Lactase Deficiency and Colonic Mucosal Eosinophilia (P19-014-19)

Abstract

ObjectivesImmunological studies in patients with lactase deficiency (LD) have suggested a role of colonic mucosal inflammatory cells in causation of some of the symptoms. We hypothesized that since eosinophils are associated with symptoms of abdominal pain and diarrhea; and patients with LD frequently manifest these symptoms, there may be an increase of eosinophils in LD. Thus, our objective was to study children with LD to assess eosinophils in their colonic mucosa. MethodsWe reviewed the pathology reports of mucosal biopsies of 86 children with LD who underwent esophagogastroduodenoscopy (EGD) and colonoscopy or only EGD. Data was abstracted from the pathology reports and analyzed. Lactase enzyme testing was performed at a reference laboratory on the mucosal biopsy specimen obtained from duodenum. The reference laboratory defined the normal range of lactase enzyme as 24.5+/− 8 micromoles per minute per gram of protein (micromoles/min), and abnormal level as <15 micromoles/min. ResultsThe subjects ranged in age from 1 to 17 years and 47 (55%) were female and all subjects had abdominal pain. The lactase enzyme levels in the study subjects ranged from 0 to 13.9. All 86 subjects underwent EGD, 6 (7%) of whom had celiac disease and 10 (12%) showed increased mucosal eosinophils in the duodenal mucosa. All subjects with celiac disease had very low (<7 micromoles/min) levels of lactase. There were 52 subjects who had colonoscopy as well, and 16 (31%) of them had increased colonic mucosal eosinophils (CME), whereas 32 (62%) showed no histopathological abnormality of colonic mucosa. ConclusionsOur study found that 31% of children with lactase deficiency manifest increased colonic mucosal eosinophils. Chemical mediators secreted by eosinophils are known to mediate abdominal pain. However, to fully understand the role of other inflammatory cells in the clinical presentation of children with LD, future studies on larger numbers of subjects that assess eosinophils and mast cells are needed. Funding SourcesIntra-departmental Funding.