Effects of subcutaneous IL-2 therapy on telomere lengths in PBMC in HIV-infected patients

In this study we investigated the effect of interleukin-2 (IL-2) on mean te rminal restriction fragment (TRF) lengths in peripheral blood mononuclear c ells (PBMC). Ten human immunodeficiency virus (HIV)-infected individuals we re included and IL-2 was administered subcutaneously with 3 x 10(6) IU thre e times a week for 24 weeks. Mean TRF length was decreased on average by 26 7 bp at week 4 (P = 0.03) and 286 bp at week 8 (P = 0.09). Individual TRF c hanges at weeks 12, 16, 20 and 24 were highly variable. However, in the 12 weeks following therapy, TRF lengths generally increased reaching baseline levels by the end of the study. At baseline, mean TRF lengths were positive ly correlated to the ratio of naive and memory phenotype within both CD4(+) and CD8(+) cells. This study shows that IL-2 treatment induces transient s hortened mean TRF lengths in PBMC from HIV-infected individuals, indicating that IL-2 enhances the lymphocyte count by peripheral proliferation or rec ruitment of memory T cells into the blood.