title: CD5+ B cells in Graves' disease: correlation with disease activity.
abstract: In the present paper the distribution of peripheral blood CD5+/CD19+ (CD5+B) and CD5-/CD19+ (CD5-B) B-lymphocytes in Graves' disease (GD) patients is analyzed in order to correlate them with disease activity, interleukin-2 (IL-2) and IL-6 binding to T and B cells as well as with anti-thyrotropin (TSH) receptor antibodies and the thyroid hormone serum levels. The combination of flow cytometry and 3-color immunofluorescence revealed a remarkable increase in the absolute numbers of CD5+ B cells in hyperthyroid-untreated GD patients (218 +/- 137 x 10(6)/l vs. 66 +/- 69 x 10(6)/l in healthy subjects, p < 0.01) that gradually fell to normal values once hyperthyroidism had been controlled by methimazole. However, relative numbers of CD5+ B cells persisted at a relatively stable but increased level in GD patients in long term remission of an average of 3.1 years. This was also confirmed in a follow-up study of a group of 12 newly diagnosed patients during the first 90 days of anti-thyroid drug therapy with methimazole. No correlation was observed between either CD5+ B cells or CD5- B cells and the serum levels of pathogenic anti-TSH receptor antibodies. Increased numbers of CD5+ B cells were related to the increased free thyroxine and total triiodothyronine serum levels. In addition, a strong correlation between both the absolute levels of B cells binding to exogenous IL-2 and IL-6 and the absolute number of CD5+ B cells in hyperthyroid GD patients (LR = 0.798, p < 0.001; LR = 0.569, p < 0.01, respectively) was observed. These results suggest that CD5+ B cells in GD are partly regulated by thyroid hormone serum levels as well as by IL-2 and IL-6 binding to B cells. Nevertheless, they are not involved, at least directly, in the production of anti-TSH receptor antibodies.
authors.affiliation: Servicio de Endocrinología, Universidad de Salamanca, Spain.
authors.forename: J J
authors.initials: JJ
authors.lastname: Corrales
authors.forename: A
authors.initials: A
authors.lastname: Orfao
authors.forename: A
authors.initials: A
authors.lastname: López
authors.forename: M T
authors.initials: MT
authors.lastname: Mories
authors.forename: J M
authors.initials: JM
authors.lastname: Miralles
authors.forename: J
authors.initials: J
authors.lastname: Ciudad
mesh_terms: D000328:Adult; D001402:B-Lymphocytes / Q000276:immunology*; D018956:CD5 Antigens / Q000032:analysis*; D005260:Female; D006111:Graves Disease / Q000276:immunology*; D006801:Humans; D007376:Interleukin-2 / Q000494:pharmacology; D015850:Interleukin-6 / Q000494:pharmacology; D008297:Male; D008875:Middle Aged; D011989:Receptors, Thyrotropin / Q000276:immunology
chemical_list: D018956:CD5 Antigens; D007376:Interleukin-2; D015850:Interleukin-6; D011989:Receptors, Thyrotropin