Rheumatoid Arthritis: Partanen J

Koskinen LL, Korponay-Szabo IR, Viiri K, Juuti-Uusitalo K, Kaukinen K, Lindfors K, Mustalahti K, Kurppa K, Adány R, Pocsai Z, Széles G, Einarsdottir E, Wijmenga C, Mäki M, Partanen J, Kere J, Saavalainen P. · Department of Medical Genetics, and Research Programo f Molecular Medicine, University of Helsinki, Finland. · J Med Genet. · Pubmed #18077767 No free full text.

Abstract: BACKGROUND: Coeliac disease is caused by dietary gluten, which triggers chronic inflammation of the small intestine in genetically predisposed individuals. In one quarter of the patients the disease manifests in the skin as dermatitis herpetiformis. Recently, a novel candidate gene, myosin IXB on chromosome 19p13, was shown to be associated with coeliac disease in the Dutch and Spanish populations. The same gene has previously been associated with inflammatory bowel disease, systemic lupus erythematosus and rheumatoid arthritis risk, making myosin IXB a potential shared risk factor in these inflammatory disorders. METHODS: In this study, previously reported myosin IXB variants were tested for genetic linkage and association with coeliac disease in 495 Hungarian and Finnish families and in an additional 270 patients and controls. Results and CONCLUSION: The results show significant linkage (logarithm of odds (LOD) 3.76, p = 0.00002) to 19p13 which supports the presence of a genuine risk factor for coeliac disease in this locus. Myosin IXB variants were not associated with coeliac disease in this study; however, weak evidence of association with dermatitis herpetiformis was found. The association could not explain the strong linkage seen in both phenotypes, indicating that the role of other neighbouring genes in the region cannot be excluded. Therefore, more detailed genetic and functional studies are required to characterise the role of the myosin IXB gene in both coeliac disease and dermatitis herpetiformis.

Iltanen S, Collin P, Korpela M, Holm K, Partanen J, Polvi A, Mäki M. · Institute of Medical Technology, University of Tampere, Finland. · Am J Gastroenterol. · Pubmed #10201480 No free full text.

Abstract: OBJECTIVE: Many autoimmune diseases occur concomitantly with celiac disease. We investigated prospectively the occurrence of celiac disease and small-bowel mucosal inflammation in patients with primary Sjögren's syndrome. METHODS: A total of 34 patients with primary Sjögren's syndrome and 28 controls underwent small bowel biopsy. Villous morphology, jejunal intraepithelial lymphocytes, and mucosal HLA-DR were evaluated and DQA and DQB alleles, serum antiendomysial, and antigliadin antibodies were examined. RESULTS: Five (14.7%) of 34 Sjögren's syndrome patients were found to have celiac disease. The density of jejunal intraepithelial gammadelta+ T cells was increased in all celiac and in four nonceliac patients. All celiac patients, 69% of nonceliac Sjögren's syndrome patients, and 11% of control subjects showed enhanced HLA-DR expression (p < 0.001). HLA DQ2 was present in 19 (56%) patients with Sjögren's syndrome, including all five with celiac disease. CONCLUSIONS: The findings show a close association between Sjögren's syndrome and celiac disease. Even among nonceliac patients with primary Sjögren's syndrome, an ongoing inflammation is often present in the small bowel mucosa.