title: Serum IgG activity against cyclic citrullinated peptide in patients evaluated for rheumatoid factor correlates with the IgM isotype.
abstract: The purpose of this study was to evaluate the frequency of seric antibodies against cyclic citrullinated peptide (a-CCP) in patients tested for rheumatoid factor (RF) reactivity, and to analyze the correlation between their titers. We obtained serum from 112 consecutive patients (85 female), aged 47.2 +/- 13.4 years and from 46 clinically healthy subjects (CHS). Patients where stratified into four subgroups: rheumatoid arthritis (RA), probable RA (PRA), spondylarthropathies and other diagnosis. The a-CCP antibodies were determined by enzyme linked immunoassay (ELISA), RF by nephelometric test (IgM) and ELISA (IgG and IgM). Analysis of variance (ANOVA) showed statistically that a-CCP antibodies differs among RA versus CHS and other diagnosis; PRA versus CHS and other diagnosis. A significant Rho value of 0.84 (P < 0.05, Spearman's correlation) was identified between a-CCP antibodies and RF in PRA subgroup. When a correlation of a-CCP antibodies with RF (both isotypes) was done, the higher correlation was observed against IgM RF. The data suggests different pathways and times for each antibody generation.
authors.affiliation: Unidad de Investigación Médica en Epidemiología Clínica, UMAE, HE, CMNO, IMSS, Guadalajara, Jalisco, México.
authors.forename: M G
authors.initials: MG
authors.lastname: Zavala-Cerna
authors.forename: A
authors.initials: A
authors.lastname: Nava
authors.forename: E
authors.initials: E
authors.lastname: García-Castañeda
authors.forename: J
authors.initials: J
authors.lastname: Durán-González
authors.forename: M J
authors.initials: MJ
authors.lastname: Arias-Merino
authors.forename: M
authors.initials: M
authors.lastname: Salazar-Páramo
mesh_terms: D000328:Adult; D001172:Arthritis, Rheumatoid / Q000097:blood / Q000276:immunology*; D001323:Autoantibodies / Q000097:blood / Q000276:immunology; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000276:immunology; D007075:Immunoglobulin M / Q000097:blood / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D010456:Peptides, Cyclic / Q000276:immunology*; D012217:Rheumatoid Factor / Q000145:classification / Q000276:immunology*; D025242:Spondylarthropathies / Q000097:blood / Q000276:immunology
chemical_list: D001323:Autoantibodies; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D010456:Peptides, Cyclic; C487763:cyclic citrullinated peptide; D012217:Rheumatoid Factor