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Objective: A slight to moderate increase in autoantibodies to transglutaminase 2 (TG2), but no morphological evidence of villous atrophy to confirm the diagnosis of celiac disease (CD) poses a challenge for clinicians. Our aim was to study the matrix metalloproteinase (MMP) profile, proliferative and apoptotic characteristics of jejunal biopsies obtained from such pediatric patients in order to find markers predictive of early changes in extracellular matrix degrading enzymes in the development of CD., Material and Methods: Twenty-eight children with positive screening tests (increase in transglutaminase and/or endomysium antibodies), but minor histological changes in the gut (Marsh grade 0-2), were studied and followed up for 2-3 years. In situ hybridizations for MMP-1, -3 and -12 were performed and sections were immunostained for MMP-19 and -26. Proliferating cells were identified by Ki-67 immunostaining and apoptotic cells using the TUNEL technique., Results: MMP-12 was detected in macrophages in 16/28 samples and its expression was associated with increased autoantibodies for TG2 and densities of CD3 and gammadelta positive T-cells in the epithelium. The number of stromal MMP-26 positive cells was high in patients with high TG2 titers. Expression of MMP-12, MMP-1 and -3 clustered in children with type 1 diabetes (T1D) and the proportion of apoptotic mucosal cells was increased in patients with T1D compared to the others. When children with CD were compared to those who did not develop it, the numbers of IEL, cryptal Ki-67, CD-3, and MMP-12 positive cells were higher and showed the most significant differences., Conclusions: In pediatric patients, increased numbers of MMP-12 positive macrophages in lamina propria associate with high titers of antibodies to TG2 and proness to CD. A stage of mild inflammation may contribute to the upregulation of MMPs in the gut of patients with T1D.

Objective: To determine whether biosynthesis of aminopeptidase N (ApN), alkaline phosphatase (AP), and total microvillus membrane protein is altered in Irish Setters with gluten-sensitive enteropathy (GSE)., Animals: A litter of 6 Irish Setters with GSE and 3 healthy Greyhounds., Procedures: Explants obtained from affected dogs at 4 and 12 months were maintained in vitro and were compared with material from healthy control dogs. Biosynthesis of ApN and AP was monitored by incorporation of [35S]methionine and immunoprecipitation of these enzymes., Results: Jejunal explants from affected Irish Setters had significantly higher rates of biosynthesis of total protein, microvillus membrane protein, AP, and ApN, compared with control tissue. Two forms of ApN with apparent molecular mass of 155 and 135 kd and 4 forms of AP with apparent molecular mass of 210 to 260, 150, 130, and 105 kd were identified in total membrane fractions from control and affected dogs., Conclusions: Reduced activities of ApN and AP in dogs with GSE are not attributable to decreased synthesis of these proteins and document enhanced synthesis of microvillar membrane proteins, which may be a compensatory response to enterocyte damage. The 150-kd form of AP was most prominent in tissue from the most affected dogs, probably representing an early form of this enzyme. In contrast, the 105-kd form was most intense in tissue from controls and less intense in tissue of affected dogs.

The distribution of sodium- and potassium-stimulated ATPase (Na,K-ATPase) along the crypt-villus axis and crypt cytokinetics were examined in an infective model of celiac disease produced by infection of the rat with the nematode Nippostrongylus brasiliensis. In controls, levels of enzyme activity remained stable during enterocyte migration to the villous apex. In the jejunum of infected rats, the structural lesion of villous atrophy and crypt hyperplasia, observed at day 10 of infection, was associated with a three-dimensional expansion of the crypts. Cell cycle time was shortened and this resulted in a markedly increased crypt cell production rate. Enterocytes emerged from the crypts at a faster rate, and this functional immaturity was paralleled by decreased Na,K-ATPase activity. Further decreases in enzyme levels were observed during enterocyte migration along the villi. This may reflect enterocyte damage or increased enzyme turnover. In the ileum of these animals, enterocyte maturation was prolonged and enzyme activity was increased at the level of the crypt villus junction with further increases noted during enterocyte transit. These changes in ileal Na,K-ATPase appear to be adaptive.

Two hundred and ninety four duodenal and jejunal mucosal biopsy specimens from patients with coeliac disease, treated and untreated, and other conditions were examined histologically and by histochemical staining for five peptidase and three disaccharidase enzymes to determine profiles of activity. Suppression of activity paralleled the histology with the following enzymes: lactase, trehalase, brush border endopeptidase, dipeptidyl peptidase II and isomaltase. Lactase, trehalase, and brush border endopeptidase were specifically suppressed in untreated coeliac disease and were diagnostically useful. Examination of a combination of enzymes is recommended.

