Influence of age on CD4 cell recovery in human immunodeficiency virus-infected patients receiving highly active antiretroviral therapy: Evidence fromthe EuroSIDA study

Influence of age on the CD4 cell response to highly active antiretroviral t herapy (HAART) was examined in 1956 patients (median age, 37.2 years) in th e EuroSIDA study. Median initial CD4 cell count was 192 X 10(6) cells/L, fo llow-up was 31 months, and time to maximum CD4 cell response was 20 months. Age groups were not different for baseline CD4 cell count, baseline human immunodeficiency virus RNA load, or treatment history. CD4 cell increase, s tratified by age quartiles, differed during months 3-36 of HAART (P = .023) . Maximum CD4 cell increase from start of HAART differed by age group (P = .0003), as did maximum CD4 cell count (P < 10(-4)). Multivariate analysis c onfirmed the inverse relationship between age and maximum CD4 cell response (P = .023). Time to a CD4 increase of >200 X 10(6) cells/L was shorter for patients in the younger age groups (P = .0026), as confirmed by multivaria te analysis (P < 10(-4)). Younger age may favor CD4 cell restoration becaus e of preserved thymic function.