[Local immune reaction in human intestinal spirochetosis]

The pathogenetic and clinical importance of intestinal spirochaetes in man is still unresolved. In 12 patients mainly presenting with mild diarrhoea, light and electron microscopy demonstrated massive spirochaetal infestation of the colonic mucosa (spirochaetosis). There were several hitherto unreported features: spirochaetes adhered not only to the surface epithelium of the intestine but were also present within epithelial cells and subepithelial macrophages; many partially degranulated mast cells were noted within the epithelium; there was a marked increase of IgE plasma cells within the lamina propria. In control biopsies intraepithelial mast cells were absent and IgE cells occurred only sporadically. Penetration of the microorganisms into the intestinal mucosa may be responsible for this unusual immune response. Spirochaetes, symptoms and findings disappeared after antibiotic therapy. The authors therefore suggest that intestinal spirochaetosis can cause clinical symptoms in man, and that spirochaetes should not invariably be considered harmless commensals.