Abundance of surfactant-like particles reflects mucosal integrity in patients with peptic ulcer disease

Background - Surfactant-like particles, normal products of the human enterocyte, are released into the lumen and secreted into blood. Aims - To assess their role as markers for mucosal functional integrity, this study examined their content in biopsy specimens and serum of patients with duodenal ulcer disease, compared with non-diseased control subjects. Patients - Endoscopic biopsy specimens were taken 1-2 cm from areas of active inflammation or ulcer (peptic ulcer patients) or just beyond the duodenal bulb (normals) in 35 consecutive subjects. Methods - After staining for phospholipid, extracellular and intracellular particles were counted on transmission electron micrographs of coded specimens. Serum was obtained from 24 patients, and densitometry of the 59 kDa band detected on western blot by antiserum against human jejunal particle was measured. Results - Normal duodenum (n = 15) contained more particles (44 (4 7)) particles/block, mean (SD) than active duodenal ulcer (n = 13, 17 (3.9)) or gastritis/duodenitis patients (n = 4, 9 (2.7)). Three patients examined after healing of duodenal ulcers showed abundant particles (n = 3, 67 (2.2)). Similarly, the 59 kDa band was decreased in serum of patients with active peptic ulcer disease (n = 11, 0.25 (0.04) absorbance units) compared with normal patients (n = 10, 0.40 (0.03)) or healed ulcers (n = 3, 0.62 (0.04)). There was good correlation between morphological mucosal particle abundance and particle protein content of serum assayed from the same patients (r = 0.831). These changes were independent of Helicobacter pylori status. Conclusion - The mucosal and serum content of surfactant-like particles may reflect general mucosal integrity of the enterocytes from which they are derived.