Intraepithelial gamma/delta-positive T lymphocytes and intestinal villous atrophy

Lymphocytic duodenitis or microscopic enteritis and gluten-related conditions: what needs to be explored?

Microscopic enteritis (ME) is characterized by abnormal infiltration of intraepithelial lymphocytes in intestinal mucosa. It was described as duodenal lymphocytosis or lymphocytic duodenitis until the dedicated Consensus Conference of 2015. ME represents a common feature of several gluten-mediated and non-gluten related diseases; therefore, it is an umbrella term embracing several conditions. The most frequent causes of ME are gluten-related disorders (celiac disease, non-celiac gluten sensitivity, wheat allergy), Helicobacter pylori infection and drug-related damages. Less frequently, ME may be secondary to inflammatory bowel disease, some autoimmune conditions, immunoglobulin deficiencies, blood malignancies, infections and irritable bowel syndrome. Therefore, the differential diagnosis of ME may be challenging. The diagnosis of ME needs to be driven by predominant symptoms and patient history. However, it is often difficult to achieve an immediate identification of the underlying condition, and a broad variety of diagnostic tests may be required. Ultimately, long-term surveillance is needed for a final diagnosis in many cases, since a hidden or quiescent condition may be disclosed after a period of latency. In any case, strict collaboration between the clinician and the pathologist is pivotal. The treatment of ME should be personalized, depending on the underlying disease. For gluten-related conditions (celiac disease, gluten sensitivity, wheat allergy, dermatitis herpetiformis), a gluten-free diet may be proposed. For other conditions, a targeted etiologic treatment is necessary. In conclusion, ME represents a novel entity that is attracting increasing interest. The growing epidemiologic trend confirms that it will become a common condition in clinical practice.

Usefulness of small-bowel mucosal transglutaminase-2 specific autoantibody deposits in the diagnosis and follow-up of celiac disease

BACKGROUND

Diagnosis of celiac disease may be problematic in that small-bowel villous atrophy sometimes occurs in conjunction with other enteropathies, develops gradually and may be patchy. Furthermore, as the often compromised quality of biopsy specimens renders diagnosis difficult, new diagnostic tools are warranted.

GOALS

As the celiac disease-specific autoantibodies are found deposited at their production site, in the small-bowel mucosa, they may be useful in diagnostics, especially in problematic cases. We therefore systematically assessed the occurrence of celiac-specific autoantibody deposits in a large cohort of celiac patients, and established how IgA deposits decline after initiation of a gluten-free diet.

METHODS

Transglutaminase-2 specific mucosal IgA autoantibody deposits were determined from small-bowel mucosal biopsies in 261 untreated, 71 short-term (1 y), and 105 long-term (2 to 41 y) treated celiac disease patients and in 78 nonceliac controls. The presence of the deposits was compared with celiac serology, mucosal villous morphology and density of intraepithelial lymphocytes.

RESULTS

All untreated celiac disease patients had mucosal autoantibody deposits and their intensity was moderate or strong in 90% of cases. In contrast, 18% of the controls had weak depositions. During a gluten-free diet the intensity of the deposits diminished, but was still faintly positive in 56% of long-term treated celiac patients. The efficiency of the test in determining mucosal autoantibody deposits was superior to serology and inflammatory markers.

CONCLUSIONS

Mucosal transglutaminase-2 specific autoantibody deposits proved to be accurate gluten-dependent markers of celiac disease and would thus be of value in the diagnostics and dietary monitoring of this disorder.

Small-bowel mucosal transglutaminase 2-specific IgA deposits in coeliac disease without villous atrophy: a prospective and randomized clinical study

OBJECTIVE

In coeliac disease, autoantibodies directed against transglutaminase 2 are produced in small-bowel mucosa, and they have been found to be deposited extracellularly. The aim of this study was to investigate whether such mucosal IgA deposits are important in the diagnostic work-up of early-stage coeliac disease without small-bowel mucosal villous atrophy.

MATERIAL AND METHODS

Forty-one adults suspected of coeliac disease owing to increased density of mucosal gamma(delta)+ intraepithelial lymphocytes but normal villous morphology were randomized to gluten challenge or a gluten-free diet for 6 months. Clinically and histologically verified gluten dependency was compared with existence of small-bowel mucosal transglutaminase 2-specific extracellular IgA deposits and (coeliac disease-type) HLA DQ2 and DQ8; 34 non-coeliac subjects and 18 patients with classical coeliac disease served as controls.

RESULTS

Of the 41 patients, 5 in the challenge group and 6 in the gluten-free diet group were clinically gluten sensitive; all 11 had HLA DQ2 or DQ8. Ten of these 11 patients showed transglutaminase 2-targeted mucosal IgA deposits, which were dependent on gluten consumption. Minimal IgA deposits were seen in only 3 out of 30 patients with suspected coeliac disease without any clinically detected gluten dependency. The deposits were found in all classical coeliac patients and in none of the non-coeliac control subjects.

