Starting antiretroviral therapy for HIV when CD4 counts are as high as 500 cells/µL reduces mortality risks by as much as 94%, according to several recent studies.
Current guidelines recommend treatment for asymptomatic patients who have a CD4 count <350. “This was formulated from data based on older medications that produced more side effects than current treatments,” researchers explain. “Current therapies cause fewer side effects and are better tolerated and more effective, so we can safely start treating patients earlier.”
The report details two studies involving 17,517 asymptomatic patients treated between 1996 and 2005. Twenty-two research groups at more than 60 sites in the United States and Canada collaborated on the data (N Engl J Med. 2009;360:1815-1826).
The first trial involved 8,362 patients, of whom 2,084 (25%) initiated therapy at a CD4 count of 351-500 and 6,278 (75%) deferred therapy. Patients in the deferred-therapy group had a 69% increased risk of death as compared with early therapy group.
In the other analysis of 9,155 different patients, 2,220 (24%) initiated therapy at a CD4 count >500 mm3 and 6,935 (76%) deferred therapy. This trial showed a 94% increase in the relative risk of death among the deferred-therapy group as compared with those who started the therapy earlier.
Meanwhile, British researchers published similar results in an unrelated analysis that involved 45,691 patients (Lancet. 2009;373:1352-1363). Deferring therapy until a CD4 count was between 251 and 350 was associated with a 28% higher rate of AIDS and death than starting therapy in the 351-450 range.
Many clinicians consider a higher threshold for starting therapy. A recent editorial states, “Five years ago, most experienced clinicians could have made an excellent case for treatment to be deferred. Today, if a similar patient were eager to start, we should be ready and willing to prescribe therapy—with ongoing careful monitoring of toxic effects that could arise during decades of treatment” (N Engl J Med. 2009;360:1897-1899).