Z Gastroenterol 2009; 47 - P083
DOI: 10.1055/s-0029-1241334

The role of osteopontin (OPN/SSP1) gene variants in inflammatory bowel disease

J Glas 1, J Seiderer 1, HP Török 1, B Göke 1, T Ochsenkühn 1, S Brand 1
  • 1Klinikum der Universität München-Großhadern, Medizinische Klinik II, München, Germany

Introduction: Osteopontin plays an important role in chronic inflammatory and autoimmune diseases and has also found to be involved in the pathogenesis of inflammatory bowel disease (IBD). The aim of our study was to analyze the potential association of osteopontin (OPN/SPP1) gene variants in a large and well-characterized cohort of European IBD patients.

Aims & methods: Genomic DNA from 2819 Caucasian individuals (n=841 patients with Crohn's disease (CD), n=473 patients with ulcerative colitis (UC), and n=1505 healthy unrelated controls) was analyzed for nine OPN/SPP1 SNPs (rs2728127, rs2853744, rs11730582, rs11439060, rs28357094, rs4754=p.Asp80Asp, rs1126616=p.Ala236Ala, rs1126772 and rs9138).

Results: In all three subgroups (CD, UC, and controls), the allele frequencies of the nine OPN/SPP1 SNPs were in accordance with the predicted Hardy-Weinberg equilibrium. With the exception of rs4754, no significant differences in the allele frequencies were observed comparing CD and UC patients to healthy controls. Our analysis revealed a weak protective effect of SNP rs4754 (p.Asp80Asp) regarding CD susceptibility (p=1.28×10-2; OR (95% CI) 0.85 [0.74–0.96]) and UC susceptibility, although the association with UC did not reach significance in univariate analysis (p=5.25×10-2; OR (95% CI) 0.85 [0.70–1.00]). Moreover, both associations of rs4754 (regarding CD and UC susceptibility) were not statistically significant after Bonferroni correction suggesting that these OPN/SPP1 variants are not major contributors to IBD susceptibility on their own.

Conclusion: Our study could not identify osteopontin (OPN/SPP1) gene variants as major disease susceptibility genes in CD or UC in a large European cohort. Further studies on phenotypic consequences and potential epistatic interactions will be required.