The inflammatory reaction in mucosa during healing of gastric ulcers in humans.

To evaluate the inflammatory changes during ulcer healing, we measured myeloperoxidase (MPO) activity and the inflammatory cytokine interleukin-8 (IL-8) in the gastric mucosa of 51 patients with gastric ulcers and 5 normal controls. MPO activity was measured by enzyme assay and IL-8 by ELISA, using biopsy samples taken from the ulcer margin and at 3 and 6 cm from the ulcer. Levels of MPO activity were significantly higher than in normal controls and peaked at the A2 (active) stage, and then gradually decreased and returned to basal levels at the S2 (scarring) stage. The area of increased MPO activity around the gastric ulcer was approximately 6 cm in diameter at the A2 stage, and this area decreased as the ulcer healed. IL-8 levels in gastric mucosa also increased significantly at the A2 stage, and the changes paralleled those of MPO activity during ulcer healing. MPO activity correlated well with the IL-8 level.