Background : The continuing flow of scientific development in coeliac disease in the past decade points to the need for the formulation of a new concept of pathophysiology and clinical approach to the coeliac condition. Immunogenetic studies have shown a correlation of the disease to the HLA region on the short arm of chromosome 6; immunological research has led to the concept of a T-cell-driven immunologic response of the small intestine, with the identification of highly sensitive and specific antibodies; and our understanding of the histopathology of coeliac disease has changed dramatically, initiated by the proposition of a spectrum of gluten-sensitive enteropathy by Marsh in 1992. Clinical studies report a significant change in patient characteristics and epidemiology. The incidence of the disease has shifted to a majority of adult coeliacs, and it may present with less severe symptoms of malabsorption. Screening studies suggest an overall prevalence of up to 1 in 200-300. Methods : Update on histopathology concentrating on the work of our research group. Results : We specifically describe the work of our group in Arnhem concerning the identification and validation of the spectrum of intestinal histopathology in gluten-sensitive enteropathy, i.e. lymphocytic enteritis (Marsh I lesion), lymphocytic enteritis with crypt hyperplasia (Marsh II lesion), and villous atrophy, subdivided into partial villous atrophy (Marsh IIIA), subtotal villous atrophy (Marsh IIIB) and total villous atrophy (Marsh IIIC). Special attention is given to a subgroup of 'refractory coeliacs', including the identification of (pre-)malignant aberrant T cells in the intestinal mucosa of these patients. Conclusion : New data on immunogenetics, epidemiology, histopathology and patient characteristics point to a significant change of view on coeliac disease.

Background: To determine the applicability and sensitivity of a urine self-test to detect gluten-immunogenic-peptides (GIP) in daily-life for patients with coeliac disease and correlate the test results with reported symptoms. Methods: We performed a prospective double-blinded placebo-controlled study, including adults with coeliac disease adhering to a strictly gluten-free diet. Patients were administered gluten in test-cycles of ascending doses of 50, 100, 200, and 500 mg alternated with placebo. Urine portions from 2, 5–17 h after the ingestion were collected and analyzed for GIP using the iVYCHECK-GIP-Urine rapid lateral flow test. Patients completed a diary mapping symptoms (nausea, bloating, diarrhea, abdominal pain, and lower level of energy). Results: We enrolled 15 patients and 7 received all 4 cycles with increasing gluten dosing. GIP was detected from urine in 47% of the patients receiving 50 mg gluten and in 86% with 500 mg gluten. We detected GIP in 20–50% of urine samples after placebo. There was no correlation between symptoms, gluten administration and/or GIP in urine. Conclusions: Gluten intake, even with a dose as low as 50 mg, leads to detectable urinary GIP concentrations. There is no correlation of coeliac disease ascribed symptoms with detection of urinary GIP.

PNAd and MAdCAM-1 addressins on venules are of importance in T-cell homing and potential therapeutic targets in ulcerative colitis (UC). Normally, PNAd⁺ high endothelial venules (HEVs) are only present in lymphoid organs, whereas small numbers of MAdCAM-1⁺ venules can be seen in non-lymphoid tissue. We aimed to study their presence in the intestinal mucosa of UC patients at diagnosis and during follow-up, and their correlation with disease activity. Colonic biopsy specimens of 378 UC patients were analyzed by immunohistochemistry for CD3, CD20, ERG, MECA-79 (PNAd) and MECA-376 (MAdCAM-1) and compared to healthy controls (HC). The proportion of PNAd⁺HEVs in UC at diagnosis was 4.9% (IQR 2.0%–8.3%), while none were detected in HC. During follow-up, PNAd⁺HEVs completely disappeared in remission (n = 93), whereas the proportion in active disease was similar to baseline (n = 285, p = 0.39). The proportion of MAdCAM-1⁺venules in UC at baseline was 5.8% (IQR 2.6–10.0). During follow-up, the proportion in remission was comparable to diagnosis, but upregulated (7.5% (IQR 4.4–10.9), p = 0.001) in active disease. In conclusion, PNAd⁺HEVs appear in UC during active inflammation which could thus serve as a marker for disease activity, whereas MAdCAM-1⁺venules remain present after inflammation is resolved and increase after subsequent flares, reflecting chronicity and potentially serving as a therapeutic target.