Treatment guidelines that recommend antiretroviral therapy in all adults with CD4 cell counts below 200 cells/mm3 are not being followed by one in five individuals with severe immunosuppression, according to data presented by the Health Protection Agency (HPA) to the Twelfth Annual Conference of the British HIV Association (BHIVA) in Brighton last month. Of particular concern is that 70% were not due to late diagnosis, and there was much regional variation, with the highest proportion not on treatment in the North East and South West of England.
Since 2001, British HIV Association (BHIVA) treatment guidelines have recommended that highly active antiretroviral therapy (HAART) should be commenced prior to CD4 cell counts falling below 200 cells/mm3. Several large cohort studies have found that the short-term risk of illness or death is much greater at these lower CD4 cell counts, but a BHIVA re-audit examining patients starting therapy at UK clinics in 2004, presented at BHIVA's London conference last Autumn, found that 62% of patients commenced HAART once CD4 cell counts had fallen below 200 cells/mm3, including 22% who did not commence HAART until their CD4 cell counts had fallen below 50 cells/mm3. Starting HAART at low CD4 cell counts was associated with recent (i.e. late) diagnosis.
The HPA collects demographic, immunologic, virologic, symptom and treatment-related data on every diagnosed HIV-positive individual seen for HIV-related treatment or care in England, Wales and Northern Ireland. This Survey of Prevalent HIV Infections Diagnosed (SOPHID) data was used to determine the percentage of diagnosed HIV-positive individuals with CD4 cell counts below 200 cells/mm3, who were not on anti-HIV treatment at one point in time in 2004, and to investigate possible reasons for this.
Out of 40,265 individuals reported to SOPHID in 2004, 35,242 (88%) adults aged over 15 had both CD4 and treatment-related data. Almost 5,000 (14%) had CD4 cell counts below 200 cells/mm3, of whom 950 (19%) were not receiving any antiretroviral therapy.
In univariable analysis, age, clinical stage of HIV disease, and geographical region of care were associated with not being on treatment (all p
Around 25% of all individuals between 15 and 34 years of age with CD4 counts below 200 cells/mm3 were not on antiretroviral therapy, whereas about 15% of individuals with low CD4 counts aged over 44 were not on anti-HIV treatment.
Individuals who were asymptomatic were more likely not to be on treatment compared with those who were symptomatic and/or had an AIDS diagnosis. Although not all deaths were reported to SOPHID in 2004, more than 50% of individuals reported to have died in 2004 with CD4 cell counts below 200 cells/mm3 were not on antiretroviral therapy.
There was a significant variation between regions - from 36% and 30% not on therapy in the North East and South West of England, respectively, to 9% not on therapy in Northern Ireland - and multivariable analysis did not find these differences could be explained by a different case mix of patients.
The HPA also considered more comprehensive data from London, in order to assess how many individuals were not on therapy due to recent (i.e. late) diagnosis, and found that about 30% of individuals were diagnosed within three months. The HPA also compared their 2004 SOPHID data to their 2003 data and found that 53% of individuals with low CD4 cell counts who were not on antiretroviral therapy in 2004 had CD4 cell counts below 200 cells/mm3 in 2003 and should, therefore, have been recommended therapy before 2004.
Tim Chadborn, presenting, concluded that one in five diagnosed HIV-positive individuals with CD4 cell counts below 200 cells/mm3 were not on any antiretroviral therapy in 2004; that individuals with HIV-related symptoms and AIDS were more likely to be on antiretrovirals than asymptomatic individuals; that older individuals were more likely to be on treatment; and that differences in case mix between regions did not explain all of the differences in proportions with low CD4 cell counts not on treatment.
Of concern, and requiring further investigation, he said, was that more than half of diagnosed HIV-positive individuals with low CD4 cell counts in 2004 and not on treatment, who were also seen in 2003, had low CD4 cell counts in 2003 and should have already have been on therapy.
Chadborn T et al. Adults with low CD4 cell counts that were not receiving antiretroviral therapy in England, Wales and Northern Ireland in 2004. HIV Med 7 (supplement 1), abstract O01, 2006.