Biomedical subjects
Publications and source records attributed to P J Kumar.
Bleeding from duodenal varices in portal hypertension may not be recognized, resulting in a delay in diagnosis. Early detection is important as duodenal varices are a potential source of massive hemorrhage. We report two cases with recurrent upper gastrointestinal hemorrhage in whom accurate diagnosis was made only after extensive investigation including repeated endoscopic examination.
Although intestinal tuberculosis is rare in this country, increasing numbers of patients are now being seen, particularly in the immigrant population. We present the history of a lady who had acute diarrhoea and in whom the radiological and endoscopic findings looked very similar to those seen in Crohn's disease. The radiological presentation included widespread aphthous ulceration, a feature that has rarely been reported in tuberculous colitis.
Patients receiving non-steroidal anti-inflammatory drugs (NSAIDs) are at an increased risk of gastroduodenal erosions, ulcers, and the associated complications of haemorrhage, perforation, and death. Many NSAID associated ulcers that bleed or perforate have been asymptomatic until the time of presentation and conversely many patients with dyspepsia do not have ulcers. Symptoms are a poor guide to the presence of an ulcer. During continued treatment with NSAIDs misoprostol is the best choice for NSAID induced gastroduodenal damage; it achieves higher rates of healing than other drugs in these circumstances. Misoprostol is superior to other drugs in the prevention of gastric damage but misoprostol and H2 antagonists are of similar benefit in the duodenum. Prophylactic studies have all used endoscopic damage as an endpoint, and much larger studies will be needed to show an effect of misoprostol on the incidence of ulcer complications. There are no clear guidelines as to which patients should receive prophylactic treatment with misoprostol but those particularly at risk of ulcer complications--that is, those with previous peptic ulceration, the elderly, medically unfit, patients receiving large doses of NSAIDs, and those patients receiving steroids in addition to NSAIDs--should be considered.
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We previously noted a region of amino acid sequence homology between A-gliadin, a major alpha-gliadin component known to activate coeliac disease, and the early region E1b protein of human adenovirus serotype 12 (Ad12), an adenovirus isolated from the human intestinal tract. In the present study sera from coeliac disease patients from the United Kingdom and the United States were assayed for neutralising antibody to Ad12 as evidence of past exposure to that virus and for antibody to synthetic peptides of A-gliadin from the region of shared sequence with the Ad12 E1b protein. Eighty nine per cent of untreated coeliac disease patients had evidence of previous Ad12 infection. There was also a significant increase in the prevalence of neutralising antibody to Ad12 among treated adults (33.3%) and children (30.8%) with coeliac disease compared with controls (0-12.8%) in the western USA and in London. There was no evidence for an increased prevalence of infection with a closely related adenovirus, adenovirus 18, or another enteric virus, Echovirus 11, among coeliac disease subjects. Additional studies documented that a region of A-gliadin that shares amino acid sequence homology with the adenovirus 12 E1b protein could be recognised as an antigenic determinant in active coeliac disease patients. Taken together, these data are compatible with the hypothesis that a viral protein may play a role in the pathogenesis of coeliac disease, perhaps by virtue of immunological cross reactivity between antigenic determinants shared by the viral protein and alpha-gliadins.
Twenty-eight patients, thought to have coeliac disease and on gluten free diets, were put on a normal diet to confirm their diagnoses. Nineteen had been diagnosed in adult life (ACD) and nine in childhood (CCD). Patients were assessed on jejunal, morphological, and symptomatic parameters. Eighteen patients with ACD relapsed within seven weeks. Nine patients with CCD relapsed at variable times but five took longer than seven weeks, the longest period beint 10 months. Seven patients had no symptoms despite morphological deterioration during challenge and one patient, with ACD, did not relapse and was HLA B8 negative. This patient with ACD had subtotal villous atrophy on two jejunal biopsies and later showed morphological improvement on a gluten free diet. There was no correlation between the relapse time and time spent on a gluten free diet.
Three patients with coincident coeliac disease and inflammatory bowel disease are described. In 2 patients with known coeliac disease the recurrence of diarrhoea was not due to dietary deviation but to an additional large bowel pathology.
Five of 33 patients with dermatitis herpetiformis (DH) were found to have gastric parietal cell antibody in their sera, whereas it was not found in 30 healthy controls of comparable age distribution. Fifteen of the patients with DH underwent further studies to investigate the histological and functional state of their gastric mucosa. Atrophic gastritis was found in all five patients whose sera contained gastric parietal cell antibody and in three of 11 patients with no antibody in their sera. In addition, there was marked impairment of acid secretion in the DH group as a whole, but, apart from one patient with overt pernicious anaemia (PA), there was no evidence of malabsorption of B12.
