The immunology of coeliac disease

Coeliac disease in adults

Coeliac disease is a chronic disease characterized by small bowel villous atrophy which impairs nutrient absorption and improves on withdrawal of wheat gliadins and barley, rye and oat prolamins from the diet. Knowledge of the adult form of coeliac disease has greatly improved in recent years. Although this knowledge is not yet sufficiently widespread among referring clinicians, it has, over the past few years, allowed an increasing number of patients to be diagnosed with subclinical forms characterized by minor, transient or apparently unrelated symptoms. As a consequence, our views on the clinical and epidemiological aspects of this condition, the prevalence of which in the general population is believed to be close to 1 in 300, have changed and are still changing. Since it has been demonstrated that a strict gluten-free diet is protective against the complications of adult coeliac disease, it is important that even subclinical and silent forms are diagnosed and treated as early as possible. Non-invasive screening tests, such as anti-gliadin and anti-endomysium antibody estimation, should therefore be used systematically in groups considered to be at risk of coeliac disease. These include first-degree relatives of coeliac patients and patients with insulin-dependent diabetes mellitus, iron-deficiency anaemia, epilepsy with cerebral calcification, recurrent aphthous stomatitis and dental enamel hypoplasia. Other conditions will probably be identified in the near future.

Malignant lymphoma in coeliac disease: various manifestations with distinct symptomatology and prognosis?

OBJECTIVES

To study the different forms of malignant lymphoma complicating coeliac disease in a low-prevalence area, according to extranodal-nodal and extraintestinal-intestinal manifestations.

SUBJECTS AND SETTING

Patients recruited from two University Hospitals (Amsterdam, Leiden) and from PALGA (National Dutch data-bank) over a 16-year period.

DESIGN

Review of hospital charts with respect to clinical presentation and treatment of both coeliac disease and malignant lymphoma. Re-evaluation of morphology and staging by immunoperoxidase, enzyme- and immunohistochemical stainings on unstained and frozen materials.

MAIN OUTCOME MEASURES

Clinical behaviour and T- or B-cell morphology of extranodal intestinal, extranodal extraintestinal and nodal intestinal disease.

RESULTS

Fourteen cases of enteropathy-associated lymphoma could be traced, 10 with a history of coeliac disease, four primarily presenting with malignant lymphoma. The usual extranodal intestinal lymphoma (eight cases) presented with abdominal pain, weight loss, and malabsorption. Six had atypical disease: four presented with extranodal extraintestinal disease, located in the skin or the respiratory tract; two patients had intractable malabsorption and oedema caused by a nodal intestinal lymphoma. Re-evaluation with additional immunohistochemical stainings in 11 patients showed a pleomorphic malignant infiltrate of histiocyte-like cells of T-cell origin, with a pattern of CD3+; CD4-; CD5 +/-; CD7+ and CD8-. It also established a more appropriate diagnosis in four, an 0.6-year earlier diagnosis in six, and an upgraded stage of disease in two patients. A more extensive spread and poorer outcome appeared to become more probable in the ranking order of extranodal intestinal, extranodal extraintestinal and nodal intestinal lymphoma.

CONCLUSIONS

A proper and timely diagnosis of enteropathy-associated lymphoma requires clinical vigilance and unrelentless perseverance to obtain adequate fresh and frozen tissue for histochemical staining. Further research in a larger number of patients is warranted to investigate the relation between the primary site of the lymphoma, i.e. extranodal intestinal, extranodal extraintestinal, or nodal intestinal, and (its impact on) clinical presentation and prognosis.

Helicobacter pylori serology in patients with coeliac disease and dermatitis herpetiformis

AIMS

To investigate whether Helicobacter pylori infection or autoimmune gastritis is responsible for the reported increase in gastric pathology and abnormalities of gastric function in patients with coeliac disease and dermatitis herpetiformis (DH).

METHODS

Serum H pylori IgG antibodies were assayed by enzyme linked immunosorbent assay and intrinsic factor antibodies by radioimmunoassay in 99 patients with coeliac disease and 58 patients with dermatitis herpetiformis from two geographic areas.

RESULTS

H pylori positivity in patients with coeliac disease and dermatitis herpetiformis increased with age, reaching 50% and 70%, respectively, in patients over 50 years. The percentage H pylori seropositivity in coeliac disease did not differ from the percentage positivity observed in 250 similarly aged blood donors from the same geographic area (Leeds). Seropositivity in patients with dermatitis herpetiformis was not significantly different from the level of positivity observed in 98 age matched patients without dermatitis herpetiformis attending the same Edinburgh dermatology clinic. Only one patient with coeliac disease had positive intrinsic factor antibodies. H pylori seropositivity in Edinburgh control subjects under 30 years of age (41.9%) was significantly higher (p less than 0.03) than in Leeds controls (18%) of corresponding age. An increasing prevalence of H pylori seropositivity with age in coeliac disease and dermatitis herpetiformis paralleled that of the control groups.

CONCLUSIONS

Gastritis in coeliac disease and dermatitis herpetiformis is largely caused by H pylori infection at a level that is no different from that of the general population. Any increase in the prevalence of gastritis in these two diseases might be caused by lymphocytic gastritis rather than pernicious anaemia.

Expression of the LFA-1 beta 2 integrin (CD11a/CD18) and ICAM-1 (CD54) in normal and coeliac small bowel mucosa

The leucocyte adhesion molecules (beta 2 integrins) comprise CD11 alpha-chains and a common beta-chain (CD18). CD11a (leucocyte function-associated antigen 1, LFA-1) is expressed by most T cells, and is involved in antigen presentation by macrophages via its counter-receptor, intercellular adhesion molecule (ICAM-1, CD54). By criteria of double-label immunofluorescence of cryostat tissue sections, virtually all lamina propria T cells of the normal small bowel were found to express LFA-1 strongly. By contrast, only 30-60% of intra-epithelial lymphocytes (IEL) expressed detectable LFA-1, most of which were LFA-1 weak and CD18-. ICAM-1 was expressed strongly only by vascular endothelium. In coeliac disease, there was a modest increase of diffuse ICAM-1 expression in the lamina propria, mainly in the subepithelial zone, where ICAM-1+ macrophages were occasionally seen. There was also a slight overall increase in CD11a expression by IEL, seen predominantly in surface epithelium and mainly by the CD4+ minority subset, but not by CD4-CD8- (TcR gamma delta +) cells. These data suggest that the LFA-1/ICAM-1-dependent antigen presentation pathway is of minor importance to IEL in the normal small bowel, and does not assume a major role in coeliac disease.