title: Altered expression of chemokine receptor CXCR5 on T cells of myasthenia gravis patients.
abstract: Myasthenia gravis (MG) is characterized by the T cell-dependent production of anti-acetylcholine receptor (AChR) antibodies. The chemokine receptor CXCR5 regulates lymphocyte migration and is expressed on a subset of CD4+ T cells named follicular helper T cells (T(FH)), the key modulators of antibody production by B cells. We studied the frequency of CXCR5-positive lymphocytes in the peripheral blood of MG patients before and after therapy (thymectomy plus glucocorticoid). Before therapy, the MG patients showed a significantly higher frequency of CXCR5+ CD4+ T cells in the peripheral blood compared with the control group, while no significant difference in the percentages of CXCR5+ CD4+ T cells was observed between the patients of the hyperplasia group and those of the thymoma group. The CXCR5+ CD4+ T cell frequency correlated with the disease severity. The CXCR5+ CD4+ T cell frequency of MG patients positive for other autoantibodies together with anti-AChR antibodies was significantly higher than in those having only anti-AChR antibodies. After therapy, the CXCR5+ CD4+ T cell percentage decreased gradually to the control level with a significant inverse correlation between the CXCR5+ CD4+ T cell frequency and duration after the initiation of MG therapy. The CXCR5+ CD4+ T cell populations in the hyperplastic thymuses and thymomas were not significantly different from those in the control thymuses. These results suggest that CXCR5+ CD4+ T cells play an important role in the disease activity of MG and that some MG patients have a systemic abnormality in T cell-dependent antibody production.
authors.affiliation: Department of Neurology, Tohoku University School of Medicine, 1-1 Seiryo-Machi, Aobaku, Sendai 980-8574, Japan.
authors.forename: Ryuji
authors.initials: R
authors.lastname: Saito
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Onodera
authors.forename: Hideaki
authors.initials: H
authors.lastname: Tago
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Suzuki
authors.forename: Masayuki
authors.initials: M
authors.lastname: Shimizu
authors.forename: Yuji
authors.initials: Y
authors.lastname: Matsumura
authors.forename: Takashi
authors.initials: T
authors.lastname: Kondo
authors.forename: Yasuto
authors.initials: Y
authors.lastname: Itoyama
mesh_terms: D000328:Adult; D000368:Aged; D001402:B-Lymphocytes / Q000378:metabolism; D015496:CD4-Positive T-Lymphocytes / Q000378:metabolism; D018414:CD8-Positive T-Lymphocytes / Q000378:metabolism; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D018655:Lymphocyte Count; D008297:Male; D008875:Middle Aged; D009157:Myasthenia Gravis / Q000097:blood* / Q000473:pathology / Q000503:physiopathology / Q000628:therapy; D054380:Receptors, CXCR5; D019707:Receptors, Chemokine; D018121:Receptors, Cytokine / Q000097:blood* / Q000378:metabolism; D012720:Severity of Illness Index; D013601:T-Lymphocytes / Q000378:metabolism*; D013945:Thymoma / Q000097:blood / Q000378:metabolism; D013950:Thymus Gland / Q000378:metabolism / Q000473:pathology; D013953:Thymus Neoplasms / Q000097:blood / Q000378:metabolism
chemical_list: C095085:CXCR5 protein, human; D054380:Receptors, CXCR5; D019707:Receptors, Chemokine; D018121:Receptors, Cytokine