Density of gamma/delta T cells in small bowel mucosa related to HLA-DQ status without coeliac disease

Microscopic enteritis: Bucharest consensus

Microscopic enteritis (ME) is an inflammatory condition of the small bowel that leads to gastrointestinal symptoms, nutrient and micronutrient deficiency. It is characterised by microscopic or sub-microscopic abnormalities such as microvillus changes and enterocytic alterations in the absence of definite macroscopic changes using standard modern endoscopy. This work recognises a need to characterize disorders with microscopic and submicroscopic features, currently regarded as functional or non-specific entities, to obtain further understanding of their clinical relevance. The consensus working party reviewed statements about the aetiology, diagnosis and symptoms associated with ME and proposes an algorithm for its investigation and treatment. Following the 5^th International Course in Digestive Pathology in Bucharest in November 2012, an international group of 21 interested pathologists and gastroenterologists formed a working party with a view to formulating a consensus statement on ME. A five-step agreement scale (from strong agreement to strong disagreement) was used to score 21 statements, independently. There was strong agreement on all statements about ME histology (95%-100%). Statements concerning diagnosis achieved 85% to 100% agreement. A statement on the management of ME elicited agreement from the lowest rate (60%) up to 100%. The remaining two categories showed general agreement between experts on clinical presentation (75%-95%) and pathogenesis (80%-90%) of ME. There was strong agreement on the histological definition of ME. Weaker agreement on management indicates a need for further investigations, better definitions and clinical trials to produce quality guidelines for management. This ME consensus is a step toward greater recognition of a significant entity affecting symptomatic patients previously labelled as non-specific or functional enteropathy.

Diagnostic criteria for coeliac disease: time for change?

A spectrum of histological changes may be seen in coeliac disease. Interpretation of duodenal biopsies can be problematic due to inadequate specimens or difficulties in detecting the minimal histological lesion. If serology is negative but clinical suspicion is high, a duodenal biopsy should always be performed. A combination of histology, serology, morphometry and HLA typing may be helpful in equivocal cases. Small intestinal histology is the current gold-standard diagnostic test for coeliac disease. Serological tests, immunohistochemistry and HLA typing may also have a role in the diagnostic algorithm. IgA antigliadin antibodies have mainly been replaced by IgA antiendomysial antibodies and IgA antitissue transglutaminase antibodies. The high sensitivity and specificity of these new markers have been used to challenge the necessity of obtaining a duodenal biopsy to confirm the diagnosis. It is widely recognized that relying on duodenal biopsies may be problematic. In equivocal cases where the biopsy material cannot be relied on accurately, further diagnostic tests are necessary. Quantitative morphometry and immunohistochemistry may be of value in identifying intraepithelial lymphocytes and a specific subset bearing the gamma/delta receptor. HLA-DQ2 may have a role in excluding the diagnosis in equivocal cases, its main limitation being its high frequency in the normal population. Each diagnostic test, namely histology, serology or genetic typing has limitations. A combination of these diagnostic tests should be used to clarify the full breadth of the gluten sensitivity spectrum, in particular, in those cases where duodenal histology may be equivocal.

Side-effects of complementary and alternative medicine

Complementary and alternative medicine are increasingly used to diagnose or treat allergic diseases, and numerous studies have reported benefits of this type of medicine. This article presents a review of the literature on risks of these methods. The potential sensitizing capacity of numerous herbal remedies may lead to allergic contact dermatitis and more rarely to IgE-mediated clinical symptoms. Mechanical injuries may be observed following acupuncture leading to pneumothorax, cardiac tamponade or spinal injury. Infectious complications after acupuncture include hepatitis and bacterial endocariditis. Organ toxicity has been observed associated with various herbal preparations involving the liver, kidneys, and the heart. Some herbs may have cancerogenic properties. Severe nutritional deficiencies can occur in infants and small children given strict alternative diets, resembling 'kwashiorkor'. Finally, among other miscellaneous adverse effects, adulteration with steroids, and herbal and drug interactions are discussed. The pattern of side-effects is similar to that observed by the use of conventional medicine. Therefore, caution may be justified using both conventional and unconventional methods. Only if the benefit is proven and the side-effects are established, should a given method be chosen.

