Clinical utility of quantitative multi-antibody Polycheck immunoassays in the diagnosis of coeliac disease

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(Ig G)or class A(Ig A)in serum.Lines of relevant antigens are coated together with five Ig G or Ig A standard lines used for the standard curve as positive control.PCP IgA consists of human recombinant human tissue transglutaminase(t TG)and deamidated gliadin peptides(DGP)as targets to detect Ig A antibodies.PCP IgG consists of t TG,DGP and IF(intrinsic factor)antigens to detect antibodies in Ig G class.PCPs were performed on 50 CD patients,including 6 cases with selective Ig A deficiency,and 50 non-coeliac controls.CD diagnosis was performed according to the ESPGHAN recommendations:The presence of specific anti-t TG-Ig A or anti-DGP-Ig G(in the case of Ig A 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 Eli A Celikey test.The highest specificity and positive predictive value(both 100%)were observed for the detection of Polycheck anti-t TG-Ig A antibodies.The highest sensitivity and negative predictive value(both 100%)were achieved by Polycheck anti-DGPIg G 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.