Brief Article
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World J Gastroenterol. Aug 21, 2013; 19(31): 5111-5117
Published online Aug 21, 2013. doi: 10.3748/wjg.v19.i31.5111
Diagnostic accuracy of a new point-of-care screening assay for celiac disease
Faiza Benkebil, Christophe Combescure, Silvia I Anghel, Cécile Besson Duvanel, Michela G Schäppi
Faiza Benkebil, Vidymed, 1007 Lausanne, Switzerland
Christophe Combescure, CRC and Division of Clinical Epidemiology, Department of Health and Community Medicine, University of Geneva and University Hospitals of Geneva, 1007 Geneva, Switzerland
Silvia I Anghel, R and D Department, Augurix, BioArk, 1870 Monthey, Switzerland
Cécile Besson Duvanel, Scientific Officer, Augurix, BioArk, 1870 Monthey, Switzerland
Michela G Schäppi, Pediatric Gastroenterology Unit, Pediatrics Department, Geneva University Hospitals, 1211 Geneva, Switzerland
Author contributions: Benkebil F designed the study and performed the research; Combescure C performed the statistical analysis and wrote the paper; Anghel SI performed the data analysis and wrote the paper; Besson Duvanel C designed the study and wrote the paper; Schäppi MG designed the study, performed the research, and wrote the paper.
Supported by the Swiss Celiac Association, Association Romande de Coeliakie, No. ME 8309 awarded to Schäppi MG
Correspondence to: Michela G Schäppi, MD, PhD, Clinique des Grangettes 7, Chemin des Grangettes, 1224 Chêne-Bougeries, Switzerland. michela.tempia@grangettes.ch
Telephone: +41-22-3050578 Fax: +41-22-3050579
Received: January 29, 2013
Revised: April 23, 2013
Accepted: May 8, 2013
Published online: August 21, 2013
Processing time: 202 Days and 1.4 Hours
Abstract

AIM: 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).

CONCLUSION: 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.

Keywords: Celiac disease; Deamidated gliadin; Total immunoglobulin A; Screening; Point-of-care assay

Core tip: The aim of the present study was to evaluate the clinical accuracy of a new point-of-care device that is based on deamidated gliadin peptides (DGP) for diagnosis of celiac disease (CD). One-hundred-and-twelve patients with clinical symptoms suggestive of CD and/or first-degree relatives of CD patients, and patients with confirmed CD on a gluten-free diet, were prospectively enrolled in the study. The actual CD diagnosis had been based on serum-positive immunoglobulin A anti-tissue transglutaminase results by enzyme-linked immunosorbent assay and on biopsy findings. Overall evaluation shows that the new DGP-based rapid point-of-care test is an excellent screening tool for high-risk populations.