D. Agape

Increased jejunal intraepithelial lymphocytes bearing γ δ T-cell receptor in dermatitis herpetiformis

T-cell receptor 1 (gamma/delta) expression was studied in 19 jejunal or duodenal specimens from patients with dermatitis herpetiformis and in 16 jejunal or duodenal specimens showing normal histology. In normal specimens, gamma/delta+ cells represented 10.8% of intraepithelial CD3+ lymphocytes. Around 50% of these cells were recognized by the A13 monoclonal antibody, which detects products of the V gamma 1/V delta 1 gene rearrangement and the non-disulfide-linked form of T-cell receptor 1. The remaining 50% reacted with the BB3 monoclonal antibody, which recognizes products of the V gamma 9/V delta 2 rearrangement and the disulfide-linked form of receptor. Very few gamma/delta+ cells were observed in the lamina propria. In jejunal specimens from patients with dermatitis herpetiformis, a significant increase in the prevalence of gamma/delta+ intraepithelial lymphocytes was observed (P less than 0.001). This finding was largely accounted for by an increase in those cells recognized by the A13 monoclonal antibody, thus possibly expressing the V gamma 1/V delta 1 rearrangement and the nondisulfide-linked form of receptor. These data suggest that similar pathogenetic mechanisms may be active in determining the jejunal damage in celiac disease and dermatitis herpetiformis.

Antibodies to gliadin in adult coeliac disease and dermatitis herpetiformis

Antibodies to gliadin, searched for by indirect immunofluorescence and a micro-ELISA, were detected in 16 (64%) of 25 sera from patients with adult coeliac disease and in 13 (45%) of 29 with dermatitis herpetiformis. Although the sensitivity of the two tests was relatively low in the whole groups, it increased when only cases with severe jejunum abnormalities were considered (93% for coeliac disease and 81% for dermatitis herpetiformis). A significant correlation was found between antigliadin antibodies and the severity of jejunum damage in both diseases. Moreover, most coeliac and dermatitis herpetiformis patients with antigliadin antibodies were on normal diet. The specificity of the tests was 100% for the immunofluorescence and fairly good for the micro-ELISA, as only 5 (11%) of the 46 disease control patients (Crohns disease, ulcerative colitis) were positive for antigliadin antibodies. R1-reticulin antibody test was equally specific but less sensitive in both groups. We conclude that antigliadin antibodies are useful in the diagnosis of patients with active adult coeliac disease and dermatitis herpetiformis with gluten-sensitive enteropathy. Moreover, the two tests make it possible to monitor the compliance to gluten-free diet in both diseases.

Eradication of esophageal varices by endoscopic sclerotherapy: how much is enough?

To clarify if complete eradication of varices from the lower esophagus by endoscopic sclerotherapy is really essential to prevent rebleeding, or if reduction of varices below a certain size can be considered a sufficient result, we compared the fate of 72 patients in whom sclerotherapy was stopped after one of the following endoscopic endpoints was reached: complete eradication (15 patients, group 1), partial eradication with residual small white varices (32 patients, group 2), and partial eradication with residual small blue varices (25 patients, group 3). The incidence of variceal recurrences and recurrent bleeding over a median follow-up of 17 months after stopping sclerotherapy did not differ significantly in the three groups. Analysis of the time course of variceal recurrences showed that the recurrence-free interval was almost identical in group 1 and group 2 patients (13 and 14 months, respectively). Group 3 patients had a shorter recurrence-free interval (8.3 months), but the difference was not statistically significant. We conclude that sclerotherapy can be stopped safely when either complete eradication or reduction of varices to small white columns is obtained.

Evaluation of structural and secretory glycoconjugates in normal human jejunum by means of lectin histochemistry

SummaryThe labelling pattern of eight lectins was studied in jejunal samples from ten normal subjects, in order to define the normal distribution of structural and secretory glycoconjugates in the small bowel.The following lectins were studied by means of a peroxidase technique on formalin-fixed samples: Arachis hypogaea, Ricinus communis, Canavalia ensiformis, Lens culinaris, Phaseolus vulgaris, Triticum vulgaris, Ulex europaeus, Dolichos biflorus. Phaseolus vulgaris reacted with goblet cell mucus throughout the villus-crypt axis.Conversely Ulex europaeus, Dolichos biflorus and Triticum vulgaris lectin labelling of globet cells appeared to be confined to the upper part of the villi. This finding suggests that during cell migration from crypt to villus tip, the continuing maturation of goblet cells is associated with the differentiation of secretory carbohydrates, which probably parallels the cell maturation cycle. Lectin histochemistry appears to be a reliable tool for the study of structural and secretory glycoconjugates in the jejunal mucosa, and might be of value in the study of diseases in which the cell-maturation cycle in the small bowel is altered.

