[TuOrB1141] Low CD4 count predicts less durable virologic response to highly active antiretroviral therapy (HAART) in naïve patients

14th International AIDS Conference

Barcelona, Spain — July 7-12, 2002

[TITLE:] Low CD4 count predicts less durable virologic response to highly active antiretroviral therapy (HAART) in naïve patients

[AUTHOR(S):] Brooks,J.T.; Hanson,D.L.; McNaghten,A.D.; Swerdlow,D.L.¹

Int Conf AIDS. 2002 Jul 7-12;14:Abstract No. TuOrB1141

BACKGROUND: We sought to determine if plasma viral load (VL) reductions are less durable in HIV-infected persons with low CD4 counts, which could influence when to begin HAART.

METHODS: We examined the relationship between CD4 count at HAART initiation and virologic response in persons with no known history of prior HAART who began therapy after 1996. We used data from the ASD Project, which longitudinally abstracts medical records of HIV-infected persons >13 years old at >100 clinics in 11 U.S. cities. We analyzed the effect of CD4 count at HAART initiation, as well as other variables, on estimated time to virologic failure (VFAIL) using a log-logistic regression model and interval-censoring while controlling for demographics, AIDS-defining opportunistic infections, year of HAART intiation, baseline VL, and VL assay type. We defined VFAIL as >0.5 log₁₀ increase from VL nadir after HAART initiation followed by a 2nd equally or more elevated VL or by a switch in ART.

RESULTS: We identified 470 persons followed a median of 176 days (25-75% range: 71-318 days) after starting HAART. There were 31 (7%) virologic failures. The estimated probability of VFAIL by 6 months was 10.7% (95% confidence interval [CI] 6.6-15.7), 5.1% (95% CI 1.1-12.0), and 0.3% (95% CI 0.0-1.6) for persons with CD4 count 0-199, 200-349, and > 350 cells/mL, respectively. In mutivariate analysis, VFAIL occurred significantly earlier (at least 50% sooner) in persons with CD4 0-199 and 200-349 cells/mL compared to >350 cells/mL. The effect of CD4 count on time to VFAIL was independent of the effect of maximal VL decline after starting HAART.

CONCLUSIONS: HIV-infected persons with CD4 counts <350 cells/mL experience significantly less durable virologic responses to initial HAART. The small number of observations and potentially confounding effects of viral resistance and adherence to HAART limit our findings. Longer follow-up is suggested.

Presenting author: J T Brooks

1J T Brooks; Centers for Disease Control and Prevention, Division of HIV/AIDS Prevention, Centers for Disease Control and Prevention, 1600 Clifton Road, Atlanta, GA

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