title: Diagnostic value of a guaiac occult blood test and faecal alpha 1-antitrypsin.
abstract: This study evaluates the diagnostic accuracy of a faecal occult blood test and faecal alpha 1-antitrypsin in the investigation of patients with gastrointestinal symptoms or iron deficiency anaemia. One hundred and seventy nine patients with either iron deficiency anaemia (n = 67), changed bowel habit and aged > 39 years (n = 107), or a history suggestive of melaena (n = 5) provided faecal samples. After investigation, 32 patients had a diagnosis of possible gastrointestinal bleeding and 139 patients had no evidence of gastrointestinal bleeding. Eight patients had a cause of enteric protein loss in the absence of gastrointestinal bleeding and were excluded from subsequent analysis. The faecal alpha 1-antitrypsin test was diagnostically more accurate than the guaiac test in identifying probable gastrointestinal bleeding (82% and 72% respectively, p < 0.05). This faecal alpha 1-antitrypsin test was also more specific (83% and 72% respectively, p < 0.05), but was not significantly more sensitive (78% and 72% respectively). The sensitivity of these tests was insufficient to recommend their use for most patients in this study.
authors.affiliation: Department of Gastroenterology, Birmingham Heartlands Hospital.
authors.forename: A
authors.initials: A
authors.lastname: Moran
authors.forename: D
authors.initials: D
authors.lastname: Husband
authors.forename: A F
authors.initials: AF
authors.lastname: Jones
authors.forename: P
authors.initials: P
authors.lastname: Asquith
mesh_terms: D000328:Adult; D000368:Aged; D018798:Anemia, Iron-Deficiency / Q000209:etiology; D005243:Feces / Q000737:chemistry*; D006471:Gastrointestinal Hemorrhage / Q000150:complications / Q000175:diagnosis* / Q000209:etiology; D006801:Humans; D008875:Middle Aged; D009780:Occult Blood; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D000515:alpha 1-Antitrypsin / Q000032:analysis*
chemical_list: D000515:alpha 1-Antitrypsin