Gastrointestinal and liver diseases Dynamic thiol/disulphide homeostasis in celiac disease Mustafa Kaplan1, Ihsan Ates2, Mahmut Yuksel1, Yasemin Ozderin Ozin1, Murat Alisik3, Ozcan Erel3, Ertugrul Kayacetin1 1Turkey Yuksek Ihtisas Training and Research Hospital, Department of Gastroenterology, Ankara, Turkey 2Ankara Numune Training and Research Hospital, Department of Internal Medicine, Ankara, Turkey 3Yıldırım Beyazıt University Medical Faculty, Department of Biochemistry, Ankara, Turkey Gastrointestinal and liver diseases P.0359 Introduction Results In patients with celiac disease, native thiol (p=0.027) and total thiol (p=0.031) levels were lower, while disulphide (p<0.001) level, disulphide/native thiol (p<0.001) and disulphide/total thiol (p<0.001) ratios were higher compared to the control group. In patients who do not comply with a gluten-free diet, disulphide/native thiol ratio was found higher compared to the patients who comply with the diet (p<0.001). In patients with any autoantibody-positive, disulphide/native thiol ratio was observed higher compared to the patients with autoantibody-negative (p<0.05). It is found that there is a negative correlation between celiac autoantibodies, and native thiol, total thiol levels and native thiol/total thiol ratio, while a positive correlation is observed between c-reactive protein, disulphide, disulphide/native thiol and disulphide/total thiol levels. Celiac disease, observed in genetically predisposed individuals, is a chronic/autoimmune disease of the small intestine. It is characterized by symptoms such as mucosal damage induced by gliadin, malabsorption, anemia, diarrhea and growth retardation. While environmental, genetic and immunological factors have a role in etiopathogenesis of the disease; oxidative stress has also been shown to play a critical role in the development. Objectives Conclusions The aim of this study is to determine dynamic thiol/disulphide homeostasis in celiac disease by using a newly developed colorimetric method, and to examine the relationship between thiol/disulphide homeostasis, celiac autoantibodies and gluten-free diet. This study is first in the literature which found that the patients with celiac disease the dynamic thiol/disulphide balance shifts through disulphide form compared to the control group. The positive correlation between celiac autoantibodies and c-reactive protein with disulphide/native thiol level suggests that abnormal thiol/disulphide homeostasis in celiac disease might be associated with autoimmunity and inflammation. References Methods Seventy three patients with celiac disease (female/male: 58/15) and 73 healthy volunteers (female/male: 55/18) were enrolled in the study. In both groups, thiol/disulphide homeostasis was examined with a new colorimetric method recently developed by Erel and Neselioglu. 1 Di Sabatino A, Corazza GR. Coeliac disease. Lancet 2009; 373: 1480-93 2 Lurz E, Scheidegger U, Spalinger J, Schoni M, Schibli S. Clinical presentation of celiac disease and the diagnostic accuracy of serologic markers in children. European journal of pediatrics 2009; 168: 839-45 3 Cheeseman KH, Slater TF. An introduction to free radical biochemistry. British medical bulletin 1993; 49: 481-93