Molecular Analysis for Differential Diagnosis of Small Bowel Obstruction: Expression of Proinflammatory Cytokines and Diamine Oxidase Activity

BACKGROUND: A small bowel obstruction is classified as simple (nonstrangulated) or strangulated. The early recognition with correct diagnosis of small bowel obstruction is a critical issue as the release from strangulation requires surgical emergency. METHODS: To evaluate the physiological effect on small bowel obstruction, a metallic ring was put in the small intestine (simple ileus) and a loop obstruction was made with keeping the blood flow (strangulated obstruction). Serum level of cytokines, IL-6, TNF-α, and IL-1β as well as endotoxin and seromuscular enzymes, CPK and LDH, were serially analyzed. Serum and mucosal DAO activity were also assessed. RESULTS: Endotoxin was increased at 18 h through 48 h in strangulated obstruction, but not detected in the simple ileus. Early proinflammatory cytokines were significantly elevated in strangulated obstruction. High expression of IL-6 prolonged after 12h. Transiently expressed IL-1β peaked at 12h, TNF-α was increased at 18 h. In simple ileus, these expressions of cytokines were low and slow. LDH and CPK were significantly elevated at 48h, but there were no difference between simple ileus and strangulated obstruction. Serum DAO activity was significantly increased in simple ileus, but gradually decreased in strangulated obstruction, while mucosal DAO activity was decreased in both groups. CONCLUSIONS: High level of serum IL-6 is an early marker for strangulated obstruction. The pattern of serum DAO activity, decrease in strangulated obstruction and increase in simple ileus, might be useful molecular parameter in the early and proper diagnosis of small bowel obstruction.