Jejunal mucosal morphology in healthy north Indian subjects

Enteropathies of Infancy and Childhood

Intestinal biopsies constitute an ever-increasing portion of the pathologist's workload, accounting for nearly two-thirds of specimens accessioned yearly by the pathology department at The Children's Hospital of Philadelphia. The widespread use of endoscopy and gastrointestinal biopsies in current clinical practice presents the pathologist with a diversity of intestinal mucosal appearances corresponding to disease states of variable clinical severity, requiring close collaboration between clinician and pathologist for optimal interpretation. Many of the entities resulting in severe diarrhea of infancy have been recognized only in the last several decades, and although rare, the study of these disorders, especially when combined with the powerful methods of present-day genetics and molecular biology, has afforded important insights into enterocyte development and function, and intestinal immunity and tolerance. Other conditions once considered infrequent, such as celiac disease, have now been recognized to be much more common and can present with a wide range of pathologic features.

Coeliac disease: an update for pathologists

Coeliac disease is the manifestation of an immune hypersensitivity reaction towards gluten and related proteins, in genetically predisposed people. Although the precise pathogenesis of this condition remains to be fully elucidated, it is probably multifactorial in origin. The diagnosis of coeliac disease has traditionally depended on intestinal biopsies alone; nowadays, the diagnosis has been expanded to include an array of serological markers. This review is intended to offer pathologists an update of the relevant history and immunopathology pertaining to coeliac disease and also to offer recommendations on the ongoing responsibilities of the pathologist in the diagnosis and reporting of coeliac disease.

Tropical enteropathy: a T-cell-mediated crypt hyperplastic enteropathy

OBJECTIVE

Tropical enteropathy is widespread throughout the tropics, but its pathogenesis is unknown. T-cell activation has been demonstrated to result in enteropathy in vitro and in animal models, and occurs in untreated patients with coeliac disease. We have therefore examined the hypothesis that T-cell activation is important in the pathogenesis of tropical enteropathy.

PATIENTS AND METHODS

Healthy black Zambian subjects were compared with black and white South Africans. Quantitative microscopy was conducted on distal duodenal biopsies. Mucosal T-cell activation was quantitated by dual colour immunofluorescence staining for CD3 plus CD69 or HLA-DR. Crypt proliferation was measured by direct counting of Feulgen-stained mitotic figures, and systemic immune activation by assay of serum tumour necrosis factor alpha (TNF-alpha).

RESULTS

Villous height was reduced (P = 0.0004), crypt depth increased (P < 0.0001), and mitoses per crypt increased (P = 0.014) in black Zambians compared with black and white South Africans. Mucosal thickness was similar. Intraepithelial lymphocyte count was increased in the black groups compared with whites (P = 0.03). CD3+CD69+ (P = 0.0007) and CD3+HLA-DR+ (P < 0.0001) expression was increased in black Zambians compared with black and white South Africans. Serum TNF-alpha was similar in all groups.

CONCLUSIONS

Tropical enteropathy is associated with mucosal T-cell activation and crypt hyperplasia. Tropical enteropathy occurs in the absence of malnutrition, diarrhoea or systemic illness.

Tropical sprue and subclinical enteropathy: a vision for the nineties

Aside from infectious intestinal diseases with known etiology, there is a group of gastrointestinal disorders mainly affecting the small intestine of individuals predominantly living in and less often visiting or returning from the Third World, usually the tropics, and ranging from asymptomatic structural and/or functional abnormalities of the gastrointestinal mucosa (subclinical enteropathy, SE) to a fully symptomatic condition highlighted by malabsorption of nutrients with associated nutritional deficiencies responsive to folate and broad spectrum antibiotic treatment (tropical sprue, TS). Mounting evidence supports an infectious cause in many instances. The exact nature of the infection, whether initiated and/or perpetuated by enterotoxigenic coliform bacteria, virus(es) or a combination of these, is not clear. Further studies, including those using molecular techniques, are needed in order to clarify various aspects of these widely prevalent disorders.

Morphometric studies in duodenal biopsies from patients with coeliac disease: the effect of the steroid fluticasone propionate

Morphometric measurements have been performed on small intestinal biopsy specimens from patients with untreated coeliac disease before and after six weeks oral treatment with a steroid of low systemic bioavailability (fluticasone propionate). Measurements were obtained by point counting and also by a computer-aided measuring system with reference to a constant area of the muscularis mucosa. Fluticasone propionate led to a parallel reduction in the intraepithelial lymphocyte count within the surface (P less than 0.001) and crypt epithelium (P less than 0.01). The intra-epithelial lymphocyte count assessed by reference to constant areas of the muscularis mucosa and surface epithelium were decreased two-fold (P less than 0.01) and seven-fold (P less than 0.001) respectively. Fluticasone propionate treatment also led to significant increases in the absorptive surface epithelium as shown by an increase in the villus:crypt ratio (P less than 0.01), the epithelial cell height (P less than 0.01) and two- to three-fold increases in the area and length of the surface epithelium (P less than 0.001). Short-term fluticasone propionate treatment appears to exert a powerful beneficial effect upon duodenal morphology in patients with coeliac disease. Whether the alterations seen are comparable to a similar period of gluten withdrawal is not yet known.

Small bowel morphology in British Indian and Afro-Caribbean subjects: evidence of tropical enteropathy

Distal duodenal biopsy specimens taken from 30 white, 35 Indian, and 20 Afro-Caribbean residents of West Birmingham during routine endoscopy for dyspepsia, were assessed by dissecting microscopy and morphometry. Finger-shaped villi were significantly less frequent in the Indian and Afro-Caribbean subjects than in the white subjects when assessed by dissecting microscopy (p less than 0.005), and both immigrant groups had decreased mucosal thickness (p less than 0.01), villous height (p less than 0.001), villous:crypt ratios (p less than 0.01) and enterocyte height (p less than 0.05) compared with the white group. In the Indian subjects, villous height and villous:crypt ratios correlated significantly with the time since the last visit to the Indian subcontinent (p less than 0.005). Serum alkaline phosphatase values were significantly higher in the Indian subjects compared with the whites (p less than 0.02), and serum globulins were increased in both the Afro-Caribbean and Indian subjects (p less than 0.01). There were no correlations between morphometric indices and body habitus or biochemical or haematological indices and the long term effect of the morphological changes is not clear.