The proportional and absolute numbers of circulating thymus dependent lymphocytes (T cells) were reduced in untreated patients with coeliac disease but were normal after treatment with a gluten free diet. There was an inverse correlation between circulating T cell numbers and jejunal intraepithelial lymphocytes. This evidence suggests a possible role for T cells in the pathogenesis of coeliac disease and is a further example of disturbed cell mediated immunity in this condition.
Jejunal lamina propria plasma cells and eosinophils and intraepithelial lymphocytes were raised in coeliac children on gluten-containing diets, but only intraepithelial lymphocytes were increased in patients on gluten-free diets. In contrast, lamina propria lymphocytes were reduced in children with coeliad disease on gluten-containing diets but were normal in paitents on gluten-free diets. In children with coeliac disease who were studied serially, lamina propria plasma cells and eosinophils and intraepithelial lymphocytes increased, and lamina propria lymphocytes decreased, within three months of the reintroduction of gluten to the diet. These observations are essentially similar to those made in the adult form of the disease and suggest that more than one type of immunological reaction is involved in the pathogenesis of the jejunal lesion.
Jejunal mucosal immunoglobulin-containing cells of all three major classes (IgA, IgM, IgG) were increased in coeliac children on gluten-containing diets but only IgM cell numbers were raised in those on gluten-free diets. Patients with subtotal villous atrophy had greater numbers of immunoglobulin-containing cells than patients with normal mucosa. In previously treated patients studied before and after three months on a gluten-containing diet ther was an increase in all three classes of cell, IgM containing cells showing the greatest proportional rise. Basement membrane staining with anti-IgA serum occurred in coeliacs and was most intense in untreated patients. Apart from one patient with very low levels of serum IgA, serum immunoglobulins did not differ from normal. However, after reintroduction of gluten to the diet a significant fall in serum IgM concentrations occurred compared with levels in the same patients while on gluten-free diets. It seems probable that both IgA and IgM systems are important in the immunopathogenesis of the small intestinal lesion of childhood coeliac disease.
Serum antibodies to a variety of dietary proteins were investigated in 26 patients with adult coeliac disease (ACD, 14 untreated and 17 treated with a gluten-free diet) and 38 patients with dermatitis herpetiformis (DH) with varying small bowel abnormalities. The incidence of one or more positive tests was highest in untreated ACD (73.4%) and DH with subtotal villous atrophy (57.4%). This incidence fell with morphological improvement, being 56.4% in treated ACD patients with partial villous atrophy (PVA), and 33.4% in DH with PVA, and 0% in DH with normal biopsies. The height of the serum antibody titre also fell with morphological improvement. These results show that there is an abnormally high incidence of dietary antibodies in patients with DH, and this correlates with the degree of small bowel damage.
A double-lumen perfusion technique has been used to investigate jejunal and ileal absorption of glucose, water, and electrolytes in a group of patients with untreated adult coeliac disease. Correct positioning of the tube was confirmed by measuring the differential jejunal and ileal handling of bicarbonate. Eight control subjects and eight patients with coeliac disease were perfused with an isotonic electrolyte solution containing 50 mM glucose and 25 mM bicarbonate. The group of coeliac patients had impaired jejunal absorption of glucose (P less than 0.001), water (P less than 0.01), sodium (P less than 0.02), and chloride (P greater than 0.05) compared with the control group. In contrast the group of coeliac patients had normal ileal glucose and water absorption and increased ileal sodium (P greater than 0.01) and chloride (P greater than 0.05) absorption compared with the controls. Evidence for ileal adaptation was found in three individual patients who had absorptive values outside 2SD of the normal mean. The results indicate that the distal small intestine in coeliac disease has the ability to adopt to the damage and loss of absorptive capacity in the proximal small intestine.
The cellular infiltrate of the jejunal mucosa has been studied in patients with both treated and untreated adult coeliac disease and dermatitis herpetiformis and serially in treated patients before and after the reintroduction of gluten to the diet. In adult coeliac disease and dermatitis herpetiformis the jejunal mucosa showed similar abnormalities of the cellular infiltrate which was characterized by an increase in intraepithelial lymphocytes and lamina propria plasma cells and eosinophils, with the greatest numbers of cells occurring in untreated patients. At 24-48 hours following a single 25-g gluten challenge there was an increase in lamina propria plasma cells, lymphocytes and eosinophils and intraepithelial lymphocytes. This rise was sustained after seven days on a gluten-containing diet for all of these cell groups except lamina propria lymphocytes. These responses were essentially similar in both adult coeliac disease and in those dermatitis herpetiformis patients who had jejunal lesions before treatment. In dermatitis herpetiformis patients with normal jejunal morphology on a normal diet there was an upward trend in lamina propria plasma cells and intraepithelial lymphocytes within one to three weeks of taking extra dietary gluten. These results are compatible with the view that more than one immunological mechanism may be responsible for the pathogenesis of the jejunal lesion of coeliac disease and dermatitis herpetiformis.
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