The potential for CD4 cell increases in HIV-positive individuals who control viraemia with highly active antiretroviral therapy.
OBJECTIVE
To study the long-term CD4 cell responses to highly active antiretroviral therapy (HAART) in treatment-naive patients whose viral loads remained below 500 copies/ml for prolonged periods.


METHODS
A total of 237 patients whose viral loads remained below 500 copies/ml for one year or more. Median follow-up was 1.9 years.


METHODS
CD4 cell counts were analysed to investigate long-term immunological response using mixed-effects models with the slope allowed to change after 1, 12 and 24 months of HAART.


RESULTS
The median baseline CD4 cell count was 175 cells/mm3. After an initial rapid increase in the first month after HAART (97.2 cells/mm3 a month), increases in CD4 cell counts continued less rapidly (11.6 cells/mm3 a month). This increase slowed by 2.4 cells/mm3 a month after one year. CD4 cell counts continued increasing after 2 years, but the rate of increase again slowed (estimated slope at 2 years 5.4 cells/mm3 a month; decrease in slope from year 2 compared with years 1-2 3.7 cell/mm3 a month). A total of 198 out of 211 patients (94%) with measurements at baseline and one year experienced an increase in CD4 cell counts in this interval; 81 and 67% had an increasing slope between 1 and 2 and 2 and 3 years, respectively. By the end of follow-up, CD4 cell counts had increased by 319 cells/mm3, and were more than 500 cells/mm3 in 40% of patients.


CONCLUSIONS
Although the rate of immune recovery slowed after 2 years, CD4 cell counts rose in most and began to return to levels seen in HIV-negative individuals.
Smith
Colette J
CJ
Royal Free Centre for HIV Medicine and Department of Primary Care and Population Sciences, Royal Free and University College Medical School, Royal Free Campus, London, UK. c.smith@pcps.ucl.ac.uk
Sabin
Caroline A
CA
Lampe
Fiona C
FC
Kinloch-de-Loes
Sabine
S
Gumley
Helen
H
Carroll
Anne
A
Prinz
Beth
B
Youle
Mike
M
Johnson
Margaret A
MA
Phillips
Andrew N
AN
D000328:Adult; D023241:Antiretroviral Therapy, Highly Active; D018791:CD4 Lymphocyte Count; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D005260:Female; D005500:Follow-Up Studies; D015658:HIV Infections / Q000188:drug therapy* / Q000276:immunology; D006801:Humans; D008297:Male; D019562:Viral Load; D014766:Viremia / Q000276:immunology / Q000517:prevention & control*