title: Diagnostic accuracy of a new point-of-care screening assay for celiac disease.
abstract: OBJECTIVE
  To determine the diagnostic accuracy of a new point-of-care assay detecting anti-deamidated gliadin peptides in celiac disease (CD) patients.
  
  
  METHODS
  One-hundred-and-twelve patients (age range: 1.8-79.2 years old) with clinical symptoms suggestive of CD and/or first-degree relatives (FDR) of CD patients (n = 66), and confirmed CD on a gluten-free diet (GFD) (n = 46), were prospectively enrolled in the study at Gastroenterology outpatient clinics for adult patients and from the Gastroenterology Consultation Ward at the Pediatric Department of the University Hospital of Geneva. Written informed consent was obtained from all subjects enrolled. The study received approval from the local ethics committee. The original CD diagnosis had been based on serum-positive IgA anti-tissue transglutaminase enzyme-linked immunosorbent assay (ELISA) (QuantaLite™, Inova Diagnostics, San Diego, CA, United States) and on biopsy results. Serum samples from all study participants were tested by the new CD lateral flow immunochromatographic assay (CD-LFIA) device, Simtomax® Blood Drop (Augurix SA, BioArk, Monthey, Switzerland) to detect immunoglobulin (Ig)A and IgG antibodies against deamidated gliadin peptides. The diagnostic performance was evaluated using receiver operating characteristic curves with 95%CIs. A cut-off of 2 on the Rann colorimetric scale was used to calculate the device's sensitivity and specificity.
  
  
  RESULTS
  CD-LFIA was highly accurate in detecting untreated celiac patients. In the group of patients with CD symptoms and/or FDR, eight new cases of CD were detected by ELISA and biopsy. All of these new cases were also correctly identified by CD-LFIA. The test yielded four false positive and four false negative results. The false positive results were all within the groups with clinical symptoms suggestive of CD and/or FDR, whereas the false negative results were all within the GFD group. The test yeld a sensitivity of 78.9% (95%CI: 54.4-93.9) and specificity of 95.7% (95%CI: 89.4-98.8), and the area under the curve reached 0.893 (95%CI: 0.798-0.988). The Kappa coefficient, calculated according to the values obtained by two readers from the same device, was of 0.96 (SE: 0.06). When the GFD patients were excluded from the analysis, the area under the curve reached 0.989 (95%CI: 0.971-1.000) and the Kappa coefficient, calculated according to the values obtained by two readers from the same device, became 0.96 (SE: 0.07). Furthermore, using the Rann scale cut-off of 2 without the GFD patients, sensitivity was 100% and specificity was 93.1% (95%CI: 83.3-98.1).
  
  
  CONCLUSIONS
  The new CD-LFIA rapid screening test shows good diagnostic accuracy, sensitivity and specificity, and may rule out CD in patients with CD-related symptoms.
authors: Vidymed, 1007 Lausanne, Switzerland.
authors: Faiza
authors: F
authors: Benkebil
authors: Christophe
authors: C
authors: Combescure
authors: Silvia I
authors: SI
authors: Anghel
authors: Cécile
authors: C
authors: Besson Duvanel
authors: Michela G
authors: MG
authors: Schäppi
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D019540:Area Under Curve; D001323:Autoantibodies / Q000097:blood; D015415:Biomarkers / Q000097:blood; D001706:Biopsy; D002446:Celiac Disease / Q000097:blood / Q000175:diagnosis* / Q000178:diet therapy / Q000276:immunology; D002648:Child; D002675:Child, Preschool; D002846:Chromatography, Affinity; D055050:Diet, Gluten-Free; D004797:Enzyme-Linked Immunosorbent Assay; D005188:False Negative Reactions; D005189:False Positive Reactions; D005260:Female; D019204:GTP-Binding Proteins; D005903:Gliadin / Q000276:immunology*; D006801:Humans; D007070:Immunoglobulin A / Q000097:blood*; D007074:Immunoglobulin G / Q000097:blood*; D007223:Infant; D008297:Male; D008875:Middle Aged; D010349:Patient Compliance; D010446:Peptide Fragments / Q000276:immunology*; D019095:Point-of-Care Systems; D011237:Predictive Value of Tests; D011446:Prospective Studies; D000091345:Protein Glutamine gamma Glutamyltransferase 2; D012372:ROC Curve; D015203:Reproducibility of Results; D013557:Switzerland; D011503:Transglutaminases / Q000276:immunology; D055815:Young Adult
chemical_list: D001323:Autoantibodies; D015415:Biomarkers; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D010446:Peptide Fragments; D005903:Gliadin; D000091345:Protein Glutamine gamma Glutamyltransferase 2; D011503:Transglutaminases; D019204:GTP-Binding Proteins
keywords: Celiac disease; Deamidated gliadin; Point-of-care assay; Screening; Total immunoglobulin A
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