The results are reported from the study on 120 patients, 30 of them with gluten enteropathy, 50--with chronic unspecified enteritis and 40--with chronic ulcerous colitis. Small intestinal aspiration biopsy was performed to all patients with histomorphological, electron microscopic, enzymatic and immune-fluorescent study. The secretory immunoglobulins in the jejunal juice were studied in 40 patients. Morphological changes, various degrees, were established, that correlate with the increased number of IgG and IgM secretory cells. The exclusion of gluten from the diet in case of gluten enteropathy was followed by normalization of the number and percentage ratio of IgSC and of secretory immunoglobulins. The enzymatic and immune disorders, in chronic unspecific enteritis correlate with the electron microscopic and precede the histologic ones. The role of immune system of small intestine in the etiology and pathogenesis of the various intestinal diseases is discussed.

Disaccharidase estimations on 115 consecutive jejunal biopsies are reported. The patients were divided into four groups: 1. Normal jejunal biopsy light microscopy, not milk intolerant, 82 cases. 2. Normal jejunal biopsy light microscopy, milk intolerant, eight cases. 3. Patients with giardiasis, 11 cases. 4. Coeliac disease patients, 14 cases. The lowest disaccharidase levels were found in coeliac disease, with giardiasis cases showing intermediate levels. Poor correlation of lactase levels with milk intolerance was found. Three cases in Group 1 showing lowered lactase levels were given metronidazole and showed remission of clinical symptoms, raising the possibility that they had undiagnosed infections with Giardia lamblia.

By use of a radiometric assay transglutaminase activity was demonstrated for the first time in human jejunal mucosa. The activity is similar to that in other tissues, with a pH optimum of 9.0, an absolute requirement for Ca2+ and an apparent Km for putrescine of 0.15 mmol/l. Assay of jejunal transglutaminase activity with a variety of dietary proteins as acceptors showed high activity with gliadin, comparable with that of the standard substrate, dimethylcasein. Deamidation of the gliadin markedly reduced its acceptor activity. Collagen, ovalbumin, elastin and zein exhibited very low acceptor activities. Increased transglutaminase activity was demonstrated in jejunal biopsies from four patients with untreated coeliac disease compared with 14 control subjects and eight patients with inflammatory bowel disease. Eight patients with coeliac disease in remission, with normal levels of brush border alpha-glucosidase, showed elevated transglutaminase activities compared with those of controls. It is postulated that intestinal transglutaminase activity may be important in gliadin binding to tissues and thus in the pathogenesis of coeliac disease.

1. Jejunal biopsies from five patients with non-responsive coeliac disease have been subjected to analytical subcellular fractionation and enzymic microassay in order to compare the organelle pathology of this group with untreated but glutensensitive patients. 2. Compared with the gluten-sensitive group these non-responsive patients showed marked reduction of the endoplasmic reticulum enzymes, normal activities of lysosomal enzymes and slightly less severely reduced brush border activities. 3. It is suggested that the present biochemical studies in combination with previous clinical reports and measurements of DNA and protein synthesis by cultured mucosal biopsies delineate non-responsive coeliac disease as a distinct entity. 4. The patients were treated with oral prednisolone (20 mg daily) for between 5 and 9 weeks and the properties of the jejunal biopsies restudied. 5. Although morphologically there was only a partial restoration of the villus architecture the enzymic alterations and organelle abnormalities returned essentially to normal values.

1. Reduced activities of four enzymes from brush borders were found in intestianl biopsies from patients with untreated coeliac disease. The activities returned towards control values after treatment by gluten withdrawal. Parallel changes were noted for the cytosol enzyme lactate dehydrogenase. 2. Measurement of brush-border integrity by differential centrifugation of biopsy extracts indicated increased fragility of the brush borders in biopsies from untreated patients. Normal values were obtained for biopsies from treated patients. 3. Increased activites of six acid hydrolases (lysosomal enzymes) were found in biopsies from untreated coeliac patients. Normal values were obtained for biopsies from treated patients. 4. Assement of lysosomal integrity by assay of latent N-acetyl-beta-glucosaminidase and of sedimentable activity of four acid hydrolases demonstrated increased lysosomal fragility in untreated coeliac mucosa. These lysosomal changes return to within the normal range after treatment by gluten withdrawal. 5. The lysosomal changes are consistent with their having a pathogenic role in the enterocyte damage of coeliac disease. Possible mechanisms for the lysosomal changes are discussed.

