title: Association between larger thymic size and higher thymic output in human immunodeficiency virus-infected patients receiving highly active antiretroviral therapy.
abstract: To examine the impact of thymic size on immune recovery in patients with human immunodeficiency virus (HIV) infection, the thymus was visualized, using computed tomographic scans, in 25 HIV-infected patients who had received highly active antiretroviral therapy (HAART) for 6-18 months and had levels of viremia <500 copies/mL. For comparison, 10 control subjects were included in the study. Total and naive CD4+ cell counts were determined by flow cytometry. To determine thymic output, the number of CD4+ cells containing T cell receptor excision circles (TRECs) was measured. Qualitative immune recovery was evaluated by determination of CD4+ T cell receptor repertoire in 19 of the HIV-infected patients. Larger thymic size was associated with higher CD4+ cell counts (r=0.498; P=.011) and higher CD4+ TREC frequency (r=0.652; P<.001). Furthermore, patients with abundant thymic tissue seemed to have broader immunologic repertoires, compared with patients with minimal thymic tissue (P=.054). These findings suggest that thymopoiesis is ongoing in the adult thymus and contributes to immune reconstitution in HIV-infected patients receiving HAART.
authors.affiliation: Department of Infectious Diseases, Hvidovre Hospital, 2650 Hvidovre, Denmark.
authors.forename: Lilian
authors.initials: L
authors.lastname: Kolte
authors.forename: Anne-Mette
authors.initials: AM
authors.lastname: Dreves
authors.forename: Annette K
authors.initials: AK
authors.lastname: Ersbøll
authors.forename: Charlotte
authors.initials: C
authors.lastname: Strandberg
authors.forename: Dorthe L
authors.initials: DL
authors.lastname: Jeppesen
authors.forename: Jens O
authors.initials: JO
authors.lastname: Nielsen
authors.forename: Lars P
authors.initials: LP
authors.lastname: Ryder
authors.forename: Susanne D
authors.initials: SD
authors.lastname: Nielsen
mesh_terms: D000328:Adult; D023241:Antiretroviral Therapy, Highly Active; D018791:CD4 Lymphocyte Count; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D015658:HIV Infections / Q000000981:diagnostic imaging / Q000188:drug therapy* / Q000276:immunology* / Q000821:virology; D015497:HIV-1 / Q000276:immunology; D006801:Humans; D008297:Male; D008875:Middle Aged; D011859:Radiography; D011948:Receptors, Antigen, T-Cell / Q000378:metabolism; D013950:Thymus Gland / Q000000981:diagnostic imaging* / Q000502:physiology*; D015898:Tomography Scanners, X-Ray Computed
chemical_list: D011948:Receptors, Antigen, T-Cell