Outcomes for HIV-positive patients taking antiretroviral therapy in the UK have improved significantly in recent years, and are projected to continue to do so until at least 2012, according to a report in HIV Medicine.
Mortality rates fell in real terms, and the number of patients with a CD4 cell count below 200 cells/mm3 was halved. Although the proportion of individuals experiencing triple-class treatment failure increased, 52% of such patients nevertheless had an undetectable viral load.
“The success of ART [antiretroviral therapy] has improved markedly over the period 2000-2007, with five in every six ART-treated patients having a viral load < 50 copies/ml. Nine in 10 of all patients now have a CD4 count above the particularly high risk level of 200 cells/mm3”, comment the investigators.
Investigators undertook to their study to see if outcomes for HIV-positive patients in the UK were being maintained, or even improved. They monitored key indicators of the success of antiretroviral therapy from 2000-2007: mortality; low CD4 cell count; multi-class resistance; and detectable viral load.
They also designed a computer model to project future outcomes amongst patients in the UK until 2012.
Information for the study was obtained from the UK Collaborative HIV Cohort (UK-CHIC), as well as the Health Protection Agency’s Survey of Prevalent HIV Infections Diagnosed (SOPHID) study.
The number of patients in the UK-CHIC increased by over 50%, from 9041 in 2000 to 14, 812 in 2007.
When these figures were combined with data from the HPA, it was projected that the total number of patients receiving HIV care in the UK would increase to 74,000 by 2012, of whom 73% would be taking antiretroviral therapy.
By 2007, 81% of patients with experience of antiretroviral therapy had taken an NNRTI, 56% a protease inhibitor, and 39% had experience of treatment with all three of the original classes of anti-HIV drugs.
There was a substantial fall in the proportion of patients with a CD4 cell count below 200 cells/mm3 (19% in 2000, 8% in 2007). This was accompanied by an increase in the percentage of patients taking HIV therapy who had a viral load below 50 copies/ml (62% in 2000, 83% in 2007).
The observed annual number of deaths amongst patients with HIV remained stable between 2000-2007, and the computer model suggested that there would be no substantial increase through to 2012. The investigators comment, “there is no apparent increasing trend in the numbers of deaths, despite the increasing number of people infected with HIV, indicating a decrease in the death rate.”
Nevertheless, there was an increase in the number of patients with experience of the three main classes of antiretrovirals (35% in 2000, 39% in 2007). Moreover, the proportion of patients extensively exposed to all three classes also rose from 14% in 2000 to 19% in 2007.
Based on data from the UK-CHIC, the investigators estimated that the proportion of patients with extensive triple class treatment failure increased from 1% in 2000 to 4% in 2007.
The success of ART [antiretroviral therapy] has improved markedly over the period 2000-2007, with five in every six ART-treated patients having a viral load < 50 copies/ml. Researchers from UK-CHIC and SOPHID
However, improvements in HIV treatment meant that the proportion of patients who had experienced extensive treatment failure who had a detectable viral load fell from 80% in 2000 to 48% in 2007.
“This decrease is projected to continue as more patients start newer drugs, including those from the newly available classes such as integrase inhibitors and perhaps CCR5 antagonists”, write the researchers.
Such a fall in the number of treatment-experienced patients with a detectable viral load is likely to have public health benefits. The investigators comment, “our results have positive implications for future transmission of resistant virus, with the proportion of new infections with resistant virus predicted to remain low.”
The researchers believe that the improvements in outcomes between 2000 and 2007 are “remarkable”. They conclude that newly licensed drugs and future developments in HIV treatment and care will mean that further improvements in outcomes are likely for extensively treated patients.
Bansi L et al. Trends over calendar time in antiretroviral treatment success and failure in HIV clinic populations. HIV Medicine 11: 432-38, 2010.