A hypothesis for the pathogenesis of Crohn's disease based on an ultrastructural study.

The epitheloid cells forming the granulomata of Crohn's disease show striking vacuolation from the coalescing of pinocytotic vesicles with double membrane-bound bodies and their subsequent fusion with lysosomal dense bodies. The fine detail of the granulomata in each individual is uniform but varies from case to case in such a way as to suggest an episodic stimulation of pinocytosis and vacuole formation. The production of such granulomata with these cyclical appearances is consistent with an intermittent stimulus by exogenous antigen or antigen antibody complexes arriving in the diet.