Gay men choose to start anti-HIV therapy earlier than individuals from other HIV risk groups and go on to have a better immunological response to antiretroviral treatment, French investigators report in the November edition of HIV Medicine. “The better biological prognosis of homosexual patients in our cohort suggests that early treatment is beneficial”, comment the investigators, a statement in line with a recent recommendation from some the world’s leading HIV physicians that HIV therapy should be started when patients have a CD4 cell count above 350 cells/mm3.
The benefits of potent antiretroviral therapy are well known. Indeed, many doctors are now hopeful that the timely and appropriate use of anti-HIV drugs will enable HIV-positive individuals to live a normal life span.
But even in countries where there is widespread access to HIV therapy, not all individuals who could benefit from antiretroviral drugs are accessing them. Studies have found that gay men are more likely to access HIV therapy than injecting drug users, and there are conflicting data regarding the response to antiretroviral treatment in gay men and heterosexuals.
French investigators were concerned that studies looking at responses to HIV therapy may have had methodological limitations. In particular, studies have tended to group all patients who start HIV therapy together and have not differentiated between those who needed to start HIV therapy immediately due to late disease diagnosis and individuals who have been receiving long-term HIV care.
They therefore designed a study involving over 5,000 patients enrolled on the French national HIV database and receiving free care at 62 hospitals across the country. They wished to determine if gender and HIV transmission group influenced the timing of elective anti-HIV therapy; and, if the timing of elective HIV therapy had an effect on individuals’ immunological, virological and clinical response to treatment.
The study involved patients who received care between 1997 and 2001. To ensure that patients who needed to start HIV treatment due to late diagnosis were not included in their analysis, the investigators excluded all individuals who started HIV therapy within three months of entry onto the HIV national database, or who received an AIDS diagnosis within this time period.
Investigators wished to see if there was any difference between transmission groups in the amount of time it took for the CD4 cell count to increase by 100 cells/mm3, for viral load to fall below 500 copies/ml, and if any group of patients was more likely to progress to AIDS or death despite the use of potent HIV drugs. Follow-up was until the end of 2002.
A total of 2,491 patients who met the investigators’ criteria started antiretroviral therapy. Gay men started HIV therapy with a higher CD4 cell count than all other groups (p
Two years after entry into the cohort, anti-HIV therapy had been started by a higher proportion of gay men than any other risk group (38%, versus 33% heterosexuals, 31% injecting drug users, 30% others). The investigators calculated that heterosexuals were 16% less likely to commence anti-HIV therapy than gay men (p
An increase in CD4 cell count of at least 100 cells/mm3 was defined by the investigators as a satisfactory immunological outcome. Gay men reached this outcome significantly faster than all other groups of patients (p
At the end of follow-up in late 2002, gay men had higher CD4 cell counts than patients from all other risk groups (p
Gay men also achieved a favourable virological outcome - a viral load below 500 copies/ml - more rapidly than all the other groups of patients (p
A total of 169 new AIDS events and 40 deaths occurred during the study. The rate of disease progression was similar for all risk groups.
“Homosexual patients receive HAART earlier than heterosexual patients, injecting drug users and other patients and have a better immunological response”, write the investigators.
They note that over 50% of gay men started HIV therapy with a CD4 cell count above 350 cells/mm3 compared to 36% of heterosexuals and 34% of injecting drug users. They believe that this could explain the different immunological outcomes.
The investigators speculate that gay men may be offered HIV therapy earlier than other patient groups. They also suggest that gay men are more likely to accept HIV treatment when they are offered it.
Despite the finding that gay men have a better biological prognosis due to the earlier initiation of HIV therapy, the investigators say that until randomised controlled trials support commencement of HIV treatment at higher CD4 cell counts, treatment decisions should be made on an individual basis.
Fardet L et al. Influence of gender and HIV transmission group in initial highly active antiretroviral therapy prescription and response. HIV Med 7: 520 - 529, 2006.