Karin E Lundberg

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Antibodies to citrullinated proteins (ACPA), i.e., to peptides posttranslationally modified by the conversion of arginine to citrulline, are specific serological markers for rheumatoid arthritis (RA). Studies on anticitrulline immunity, summarized in this review, demonstrate that the criterion-based syndrome RA should be subdivided into at least two(More)
OBJECTIVE To investigate whether smoking and HLA-DR shared epitope (SE) genes may interact in triggering immune reactions to citrulline-modified proteins. METHODS In a case-control study involving patients with recent-onset rheumatoid arthritis (RA), we studied interactions between a major environmental risk factor (smoking), major susceptibility genes(More)
Rheumatoid arthritis (RA) is now clearly a true autoimmune disease with accumulating evidence of pathogenic disease-specific autoimmunity to citrullinated proteins. Citrullination, also termed deimination, is a modification of arginine side chains catalyzed by peptidylarginine deiminase (PAD) enzymes. This post-translational modification has the potential(More)
OBJECTIVE To map the antibody response to human citrullinated alpha-enolase, a candidate autoantigen in rheumatoid arthritis (RA), and to examine cross-reactivity with bacterial enolase. METHODS Serum samples obtained from patients with RA, disease control subjects, and healthy control subjects were tested by enzyme-linked immunosorbent assay (ELISA) for(More)
Antibodies against citrullinated proteins are highly specific for rheumatoid arthritis (RA), but little is understood about their citrullinated target antigens. We have detected a candidate citrullinated protein by immunoblotting lysates of monocytic and granulocytic HL-60 cells treated with peptidylarginine deiminase. In an initial screen of serum samples(More)
Autoantibodies directed against citrulline-containing proteins have an impressive specificity of nearly 100% in patients with rheumatoid arthritis and have been suggested to be involved in the disease pathogenesis. The targeted epitopes are generated by a post-translational modification catalysed by the calcium-dependent enzyme peptidyl arginine deiminase(More)
OBJECTIVE To investigate protein citrullination by the periodontal pathogen Porphyromonas gingivalis as a potential mechanism for breaking tolerance to citrullinated proteins in rheumatoid arthritis (RA). METHODS The expression of endogenous citrullinated proteins was analyzed by immunoblotting of cell extracts from P gingivalis and 10 other oral(More)
Autoimmunity in rheumatoid arthritis (RA) is characterized by an antibody response to citrullinated proteins. Two of the risk factors for RA-HLA-DRB1 shared epitope alleles and smoking-are also associated with periodontitis, which is largely, but not exclusively, caused by Porphyromonas gingivalis infection. Furthermore, RA and periodontitis have a similar(More)
This review describes how studies on interactions between genetic variants, and environmental factors, mainly smoking, contribute to the understanding of how autoimmunity to post-translationally (citrullinated) proteins/peptides may occur and potentially contribute to certain subsets of rheumatoid arthritis. A main message is that studies on specific immune(More)
OBJECTIVE To investigate the role of the periodontal pathogen Porphyromonas gingivalis in the etiology of rheumatoid arthritis (RA) by analyzing the antibody response to the P gingivalis virulence factor arginine gingipain type B (RgpB) in relation to anti-citrullinated protein antibodies (ACPAs), smoking, and HLA-DRB1 shared epitope (SE) alleles in(More)