The role of the cytokines and cell-adhesion molecules on the immunopathology of acute appendicitis

OBJECTIVE: To study the local expression of the proinflammatory cytokine such as interferon gamma and anti-inflammatory cytokine like interleukin-10 (IL-10) and their role in cell adhesion molecules (CAM) expression on the surface of endothelial cell at the site of inflammation in acute appendicitis. The local expression of these cytokines and CAM was correlated with clinical findings to shed light on their role in the pathogenesis of acute appendicitis.

METHODS: Thirty-five patients with acute appendicitis and 6 apparently normal appendices were removed incidentally from individuals presented with problems other than appendicitis, were included in this prospective study. They were attendant of the emergency room in Al-Khadhumiyah Teaching Hospital in Baghdad, from October 2003 to September 2004. Cell adhesion molecules (intracellular adhesion molecule-1 [ICAM-l], ICAM-3 and vascular cell adhesion molecule-1 [VCAM-1]) were detected by immunohistochemistry while IL-10 and interferon gamma were detected by in situ hybridization. The specimens were classified into 5 groups; early acute appendicitis, phlegmonous appendicitis, ulcero-phlegmonousappendicitis, and gangrenous appendicitis, and the fifth group included specimens that showed no histopathological changes, defined as histologically normal appendix.

RESULTS: Intracellular adhesion molecule-1, VCAM-I, IL-10 and interferon gamma were expressed weakly in the control group, while ICAM-3 was not detected in the control group. The average score for ICAM-I, VCAM-1 and the percentage of cells expressing IL-l0 and interferon gamma were significantly higher in the patient groups when compared with the control group. Intracellular adhesion molecule-3 was expressed in the patient group.

CONCLUSION: The kinetics of CAM expression were tightly correlated to the balance between IL-10 and interferon gamma especially after 12.5 hours from the first symptoms experienced by the patients. The interferon gamma was the main player and the most significant factor that leads to shifting of cases towards gangrenous appendicitis.