HAART has led to a sustained reduction in AIDS and death in EuroSIDA cohort

Data from the EuroSIDA cohort published in the July 4^th edition of The Lancet show that HAART has had a sustained effect in reducing the incidence of AIDS and death.

Investigators analysed data from 9,803 patients from 70 different HIV treatment centres in Europe, Argentina and Israel.

Rates of AIDS and death were calculated over three time periods: pre-HAART (1994-95), early HAART (1996 – 1998) and late HAART (1998 – 2002). Over 30,000 patients years of follow-up were available for analysis by the investigators.

The demographics of the patient population altered between 1994 and 2002, with the proportion of intravenous drug users falling from 26.8% of the cohort in the pre-HAART era to 22.9% in the late-HAART period. Patients became significantly less likely to have an AIDS-defining illness at the point of their recruitment to the cohort, and less likely to have required treatment or prophylaxis for an opportunistic infection (both p

Median CD4 cell count increased from 164 cells/mm³ during the first six month period of analysis in 1994-95, by approximately ten to 30 cells per six month period to 424 cells/mm³ amongst patients in the last period of follow-up.

The increase in CD4 cell count was accompanied by a decline in the incidence of AIDS and death from 43.5 per 100 patients years of follow-up in the first six months of analysis between 1994 and 95, to less than five per patient year of follow-up for the final study period in 2002.

A dramatic decline in the incidence of AIDS and death seen with the introduction of HAART in 1996 was sustained into the later HAART period, with a further 8% fall in AIDS or death for every six month period after September 1998.

After adjustment for CD4 cell count at recruitment, age, previous HAART treatment and AIDS at enrollment, the investigators found that the risk of an AIDS event or death still fell significantly from the pre-HAART (RH 1.31, 95% CI, 1.10 – 1.57, p= 0.0032), to the late-HAART period (RH 0.72, 95% CI, 0.58 – 0.90, p=0.0035).

Amongst patients with very advanced immune suppression and a CD4 cell count below 20 cells/mm³, the risk of death fell by 50% between the pre-HAART and late-HAART periods (p

”The results of this study with over 30,000 [patient years of follow-up] show that the combined incidence of AIDS and death has continued to fall in the later years of HAART”, note the investigators.

This could be explained partly by a dramatic increase in average CD4 cell count in the cohort, but the investigators also suggest a role for doctors becoming more experienced in the use of HAART. In particular, the investigators emphasise that doctors have increased experience of prescribing salvage therapy, explaining the falling mortality amongst patients with CD4 cell counts below 20 cells/mm³. Problems with side-effects and adherence do not appear to have resulted in increased morbidity and mortality, note the authors.

Changed causes of illness and death are commented on by the investigators, who note that “the illnesses associated with advanced HIV…disease during the early part of the epidemic… are now rarely seen, but diseases of specific organs (kidney, liver, heart) or non-AIDS-defining illnesses might arise more frequently and could be associated with substantial morbidity and mortality.”

The investigators conclude, “the introduction and continued use of HAART…has resulted in very low morbidity and mortality across Europe, suggesting that limitations of current treatment, including potential adverse effects of long-term HAART and problems with compliance, have not yet affected the clinical success of HAART”.

Further information on this website

AIDS deaths down, but new causes of death at largest UK HIV clinic - news story