There is an increased risk of AIDS-related diseases or death among HIV-positive people with relatively high CD4 cell counts, a U.K. research team reports. These findings, the authors suggest in the August 20 issue of AIDS, speak to the growing need for studies exploring the value of starting HIV treatment earlier than is currently recommended.

Compared to those with CD4s above 650, HIV-positive people not on treatment with counts between 500 and 649 face a 55 percent increased risk of AIDS or death, the 25,274-patient U.K. Collaborative HIV Cohort (CHIC) found. The most common AIDS complications seen in patients with CD4s higher than 350 were Kaposi’s sarcoma (KS), Pneumocystis pneumonia (PCP), thrush and tuberculosis. Death rates, whether from from AIDS or non-AIDS causes, were not broken out separately by the investigators.

With studies such as this one showing a notable risk of AIDS and death among positive people with relatively healthy immune systems—along with results from the SMART study and other trials showing higher rates of AIDS, death, cardiovascular disease, and kidney problems among those not on HIV treatment, even those with higher CD4 counts—the CHIC study authors expressed the need for research exploring the benefits and risks of starting treatment with CD4s of 500 or higher. According to guidelines issued by the U.S. Department of Health and Human Services, starting antiretroviral therapy is currently recommended for all HIV-positive people with CD4 counts between 200 and 350.