title: Titre and affinity of propylthiouracil-induced anti-myeloperoxidase antibodies are closely associated with the development of clinical vasculitis.
abstract: Substantial evidences suggested that propylthiouracil (PTU) could induced anti-myeloperoxidase (MPO) antibodies in sera from patients with hyperthyroidism, however, only a subgroup of the PTU-induced anti-MPO antibody positive patients developed clinical evident vasculitis. The aim of this study is to compare the titres and affinities of PTU induced anti-MPO antibodies in sera from patients with hyperthyroidism with and without clinical vasculitis. Anti-MPO antibody positive sera from patients diagnosed hyperthyroidism with (n = 13) and without (n = 14) clinical evident vasculitis were collected. The titre was determined by MPO-ELISA and expressed as logarithm value (lgT). The affinity constant (aK) of anti-MPO IgG was measured by antigen inhibition assay. The titre and aK values were compared between patients with and without vasculitis. In patients with vasculitis, the mean lgT of anti-MPO antibodies was 3.62 +/- 0.66; the median aK was 4.47 x 10(7)M(-1). In patients without vasculitis, the mean lgT was 2.54 +/- 0.29; the median aK was 0.14 x 10(7)M(-1), and both were significant lower than those in patients with vasculitis (t = 5.464; P = 0.000 & z = -4.373; P = 0.000, respectively). We concluded that the titre and affinity of anti-MPO antibodies might be associated with the development of clinical vasculitis in patients with PTU-induced ANCA.
authors.affiliation: Department of Nephrology, Peking University First Hospital, Beijing, PR China.
authors.forename: Hua
authors.initials: H
authors.lastname: Ye
authors.forename: Ying
authors.initials: Y
authors.lastname: Gao
authors.forename: Xiao-Hui
authors.initials: XH
authors.lastname: Guo
authors.forename: Ming-Hui
authors.initials: MH
authors.lastname: Zhao
mesh_terms: D000293:Adolescent; D000328:Adult; D000906:Antibodies / Q000276:immunology*; D000915:Antibody Affinity / Q000276:immunology; D002648:Child; D005260:Female; D006801:Humans; D006980:Hyperthyroidism / Q000276:immunology; D007074:Immunoglobulin G / Q000276:immunology; D008297:Male; D008875:Middle Aged; D009195:Peroxidase / Q000276:immunology*; D011441:Propylthiouracil / Q000276:immunology*; D014657:Vasculitis / Q000276:immunology*
chemical_list: D000906:Antibodies; D007074:Immunoglobulin G; D011441:Propylthiouracil; D009195:Peroxidase