Anti-cyclic citrullinated peptide antibodies and rheumatoid factor in rheumatoid arthritis patients and relatives from Brazil

• Published in: Rheumatology (Oxford, England) England), 2010-08, Vol.49 (8), p.1590-1593
• Main Authors: Goeldner, Isabela, Skare, Thelma L., de Messias Reason, Iara T., Nisihara, Renato M., Silva, Marília B., da Rosa Utiyama, Shirley R.
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; Aged; Aged, 80 and over; Anti-cyclic citrullinated peptide antibody; Antibodies, Antinuclear - genetics; Arthritis, Rheumatoid - genetics; Arthritis, Rheumatoid - physiopathology; Biological and medical sciences; Brazil; Case-Control Studies; Child; Diseases of the osteoarticular system; Family; Female; Genetic Predisposition to Disease; Humans; Inflammatory joint diseases; Male; Medical sciences; Middle Aged; Pedigree; Peptides, Cyclic - antagonists & inhibitors; Peptides, Cyclic - genetics; Predictive Value of Tests; Rheumatoid arthritis; Rheumatoid Factor - genetics; Statistics as Topic; Young Adult
• ISSN: 1462-0324; 1462-0332
• DOI: 10.1093/rheumatology/keq134

Objectives. To evaluate the prevalence of anti-cyclic citrullinated peptide (anti-CCP) antibodies and RF in RA patients and their relatives from Southern Brazil. Methods. Anti-CCP2 and IgM-RF were evaluated in 156 RA patients and 200 relatives. Sera from 100 healthy unrelated individuals were used as control. The anti-CCP2 was detected by ELISA and the IgM-RF using the latex agglutination test. Results. We identified 117 anti-CCP2 (75%)-positive and 106 RF (67.9%)-positive patients. Anti-CCP2 was increased in relatives (5.5%; 11/200) when compared with unrelated individuals (1%; P = 0.050). Titre of anti-CCP2 in RA patients did not differ from relatives [140.4 (75.7) vs 115.6 (84.2) U, respectively; P = 0.30]. Positive relatives were younger than patients for anti-CCP2 (P = 0.0081), RF (P < 0.001) and both concomitantly (P = 0.012), and although there was no difference for anti-CCP2 positivity according to gender, increased RF positivity and concomitant anti-CCP2/RF were observed in the female relatives (P = 0.067 and 0.082, respectively). No difference regarding the relative degree of tobacco use in relatives was detected. Among the 11 anti-CCP2-positive relatives, 2 females had RA diagnosis established and 6 individuals presented with joint symptoms suggestive of RA. Conclusion. The results demonstrate a significant positivity of anti-CCP2 in relatives of RA patients from Brazil and reinforce the importance of serological tools to identify undiagnosed RA.