"Adding DNA-test for Screening of HLA-DQ2 and DQ8 to Improve the Early Diagnosis of Celiac Disease at the Dutch Preventive Youth Healthcare Centres (GLUTEN-GEN)"

Celiac Disease (CD) is an immune-mediated systemic disorder elicited by the ingestion of gluten containing cereals from the normal diet, among others wheat, rye and barley. The disease is characterized by a variable combination of gluten-dependent clinical manifestations, CD specific antibodies, human leukocyte antigen (HLA)-DQ2 or HLA-DQ8 haplotypes and chronic inflammation of the small bowel[1,2]. T-cells in the lamina propria of the small bowel recognize the gluten peptides when they are bound to the HLA class II specificities DQ2 and/or DQ8 on antigen-presenting cells.

CD is one of the most common lifelong food- related disorders; it has a frequency of 1% in the general population: this corresponds to 170.000 persons in the Netherlands, and of them at least 30.000 children[3-7]. However, CD is frequently unrecognized, partially because of its variable clinical presentations and symptoms, ranging from malabsorption with chronic diarrhoea, poor growth in children and weight loss, to nonspecific signs and symptoms like chronic fatigue, osteoporosis/reduced bone mineral density, gastrointestinal symptoms or elevated liver enzymes [5,7,8]. Unrecognized and thereby undiagnosed and untreated disease is associated with short- and long-term complications such as delayed puberty, neuropsychiatric disturbances, associated autoimmune disease, miscarriages, small-for-date-births, osteoporosis, and, rarely, malignancy. CD has a considerable health burden for society and yields extensive negative economic consequences, thereby presenting a resource challenge for current and future health systems [9]. Once diagnosed, the patient's health status improves after treatment with a gluten free diet (GFD).

That timely diagnosis and treatment of CD could be achieved by active case-finding, show the preliminary results of the ongoing ZonMw sponsored project GLUTENSCREEN (531002001; www.glutenscreen.nl). In this active case finding project, started at February 2019, all children aged 1-4 years who attend the Preventive Youth Health Care Centres (YHCCs) in the region of Kennemerland are yearly assessed for 10 CD-related symptoms during their regular consultation. If a child has one or more symptoms, the parents of the child are invited to participate. After informed consent, a point of care test (POCT) assessing CD-specific antibodies against tissue-transglutaminase (TGA) from a droplet of blood, is performed onsite at the YHCCs. If the POCT is positive (TGA present), CD is highly suspected and the child is referred to the Leiden University Medical Centre (LUMC) for diagnosis according to the standard of care[1,2]. The preliminary results of GLUTENSCREEN are beyond expectations: From the 14.917 children attending the YHCCs, 5.512 (37.0%) of them had one or more CD-related symptoms.

The parents of 3.203 (58.1%) children gave informed consent for a POC-test. In 61 (1.9%) children the POC-test was positive. After additional investigations at our hospital, CD was confirmed in 55 children (1.7% of the tested children) (serum IgA TGA >10xULN and IgA against endomysium (EMA) positive) and ruled out in 5 children with dubious/positive POC test: in two children HLA-DQ2/8 was negative with negative TGA in serum (ELISA-test), in 3 children with TGA <10 x ULN (ELISA-test) in whom small bowel biopsies showed Marsh 1 lesions. One child still needs to be seen in the hospital (parents refused till now) (www.glutenscreen.nl). From the parents who were invited for GLUTENSCREEN, almost 80% is willing to participate if the POCT could be performed during the regular visit at the YHCC. All health care professionals reported that early CD detection by case-finding adds value to the preventive care they offer at the YHCCs.

These preliminary results of our active CD case-finding project at the Preventive YHCCs in the Netherlands illustrate that early detection of CD at the Preventive YHC is feasible and well-accepted by parents and health care professionals.