More Evidence Points to Benefits of Early Antiretroviral Therapy

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The latest data come from a study by researchers at s Hopkins University in Baltimore, reported in the February 1, 2007 issue of Clinical Infectious Diseases.

R D and J C Keruly. CD4+ cell count 6 years after commencement of highly active antiretroviral therapy in persons with sustained virologic suppression. Clinical Infectious Diseases 44(3): 441-446. February 1, 2007.

Conclusion

The authors concluded that only patients with baseline CD4 cell counts above 350 cells/mm3 returned to nearly normal CD4 counts after 6 years of follow-up.

"Significant increases were observed in all CD4+ cell count strata during the first year, but there was a lower plateau CD4+ cell count at lower baseline CD4+ cell strata," they wrote.

"These data suggest that waiting to start HAART at lower CD4+ cell counts will result in the CD4+ cell count not returning to normal levels."

Methods

The investigators characterized the increase in CD4 cell counts among participants in the s Hopkins HIV Clinical Cohort who maintained sustained virological suppression (HIV RNA < 400 copies/mL) on HAART for up to 6 years. They also assessed the development of new AIDS-defining illnesses or death.

The analysis included 655 participants with a median age of 39 years; 69% were men, 70% were black, 38% had a history of injection drug use; 31% were men should had sex with men; and 22% were presumably infected with HIV via heterosexual transmission. Patients were stratified according to baseline CD4 count:

• 200 or fewer cells/mm3;• 201-350 cells/mm3;• more than 350 cells/mm3.

Results

• A total of 655 patients were observed for a median of 46 months (range 13-72 months).

• Longer duration of therapy was associated with a greater CD4 count response.

• The median increase from baseline to the most recent CD4 cell count measurement was 274 cells/mm3.• 92% of patients experienced an increase in their CD4 cell counts. • All baseline CD4 count groups experienced a significant increase in CD4 counts during the first 4 years on HAART, but reached a plateau during the final 2 years of the study.• By 6 years, the median CD4 cell counts were as follows:- 493 cells/mm3 among patients with baseline CD4 counts of 200 or less;- 508 cells/mm3 among those with baseline counts of 201-350;- 829 cells/mm3 among those with baseline counts above 350.• Proportions of patients achieving CD4 counts above 500 cells/mm3 after 6 years were as follows:- 42% of patients with baseline CD4 counts of 200 or less;- 66% of those with baseline counts of 201-350;- 85% of those with baseline counts above 350.• Proportions achieving CD4 counts above 750 cells/mm3 after 6 years were:- 12% of patients with baseline CD4 counts of 200 or less;- 21% of those with baseline counts of 201-350;- 46% of those with baseline counts above 350.• In addition to baseline CD4 cell count, injection drug use and older age were also associated with smaller CD4 cell increases.• CD4 cell increases did not differ based on patient sex, race/ethnicity, type of antiretroviral therapy (protease inhibitor vs NNRTI), or hepatitis C virus coinfection.