AIDS. 1992 Feb;6(2):213-22.
We describe the CD4 database of the Scottish Immunology Laboratories, and its uses and limitations for making short-term predictions of a CD4 cell count less than or equal to 200 x 10(6)/l (CD4(200)) and of adult AIDS cases in Scotland.
The date of the earlier of two consecutive samples (typically 3 months apart) both with CD4 cell counts less than or equal to 200 x 10(6)/l was taken to define when a patient had passed the CD4(200) threshold (referred to as a CD4(200) case). The CD4 database comprises HIV-1-seropositive adults in the four main risk groups [homosexual/bisexual (1), injecting drug users (IDU; 2), heterosexual contact (3), and undetermined (9)] from Scotland's three principal areas of population (Lothian, Tayside and Strathclyde) who have had a CD4 cell count of less than or equal to 500 x 10(6)/l.
Three hospitals in Scotland, the Communicable Diseases (Scotland Unit) and the Medical Research Council Biostatistics Unit, Cambridge, UK.
PATIENTS, PARTICIPANTS: The CD4 database at 31 December 1990 listed 813 patients (of whom 52% were IDU): 390 were CD4(200)/AIDS cases (of whom 44% were IDU) and 192 were AIDS cases (of whom 32% were IDU).
Individuals in risk groups 1, 2 and 3 were nearly equally represented among newly diagnosed HIV-1 infections in 1990. However, among patients with moderate immunodeficiency, IDU accounted for 50% of the total number. Co-incidence of first CD4 cell count with CD4(200) diagnosis was recorded for only 28% of IDU, but in over 50% of cases for each of the other exposure groups (57%). There was a highly significant decrease of around 80 x 10(6)/l per calendar-year-of-referral in first CD4 cell counts for patients on the CD4 database; and decreases of around 40 x 10(6)/lper decade of age at referral. Since 1988, median time from CD4(200) to AIDS diagnosis in Scotland has been approximately 2 years. Back-projection was applied to annual CD4(200)/AIDS diagnoses before 31 December 1990 and to AIDS diagnoses. From AIDS diagnoses, the central epidemic scenario underestimated past HIV-1-antibody-positive reports (up to the end of 1985). More dramatic underestimation was occasioned by back-projection from CD4(200)/AIDS diagnoses [319 inferred HIV infections compared with 445 HIV-1-antibody-positive reports to Communicable Diseases (Scotland) Unit].
First CD4 cell counts should complement new HIV-1 diagnoses. Past referrals for immunological monitoring were not uniform between risk groups in Scotland. Underascertainment of CD4(200) cases is a problem when CD4(200) cases are used as a basis for back-projection. More information concerning the incubation distribution from HIV seroconversion to CD4(200) diagnosis is required. It is likely that there are twice as many CD4(200)/AIDS as there are diagnosed cases of AIDS.
我们描述了苏格兰免疫学实验室的CD4数据库，以及其在短期预测CD4细胞计数小于或等于200×10⁶/L（CD4₂₀₀）和苏格兰成年艾滋病病例方面的用途及局限性。
选取两个连续样本（通常相隔3个月）中较早日期且CD4细胞计数均小于或等于200×10⁶/L的样本，以此来确定患者何时越过CD4₂₀₀阈值（称为CD4₂₀₀病例）。CD4数据库包含来自苏格兰三个主要人口地区（洛锡安、泰赛德和斯特拉斯克莱德）四个主要风险组[同性恋/双性恋者（1）、注射吸毒者（IDU；2）、异性接触者（3）和情况不明者（9）]中CD4细胞计数小于或等于500×10⁶/L的HIV-1血清阳性成年人。
苏格兰的三家医院、传染病（苏格兰部门）以及英国剑桥的医学研究理事会生物统计学部门。
患者、参与者：1990年12月31日的CD4数据库列出了813名患者（其中52%为注射吸毒者）：390例为CD4₂₀₀/艾滋病病例（其中44%为注射吸毒者），以及192例艾滋病病例（其中32%为注射吸毒者）。
1990年新诊断的HIV-1感染者中，风险组1、2和3中的个体比例几乎相同。然而，在免疫中度缺陷的患者中，注射吸毒者占总数的50%。仅28%的注射吸毒者首次CD4细胞计数与CD4₂₀₀诊断同时出现，但其他每个暴露组的这一比例超过50%（57%）。CD4数据库中患者的首次CD4细胞计数每年约减少80×10⁶/L；转诊时每增长十岁约减少40×10⁶/L。自1988年以来，苏格兰从CD4₂₀₀到艾滋病诊断的中位时间约为2年。对1990年12月31日之前的年度CD4₂₀₀/艾滋病诊断以及艾滋病诊断应用了反向推算。从艾滋病诊断来看，中心流行情况低估了过去的HIV-1抗体阳性报告（截至1985年底）。从CD4₂₀₀/艾滋病诊断进行反向推算导致了更严重的低估[推断有319例HIV感染，而向传染病（苏格兰）部门报告的HIV-1抗体阳性报告有445例]。
首次CD4细胞计数应作为新的HIV-1诊断的补充。苏格兰过去免疫监测转诊在风险组之间并不统一。当将CD4₂₀₀病例用作反向推算的基础时，CD4₂₀₀病例的漏查是个问题。需要更多关于从HIV血清转化至CD4₂₀₀诊断的潜伏期分布的信息。CD4₂₀₀/艾滋病病例数量可能是已诊断艾滋病病例数量的两倍。
