CD4+ T-lymphocytes natural decrease in HAART-naïve HIV-infected adults in Abidjan

Area of Science:

• Immunology
• Public Health
• Epidemiology

Background:

• Human Immunodeficiency Virus (HIV) infection leads to a decline in CD4+ T-lymphocyte counts, crucial for immune function.
• Understanding the natural history of CD4+ T-cell decline in untreated HIV-infected individuals is vital for disease management and treatment strategies.

Purpose of the Study:

• To investigate the rate of natural CD4+ T-cell decline in HIV-infected adults in sub-Saharan Africa.
• To identify factors influencing this decline, particularly in the absence of severe morbidity or highly active antiretroviral therapy (HAART).

Main Methods:

• A 7-year prospective cohort study involving biannual CD4+ T-cell measurements.
• Joint modeling approach combining a linear mixed model for CD4+ T-cell changes and a survival model for drop-out.
• Follow-up was censored at severe morbidity events or initiation of HAART.

Main Results:

• The rate of CD4+ T-cell decline was primarily associated with follow-up duration and baseline body mass index (BMI).
• Mean annual CD4+ T-cell decrease varied significantly with baseline BMI: -81/mm³ (-2.2%) for BMI 16 kg/m², -69/mm³ (-1.7%) for BMI 20.4 kg/m², and -55/mm³ (-1.2%) for BMI 25 kg/m².
• A steeper CD4+ T-cell decline was independently linked to shorter event-free follow-up periods.

Conclusions:

• The natural CD4+ T-cell decrease in sub-Saharan African adults, before HAART initiation and without severe morbidity, is comparable to rates observed in industrialized countries.
• Close monitoring of CD4+ T-cell counts is recommended for adults with low BMI in sub-Saharan African settings, where measurements may be less frequent.