OBJECTIVE:To study the accuracy of IgA- and IgC-gluten antibodies and endomysium antibodies as screening tools for endoscopy with small bowel biopsy for histologic diagnosing of coeliac disease.DESIGN:Comparing serology with histologic examination--the "gold standard" for diagnosing coeliac disease.SETTINGS:1. The municipality of Osthammar, Sweden. 2. The catchment area of the University Hospital, Uppsala, Sweden.PATIENTS:1. A random subsample (50 with dyspepsia, 50 with irritable bowel syndrome and 50 symptomless) of a representative sample from an adult Swedish general population (20-80 years; n = 1260). 2. All patients with a diagnosis of coeliac disease admitted to the University Hospital in Uppsala, Sweden during the course of 10 months.MAIN OUTCOME MEASURES:The accuracy of IgA- and IgG-gluten antibodies and endomysium antibodies.RESULTS:There were no significant correlations between IgA-gluten antibodies and IgG-gluten antibodies, on the one hand, and symptoms or symptom severity, on the other. Using duodenal biopsy results as the gold standard, IgA-gluten antibodies had a low specificity and IgG-gluten antibodies a low sensitivity, whereas endomysium antibodies had an excellent accuracy.CONCLUSION:Endomysium antibodies seem to be the screening test of choice. The load of diagnostic upper endoscopies would be considerably decreased compared to using gluten antibodies.

Increased serum levels of RF have been reported in patients with gluten sensitivity. The objective of this study was to investigate the in vivo secretion of different isotypes of RF in the small bowel in coeliac disease. Nineteen patients were investigated by perfusion of a defined jejunal segment, and the jejunal perfusion fluid was analysed for the presence of IgA and IgM anti-Fc (IgG). Five of the patients studied had serum IgA deficiency. Patients with partial/subtotal villous atrophy but no IgA deficiency (n = 7) had a four-fold increase of IgM-RF (P < 0.001) and a three-fold increase of IgA-RF (P < 0.001) compared with healthy controls (n = 29). Patients with normal jejunal mucosa but no IgA deficiency (n = 7) had similar IgA-RF and IgM-RF concentrations to healthy controls. Patients with serum IgA deficiency had no IgA-RF detectable in jejunal fluid but the highest IgM-RF concentrations, in particular in active disease. The coeliac patients had serum levels of IgA-RF and IgM-RF within the reference ranges. Jejunal fluid levels of IgA-RF and IgA-anti-gliadin antibodies were significantly correlated (P < 0.001). The data indicate that enhanced jejunal mucosal production of RF occurs above all in active coeliac disease. The findings suggest that the immune response to gluten induces a mucosal RF synthesis.

Intestinal release of inflammatory mediators and permeation of macromolecules were studied in patients suffering from Crohn's disease, celiac disease and food intolerance with the use of a system for segmental intestinal perfusion. Drug absorption and ion and bicarbonate transport were also studied in healthy subjects. Patients with Crohn's disease of the distal ileum revealed an increased release of inflammatory agents into the lumen of the proximal jejunum. Luminal provocation with different antigens in cases of celiac disease and food intolerance not only activated cells in the intestinal mucosa but also increased the leakage from plasma and lymph. Studies of drug absorption elucidated the kinetics of drug transport from intestine to plasma, and basal neurologic effects on ion and bicarbonate transport were determined.

The class and subclass distribution of antibodies against gliadin in intestinal lavage fluid, saliva and serum was investigated in individuals with coeliac disease. Serum antibodies against gliadin were mainly or even exclusively of the IgA1 subclass. In intestinal lavage fluid and saliva, antibodies of both IgA1 and IgA2 subclasses were found. In patients with and without IgA deficiency, an IgG response was detected both in serum and intestinal lavage fluid with a predominance of IgG1 in selected patients. Specific IgG2, IgG3 and IgG4 antibodies were also detected in intestinal lavage fluid, while no specific IgG2, IgG3 or IgG4 antibodies were found in serum, suggesting a local production of specific IgG antibodies. In Western blot analysis, intestinal lavage fluid and serum IgA antibodies reacted against gliadin components with a MW between 33,000 and 42,000. Serum IgA1 antibodies directed against a gliadin component with a MW slightly higher than 42,000 were also observed. Specific IgG and IgM antibodies in both the secretion and serum against gliadin components with a MW between 33,000 and 42,000 were also detected. This study shows that mucosa-derived gliadin-specific IgA and IgG antibodies may be produced even when there is an absence of specific antibodies of the corresponding immunoglobulin subclass in serum. Furthermore, the specificity of serum and intestinal lavage fluid anti-gliadin IgA1 antibodies may differ.

