Lysozyme Titres in Regional Enteritis, Miscellaneous Tissues, Microorganisms, and Excreta.∗

Summary The stools of 14 regional enteritis cases possessed a mean lysozyme content of 19.8 units per gram of stool (wet weight) and a mean daily output of 6,220 units. This is 7.34 times the mean lysozyme content of normal stools and 39.4 times the mean daily output in the stools of normal persons. These data, together with the experimental production by lysozyme of ulcerations in the canine alimentary tract,2 indicate that lysozyme is an etiologic agent in the pathogenesis of regional enteritis. A survey of various microorganisms, tissues, and excreta revealed generally high titres in fetal tissues and placenta, moderately high levels in endometrium with a suggestion of cyclic variation, and very large amounts in pus and in fluid from an enterocystoma. Low titres were found in the stools of two acute specific dysenteries and in canine gastric juice, with no measurable amounts in mass cultures from two chronic ulcerative colitis cases and one paratyphoid B culture. A case of acute infantile diarrhea exhibited a very high titre on the day of onset in the absence of organic pathology or specific infection, falling rapidly to normal with recovery. It is felt that the generally high titres of fetal tissue suggest the possibility of an important role for lysozyme in the chemistry of actively growing normal tissue. The absence of lysozyme in the colitis mass stool cultures substantiates the conclusion that intestinal lysozyme is not bacterial in origin; and the moderately low levels in the specific dysentery stools indicate that acute colitis is not necessarily accompanied by a high stool lysozyme titre.