title: Selective measurement of anti-tTG antibodies in coeliac disease and IgA deficiency: an alternative pathway.
abstract: OBJECTIVE
  To determine the ability of selective antibody testing to screen for coeliac disease in the presence of IgA deficiency and to define the sensitivity of a pathway using this method.
  
  
  METHODS
  All IgA and IgG anti-tTG tests performed at our centre between January 2008 and December 2009, using the Immunocap 250 analyser, were retrospectively reviewed. Positive results were correlated with histology. Results were used to validate our diagnostic pathway.
  
  
  RESULTS
  12 289 consecutive serological tests were reviewed. IgA deficient patients gave either an 'error' reading or very low response on the Immunocap 250 analyser. Subsequent testing of this sub-group demonstrated raised IgG anti-tTG antibodies in those with histologically proven coeliac disease.
  
  
  CONCLUSIONS
  Using our antibody screening pathway, which involves the selective use of IgG anti-tTG, sensitivity increased from 87% to 92% in those with IgA deficiency. Adoption of this pathway for coeliac screening would negate the routine screening of immunoglobulin levels, with resultant cost saving.
authors.affiliation: Department of Gastroenterology, University Hospitals Coventry and Warwickshire, Clifford Bridge Road, Coventry CV2 2DX, UK.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Harrison
authors.forename: Ka-Kit
authors.initials: KK
authors.lastname: Li
authors.forename: Michael
authors.initials: M
authors.lastname: Petchey
authors.forename: Chuka
authors.initials: C
authors.lastname: Nwokolo
authors.forename: Duncan
authors.initials: D
authors.lastname: Loft
authors.forename: Ramesh P
authors.initials: RP
authors.lastname: Arasaradnam
mesh_terms: D000888:Antibodies, Anti-Idiotypic / Q000097:blood*; D015415:Biomarkers / Q000097:blood; D002446:Celiac Disease / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D017098:IgA Deficiency / Q000276:immunology*; D007413:Intestinal Mucosa / Q000276:immunology; D008297:Male; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D012698:Serologic Tests
chemical_list: D000888:Antibodies, Anti-Idiotypic; D015415:Biomarkers