More evidence that antiretrovirals reduce the risk of non-HIV illnesses at lower CD4 cell counts

Antiretroviral treatment reduces the risk of serious non-HIV-related illness for patients with a CD4 cell count below 350 cells/mm³, according to a study conducted by investigators at Johns Hopkins University in the US and published in the October 15^th edition of Clinical Infectious Diseases.

HIV treatment guidelines in Europe and North America have recently been changed to recommend the initiation of HIV therapy once a patient’s CD4 cell count declines to around 350 cells/mm³. One of the main reasons for this recommendation was the realisation that patients with CD4 cell counts below this level had an increased risk of developing a number of illnesses not traditionally regarded as being related to HIV, such as heart, kidney and liver disease as well as some cancers.

The findings of the Johns Hopkins’ study broadly reflect those of the SMART study which found that patients taking a break from HIV treatment with a CD4 cell count below 350 cells/mm³ were more likely to develop both HIV and non-HIV-related illnesses.

Investigators from the Baltimore university studied the medical records of 2824 patients between 1997 and 2006. They looked at rates of non-HIV-related liver, kidney, heart, lung and neurological disease as well non-HIV-related cancers in these patients. They then examined individuals’ medical records to see if they could establish a link between these illnesses and the non-use of antiretroviral therapy and CD4 cell count.

A total of 817 serious non-HIV-related illnesses were observed. These illnesses were more common at lower CD4 cell counts, and were also more common amongst patients not receiving HIV treatment than those receiving anti-HIV drugs (p = 0.001).

Furthermore, not receiving antiretroviral therapy (compared to HIV treatment) was associated with a higher risk of such illnesses for patients with a CD4 cell count below 200 cells/mm³ (incidence rate, 2.7 per 100 person years vs. 1.2 per 100 person years, p = 0.0o1), and for patients with CD4 cell counts below 350 cells/mm³ (incidence rate 1.3 per 100 person years vs. o.6 per 100 person years, p = 0.002).

Patients with CD4 cell counts above 350 cells/mm³ were slightly more likely to develop serious non-HIV-related illnesses than if they were not taking HIV treatment, but the difference with patients taking anti-HIV drugs was not significant (0.8 per 100 person years vs. 0.5 per 100 person years, p = 0.18).

Other factors associated with an increased risk of non-HIV-related illnesses were age over 50, injecting drug use, and black race.

“This analysis provides evidence from clinical practice that HAART use is associated with a decreased risk of comorbidities not related to HIV infection…amongst patients with CD4 cell counts below 350 cells/mm³”, conclude the investigators, adding “HAART may have a protective effect on the occurrence of comorbidities not related to HIV infection or AIDS and may reduce the risk of AIDS-defining illness.”