Associations of antibodies against citrullinated peptides with human leukocyte antigen-shared epitope and smoking prior to the development of rheumatoid arthritis

• Published in: Arthritis Research & Therapy
• Main Authors: Kokkonen, Heidi, Brink, Mikael, Hansson, Monika, Lassen, Ewa, Mathsson-Alm, Linda, Holmdahl, Rikard, Ronnelid, Johan, Klareskog, Lars, Rantapaa-Dahlqvist, Solbritt
• Format: Article in Journal/Newspaper
• Language: English
• Published: Uppsala universitet, Klinisk immunologi 2015
• Subjects: Rheumatology and Autoimmunity; Reumatologi och inflammation; Northern Sweden
• Online Access: http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-256229; https://doi.org/10.1186/s13075-015-0638-x

Introduction: It has previously been shown that an increased number of antibodies against citrullinated peptides/proteins (ACPA) predate the onset of rheumatoid arthritis (RA). Over time antibody positivity expands, involving more specific responses when approaching the onset of symptoms. We investigated the impact of human leukocyte antigen-shared epitope (HLA-SE) alleles and smoking on the development of ACPA, as well as in combination with ACPA during the state of quiescent autoimmunity (before the onset of symptoms), on the development of RA. Methods: Blood samples donated to the Medical Biobank of Northern Sweden from individuals prior to the onset of symptoms of RA (n = 370) and after onset (n = 203) and from population-based controls (n = 585) were used. Antibodies against 10 citrullinated peptides, fibrinogen (Fib alpha 561-583, alpha 580-600, beta 62-81a, beta 62-81b, beta 36-52), vimentin (Vim2-17, 60-75), filaggrin (CCP-1/Fil307-324),alpha-enolase (CEP-1/Eno5-21), collagen type II (citC1359-369), and anti-cyclic citrullinated peptide (CCP) 2 antibodies were analysed. Results: HLA-SE-positive individuals were more frequently positive for ACPA compared with HLA-SE-negative individuals prior to the onset of symptoms of RA, particularly for antibodies against CEP-1 and Fib beta 62-81a (72). Smoking was associated with antibodies against Vim2-17 and citC1359-369. HLA-SE and smoking showed increasing association to the presence of the antibodies closer to disease onset. The highest odds ratio (OR) for development of RA was for the combination of HLA-SE alleles and ACPA positivity, especially for antibodies against Fib beta 62-81b, CCP-1/Fil307-324, and Fib beta 36-52. A gene-environment additive interaction between smoking and HLA-SE alleles for the risk of disease development was found, with the highest OR for individuals positive for antibodies against Fib beta 36-52, CEP-1, and Fib alpha 580-600. Conclusions: The relationships between antibodies against the different ACPA specificities, HLA-SE, and ...