Background: Ulcerative colitis is a chronic inflammatory disease characterized by episodes of remission and exacerbation. Patients typically presented by bloody diarrhea, abdominal pain and loss of weight. Various pro-inflammatory cytokines are currently known to play an important role in the pathogenesis of IBD. Serum amyloid A belongs to the family of acute-phase reactants. Objectives: the study aimed to assess the clinical usefulness of serum amyloid A in predicting the disease activity in ulcerative colitis patients in comparison to fecal calprotectin and C-reactive protein. Patients and methods: A total of 90 patients with UC presented for colonoscopy were included. Socio-demographic, clinical and laboratory data were recorded and patients were classified into inactive, mild, moderate and severe according to The Simple Clinical Colitis Activity Index and Mayo endoscopic sub score. FC, CRP and SAA were measured, and their association with endoscopic scores was evaluated. Results: Serum amyloid A and fecal calprotectin were significantly lower in remission than activity. Serum amyloid A at cut off value >3.97µgml could

discriminate active from remittent patients, the sensitivity, specificity, PPV, NPV and accuracy were (84.44, 55.56, 65.5, 78.1 and74.2% respectively). Regarding fecal calprotectin; at cut off value >100µgmg it could distinguish between activity and remission with sensitivity, specificity, PPV, NPV and accuracy were (88.89, 86.67, 87.0, 88.6 and 93.9% respectively). However, both marker showed no significant difference between the different grades of activity. Conclusion: Serum amyloid A level was significantly higher in active cases than remittent cases, however it could not differentiate between the different grades of ulcerative colitis activity.