622    

Background:  In low resources settings, little information on CD4 count (CD4-C) and CD4 percentage (CD4-%) evolution is available. We studied factors associated with changes in CD4-C and CD4-% in HIV-infected adults in Côte d’Ivoire, Africa.

Methods:  Height-year prospective cohort studies of HIV-1 infected adults in Abidjan (Agence Nationale de Recherche sur le SIDA (ANRS) 1203 Study). CD4-C and CD4-% were measured at baseline and every 6 months. Patients were right-censored at first WHO stage 3 or 4 defining disease or at HAART initiation if prior to 08/31/2003. Baseline values and slopes of CD4-C and CD4-% were estimated using mixed models taking into account informative drop-out, and adjusted on baseline characteristics and cotrimoxazole (CMX) prophylaxis as a time-dependant variable.

Results:  We followed up 687 patients during a median of 30 months. Seventy-five patients died, 64 were lost to follow up, and 491 were censored because of a World Health Organization (WHO) stage 3 or 4 event (n = 441) and highly active antiviral therapy (HAART) initiation (n = 50). We reviewed 2319 available CD4 measurements. The estimated baseline CD4-C and CD4-% were 304/mm³ (95% confidence interval [CI] 285; 325) and 16.4% (95% CI 15.5; 17.2), respectively. The estimated slopes of CD4-C and CD4-% were -3.4/mm³/month and -0.11%/month, respectively. In the adjusted model, the baseline CD4-C and CD4-% were significantly lower in patients with lower hemoglobin (-1.68% and -1.12 Öcells/mm³ per -1g/100mL lower), lower body mass index (BMI) (-0.23% and -0.24/mm³ Öcells/mm³ per -1kg/m² lower), older age (-0.15% and -0.10 Öcells/mm³ per + 1 year older) and higher baseline WHO clinical stage (-4.0% and -2.50 Öcells/mm³ for patients at WHO stage > 3 with a past history of tuberculosis; -4.30% and -2.93 Öcells/mm³ for patients at WHO stage > 3 with ongoing active tuberculosis, compared with patients at WHO stage < 2). CMX prophylaxis was not significantly associated with CD4-C (p = 0.36) or CD4-% (p = 0.64). The only variable associated with changes in CD4 was the BMI (with a lower BMI being associated with steeper decline, p = 0.03 for CD4-% and p = 0.06 for CD4-C).

Conclusion:  In this longitudinal study of sub-Saharan African HIV-infected adults without antiretroviral therapy, CD4 level at a given time was associated with hemoglobin, BMI, age, and WHO clinical stage, and not with CMX prophylaxis. CD4 evolution was only associated with BMI. This suggests that when at least one CD4 measure is available, knowing BMI could be enough to estimate CD4 level in the absence of opportunistic disease and antiretroviral treatment.

Keywords: CD4 count; Longitudinal study; Sub-saharan africa