Progression of HIV : follow-up of Edinburgh injecting drug users with narrow seroconversion intervals in 1983-1985

To describe progression and survival of individuals infected with HIV by injecting drug use in Edinburgh. From 313 HIV-infected patients with retrospectively estimated narrow seroconversion intervals, 260 infected via injecting drug use in the years 1983-1985 were selected for the study group. The effects of gender, age, human leukocyte antigen (HLA) type and zidovudine (ZDV) treatment on progression and survival from seroconversion; Weibull estimates of the AIDS incubation distribution and the overall survival distribution; slopes of absolute CD4 lymphocyte loss (on the square root scale) and loss of CD4 percentage. The cumulative progression rates at 10 years were 68% to CDC stage IV and 31% to AIDS with a mortality rate of 25%. Three-year survival rates for AIDS and CDC stage IV cases were 25 and 72%, respectively. Gender and age effects on progression or overall survival were not found, although those aged over 30 years experienced poorer survival from AIDS. A strong HLA (A1, B8, DR3) association with faster progression and poorer survival was found. Median survival was estimated by Weibull distribution to be 12.6 years; median AIDS-free time was estimated to be 11.6 years. CD4 cell loss was approximately linear when transformed to the square root scale as was the decline in CD4 percentage. Only HLA effects on slopes were found: A1,B8, DR3 was significantly associated with faster loss of both absolute CD4 cells and CD4 percentage (P < 0.001) and B27 was significantly associated with slower loss of CD4 percentage (P = 0.01). Edinburgh IDU do not seem to progress more rapidly than other cohorts with predominantly different risk activities. Older age was associated with poorer survival from AIDS but no gender effect was found for progression or overall survival. The clearest significant association with AIDS progression, mortality and loss of CD4 cells was the phenotype HLA A1,B8,DR3. In contrast HLA B27 was associated with slower loss of CD4 cells.