Retrospective Study
Copyright ©The Author(s) 2016. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastrointest Pharmacol Ther. May 6, 2016; 7(2): 254-260
Published online May 6, 2016. doi: 10.4292/wjgpt.v7.i2.254
Clinical utility of quantitative multi-antibody Polycheck immunoassays in the diagnosis of coeliac disease
Ewa Konopka, Maciej Grzywnowicz, Beata Oralewska, Joanna Cielecka-Kuszyk, Ilona Trojanowska, Bożena Cukrowska
Ewa Konopka, Joanna Cielecka-Kuszyk, Ilona Trojanowska, Bożena Cukrowska, Department of Pathology, the Children’s Memorial Health Institute, 04-730 Warsaw, Poland
Maciej Grzywnowicz, Department of Experimental Hematooncology, Medical University of Lublin, 20-059 Lublin, Poland
Beata Oralewska, Department of Gastroenerology, Hepatology, Nutritional Disorders and Pediatrics, the Children’s Memorial Health Institute, 04-730 Warsaw, Poland
Author contributions: Konopka E and Grzywnowicz M contributed equally; all authors contributed to this manuscript.
Supported by S135/2013 and 229/14 grants from the Children’s Memorial Health Institute.
Institutional review board statement: The study was reviewed and approved by the Children’s Memorial Health Institute Bioethical Committee Review Board.
Informed consent statement: All patient involved in the study obtained informed consent statement from the principal investigator.
Conflict-of-interest statement: Grzywnowicz M is an employee of the EMMA Paweł Majsiak company. For the remaining authors, none are declared.
Data sharing statement: Technical appendix, statistical code, and dataset available from the corresponding author at b.cukrowska@czd.pl. Informed consent for data sharing was not obtained. The presented data are anonymized and there is no risk identification.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Bożena Cukrowska, Professor, Department of Pathology, the Children’s Memorial Health Institute, Aleja Dzieci Polskich 20, 04-730 Warsaw, Poland. b.cukrowska@czd.pl
Telephone: +48-228-151091 Fax: +48-228-15197
Received: April 10, 2015
Peer-review started: April 11, 2015
First decision: August 1, 2015
Revised: October 13, 2015
Accepted: January 21, 2016
Article in press: January 22, 2016
Published online: May 6, 2016
Processing time: 376 Days and 2.4 Hours
Abstract

AIM: To evaluate the clinical utility of multi-antibody strategies in the diagnosis of coeliac disease (CD), the new quantitative Polycheck immunoassays were analysed.

METHODS: Polycheck Celiac Panels (PCPs) are immunoenzyme screening assays for the quantitative measurement of coeliac-specific immunoglobulin class G (IgG) or class A (IgA) in serum. Lines of relevant antigens are coated together with five IgG or IgA standard lines used for the standard curve as positive control. PCP IgA consists of human recombinant human tissue transglutaminase (tTG) and deamidated gliadin peptides (DGP) as targets to detect IgA antibodies. PCP IgG consists of tTG, DGP and IF (intrinsic factor) antigens to detect antibodies in IgG class. PCPs were performed on 50 CD patients, including 6 cases with selective IgA deficiency, and 50 non-coeliac controls. CD diagnosis was performed according to the ESPGHAN recommendations: The presence of specific anti-tTG-IgA or anti-DGP-IgG (in the case of IgA deficiency) antibodies, typical histopathological changes in duodenal mucosa described in Marsh-Oberhüber classification as at least grade 2. The diagnosis of the majority of the control subjects was functional gastrointestinal disorders. The PCP results were compared with reference EliA Celikey.

RESULTS: The usage of PCPs led to the correct identification of all CD patients. In our study, PCPs showed 100% agreement with the histopathological results. PCP IgA test showed a 98% concordance and correlated positively (R = 0.651, P = 0.0014) with EliA Celikey test. The highest specificity and positive predictive value (both 100%) were observed for the detection of Polycheck anti-tTG-IgA antibodies. The highest sensitivity and negative predictive value (both 100%) were achieved by Polycheck anti-DGP-IgG antibody detection. The best performance (98% sensitivity and negative predictive value, 100% specificity and positive predictive value, diagnostic accuracy - AU ROC 99%) was observed for the strategy of using both PCP IgA and IgG and determining positive outcomes of the test with two or more coeliac-specific antibodies detected. The majority of coeliac patients had multiple antibodies. All four antibodies were detected in 7 (14%) cases, 19 children (38%) were positive for three antibodies and 23 (46%) were positive for two antibodies.

CONCLUSION: The present study showed that detection of coeliac-specific antibodies with multi-antibody PCPs is effective and efficacious in the diagnosis of CD.

Keywords: Coeliac disease; Tissue transglutaminase; Deamidated gliadin peptides; Multi-antibody tests; Polycheck celiac panels

Core tip: Detection of coeliac-specific antibodies has become a useful tool in the diagnostics of coeliac disease. Different serology test combinations have been found to improve diagnosis in comparison to a single antibody test. Recently, multi-antibody strategy has been implemented in immunoassays. In this study we have found that multi-parametric quantitative Polycheck immunoassay is reliable in reference to intestinal biopsy results and measurements of anti-tissue transglutaminase-IgA by a reference method. The best overall clinical performance was obtained by a combination of both IgA and IgG panels, with two and more positively detected antibodies, to determine the outcome.