Intraepithelial lymphocyte mitosis in a jejunal biopsy correlates with intraepithelial lymphocyte count, irrespective of diagnosis

Celiac disease-like abnormalities in a subgroup of patients with irritable bowel syndrome

BACKGROUND & AIMS

Abdominal symptoms in the absence of mucosal abnormalities are features of both the irritable bowel syndrome (IBS) and latent/potential celiac disease (cd). To identify a possible subgroup of IBS patients with latent/potential cd, surrogate markers of cd were investigated in IBS patients.

METHODS

IBS patients suffering from diarrhea (n = 102), and patients with active cd (n = 10), treated cd (n = 26), and latent cd (n = 5) were included in the study. We measured serum immunoglobulin (Ig) A against gliadin and tissue-transglutaminase, and IgA and IgM against gliadin, tissue-transglutaminase (intestinal cd-associated antibodies), and the dietary proteins beta-lactoglobulin and ovalbumin in duodenal aspirate by enzyme-linked immunosorbent assay. Intraepithelial lymphocytes (IELs) were counted in histology sections, and the expression of HLA-DQ2 (A1*0501/B1*0201) was investigated by polymerase chain reaction. In 26 IBS patients, the effect of 6 months of gluten withdrawal was examined.

RESULTS

Most cd patients expressed HLA-DQ2 and had increased intestinal cd-associated antibodies, whereas cd-associated serum IgA and IEL counts were increased in active cd in contrast to treated or latent cd. In IBS patients, 35% were HLA-DQ2-positive, 23% had increased IEL counts, and 0% and 30% had increased cd-associated antibodies in serum and duodenal aspirate, respectively. Furthermore, stool frequency and intestinal IgA decreased significantly under a gluten-free diet in the subgroups of HLA-DQ2-positive and intestinal antibody-positive IBS patients when compared with IBS patients without these markers.

CONCLUSIONS

HLA-DQ2 expression and increased intestinal cd-associated antibodies are markers that can identify latent/potential cd in a subgroup of IBS patients who consequently appear to profit from a gluten-free diet.

Coeliac disease and malignancies

When compared with the general population, patients with coeliac disease (CD) have an increased risk of developing enteropathy-associated T-cell lymphoma (EATCL), esophageal and pharyngeal squamous carcinomas and small intestinal adenocarcinomas. The prevalence of histologically confirmed CD in Edinburgh and the Lothians in 1979 was 61 per 100,000. The National Health Service Central Records of all 653 subjects registered at that time have been flagged, allowing us to analyse mortality in CD. At a mean of 13.5 years, mortality overall was 1.9-fold that of the general population (115 deaths observed. 61.8 expected; p < 0.0001). For both sexes the early mortality was much greater than expected, but the excess steadily diminished with time from diagnosis. Much of the increased mortality from malignant disease was accounted for by deaths from lymphoproliferative disease and esophageal cancer. Interim re-analysis after a further 9 years shows that the pattern of later deaths is consistent with these trends. Clinical and pathological features of lymphomas in CD are described. In serum samples of 41 patients with normal villus architecture while taking a normal diet, but with minor pathological and/or immunological abnormalities, i.e. potential CD, IgA antiendomysium antibodies were positive in 7 with dermatitis herpetiformis but in only 3 others.

Intestinal T lymphocytes

The intestine is largely colonized by bacteria and further exposed to an immense array of ingested and shed immunogenic material. Therefore, the gut associated lymphoid tissue plays a major role in the human immune system. It may even constitute a unique immune system of its own, since it has been demonstrated to differ anatomically, phenotypically, functionally and on a molecular basis from its systemic counterpart and other peripheral lymphoid tissue. This is ultimately reflected by the observation in (transgenic) mice that intraepithelial T cells can develop independently of the thymus. Along the same lines, a rapidly growing body of evidences suggests that human bone marrow precursors can home to the gut epithelium, rearrange their T cell receptor genes and further differentiate in the mucosal micro environment. This, and other features that characterize the 'diffuse' mucosal T cell infiltrate will be discussed.

Intestinal antibody pattern of celiac disease: occurrence in patients with normal jejunal biopsy histology

BACKGROUND

Patients with celiac disease have immunoglobulin (Ig) M antibodies and IgA antigliadin antibody in gut secretions; this pattern of intestinal immunity may be a marker of latent celiac disease. Its frequency in patients referred for jejunal biopsy has been examined.

METHODS

Serum IgG and IgA antigliadin antibody, jejunal fluid IgA and IgM antibodies to gliadin, ovalbumin and beta lactoglobulin, and jejunal fluid IgA and IgM concentrations were measured by enzyme-linked immunosorbent assay.

RESULTS

Seventeen of 19 celiac patients on normal diet and 16 of 23 on gluten-free diet had the celiaclike antibody pattern, as did 41 of 217 other patients. Jejunal biopsy histology had been classified as normal in 38 of these, with minor abnormalities in 3; however, intraepithelial lymphocyte (IEL) counts were high in 13 cases. Trial of a gluten-free diet produced clinical improvement in 6 of 7 antibody-positive patients. After extra dietary gluten, one developed subtotal villous atrophy.

CONCLUSIONS

The celiaclike intestinal antibody pattern and a high IEL count may be markers of latent gluten-sensitive enteropathy; some of these patients are clinically gluten sensitive in the absence of enteropathy.

