title: Correlation of increases in 1,25-dihydroxyvitamin D during vitamin D therapy with activation of CD4+ T lymphocytes in HIV-1-infected males.
abstract: BACKGROUND
  In HIV-1-infected individuals, levels of CD4+ T lymphocytes are depleted and regulatory T-lymphocytes (Tregs) are elevated. In vitro studies have demonstrated effects of vitamin D on the growth and differentiation of these cells. We speculated whether supplementation with vitamin D could have an effect on CD4+ T lymphocytes or Tregs in HIV-1-infected males.
  
  
  METHODS
  We conducted a placebo-controlled randomized study that ran for 16 weeks and included 61 HIV-1-infected males, of whom 51 completed the protocol. The participants were randomized to 1 of 3 daily treatments: (1) 0.5-1.0 µg calcitriol and 1200 IU (30 µg) cholecalciferol, (2) 1200 IU cholecalciferol, (3) placebo. Percentages of the following T-lymphocyte subsets were determined: naïve CD4+ and CD8+ cells, activated CD4+ and CD8+ cells, and CD3+CD4+CD25+CD127low Tregs. Furthermore 1,25-dihydroxyvitamin D, 25-hydroxyvitamin D, and parathyroid hormone were measured.
  
  
  RESULTS
  No significant changes of the studied T-lymphocyte subsets occurred in the treatment groups compared to the placebo group. Increases in 1,25-dihydroxyvitamin D were associated with increases in activated CD4+ T lymphocytes (P = .001) and Tregs (P = .01) in adjusted models. Changes in parathyroid hormone correlated inversely with Tregs (P = .02). Smokers had higher levels of naïve CD4+ T lymphocytes (37% vs 25%;P = .01), naïve CD8+ T lymphocytes (28% vs 19%; P = .03), and Tregs (9% vs 7%; P = .03).
  
  
  CONCLUSIONS
  Cholecalciferol and calcitriol administered during 16 weeks did not change the levels of T-lymphocyte fractions compared to placebo. However, increases in 1,25-dihydroxyvitamin D were associated with an expansion of activated CD4+ cells and Tregs.
authors.affiliation: Department of Endocrinology, Hvidovre Hospital, Copenhagen, Denmark. ulrichbangbang@gmail.com
authors.forename: Ulrich
authors.initials: U
authors.lastname: Bang
authors.forename: Lilian
authors.initials: L
authors.lastname: Kolte
authors.forename: Mette
authors.initials: M
authors.lastname: Hitz
authors.forename: Susanne
authors.initials: S
authors.lastname: Dam Nielsen
authors.forename: Louise Lind
authors.initials: LL
authors.lastname: Schierbeck
authors.forename: Ove
authors.initials: O
authors.lastname: Andersen
authors.forename: Steen B
authors.initials: SB
authors.lastname: Haugaard
authors.forename: Lars
authors.initials: L
authors.lastname: Mathiesen
authors.forename: Thomas
authors.initials: T
authors.lastname: Benfield
authors.forename: Jens-Erik Beck
authors.initials: JE
authors.lastname: Jensen
mesh_terms: D000163:Acquired Immunodeficiency Syndrome / Q000097:blood / Q000188:drug therapy / Q000276:immunology*; D000328:Adult; D023241:Antiretroviral Therapy, Highly Active; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D004311:Double-Blind Method; D015497:HIV-1; D006801:Humans; D016014:Linear Models; D008213:Lymphocyte Activation; D008297:Male; D008875:Middle Aged; D010281:Parathyroid Hormone / Q000097:blood; D050378:T-Lymphocytes, Regulatory / Q000276:immunology; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood / Q000627:therapeutic use*
chemical_list: D010281:Parathyroid Hormone; D014807:Vitamin D; C097949:1,25-dihydroxyvitamin D