title: Evaluation of performance of measurement of faecal α(1)-antitrypsin clearance and technetium-99m human serum albumin scintigraphy in protein-losing enteropathy.
abstract: OBJECTIVE
  Our study aimed to compare the performance of faecal α(1)-antitrypsin clearance (AATC) and radiolabelled human serum albumin (HSA) scintigraphy in protein-losing enteropathy (PLE).
  
  
  METHODS
  Patients studied by both AATC and technetium-99m ((99m)Tc)-labelled HSA scintigraphy were recruited and categorized into PLE and non-PLE groups based on clinical and laboratory findings. The performance of AATC and (99m)Tc-labelled HSA scintigraphy was evaluated using clinical diagnosis of PLE as a gold standard.
  
  
  RESULTS
  29 patients were recruited and 13 patients were considered to have definite PLE (PLE group). In the PLE group, all patients had a positive HSA scinigraphy and 10 (77%) had demonstrable positive tracing in the early phase. Conversely, only 6 of them (46%) had elevated AATC level (>13 m/day). Results of (99m)Tc-labelled HSA scan (but not AATC) showed significant agreement with the clinical diagnosis (κ 0.35, p = 0.013). (99m)Tc-labelled HSA scintigraphy carried higher sensitivity (100 vs. 46%) and negative predictive value (100 vs. 63%) compared to AATC in diagnosing PLE. The correlation between the results of these two investigations was only modest (κ 0.27, p = 0.04). The area under the receiver operating characteristic curve of AATC level showed no optimal diagnostic cut-off for PLE.
  
  
  CONCLUSIONS
  (99m)Tc-labelled HSA scintigraphy was superior to AATC in diagnosing PLE.
authors.affiliation: Department of Medicine and Geriatrics, United Christian Hospital, Hong Kong, SAR, China. chautn@ha.org.hk
authors.forename: T N
authors.initials: TN
authors.lastname: Chau
authors.forename: M Y
authors.initials: MY
authors.lastname: Mok
authors.forename: E Y T
authors.initials: EY
authors.lastname: Chan
authors.forename: W H
authors.initials: WH
authors.lastname: Luk
authors.forename: K B
authors.initials: KB
authors.lastname: Lai
authors.forename: F T W
authors.initials: FT
authors.lastname: Li
authors.forename: V K S
authors.initials: VK
authors.lastname: Leung
authors.forename: R
authors.initials: R
authors.lastname: Wong
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D005243:Feces / Q000737:chemistry*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015609:Organotechnetium Compounds; D011237:Predictive Value of Tests; D011504:Protein-Losing Enteropathies / Q000000981:diagnostic imaging* / Q000209:etiology / Q000378:metabolism; D012372:ROC Curve; D011877:Radionuclide Imaging; D012189:Retrospective Studies; D012709:Serum Albumin / Q000378:metabolism; D055815:Young Adult; D000515:alpha 1-Antitrypsin / Q000032:analysis* / Q000378:metabolism
chemical_list: D015609:Organotechnetium Compounds; D012709:Serum Albumin; D000515:alpha 1-Antitrypsin; C107869:technetium Tc 99m serum albumin