Evidence of altered structural and secretory glycoconjugates in the jejunal mucosa of patients with gluten sensitive enteropathy and subtotal villous atrophy.

The pattern of lectin histochemistry in formalin fixed, paraffin embedded normal jejunal and subtotal villous atrophy specimens from patients with gluten sensitive enteropathy were compared. There was no significant difference in the binding pattern of five lectins (Arachis hypogaea, Canavalia ensiformis, Lens culinaris, Phaseolus vulgaris and Triticum vulgaris) between normal and abnormal specimens. There were significant changes in the binding pattern of three lectins (Dolichos biflorus, Ulex europaeus, Ricinus communis), with special reference to goblet cells staining. These changes were present in all the specimens studied, regardless of the clinical diagnosis of dermatitis herpetiformis or coeliac disease. Dolichos biflorus reactive goblet cells were significantly decreased (p less than 0.001) in abnormal tissue and confined to the luminal edge of the mucosa. Strong reactivity of goblet cells in abnormal tissue was recorded with Ricinus communis and Ulex europaeus, lectins that bind to few or no goblet cells in normal tissue. These findings show that modifications of structural and secretory glycoconjugates occur in the jejunal mucosa of patients with gluten sensitive enteropathy.

Gastric Histology and Function Tests in Italian Patients with Dermatitis Herpetiformis

Gastric mucosal histology and function were evaluated in 57 Italian subjects with dermatitis herpetiformis (DH), by means of multiple endoscopic biopsies, gastrin and pepsinogen I (Pg I) serum levels, and parietal cell antibodies (PCA). One hundred and forty-nine patients with nonulcer dyspepsia served as reference population for the prevalence of atrophic gastritis of the body. Seventeen DH patients (30%) and 23 controls (15.4%) showed atrophic gastritis of the body mucosa (p less than 0.05). Nine of the DH patients with atrophic gastritis of the body also had atrophic changes in the antrum. Six patients, all with severe atrophic gastritis, had high gastrin levels and PCA; five of these six also had low Pg I levels. We found an increased prevalence of abnormal indirect function tests among patients with atrophic gastritis is due to the younger age of the patients in our series. Thus, atrophic gastritis can be detected early on a histologic basis, but functional impairment occurs later, as the mucosal damage increases in severity.

Prevalence of duodenal and jejunal lesions in dermatitis herpetiformis

SummarySixty-eight patients with dermatitis herpetiformis underwent jejunal suction biopsies and/or multiple endoscopic duodenal biopsies to evaluate the incidence of small bowel mucosal atrophy and to compare the diagnostic yield of the two methods. Small bowel function tests were also performed to evaluate the extent of functional impairment. Small bowel lesions were observed in 89.4% of jejunal suction biopsies and in 100% of endoscopic duodenal biopsies. Of the 10 patients who underwent both procedures, one had lesions only in the duodenum, one had more severe lesions in the duodenum than in the jejunum, while the remaining 8 patients showed identical lesions at both sites. The l-h blood d-xylose test after a dose of 5 g proved more sensitive than xylosuria or serum folic acid assay in detecting subclinical malabsorption. Finally, histological features of gluten-sensitive enteropathy can be found in nearly 100% of patients with dermatitis herpetiformis. Upper gastrointestinal endoscopy with duodenal biopsies is at least as sensitive as jejunal suction biopsy in assessing small bowel involvement in dermatitis herpetiformis.

In situ identification of immune competent cells in gastrointestinal mucosa: an evaluation by immunoelectronmicroscopy.

Thein situ identification of lymphocyte subpopulations by means of immunopathological techniques using specific monoclonal antibodies provides a tool for the study of the gastrointestinal-associated lymphoid tissue (GALT) in health and disease. In this field, monoclonal antibodies have been applied previously using light microscopy and either immunofluorescence or immunoperoxidase; however, these techniques are not sensitive enough to allow precise evaluation of localization of labelling. We describe an immunoelectronmicroscopic method, which defines labelling specificity, since it allows the identification of cells by immunophenotype labelling and ultrastructural markers simultaneously. This in turn allows a better evaluation of the labelled cells and of the relationship between labelled and unlabelled cells. The main features of the method are the use of fresh tissue samples, fixing in paraformaldehyde CaCl2, and the coupling of the immune reaction to an amplification system (avidin-biotin-peroxidase complex). The technique yields a good preservation of cellular ultrastructure, together with a strong and specific immunolabelling. Our results confirm the high specificity of monoclonal antibodies when applied to immunopathology techniques. We confirm the pattern of distribution of various lymphocyte subsets in the jejunal mucosa described by other authors by light microscopy.