Intestinal disease might contribute to osteopenia. Measurements of IgA antibodies to gliadin have been established as an accepted screening procedure for detection of coeliac disease. When we applied these measurements to 92 patients with verified osteoporosis. 11 subjects (12 %) were found to have elevated levels. This is markedly higher than the incidence in healthy subjects (3%). However, the patients with raised levels of IgA antibodies displayed no clinical symptoms and no laboratory evidence of calcium malabsorption. Thus their values for serum calcium, phosphate, parathyroid hormone (PTH), alkaline phosphatase and osteocalcin, as well as the fasting urinary excretion of hydroxyproline and calcium, were similar to those found in other patients with osteoporosis. Intestinal biopsy verified coeliac disease in three patients and was normal in another three. This gives an incidence of verified coeliac disease in this patient group that is approximately tenfold higher than that in the healthy population. Subclinical coeliac disease appears to be unusually over-represented among patients with idiopathic osteoporosis, and screening for gliadin antibodies might therefore be a valuable addition to the routine assessment of the osteopenic patient. The mechanisms underlying the relationship are not clear, but calcium malabsorption is not evident.

The small intestines of healthy volunteers were challenged with ethanol during regional perfusion of a defined jejunal segment. Infusion of 30 mL of 5000 mmol/L ethanol to the perfused jejunal segment gave a maximum ethanol concentration of 973 +/- 98 (SEM) mmol/L in the jejunum lumen. This ethanol challenge induced within 20-30 minutes a 10-fold increase in albumin (P less than 0.001) and a two-fold increase in the glycosaminoglycan hyaluronic acid (P less than 0.05) in the perfusion fluid. Later during the challenge and simultaneously with a decreased jejunal loss of albumin, the jejunal recovery of prostaglandin E2 increased fourfold (P less than 0.01). The jejunal fluid concentrations of histamine and eosinophil cationic protein remained stable during the ethanol challenge. No changes in the jejunal appearance of albumin or other measured substances were seen when the maximum jejunal fluid concentrations of ethanol were less than 400 mmol/L achieved during challenge with smaller amounts of ethanol. The increased jejunal fluid appearance of hyaluronic acid after ethanol challenge indicates increased leakage from the interstitial/lymph fluid of the gut wall due to altered mucosal permeability. The relatively larger jejunal losses of albumin suggest that ethanol induces increased microvascular permeability of the jejunum as well.

The capacity to clear IgG containing immune complexes from the circulation was studied in patients with coeliac disease (n = 13), dermatitis herpetiformis (n = 8), and coeliac disease with concomitant serum IgA deficiency (n = 4). A small group of patients with active ulcerative colitis (n = 4) was included as a bowel disease control group. Clearance was estimated by measuring the disappearance rate of a bolus dose of intravenously injected IgG coated autologous erythrocytes. The mean T1/2 of clearance was prolonged in both coeliac disease (86 (24) minutes) and dermatitis herpetiformis (111 (35) minutes), compared with healthy subjects (20 (5) minutes) and coeliac patients with concomitant serum IgA deficiency (T1/2 = 17 (6) minutes). Patients with ulcerative colitis had a prolonged clearance, with a T1/2 of 195 (63) minutes. Values of circulating immune complexes were measured by four assays; C1q binding and C3, IgG, and IgA containing immune complexes. C1q binding immune complexes were detected only in IgA deficient gluten sensitive enteropathy. Patients with coeliac disease and dermatitis herpetiformis had higher values of C3, IgG, and IgA containing immune complexes than control subjects and serum IgA deficient patients with coeliac disease. The clearance rate was inversely correlated to the amount of immune complexes for the subgroups of gluten sensitive enteropathy.

Intestinal secretion rates of albumin, hyaluronan, and beta 2-microglobulin (beta 2-micro) were determined under basal conditions and after gliadin challenge of coeliac patients and healthy controls by the use of a jejunal perfusion technique. A new tube system was used where a jejunal segment is isolated between balloons and then perfused with a balanced salt solution. Under basal conditions the secretion rate of albumin was similar in the patients and controls while the secretion rate of the glycosaminoglycan hyaluronan, a high molecular weight connective tissue component, was increased more than two times in coeliac patients. Beta 2-micro was secreted in on average three-fold rates in coeliacs compared with controls. All three substances were secreted at a higher rate in patients with active disease than in those with inactive disease defined by morphological damage in small bowel biopsies. The concentrations in jejunal perfusion fluids relative to serum levels in the coeliac patients were for albumin 0.0007, beta 2-micro 0.10, and for hyaluronan 1.94. Challenge with a single dose of gliadin into the jejunal segment gave within 60 min a significant, about two-fold, increase of the secretion rates of all three measured substances. The appearance of hyaluronan could reflect a gliadin induced mucosal oedema with an enhanced leakage from the interstitial/lymph fluid, rich in this glycosaminoglycan. The observed parallel increases in the jejunal secretion of albumin and beta 2-micro after gliadin challenge are best explained by a similar mechanism.

