title: Acetylcholinesterase activity in rectal biopsies: an assessment of its diagnostic value in Hirschsprung's disease.
abstract: Acetylcholinesterase (AChE) activity was measured in rectal suction biopsies from 392 patients investigated for Hirschsprung's disease (HD). Results in HD (2.7-23.7 RU; n = 37) were not clearly differentiated from those in patients without HD (0.6-18.0 RU; n = 355). Sample instability was shown not to be a significant cause of error. From analysis of duplicate biopsies and a consideration of false-negative results, tissue inhomogeneity or incorrect siting of the biopsy appeared likely causes of error. Examination of a number of possible diagnostic decision levels indicated an optimal choice of AChE activity greater than 10 RU with an AChE activity not less than 60% of total cholinesterase activity. At a prevalence of 10%, this decision level resulted in sensitivity of 64.9%, specificity 98.7%, predictive value of positive 85.7%, and predictive value of negative 96.3%. The false positives (n = 4) and false negatives (n = 13) by these criteria were examined to detect possible common features.
mesh_terms: D000110:Acetylcholinesterase / Q000032:analysis*; D001706:Biopsy; D002648:Child; D002675:Child, Preschool; D004796:Clinical Enzyme Tests; D003106:Colon / Q000201:enzymology; D006627:Hirschsprung Disease / Q000175:diagnosis*; D006651:Histocytochemistry; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007413:Intestinal Mucosa / Q000201:enzymology; D012007:Rectum / Q000201:enzymology*
chemical_list: D000110:Acetylcholinesterase