Rheumatoid Arthritis (RA) is a chronic autoimmune disease, affecting a ~1% of the population worldwide. Although its causes are largely unknown, a considerable heritable component approximating 50... Show moreRheumatoid Arthritis (RA) is a chronic autoimmune disease, affecting a ~1% of the population worldwide. Although its causes are largely unknown, a considerable heritable component approximating 50-60% has been described. The most prominent genetic association in RA is confined to the human leukocyte antigen (HLA) locus which has been known for ~30 years. The identification of RA-associated genes outside of the HLA region, however, had been a challenge. A few years ago, one such gene, protein tyrosine phosphatase, non-receptor type 22 (lymphoid), was identified in a large genetic-association study utilizing putative functional SNPs. The aim of this thesis was to take a candidate gene approach to identify risk factors involved in rheumatoid arthritis. It is divided into three parts in which part one is dedicated towards the identification of a novel risk factor for RA and autoimmunity. This region of the genome encompasses genes highly involved in the immune system, namely Tumour Necrosis Factor Receptor associated factor 1/Complement component 5 on chromosome 9q33. In the second part, we have investigated the role of an immunoregulatory cytokine interleukin 10 located on chromosome 1q32 and in part three we have investigated the role of additional genetic risk factors in RA. Show less
