title: A reduced IL2R (CD25) expression level in first and second degree female relatives of autoimmune thyroid disease patients. A sign of a poor capability to preserve tolerance?
abstract: There is room for immune markers other than TPO-Abs to identify an increased risk to develop autoimmune thyroid disease (AITD). Our aim was to test the hypothesis that activation of CD4+ T cells is such marker in relatives of AITD patients, who have an increased risk to develop AITD. We established a controlled study on 20 TPO-Ab positive and 20 TPO-Ab negative euthyroid female relatives. All these cases had at least one 1st or 2nd degree relative with a documented autoimmune hyper- or hypothyroidism in whom we studied the percentages of circulating subsets of activated (MHC class-II, CD25 (IL-2R), CD71 or CD69+) CD4+ T cells and the level of the soluble (s)-IL2R in serum. We found that euthyroid female relatives did not show an activation of their T cell system, but a reduced expression of CD25 on CD4+ T cells. The level of the shed IL2R in serum was also lower in comparison with levels found in healthy control females. A reduced T cell activity was found in both TPO-Ab positive and negative relatives. In conclusion, female relatives with at least one 1st or 2nd degree relative with an AITD show signs of a reduced expansion capability of their T cell pool. It is hypothesized that this reduced expansion capability may affect T cell tolerance mechanisms more than T effector mechanisms.
authors.affiliation: Academic Medical Center, University of Amsterdam, Department of Endocrinology, 1105 AZ, Amsterdam Zuidoost, The Netherlands.
authors.forename: Thea G A
authors.initials: TG
authors.lastname: Strieder
authors.forename: H A
authors.initials: HA
authors.lastname: Drexhage
authors.forename: W K
authors.initials: WK
authors.lastname: Lam-Tse
authors.forename: M F
authors.initials: MF
authors.lastname: Prummel
authors.forename: J G P
authors.initials: JG
authors.lastname: Tijssen
authors.forename: W M
authors.initials: WM
authors.lastname: Wiersinga
mesh_terms: D000328:Adult; D001323:Autoantibodies / Q000097:blood; D001324:Autoantigens / Q000276:immunology; D015415:Biomarkers / Q000097:blood; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D016022:Case-Control Studies; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007453:Iodide Peroxidase / Q000276:immunology; D033862:Iron-Binding Proteins / Q000276:immunology; D008213:Lymphocyte Activation; D008875:Middle Aged; D015375:Receptors, Interleukin-2 / Q000097:blood*; D012307:Risk Factors; D017634:Self Tolerance; D016176:T-Lymphocyte Subsets / Q000276:immunology; D013967:Thyroiditis, Autoimmune / Q000235:genetics* / Q000276:immunology*
chemical_list: D001323:Autoantibodies; D001324:Autoantigens; D015415:Biomarkers; D033862:Iron-Binding Proteins; D015375:Receptors, Interleukin-2; C056658:TPO protein, human; D007453:Iodide Peroxidase