Lactase, sucrase, and alkaline phosphatase activities were measured in 833 peroral small intestinal biopsies from 373 patients with coeliac disease. Enzyme activities decreased with increasing degrees of mucosal damage. Enzyme activities in mucosae of patients with coeliac disease in remission were lower than in control groups matched for age, sex, and site of biopsy. Enzyme activities were measured in 81 patients when the mucosa was severely damaged and later when considerable improvement had occurred. Lactase activity remained low in 13% of patients under the age of 18 and in 33% of those over 18 years. Sucrase activity usually improved with histological recovery, but alkaline phosphatase activity tended to remain depressed in patients in whom lactase activity failed to improve.

It is well established that wheat, rye, and barley are harmful to patients with coeliac disease, but the effect of oats remains in doubt. Four patients with coeliac disease, who had shown complete mucosal recovery after prolonged treatment with a strict gluten-free diet, volunteered to consume oats in addition to their gluten-free diet for a period of one month and were studied by jejunal biopsy before and after the experimental period. The patients remained entirely symptom-free and, more important, the jejunal mucosa was undamaged as judged by appearances under dissecting and light microscopes, quantitative histological studies, and disaccharidase content. It is concluded that oats are harmless to coeliac subjects and can be included in a gluten-free diet.

This study has investigated the potential role of wheat in the pathogenesis of a naturally occurring enteropathy in Irish setter dogs. At eight months on a cereal-containing diet, jejunal biopsies from affected animals exhibited partial villus atrophy, increased intraepithelial lymphocytes, and distinct biochemical abnormalities in the brush border. Activities of alkaline phosphatase and leucyl-2-naphthylamidase were almost undetectable while disaccharidases were unaltered. Activity of 5'-nucleotidase (basolateral membrane) was low, and reduced malate dehydrogenase reflected a loss of mitochondrial activity, but other organelles were unaffected. Recovery was achieved on a wheat-free diet. Relapse on subsequent wheat challenge was characterized by partial villus atrophy and a selective effect on the brush border: modal density was decreased and there was a severe loss of brush-border alkaline phosphatase activity. These findings document a wheat-sensitive enteropathy in Irish setter dogs and suggest that brush-border alkaline phosphatase is specifically susceptible to damage by wheat.

In view of data suggesting that deficiency of gamma glutamyl transferase (GGT) may be the primary abnormality in the small-intestinal mucosa of patients with coeliac disease, this enzyme was measured in mucosal biopsies from coeliac patients at different stages of treatment. Activity was only slightly reduced in only one of nine well-treated patients, suggesting that deficiency of this enzyme has no primary role in the aetiology of coeliac disease.

Portions of jejunal biopsies from control subjects and from patients with coeliac disease were cultured for 24 hours using an in vitro organ culture technique. Alkaline phosphatase activity was measured in the tissue and medium before and after culture; enzyme activities were expressed per microgram tissue DNA. The increase in enzyme activity during the culture period was taken to represent net enzyme synthesis. Alkaline phosphatase synthesis by mucosa from patients with untreated gluten-sensitive coeliac disease and by mucosa from patients with non-responsive coeliac disease was significantly less than that by normal mucosa. Alkaline phosphatase synthesis by mucosa from patients with treated gluten-sensitive coeliac disease was greater than that by untreated coeliac mucosa but was less than normal mucosa. Sequential studies of alkaline phosphatase synthesis by jejunal mucosa from seven patients with coeliac disease, before and after successful treatment by gluten withdrawal, showed an increase in synthesis in all patients. Study, by analytical subcellular fractionation with sucrose density gradient centrifugation, of the properties of the organelles of cultured control tissue showed good preservation of their integrity. A striking finding, however, was the decrease in malate dehydrogenase with a corresponding marked increase in lactate dehydrogenase. This would be expected to be followed by a shift from aerobic to anaerobic metabolism. Analytical subcellular fractionation of cultured mucosa from patients with coeliac disease gave similar conclusions. There was, however, a marked improvement of the brush border abnormalities, characteristic of coeliac disease, during culture with increased enzyme activities and membrane equilibrium density in the sucrose gradients.

The effect of the topical corticosteroid clobetasone butyrate on enzyme activity and morphology of duodenal mucosa was studied in 9 patients with coeliac disease and 10 controls using organ culture techniques. There was significant increase in mucosal alkaline phosphatase, lactase and maltase activities, but inclusion of a soluble extract of gluten reduced this effect. When clobetasone butyrate was also included in the culture medium significant elevations in enzymes were again observed. Enterocyte height was not affected by incorporation of gluten into the medium. Intra-epithelial lymphocyte counts fell significantly during the culture period. This improvement was also inhibited by gluten and overcome by addition of steroid.

