Background: To assess the association between the CD4 count and clinical diseases in a cohort of Thai patients.
Methods: In all, 1902 patients who presented with human immunodeficiency virus (HIV) infection at the Chulalongkorn University Hospital in Bangkok were investigated.
Results: At the time of presentation 295 (15.5%) patients had acquired immunodeficiency syndrome (AIDS) and there was a highly significant tendency for lower CD4 counts in this group (median 67/mm3) than in patients free of AIDS (median 369/mm3). A total of 757 patients had data available on follow-up and were free of AIDS at the first visit. During a median follow-up of 0.9 years, 110 developed AIDS or AIDS-related death (12.2/100 person years). Subjects with CD4 count < 200/mm3 at initial visit showed over a ninefold increase in risk of developing AIDS compared to subjects with levels > or = 500/mm3 (relative risk [RR] = 9.1; 95% CI: 5.4-16.0). The rate/100 person years was 47.1 compared with 6.0 in subjects with levels > or = 500/mm3. After adjusting for initial CD4 count, homosexual men showed over a twofold increase in risk of developing AIDS compared to heterosexuals (RR = 2.4; 95% CI: 1.6-4.4) and intravenous drug users (IVDU) showed nearly a twofold increase (RR = 1.8; 95% CI: 0.9-3.9). The increased risk in homosexual men persisted even after further adjustment for clinical stage (RR = 2.2; 95% CI: 1.3-3.7) but the increased risk in IVDU was attenuated (RR = 1.5; 95% CI: 0.7-3.2) although it remained increased albeit non-significantly. Men tended to progress faster to AIDS than women but the difference was not significant. However, the faster progression in homosexual men was seen even when compared to heterosexual men only.
Conclusion: The rate of progression of AIDS according to CD4 count group at baseline in this Thai cohort is broadly comparable with Western cohorts. It appears that heterosexuals in Thailand show slower progression to AIDS than homosexual men.
PIP: The natural history of HIV infection was investigated in a cohort of 1902 HIV-positive patients (median age, 29 years) seen at the Chulalongkorn University Hospital in Bangkok, Thailand, in 1985-90 in whom a CD4 count was performed at the initial visit. The majority (64%) were male heterosexuals; 10% were homosexual men, 10% reported intravenous drug use, and 16% were heterosexual women. At the time of study enrollment, 295 patients (15.5%) had progressed to AIDS. AIDS patients had a significantly lower CD4 count (median, 67/cu. mm) than those without AIDS (median, 369/cu. mm). Of the 757 patients who were AIDS-free at baseline and available for follow up (median time, 0.9 years), 110 developed AIDS or died from an AIDS-related cause (12.2/100 person-years). Tuberculosis was the major AIDS-defining illness in all risk groups. 50% of those with a CD4 count under 200/cu. mm at the initial visit developed AIDS within 2 years compared with 12% of those with levels of 500/cu. mm (relative risk (RR), 9.1; 95% confidence interval (CI), 5.4-16.0). The rates per 100 person-years were 47.1 and 6.0, respectively. After adjusting for initial CD4 count, homosexual men had a relative risk of developing AIDS of 2.4 (95% CI, 1.6-4.4) compared with heterosexuals; intravenous drug users had a relative risk of 1.8 (95% CI, 0.9-3.9). The increased risk in homosexual men persisted even after further adjustment for clinical stage (relative risk, 2.2; 95% CI, 1.3-3.7), but the increased risk in intravenous drug users was attenuated (RR, 1.5; 95% CI, 0.7-3.2). Older patients progressed faster to AIDS than younger patients, but there was no significant difference between men and women in the course of disease. These findings are consistent with those of studies conducted in Western countries indicating a slower progression to AIDS in heterosexual men than homosexuals and a correlation between CD4 count and rate of progression to AIDS.