Figure 2.

Adenosine deaminase (ADA)-induced costimulatory effect in different groups of human immunodeficiency virus 1 (HIV-1)-infected donors. (a, b) T cells from HIV-1-infected patients (n = 36) were stimulated with 1 ng/ml anti-CD3 for 7 days in the absence (anti-CD3) or presence of 4 μm ADA (anti-CD3 + ADA) and proliferation was determined as [³H]thymidine incorporation. Values are expressed as the stimulation index (SI), calculated as the ratio of [³H]thymidine incorporated in stimulated T cells versus non-stimulated T cells. (a) Comparison among healthy controls, highly active antiretroviral therapy (HAART)-treated patients and untreated patients. (b) Comparison among HAART-treated patients (group 1), untreated patients who were still responders (group 2) and untreated patients with a low response (group 3). (c) The main characteristics of the three groups of HIV-1-infected patients. (d) Main correlations found in the response to anti-CD3 plus ADA stimulation in groups 1 and 2. *P< 0·05; **P< 0·01; *** P< 0·001, by paired or unpaired Student’s t-test.