Differences in susceptibility to AIDS development: a cohort study of Danish and
American homosexual-bisexual men, 1981 to 1995.
Melbye M, Begtrup K, Rosenberg PS, Biggar RJ, Goedert JJ, Knudsen K, Andersen PK
J Acquir Immune Defic Syndr Hum Retrovirol 1998 Jul 1;18(3):270-6
We estimated the annual hazard rate for progression to AIDS as defined by the 1987 case definition in HIV-infected members of a cohort of Danish and American homosexual-bisexual men who were observed from 1981 to 1995. Furthermore, we extrapolated the hazard to 25 years based on imputed future time to AIDS. Of 201 HIV-positive subjects, 112 developed AIDS before the end of follow-up. The hazard increased rapidly during the first years following infection, attained a peak of about 15% per year at year 7, and was moderately lower during years 8 through 10. In subsequent analysis, we imputed future time to AIDS in 89 subjects who had not progressed by the end of follow-up by extrapolation from subject-specific CD4 trend lines. A CD4 count of < or = 100 cells/microl was the best surrogate for clinical AIDS. Under this model, the imputed AIDS hazard stabilized at around 8% per year after 10 years. We projected that 13% (95% confidence interval [CI], 8%-19%) of the infected men may remain free from AIDS 25 years after seroconversion. Our direct data suggest that incubation times reflect a mixture of a population that is susceptible to disease progression and has short incubation periods with a group that is relatively resistant. Based on an extrapolation model, > 10% of HIV-infected persons may survive for up to 25 years without developing AIDS.
PMID: 9665505, UI: 98328442