title: Anti-type II collagen antibodies detection and avidity in patients with oligoarticular and polyarticular forms of juvenile idiopathic arthritis.
abstract: Juvenile idiopathic arthritis (JIA) refers to a heterogeneous group of illnesses that have in common the occurrence of chronic joint inflammation in children younger than 16 years of age. The diagnosis is made only on clinical assessment. The identification of antibody markers could improve the early diagnosis, optimizing the clinical management of patients. Type II collagen is one potential autoantigen that has been implicated in the process of arthritis development. The aims of our study were to investigate the occurrence of anti-type II collagen antibodies and also to determine the avidity of the antibody-antigen binding. Ninety-six patients with oligoarticular or polyarticular JIA, 13 patients with ankylosing spondylitis (AS) and 61 healthy controls (HC) were tested for anti-type II collagen antibodies by ELISA and avidity ELISA. Sensitivity and specificity were determined by the receiver operating characteristic (ROC) curve analysis. Forty-two JIA patients (44%) were positive for antibodies against type II collagen. Its detection was significantly higher in JIA patients than in AS patients (p=0.006) and HCs (p<0.0001). Furthermore, anti-type II collagen antibody detection was significantly more frequent in patients with JIA of ≤6 months duration (p=0.0007). Antibodies displaying high avidity to type II collagen were associated with disease activity (p=0.004). This study demonstrates that antibodies against type II collagen are present in the serum of patients with oligoarticular and polyarticular JIA, being its presence more prevalent in patients with early disease. It also demonstrates that JIA patients with active disease present antibodies with high avidity against type II collagen.
authors: Laboratory of Nanobiotecnology, Instituto de Genética e Bioquímica, Universidade Federal de Uberlândia, Uberlândia, Brazil; iMed - Instituto de Medicina, Faculdade de Farmácia da Universidade de Lisboa, Lisbon, Portugal. Electronic address: galber.araujo@gmail.com.
authors: Galber R
authors: GR
authors: Araujo
authors: Rheumatology Research Unit, Instituto de Medicina Molecular, Lisbon, Portugal; Rheumatology Department, Lisbon Academic Medical Center, Lisbon, Portugal.
authors: João E
authors: JE
authors: Fonseca
authors: Laboratory of Nanobiotecnology, Instituto de Genética e Bioquímica, Universidade Federal de Uberlândia, Uberlândia, Brazil.
authors: Patricia T
authors: PT
authors: Fujimura
authors: Laboratory of Immunotecnology and Imunochemistry, Instituto de Ciências Biomédicas, Universidade Federal de Uberlândia, Uberlândia, Brazil.
authors: Jair P
authors: JP
authors: Cunha-Junior
authors: Pediatric Rheumatology Department, Hospital de Clínicas, Universidade Federal de Uberlândia, Uberlândia, Brazil.
authors: Carlos H M
authors: CH
authors: Silva
authors: Rheumatology Research Unit, Instituto de Medicina Molecular, Lisbon, Portugal; Rheumatology Department, Hospital Egas Moniz, Lisbon, Portugal.
authors: Ana F
authors: AF
authors: Mourão
authors: Rheumatology Research Unit, Instituto de Medicina Molecular, Lisbon, Portugal; Rheumatology Department, Lisbon Academic Medical Center, Lisbon, Portugal.
authors: Helena
authors: H
authors: Canhão
authors: Laboratory of Nanobiotecnology, Instituto de Genética e Bioquímica, Universidade Federal de Uberlândia, Uberlândia, Brazil; Department of Medical Microbiology and Immunology, University of California Davis, Davis, CA, USA.
authors: Luiz R
authors: LR
authors: Goulart
authors: iMed - Instituto de Medicina, Faculdade de Farmácia da Universidade de Lisboa, Lisbon, Portugal; IMM - Instituto de Medicina Molecular, Faculdade de Medicina da Universidade de Lisboa, Lisbon, Portugal.
authors: João
authors: J
authors: Gonçalves
authors: Laboratory of Nanobiotecnology, Instituto de Genética e Bioquímica, Universidade Federal de Uberlândia, Uberlândia, Brazil.
authors: Carlos
authors: C
authors: Ueira-Vieira
mesh_terms: D000293:Adolescent; D000328:Adult; D000915:Antibody Affinity / Q000276:immunology*; D001171:Arthritis, Juvenile / Q000175:diagnosis / Q000276:immunology*; D001323:Autoantibodies / Q000097:blood / Q000276:immunology*; D016022:Case-Control Studies; D002648:Child; D024043:Collagen Type II / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood / Q000276:immunology; D008297:Male; D055815:Young Adult
chemical_list: D001323:Autoantibodies; D024043:Collagen Type II; D007074:Immunoglobulin G
keywords: Juvenile idiopathic arthritis; Serodiagnosis; Type II collagen