CONCLUSIONS

Clinically pertinent coeliac disease exists despite normal small-bowel mucosal villous architecture. Mucosal transglutaminase 2-specific IgA deposits can be utilized in detecting such patients with genetic gluten intolerance.

Microscopic colitis

Microscopic colitis is an umbrella term used to include two idiopathic inflammatory bowel disorders that present with chronic watery diarrhea, normal endoscopic findings and characteristic inflammatory changes on histology. Collagenous colitis and lymphocytic colitis are distinguished by the presence of a thickened subepithelial collagen table. It is likely that they are a spectrum of one disease, but this is yet to be proven. The majority of cases tend to undergo spontaneous remission within a few years of onset, and their clinical course is benign, with no increase in risk of colorectal cancer. Sufficient evidence exists to suggest that microscopic colitis occurs as a response to one or more luminal antigens. A variety of medications have been reported in the treatment of this condition, but only colloidal bismuth and budesonide have thus far been shown to be effective in randomized controlled trials.

The time-course of milk antigen-induced TNF-alpha secretion differs according to the clinical symptoms in children with cow's milk allergy

BACKGROUND

TNF-alpha secretion by blood mononuclear cells stimulated with cow's milk proteins is significantly higher in infants with active cow's milk allergy (CMA) manifested by digestive symptoms than in children who have recovered from CMA.

OBJECTIVE

The current study was undertaken to analyze the kinetics of TNF-alpha secretion and to evaluate the usefulness of the measurement of TNF-alpha release in whole blood cultures in the prediction of clinical outcome after milk challenge.

METHODS

Blood samples were obtained from 83 children maintained on a cow's milk-free diet and examined just before a cow's milk provocation. Children were divided into 4 groups according to clinical outcome: group I (active CMA with cutaneous symptoms), group II (active CMA with predominantly digestive symptoms), group III (children recovered from CMA), and group IV (control). The kinetics of TNF-alpha secretion was measured in blood cultured for 1 to 5 days at different cow's milk protein concentrations.

RESULTS

On day 1 TNF-alpha secretion was significantly higher in group I (485 [453] pg/mL, mean [SD], P <.005) and in group II (269 [102] pg/mL, P <. 005) than that observed in groups III and IV (149 [95] and 87 [71] pg/mL, respectively). Then TNF-alpha was rapidly degraded and a second peak of secretion was observed on day 5 but only in group II (278 [221] pg/mL), whereas in groups I, III, and IV a low secretion was observed (70 [61], 45 [40], and 11 [12] pg/mL, respectively, P <. 02).

CONCLUSION

These results show that the pattern of TNF-alpha secretion in response to cow's milk proteins is different in CMA infants with cutaneous or digestive symptoms and suggest that TNF-alpha release might predict clinical relapse on challenge.

Autoimmune enteropathy with severe atrophic gastritis and colitis in an adult: proposal of a generalized autoimmune disorder of the alimentary tract

BACKGROUND

We describe the case of an adult with autoimmune enteropathy consistent with both severe atrophic gastritis accompanying antral stenosis and colitis.

METHODS AND RESULTS

The patient, positive for anti-intrinsic factor antibody, had intractable diarrhea and protein-losing enteropathy. In the ileum inflammatory cells were observed infiltrating the lamina propria along with villus atrophy, and similar inflammation was also found in the lamina propria of the colon and stomach, with complete loss of specialized glands. The myenteric ganglion cells of the hypertrophied muscularis propria in the stenosed antrum showed degeneration with surrounding T-lymphocyte infiltration. There were more CD8+ than CD4 lymphocytes in the lamina propria of the stomach and colon.

CONCLUSIONS

The CD8+ (suppressor-cytotoxic) T lymphocytes may have played an important role in the production of lesions in the stomach, small intestine, and colon, so we propose this case as an example of a generalized autoimmune disorder of the alimentary tract.

IgA antiendomysium antibodies in human umbilical cord sections as a screening test in relatives of patients with celiac disease

We performed the serum IgA antiendomysium antibody (EmA) assay by indirect immunofluorescence on human umbilical cord sections in 86 subjects with celiac disease, in 187 first-degree relatives of such patients, and in a control group of 68 unrelated subjects, to investigate the suitability of the method in the screening of populations at risk of gluten sensitivity. Conventional EmA assay using monkey esophagus sections was performed in parallel experiments. The results obtained showed a perfect correlation between the two methods. All the celiac patients and none of the controls were positive for EmA. EmA positivity was also observed in 11 apparently healthy relatives: intestinal biopsy performed in five of them invariably showed villous atrophy and increase of mucosal lymphocytes. Taking into account the low cost of EmA assay on human umbilical cord, especially when compared to monkey esophagus sections, the method is probably suitable and effective in identifying latent, asymptomatic gluten sensitivity in at-risk populations.