Intestinal disaccharidase activities were determined in 294 jejunal biopsies obtained from 254 children with various disorders of the small bowel, and alkaline phosphatase activity was measured in 251 biopsies. In normal mucosa a broad range of enzyme activity was found corresponding with the data in the literature. A primary disaccharidase deficiency was observed in 5 children with congenital sucrase-isomaltase deficiency and in a 12-year-old Egyptian boy with acquired lactase deficiency. A secondary generalized depression of disaccharidase activity and a diminution of alkaline phosphatase activity existed chiefly in patients who had severe or moderate mucosal damage, also in active coeliac disease and during gluten loading, in protracted diarrhoea of infancy, chronic malabsorption of unknown origin and agammaglobulinemia. During remissions enzyme activities recovered together with mucosal improvement. Low levels of enzyme activities were also seen in some cases of protracted diarrhoea of infancy and chronic malabsorption of unknown origin although only mild mucosal lesions were demonstrated.

Using a Quinton hydraulic biopsy tube, jejunal biopsies were obtained from 10 patients with adult coeliac disease in remission and four healthy volunteers before and after administration of gluten fraction III into the proximal duodenum. The biopsies taken at hourly intervals for four hours, were analysed for changes in brush border enzymes, light microscopic appearances, and villous and crypt population counts. The results indicate that mucosal damage occurs within three to four hours of gluten administration with significant falls in brush border enzyme concentrations and villous population counts. The absence of any change in control biopsies indicates that gluten sensitivity is specific to the mucosa of patients with coeliac disease, the timing of the changes being consistent with a type III immune response or direct toxicity. Some recovery of the brush border enzymes but not the villous population was evident 24 hours after gluten administration while the crypt population showed evidence of a compensatory hyperplastic reaction.

Diamine oxidase plasma concentrations after treatment with heparin were measured and compared with the surface to volume ratio of jejunal biopsy samples assessed by a morphometric technique in patients with untreated and treated coeliac disease and in biopsied controls. As expected, enzyme activity was significantly lower in patients with untreated coeliac disease than in patients on a gluten-free diet and in biopsied controls. No difference was found between treated patients and biopsied controls. There was a significant overall correlation between plasma enzyme activity and surface to volume ratio of jejunal mucosa, although two untreated patients without an overt malabsorption syndrome but with a very low surface to volume ratio had normal enzyme activity. This study shows that in coeliac disease plasma diamine oxidase activity after treatment with heparin does not always mirror the extent of the jejunal lesions, particularly in those patients with minimal or unrelated symptoms who would benefit most from a valid screening test to identify their condition.

A naturally occurring enteropathy was identified in Irish setter dogs and wheat-sensitivity was demonstrated in a litter bred from two of the affected animals. The morphological and biochemical features of this enteropathy are described and compared to coeliac disease in man. Affected animals comprised 10 dogs that presented with poor weight gain or weight loss, with or without diarrhoea. Exocrine pancreatic function was normal and culture of duodenal juice demonstrated no marked bacterial overgrowth. Serum vitamin B12 concentrations were unaltered, but in some cases low serum and erythrocyte folate concentrations and reduced xylose absorption provided indirect evidence for proximal small intestinal disease. Examination of peroral jejunal biopsies revealed patchy morphological changes within individual animals, comprising predominantly partial, but in one case subtotal, villous atrophy. Brush border enzymes were selectively altered: the specific activities of alkaline phosphatase, leucyl-2-naphthylamidase and of zinc-resistant alpha-glucosidase were reduced by approximately 40 per cent, while activities of maltase, sucrase, lactase and gamma-glutamyl transferase were unaltered. Activity of a lysosomal enzyme was increased and there was evidence for enhanced lysosomal fragility. The activity of malate dehydrogenase, with a dual mitochondrial and cytoplasmic localisation, was decreased but there were no changes in the activities of marker enzymes for basal-lateral membranes, endoplasmic reticulum or peroxisomes. These findings, particularly the specific biochemical abnormalities, were comparable to those in partially treated coeliac disease in man; however, a specific role for wheat in the pathogenesis of the disease has yet to be defined.

Highly sensitive techniques have been used for the assay of a range of marker enzymes including lactase, sucrase, alkaline phosphatase, leucyl-beta-naphthylamidase (brush border), and 5'-nucleotidase (basolateral membrane) in jejunal biopsy homogenates from patients with adult coeliac disease with and without steatorrhoea and from a control group. The absorption of D-xylose and vitamin B12 was compared in the two groups with coeliac disease. All enzymes assayed were equally depressed in both groups of coeliac disease as compared with the controls. The absorption of D-xylose and vitamin B12 were reduced in the patients with steatorrhoea compared with those without steatorrhoea. The findings suggest that lack of steatorrhoea in some patients with coeliac disease is due to better preservation of the ileal function rather than to a less severe jejunal mucosal injury.

