Statistics from Altmetric.com
Anti-citrullinated peptide antibody (ACPA) is a highly specific serological marker for rheumatoid arthritis (RA).1,–,3 Different HLA-DRB1 alleles have been shown to be associated with the susceptibility to ACPA-positive RA.4 5 Former studies demonstrated that HLA-DRB alleles carrying a shared epitope (SE),6 consisting of a conserved amino acid motif at positions 70–74 of the HLA-DRβ chain, were strongly associated with ACPA-positive RA and with higher ACPA levels in European and Japanese populations.7,–,9 On the other hand, HLA-DRB1*09:01 was recently found to be negatively associated with ACPA levels in the Japanese.9 These observations imply that combinations of HLA-DRB1 alleles differentially influence ACPA levels in ACPA-positive RA.
To address this question, we conducted a genetic association study employing 2457 ACPA-positive Japanese RA patients. ACPA was quantified by MESACUP CCP ELISA kit (MBL Co Ltd, Nagoya, Japan) with a cut-off level of 4.5 U/ml. The patients were then divided into three groups …
Funding This work was supported by Grants-in-aid from the Ministry of Health, Labour and Welfare of Japan and from the Ministry of Education, Culture, Sports, Science and Technology of Japan as well as by research grants from the Japan Rheumatism Foundation, the Waksman Foundation and the Mitsubishi Pharma Research Foundation.
Competing interest None.
Provenance and peer review Not commissioned; externally peer reviewed.
If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.