title: Influence of myeloperoxidase-catalyzing reaction on the binding between myeloperoxidase and anti-myeloperoxidase antibodies.
abstract: In the current study, whether myeloperoxidase (MPO)-catalyzing reaction could influence the antigenicity of MPO was investigated. Hypochlorite acid, the main product of the catalytic reaction, could lower the binding between MPO-antineutrophil cytoplasmic antibodies (ANCA) and MPO when the available chlorine was higher than 0.031×10(-3) g/l. After MPO-catalyzing reaction with H(2)O(2) lower than 0.469 g/l, the binding level between MPO-ANCAcontaining plasma and MPO increased slightly. The peak binding level was 1.135 ± 0.205 (expressed by the absorbance value at 405 nm). However, with the existence of hydrogen donor (o-phenylenediamine) in the reaction system, the peak binding level between MPO-ANCA-containing plasma and post-catalyzing MPO was significantly higher (1.367 ± 0.321 vs 1.135 ± 0.205, p = 0.023). Moreover, at the approximately physical concentration of H(2)O(2) (0.02 g/l), MPO-ANCA exhibited higher titer to post-catalyzing MPO than to pre-catalyzing MPO (3.91 ± 0.84 vs 3.57 ± 0.84, p < 0.001, expressed as the lgT). These data demonstrated that MPO-catalyzing reaction could potentially increase the antigenicity of MPO.
authors.affiliation: Renal Division, Department of Medicine, Peking University First Hospital, Institute of Nephrology, Peking University, Key Laboratory of Renal Disease, Ministry of Health of China, Beijing, China.
authors.forename: Peng-Cheng
authors.initials: PC
authors.lastname: Xu
authors.forename: Jian
authors.initials: J
authors.lastname: Hao
authors.forename: Min
authors.initials: M
authors.lastname: Chen
authors.forename: Zhao
authors.initials: Z
authors.lastname: Cui
authors.forename: Ming-Hui
authors.initials: MH
authors.lastname: Zhao
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000906:Antibodies / Q000276:immunology* / Q000378:metabolism*; D019268:Antibodies, Antineutrophil Cytoplasmic / Q000097:blood / Q000276:immunology; D002384:Catalysis; D002570:Ceruloplasmin / Q000378:metabolism; D004789:Enzyme Activation / Q000187:drug effects; D005260:Female; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology; D007141:Immunoglobulin Fc Fragments / Q000378:metabolism; D007074:Immunoglobulin G / Q000737:chemistry / Q000276:immunology / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D009195:Peroxidase / Q000276:immunology* / Q000378:metabolism*; D011485:Protein Binding / Q000276:immunology; D014657:Vasculitis / Q000276:immunology; D055815:Young Adult
chemical_list: D000906:Antibodies; D019268:Antibodies, Antineutrophil Cytoplasmic; D007141:Immunoglobulin Fc Fragments; D007074:Immunoglobulin G; D006861:Hydrogen Peroxide; D009195:Peroxidase; D002570:Ceruloplasmin