A series of marker enzymes for brush borders, basolateral membrane, and lysosomes were assayed in mucosal biopsy specimens from patients with untreated and treated coeliac disease and from controls. The brush border enzymes lactase, sucrase, neutral alpha-glucosidase, alkaline phosphatase, and leucyl-beta-naphthylamidase showed reduced activities in the untreated state and complete or partial normalization during treatment. The lysosomal marker enzyme acid phosphatase increased in activity in untreated coeliac disease and was normalized by treatment. The brush border enzyme gamma-glutamyl transferase was nearly normal in untreated patients and slightly increased in treated patients. The basolateral membrane marker, 5'-nucleotidase, was reduced both in untreated and treated patients, whereas the lysosomal marker N-acetyl-beta-glucosaminidase was normal in the untreated state and decreased during treatment. The possible pathogenetic role of the three latter enzymes in coeliac disease is discussed. The patterns of the other enzymes are suggested to be attributable to the morphologic changes in the mucosa.

The jejunal mucosa of patients with coeliac disease contains significantly fewer Paneth cells (PCC) per crypt (p less than 0.001) and tissue lysozyme activity (JLA) P less than 0.001) when compared with a group of subjects with normal jejunal mucosa. Neither PCC nor JLA return to normal with complete clinical recovery and otherwise complete histological recovery on a gluten free diet. There is a significant linear correlation between JLA and PCC suggesting that the Paneth cell is the principal source of jejunal lysozyme.

The suitability of the simultaneous azocoupling reaction with 1-naphthyl-beta-D-glucoside and hexazonium-p-rosanilin in the detection of the activity of lactase (or lactase-beta-glucosidase complex) in jejunal biopsies of patients with various forms of the malabsorption syndrome was tested. Results were compared with those obtained with the indigogenic method using 4-Cl-5-Br-3-indolyl-beta-D-fucoside which is the method of choice. Both methods gave identical results as far as the relative intensity of the brush border staining was concerned. The azocoupling method applied in unfixed cold microtome sections can be recommended for the routine diagnostics of the malabsorption syndrome when the indolyl substrate is not available.

To assess the course of recovery of gluten sensitive enteropathy in adults, histological and functional recovery was studied in 22 patients, aged 20-79 years. Biopsy specimens taken at the time of diagnosis were studied in 20; after adhering to a gluten free diet for nine to 19 (mean 14) months in 14; and after adhering to the same diet for 24-48 (mean 34) months in 10 patients. Histological recovery was assessed morphometrically in the proximal jejunum. Mucosal linings significantly improved over time, but did not completely return to normal with a gluten free diet: at diagnosis the surface: volume ratio was 22% of normal, increasing to 48% and 66% after nine to 19 and 24-48 months, respectively, of a gluten free diet. Disaccharidase activities progressively increased. After 24-48 months maltase, sucrase, and isomaltase had returned to normal in the proximal jejunum; they were still significantly decreased in the distal duodenum. Duodenal and jejunal lactase activities were both below normal after 24 to 48 months. It is concluded that recovery of the intestinal mucosa of adults with gluten sensitive enteropathy during a gluten free diet continues beyond nine to 19 months and is still incomplete after two to four years. The recovery of disaccharidase activities extends from the distal to the proximal part of the small intestine, and is aligned to histological recovery.

The levels of two peptide hydrolases were studied in intestinal mucosa from normal subjects, patients with untreated coeliac disease, and treated patients. The mucosa from the untreated patients had significantly reduced activity against glycyl-glycine and leucylleucine. No such difference was found for the treated patients and it was concluded that the reduction in peptidase activity was secondary to the mucosal damage.

The activities of jejunal mucosal peptide hydrolases for glycylglycine, glycyl-L-leucine and L-leucylglycine, were assayed in 37 patients. Eight patients, four of whom had Crohn's disease, were found to have a marked reduction in the activity of glycylglycine dipeptidase and, to a lesser extent, of the other two hydrolases. Although absorption of glycine in the two groups was similar, there was malabsorption of glycylglycine in the patients with reduced dipeptidases as shown by a flat absorption curve. The importance of peptide hydrolases of small-intestinal mucosa in the final digestion of proteins, and the implications of peptidase deficiency in disease states is discussed. It is concluded that significant peptidase deficiency may occur even when the mucosa is otherwise histologically completely normal, similar to some states of disaccharidase deficiency described in recent years.