In the early years group work was focused on new ELISA methodology in gluten analysis since traditional methods had been found not to be adequately sensitive and reliable. Further work, in particular close collaboration with Professor Enrique Méndez, University of Madrid, led to improved ELISA methods with sandwich and competitive assay systems based on the monoclonal R5 antibody directed towards the gluten peptide QQPFP in gliadins, hordeins and secalins.  Immunochemical work was accompanied by mass spectrometry, HPLC, SDS-PAGE and capillary electrophoresis as supplementary methods (see Garcia et al., 2005; Méndez et al., 2005; Valdés et al., 2003).  In 2006 the R5 ELISA method was endorsed as a type 1 method by the Codex Committee of Methods on Analysis and Sampling (CCMAS).

WGPAT has worked towards a gliadin standard and has produced “PWG gliadin” as the basis for further standardization (see van Eckert et al., 2006).  This material is available in 100-mg-batches from the WGPAT chairman.

Clinical work was conducted on oats and on the safe gluten threshold in gluten-free products used for therapy of patients with coeliac disease (see Dr. Pekka Collin et al., University of Tampere, Finland; Prof. Carlo Catassi et al., University of Ancona, Italy).  These new clinical studies together with progress in analytical methodology concerning gluten analysis have led CCNFSDU in 2007 to forward to the commission the draft-revised Codex standard for foods for special dietary use for persons intolerant to gluten for final adoption. 

Coeliac disease is the main clinical topic of WGPAT work.  It is a permanent gluten-sensitive autoimmune enteropathy triggered by gluten. It has a genetic basis expressed by HLA markers (HLA DQ2, DQ8).  It is a lifelong disease affecting all age groups and it shows many clinical presentations.  Considering all of these (active, silent, latent forms) it has a prevalence of 1:100 to 1:200.  Thus it is a relatively commonly disease.  Basically it is responsive to dietary therapy, namely the gluten-free diet. Gluten-free diet is also an efficient measure to prevent macronutrient and micronutrient deficiencies as well as growth deficiency in children and also the development of refractory lesions, of additional autoimmune diseases and malignoma of the gastrointestinal tract in coeliac disease. Scientific progress has helped to improve evidence-based regulatory solutions for defining and controlling the gluten-free diet at an international level (see Wieser & Koehler, 2008; Stern, 2008).

Even after much scientific progress has been made in analytical and clinical terms, still open questions remain such as long-term challenge studies, special evaluation of highly sensitive patients, consideration of gluten consumption data in different countries of the world, inclusion of glutenin as a potentially toxic substance in coeliac disease, and the inclusion of a numerical safety factor in food regulations.  Alternative forms of therapy and prevention of coeliac disease appear at the horizon today.  Thus, much work remains to be done. WGPAT offers its active help to advance science and practice as well as evidence-based food regulations in the dietary therapy of coeliac disease.

Bibliography

García E, Llorente M, Hernando A, Kieffer R, Wieser H, Méndez E. Development of a general procedure for complete extraction of gliadins for heat processed and unheated foods. Eur J Gastroenterol Hepatol 2005; 17: 529-539.

Méndez E, Llorente M, García E, Vela C, Immer U, Janssen FW. Report of a collaborative trial to investigate the performance of the R5 enzyme-linked immuno assay to determine gliadin and gluten-free food. Eur J Gastroenterol Hepatol 2005; 17: 1053-1063.

Stern M. Current Therapy. In: Fasano A, Troncone R, Branski D (eds). Frontiers in Celiac Disease. Pediatric Adolesc Med. Basel: Karger 2008; 12: 114-122.

Stern M, Ciclitira P, van Eckert R, Feighery C, Janssen FW, Mendez E, Mothes T, Troncone R, Wieser H. Analysis and clinical effects of gluten in coeliac disease. Eur J Gastroenterol Hepatol 2001; 13: 741-747.

Valdés I, García E, Llorente M, Méndez E. Innovative approach to low-level gluten determination in foods using a novel sandwich ELISA protocol. Eur J Gastroenterol 2003; 15: 465-474.

van Eckert R, Berghofer E, Ciclitira PJ, Chirdo F, Denery-Papini S, Ellis HJ, Ferranti P, Goodwin P, Immer U, Mamone G, Méndez E, Mothes T, Novalin S, Osman A, Rumbo M, Stern M, Thorell L, Whim A, Wieser H. Towards a new gliadin reference material - isolation and characterisation. J Cer Sci 2006; 43: 331-341.

Wieser H, Koehler P. The biochemical basis of celiac disease. Cer Chem 2008; 85: 1-13.