Jejunal prostaglandin E2 secretion in patients with adult celiac disease was studied under basal conditions and after local gliadin challenge. A newly developed tube system with occluding balloons was used to perfuse a jejunal segment. After an initial basal perfusion period of 40 minutes, an average of 12 mg +/- 3 (SEM) of crude gliadin was administered into the perfused segment. Perfusion continued for an additional 100 minutes and prostaglandin E2 was determined in the effluent with a radiometric method. Patients with histologically active celiac disease (n = 7) had higher basal jejunal secretion of prostaglandin E2, 523 +/- 229 pg.cm-1.h-1 (mean +/- SEM), than both celiac patients with normalized small bowel mucosa (n = 6), 160 +/- 44 pg.cm-1.h-1, and healthy controls (n = 18), 184 +/- 38 pg.cm-1.h-1, (P less than 0.05). After gliadin challenge of the jejunal segment, a significant increase (P less than 0.05) in prostaglandin E2 secretion was noted in patients with celiac disease (n = 10). The individual maximum increase was on average fivefold and occurred 60-100 minutes after gliadin administration. In healthy controls (n = 5), no alteration in prostaglandin E2 secretion was detected after gliadin challenge. Enhanced jejunal prostaglandin 2 synthesis may be involved in the pathophysiological processes initiated by gliadin in patients with celiac disease.

Prostaglandins have been implicated in the pathophysiology of diarrhoea in coeliac disease (1,2,3). We have used a double-balloon catheter system, which allows the perfusion of a defined jejunal segment (4), to measure PGE2 in jejunal secretions.

Purpose The aim of this study was to clarify the role of eosinophils and mast cells in the small bowel in celiac disease. Patients and methods Patients with celiac disease (n = 10) were investigated by perfusion of a closed jejunal segment. The concentrations of certain granule constituents from eosinophils, eosinophil cationic protein (ECP), and from mast cells/ basophils, histamine, were measured and the jejunal secretion rates of these cellular markers were calculated. Results Compared with findings in healthy control subjects (n = 14), increased secretion rates were observed under basal conditions in patients with histopathologically active celiac disease. Gliadin, administered by perfusion to the jejunal segment, induced a fourfold increase in ECP secretion and a twofold increase of histamine secretion in patients with celiac disease (n = 7), but did not influence the secretion rates of these substances in healthy controls (n = 3). The secretion rate of ECP started to increase 20 minutes after challenge of the perfused segment with gliadin and reached maximum levels 40 minutes later. The secretion rate of histamine started to increase 40 minutes after gliadin administration. Concurrently with these inflammatory events, the secretion of albumin was doubled as a sign of increased mucosal leakage. Conclusion These data indicate that eosinophils and mast cells are both involved in the early gliadin-induced reactions of the small intestine, and suggest that these cells are effector cells participating in the celiac lesion of the mucosa. The aim of this study was to clarify the role of eosinophils and mast cells in the small bowel in celiac disease. Patients with celiac disease (n = 10) were investigated by perfusion of a closed jejunal segment. The concentrations of certain granule constituents from eosinophils, eosinophil cationic protein (ECP), and from mast cells/ basophils, histamine, were measured and the jejunal secretion rates of these cellular markers were calculated. Compared with findings in healthy control subjects (n = 14), increased secretion rates were observed under basal conditions in patients with histopathologically active celiac disease. Gliadin, administered by perfusion to the jejunal segment, induced a fourfold increase in ECP secretion and a twofold increase of histamine secretion in patients with celiac disease (n = 7), but did not influence the secretion rates of these substances in healthy controls (n = 3). The secretion rate of ECP started to increase 20 minutes after challenge of the perfused segment with gliadin and reached maximum levels 40 minutes later. The secretion rate of histamine started to increase 40 minutes after gliadin administration. Concurrently with these inflammatory events, the secretion of albumin was doubled as a sign of increased mucosal leakage. These data indicate that eosinophils and mast cells are both involved in the early gliadin-induced reactions of the small intestine, and suggest that these cells are effector cells participating in the celiac lesion of the mucosa.