F4/1 - PREDICTING THE LONG TERM SLOPE OF CD4+T-CELL COUNTS FOR DIFFERENT HIGHLY ACTIVE ANTIRETROVIRAL THERAPIES (HAART) IN THERAPY NAÏVE PATIENTS

9^TH EUROPEAN AIDS CONFERENCE (EACS)
1^st EACS RESISTANCE & PHARMACOLOGY WORKSHOP

October 25 - 29, 2003 Warsaw, Poland

7.7 Immunology and Virologic Limitations of HAART

F4/1 - PREDICTING THE LONG TERM SLOPE OF CD4+T-CELL COUNTS FOR DIFFERENT HIGHLY ACTIVE ANTIRETROVIRAL THERAPIES (HAART) IN THERAPY NAÏVE PATIENTS

* Gras L.¹, van de Wiel M.A.¹, van Valkengoed I.¹, van Sighem A.¹, Ghani A.C.², de Wolf F. (1,2) for the ATHENA observational cohort

(1) HIV Monitoring Foundation, Amsterdam, the Netherlands,² Department of Infectious Disease Epidemiology, Imperial College, London, U.K.

Background of Study: The short-term virological and immunological efficacy of HAART in the treatment of HIV infected patients has been demonstrated in clinical trials. The longer term immunological benefit of different regimens remain unknown.

Methods: 1069 patients starting first-line HAART containing a 3TC+d4T or 3TC+AZT backbone combined with either one NNRTI or one or two PI's were selected from the ATHENA observational cohort. The average slope of log CD4+T-cell count during initial HAART between 12 and 96 weeks was modelled using a two-level mixed effects model, adjusted for duration of regimen, CD4+T-cell count and HIV-RNA at 0 and 12 weeks, age, sex, risk group and year of initiating HAART.

Results: In the group of patients with >200 CD4 cells/mm³ after 12 weeks, the slope of log CD4+T-cell count was 0.0116 higher for 3TC+d4T (n=143) than for 3TC+AZT starting patients (n=592), (p=0.004). The slope was 0.0166 higher for NFV (n=129) than NVP starting patients (n=130), (p=0.045). CD4+T-cell count was estimated to increase between 12-96 weeks from 430 to 463 cells/mm³ for NFV patients and to 447 cells/mm³ for NVP patients. All other PI/NNRTI differences (IDV (n=164), IDV+RTV (n=40), SAQ (n=73), SAQ+RTV (n=38), RTV (n=90), KAL (n=34), EFV (n=37)) were non-significant. In the £200 CD4 cells/mm³ patient group (n=298) differences were non-significant.

Conclusions: Our results suggest that few clinically important differences exist in long term CD4+T-cell count between common regimens. Other factors e.g. toxicity, resistance, short term therapy effect should have priority when deciding which antiretroviral therapy to start. However, these findings require verification in larger cohorts.

Presenting Author: Luuk Gras, HIV Monitoring Foundation, Meibergdreef 9, 1105 AZ, Amsterdam, Netherlands, Phone: +31 20 5666781

031025
18