Response to antiretroviral therapy: improved survival associated with CD4 above 500 cells/μl.
ABSTRACT We investigated the association between immune response and mortality in four HIV African programs supported by Médecins Sans Frontières.
Multicentric retrospective cohort study.
All antiretroviral therapy (ART) naive adults (>15 years) who initiated therapy between March 2001 and November 2010 and receiving therapy for 9 months or more were included. We described the evolution of mortality over time. Mixed Poisson models were used to assess the effect of updated CD4 cell counts and other potential risk factors on mortality.
A total of 24 037 patients, of which 68% were women, contributed 69 516.2 person-years of follow-up. At ART initiation, 5718 patients (23.7%) were classified as WHO clinical stage 4, 1587 (6.6%) had a BMI below 16 kg/m and 2568 (10.7%) had CD4 cell count below 50 cells/μl. A total of 568 (2.4%) deaths were recorded during the study period. In the CD4 response categories 500 cells/μl or more, 350-499, 200-349, 50-199 cells/μl and less than 50 cells/μl, unadjusted mortality rates were 0.36; 0.58; 0.88; 1.91 and 7.43 per 100 person-years, respectively. In multivariate analysis, higher mortality was observed in patients with CD4 response levels 350-499 cells/μl [adjusted hazard ratio (aHR) 1.70, 95% confidence interval (CI) 1.26-2.30] and for those between 200-349 (aHR 2.56; 95% CI 1.93-3.38), compared to those with 500 cells/μl or more.
The observed higher survival of patients with a CD4 response to ART higher than 500 cells/μl supports the need of further research to evaluate the individual benefit of initiating ART at higher CD4 levels in sub-Saharan Africa.
Article: Laboratory and clinical predictors of disease progression following initiation of combination therapy in HIV-infected adults in Thailand.[show abstract] [hide abstract]
ABSTRACT: Data on determinants of long-term disease progression in HIV-infected patients on antiretroviral therapy (ART) are limited in low and middle-income settings. Effects of current CD4 count, viral load and haemoglobin and diagnosis of AIDS-defining events (ADEs) after start of combination ART (cART) on death and new ADEs were assessed using Poisson regression, in patient aged ≥ 18 years within a multi-centre cohort in Thailand. Among 1,572 patients, median follow-up from cART initiation was 4.4 (IQR 3.6-6.3) years. The analysis of death was based on 60 events during 6,573 person-years; 30/50 (60%) deaths with underlying cause ascertained were attributable to infections. Analysis of new ADE included 192 events during 5,865 person-years; TB and Pneumocystis jiroveci pneumonia were the most commonly presented first new ADE (35% and 20% of cases, respectively). In multivariable analyses, low current CD4 count after starting cART was the strongest predictor of death and of new ADE. Even at CD4 above 200 cells/mm(3), survival improved steadily with CD4, with mortality rare at ≥ 500 cells/mm(3) (rate 1.1 per 1,000 person-years). Haemoglobin had a strong independent effect, while viral load was weakly predictive with poorer prognosis only observed at ≥ 100,000 copies/ml. Mortality risk increased following diagnosis of ADEs during cART. The decline in mortality rate with duration on cART (from 21.3 per 1,000 person-years within first 6 months to 4.7 per 1,000 person-years at ≥ 36 months) was accounted for by current CD4 count. Patients with low CD4 count or haemoglobin require more intensive diagnostic and treatment of underlying causes. Maintaining CD4 ≥ 500 cells/mm(3) minimizes mortality. However, patient monitoring could potentially be relaxed at high CD4 count if resources are limited. Optimal ART monitoring strategies in low-income settings remain a research priority. Better understanding of the aetiology of anaemia in patients on ART could guide prevention and treatment.PLoS ONE 01/2012; 7(8):e43375. · 4.09 Impact Factor