Thymopoiesis in HIV-infected adults after highly active antiretroviral therapy.

Journal Article (Journal Article)

The thymus of HIV-seropositive patients can enlarge as CD4+ T cell counts increase on highly active anti-retroviral therapy (HAART). This may indicate development of new T cells or represent mature peripheral T cells recirculating to the thymus. To define the etiology of the enlargement, the thymuses of two HIV-infected individuals on HAART were biopsied. For more than 3 years before initiation of HAART, both patients (38 and 41 years of age) had documented CD4+ T lymphopenia. Peripheral blood samples were obtained to assess circulating CD4+ CD45RA+ CD62L+ T cells, which were thought to have recently developed in the thymus. Peripheral blood T cells from both patients and thymocytes from the second patient were also tested for levels of DNA episomes formed during T cell receptor gene rearrangement (T cell receptor rearrangement excision circles, TRECs). With HAART, peripheral blood CD4+ T cell counts increased from approximately 60/mm(3) to 552/mm(3) and 750/mm(3) for patients 1 and 2, respectively. Thymic biopsies from both patients showed normal thymus histology with active thymopoiesis. Percentages of peripheral blood CD4+ CD45RA+ CD62L+ T cells and quantitation of T cell TRECs also reflected active thymopoiesis in both patients. Thus, in these two HIV-seropositive adults examined after initiation of HAART, thymic enlargement represented active thymopoiesis. Thymopoiesis in adult AIDS patients may contribute to immune reconstitution even after prolonged CD4+ T lymphopenia.

Full Text

Duke Authors

Cited Authors

  • Markert, ML; Alvarez-McLeod, AP; Sempowski, GD; Hale, LP; Horvatinovich, JM; Weinhold, KJ; Bartlett, JA; D'Amico, TA; Haynes, BF

Published Date

  • November 20, 2001

Published In

Volume / Issue

  • 17 / 17

Start / End Page

  • 1635 - 1643

PubMed ID

  • 11779351

Pubmed Central ID

  • 11779351

International Standard Serial Number (ISSN)

  • 0889-2229

Digital Object Identifier (DOI)

  • 10.1089/088922201753342040


  • eng

Conference Location

  • United States