Letter: Atrophic gastritis and dermatitis herpetiformis

Autoimmune bullous diseases associations

The presence of one autoimmune disorder helps lead to the discovery of other autoimmune conditions. It is thought that diseases in which autoimmunity is a feature tend to be associated together more often than one can ascribe to chance. A variety of diseases have been implicated in the onset of intraepidermal and subepidermal autoimmune diseases. The presence of one autoimmune disease should alert the physician to watch for a second immunologic disorder. A list of autoimmune bullous diseases associations includes autoimmune bullous diseases, pemphigus, pemphigoid, epidermolysis bullosa acquisita, dermatitis herpetiformis (Duhring), linear immunoglobulin A disease, and multiple autoimmune syndrome.

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.

Local immunoglobulin production is different in gastritis associated with dermatitis herpetiformis and simple gastritis

The degree of inflammation and atrophy in gastric body mucosal specimens (n = 38) from 28 patients with dermatitis herpetiformis (DH) was graded histologically. Immunoglobulin (Ig) producing cells were enumerated by paired immunofluorescence staining in a 500 microns wide section area from the muscularis mucosae to the lumen (mucosal 'tissue unit'). The number of immunocytes of the three main classes (IgA, IgM, and IgG) was significantly raised with increasing degree of gastritis. All three classes were increased in specimens showing atrophy compared with those without atrophy. IgA cells predominated as in simple gastritis, but a striking difference was a marked increase of IgM cells in specimens with the most pronounced DH-associated gastritis. Relative class distribution of immunocytes within different mucosal zones showed that the percentage of IgA cells was significantly higher in the luminal than in the basal zone, whereas the contrary was true for IgG cells. IgM cells did not show any zonal preference. No relation was seen between small bowel and gastric lesions. The disproportionate increase of gastric IgM producing cells in DH might nevertheless reflect seeding of precursor cells of the secretory immune system generated in the proximal small intestine where the local IgM response is relatively pronounced.

Immunologic and gastrointestinal abnormalities in dermatitis herpetiformis

Eighty patients with untreated dermatitis herpetiformis (DH) were studied. The final diagnosis was made after completion of immunofluorescence (IF) studies of the skin, iodine provocation tests and gastrointestinal investigations. IgA deposits in the skin and the HLA-DRw3 B-cell alloantigen can be demonstrated in nearly all cases of DH. Positive iodine provocation test and gastrointestinal abnormalities are present in about 78% of the cases. For diagnostic purposes tissue typing and intestinal biopsy is of value in addition to IF studies of the skin.

The cellular infiltrate of the jejunum in adult coeliac disease and dermatitis herpetiformis following the reintroduction of dietary gluten

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.