The biology and pathobiology of the intestinal intraepithelial lymphocyte: a review of the literature

Intraepithelial lymphocytes represent a population of lymphocytes situated in the epithelial layer of all mucosae. In this report their biological and pathobiological features, with emphasis on intestinal intraepithelial lymphocytes, are reviewed.

Compliance of adolescents with coeliac disease with a gluten free diet

A cohort of 123 patients with coeliac disease, diagnosed in the first three years of life and followed up for at least 10 years, was reevaluated during the teenage period in terms of compliance with the diet and clinical state. Mucosal structure and lymphocytes were assessed in small intestinal biopsy specimens obtained from 36 subjects, by computerised image analysis. Of these adolescents with coeliac disease, 65% were adhering to a strict gluten free diet, 11.4% were on a gluten free diet but with occasional gluten intake, and 23.6% were on a gluten containing diet. Clinical symptoms occurred more frequently in patients on a gluten containing diet, but not in patients on a semi-strict diet. Occasional intake of small amounts (0.06-2 g/day) of gluten did not produce increased concentrations of antigliadin antibodies but resulted in an appreciably increased crypt epithelial volume and expanded crypt intraepithelial lymphocyte population.

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.

Proliferative responses of human intraepithelial lymphocytes to various T-cell stimuli

Human intraepithelial lymphocytes (IEL) are CD8+ T cells located between intestinal epithelial cells, capable of only minimal proliferation to mitogens but brisk proliferation to mitogens combined with sheep red blood cells. This study examines this differential response of IEL. Both IEL and CD8+ T lymphocytes from the peripheral blood are predominantly CD2+, CD3+, CD4-, CD5+, CD8+, and express the alpha beta subunits of the T-cell receptor. Human IEL express the same densities of the CD2, CD3, and CD8 antigens but a lower density of the CD5 antigen than do peripheral blood CD8+ T cells. The proliferation of IEL is significantly less than that of peripheral blood CD8+ T lymphocytes in response to phytohemagglutinin, to concanavalin A, or to anti-CD3 antibody bound to Sepharose (p less than 0.05). Supplementing IEL with interleukin-1, interleukin-2, or autologous peripheral blood macrophages does not completely reconstitute the proliferative response of IEL to these stimuli. Rather, the low proliferation of IEL to these stimuli is due to incomplete activation, as demonstrated by the low percentage of CD25 (Tac)+ lymphocytes with concanavalin A or the low density of the CD25 antigen with phytohemagglutinin. Both IEL and peripheral blood CD8+ T lymphocytes proliferate minimally in response to alloantigens or to interleukin-2, but briskly in response to stimuli of the CD2 receptor such as the combination of anti-T11(2) and anti-T11(3) antibodies or mitogen and sheep red blood cells. The sheep red blood cells enhance the mitogen-induced response of IEL by augmenting events of activation, both interleukin-2 production and interleukin-2 receptor expression. Thus, IEL represent an unusual compartment of CD2+, CD3+ T lymphocytes that are activated more completely by stimuli of the CD2 receptor than by stimuli of the CD3 receptor or by T-cell mitogens.

Gluten-sensitive enteropathy in childhood

Genetic and environmental factors (breast feeding, probably viral infections) play a role in the expression of the disease. Prevalence of GSE in childhood did not substantially decrease in the last 15 years in all European countries, where GSE is still more common in infantile age and presents frequently gastrointestinal symptoms. A decrease has been reported in childhood in several United Kingdom areas and in Finland, where the clinical presentation is changing, shifting upward with age and coming closer to the adult type of the disease. The following clinical problems have been reported in the recent literature: enamel hypoplasia; monosymptomatic short stature; arthritis and other immunologic diseases; association with diabetes, atopy, Iga deficiency, and probably Down's syndrome. Delay in puberty and other peculiar problems of the disease have been described in adolescents. Tests assessing the permeability of the small intestine and the blood levels of antigliadin antibodies have recently gained success as noninvasive tools for the diagnosis of the GSE. The gluten should be withdrawn from the diet and the challenge with gluten should be performed not before 12 months of gluten-free diet with an accurate timing of the biopsy on the basis of the antigliadin and antireticulin antibodies, to avoid clinical and growth damage. Celiac children do require a permanent gluten-free (and not poor) diet. In reality, too many celiac adolescents are off-diet.

The immunology of coeliac disease

Coeliac disease is defined as that disorder in which there is an abnormality of the small intestinal mucosa manifested by contact with the gluten of wheat and certain other cereal grains. In the immunological theory of the pathogenesis of coeliac disease, gluten, or a component, is viewed as the antigen responsible for the immune response. The search for the gluten component responsible for 'toxicity' and, by implication, antigenicity, is described. The antigen may be presented differently to the immune system by an abnormal cell membrane, either of the enterocyte, lymphocyte or macrophage. Alternatively, increased amounts of antigen may be absorbed due to increased membrane binding or permeability, either of which could be genetically determined. As a further possibility, coeliac disease may occur because the patients are immunologically hyperresponsive and this too appears to be genetically determined. The perturbations which occur in the mucosal immune system and the systemic immune system are described. It is conceivable that the major complications described (intestinal ulceration, malignancy and splenic atrophy) result from immunological disturbances. The incidence of childhood coeliac disease is declining, which may be due to altered exposure to, or increased protection from, the antigen in infancy, or to changes in environmental factors. The immunological mystery of coeliac disease continues to excite interest and fascination, and has certainly been a stimulus to our deeper understanding of gastrointestinal immunology.