋病诊断前从非SI表型转变为SI表型（4年累积发病率分别为14.6%和28.4%）。在有记录的HIV感染日期的参与者中，IDU中SI的累积发病率低于同性恋男性（4年累积发病率分别为6.2%和20.7%）。在艾滋病诊断时，IDU中所有艾滋病病例的21%具有SI表型，而同性恋男性中这一比例为54%。在两个风险组中，从非SI转变为SI后均发现CD4加速下降。SI表型似乎是艾滋病的一个预测指标（多变量相对风险为5.33），独立于基线时的CD4细胞计数和p24抗原。在多变量时间依赖性分析中，SI表型的相对风险大幅下降，这与SI表型对进展为艾滋病的影响是由CD4细胞计数介导的假设一致。
在两个风险组中，SI表型均与CD4加速下降和进展为艾滋病有关。IDU中SI表型的流行率和发病率显著较低，这可能意味着与传播组相关的HIV感染发病机制和自然史存在差异。
