title: Derailed B cell homeostasis in patients with mixed connective tissue disease.
abstract: Mixed connective tissue disease (MCTD) is a systemic autoimmune disorder, characterized by the presence of antibodies to U1-RNP protein. We aimed to determine phenotypic abnormalities of peripheral B cell subsets in MCTD. Blood samples were obtained from 46 MCTD patients, and 20 controls. Using anti-CD19, anti-CD27, anti-IgD and anti-CD38 monoclonal antibodies, the following B cell subsets were identified by flow cytometry: (1) transitional B cells (CD19+CD27-IgD+CD38(high)); (2) naive B cells (CD19+CD27-IgD+CD38(low)); (3) non-switched memory B cells (CD19+CD27+IgD+); (4) switched memory B cells (CD19+CD27+IgD-); (5) double negative (DN) memory B cells (CD19+CD27-IgD-) and (6) plasma cells (CD19+CD27(high)IgD-). The proportion of transitional B cells, naive B cells and DN B lymphocytes was higher in MCTD than in controls. The DN B cells were positive for CD95 surface marker. This memory B cells population showed a close correlation with disease activity. The number of plasma cells was also increased, and there was an association between the number of plasma cells and the anti-U1RNP levels. Cyclophosphamide, methotrexate, and corticosteroid treatment decreased the number of DN and CD27(high) B cells. In conclusion, several abnormalities were found in the peripheral B-cell subsets in MCTD, which reinforces the role of derailed humoral autoimmune processes in the pathogenesis.
authors.affiliation: Department of Medicine, Department of Clinical Immunology, Medical and Health Science Center, University of Debrecen, Debrecen, Hungary.
authors.forename: A
authors.initials: A
authors.lastname: Hajas
authors.forename: S
authors.initials: S
authors.lastname: Barath
authors.forename: P
authors.initials: P
authors.lastname: Szodoray
authors.forename: B
authors.initials: B
authors.lastname: Nakken
authors.forename: P
authors.initials: P
authors.lastname: Gogolak
authors.forename: Z
authors.initials: Z
authors.lastname: Szekanecz
authors.forename: E
authors.initials: E
authors.lastname: Zold
authors.forename: M
authors.initials: M
authors.lastname: Zeher
authors.forename: G
authors.initials: G
authors.lastname: Szegedi
authors.forename: E
authors.initials: E
authors.lastname: Bodolay
mesh_terms: D000305:Adrenal Cortex Hormones / Q000008:administration & dosage; D015703:Antigens, CD / Q000378:metabolism; D001323:Autoantibodies / Q000097:blood; D016175:B-Lymphocyte Subsets / Q000187:drug effects / Q000276:immunology*; D002478:Cells, Cultured; D003520:Cyclophosphamide / Q000008:administration & dosage; D018450:Disease Progression; D006706:Homeostasis / Q000187:drug effects; D006801:Humans; D017578:Immunoglobulin Class Switching; D007156:Immunologic Memory; D016130:Immunophenotyping; D008727:Methotrexate / Q000008:administration & dosage; D008947:Mixed Connective Tissue Disease / Q000188:drug therapy / Q000276:immunology*; D010950:Plasma Cells / Q000187:drug effects / Q000276:immunology*; D017412:Ribonucleoprotein, U1 Small Nuclear / Q000276:immunology
chemical_list: D000305:Adrenal Cortex Hormones; D015703:Antigens, CD; D001323:Autoantibodies; D017412:Ribonucleoprotein, U1 Small Nuclear; D003520:Cyclophosphamide; D008727:Methotrexate