Herbal hepatotoxicity: an expanding but poorly defined problem

Alternative therapies, including herbal remedies, are popular in the general population and even more so among patients with liver disease. The use of such products is now well established in western society and is no longer confined to traditional medicine practitioners in Asia, Africa and the Middle-East. Their perceived benefits remain generally unproven and concern about adverse effects is leading to closer scrutiny of these products. Herbal hepatotoxicity has been recognized for many years, but new agents are constantly being identified. The varied manifestations of liver injury include steatosis, acute and chronic hepatitis, hepatic fibrosis, zonal or diffuse hepatic necrosis, bile duct injury, veno-occlusive disease, acute liver failure requiring liver transplantation and carcinogenesis. Potential interactions between herbal medicines and conventional drugs may interfere with patient management. Concurrent use of such products is not often disclosed unless specifically sought after and can lead to perpetuation of the liver injury. The present review focuses on emerging herbal hepatotoxins, newer patterns of liver injury among the older agents and provides an updated tabulation of the adverse effects of major herbal hepatotoxins. Key issues of diagnosis and prevention of this growing problem are addressed. Continued public education, physician awareness and more stringent licensing are required to tackle this growing problem.

Food-induced malabsorption syndromes

A syndrome of chronic diarrhea, vomiting, and failure to thrive was described 35 years ago. The syndrome was caused by damage in the jejunum after ingestion of cow's milk. Symptoms appeared in young infants shortly after introduction of cow's milk formula. Patients had moderate steatorrhea, decreased absorption of D-xylose, and, often, iron-deficiency anemia and hypoproteinemia. They had strong IgA and IgG antibodies to cow's milk. IgE antibodies to cow's milk were negative, as a rule. Indicators of cell-mediated immune reaction to cow's milk proteins were often positive. Patients were tolerant to cow's milk by the age of 3 years. Malabsorption was due to damage to the jejunal mucosa: Varying villus atrophy was associated with inflammation in surface epithelium and lamina propria. The epithelial cell renewal rate increased. Surface epithelial cells decreased in height, with short, furry microvilli and large aggregates of lysozymes. The number of intraepithelial lymphocytes was markedly increased, but normalized during cow's milk elimination. Most of these lymphocytes had alpha/beta T-cell receptors, and many were cytotoxic. Some specimens had an increase in gamma/delta T-cell receptor-bearing cells. In the lamina propria, CD4+ cells predominated, and some of them were activated. IgA- and IgM-containing cells were markedly increased during cow's milk exposure, but IgE cells were not abnormal. The density of eosinophils was moderately increased. Secretion of interferon-gamma by cells isolated from patients' intestines was markedly increased. Morphologic and immunologic findings suggest that T-cell-mediated reaction to proteins in cow's milk is present in the small intestines of patients with this syndrome and causes this enteropathy.

Increased lymphocyte infiltration in duodenal mucosa from patients with psoriasis and serum IgA antibodies to gliadin

In a screening study concerning IgA and IgG antibodies to gliadin (IgA AGA and IgG AGA, respectively) in psoriasis, raised levels of IgA and AGA were found to be more common than in a reference group. To determine whether elevated AGA levels were associated with an increased number of intraepithelial lymphocytes, 33 patients with IgA AGA (n = 28) or IgG AGA (n = 5) values above 90% of the reference values (> 50 units/ml IgA AGA and < 12 units/ml IgG AGA) underwent gastroduodenoscopy and duodenal biopsy in a prospective study. For comparison, six patients with low levels of both IgA AGA and IgG AGA were included. Five biopsy specimens were taken in each patient. Paraffin-embedded specimens were examined with regard to the degree of intraepithelial lymphocyte infiltration, and scored from 0 to 3. Biopsy specimens with a score of 0 had one mononuclear cell or less per four epithelial cells. The specimens were also examined with regard to the presence of intraepithelial CD3+ T lymphocytes and gamma/delta+ T lymphocytes. In the six patients with low IgA AGA and low IgG AGA, the biopsy score was 0. Fourteen of the 33 patients with raised AGA had a score of > or = 1; of these, 12 had raised IgA AGA and two had slightly raised IgG AGA. Two of the patients with raised IgA AGA had partial villous atrophy, but the majority had normal villous architecture. There was a significant correlation both between the biopsy score and the number of intraepithelial CD3+ cells and between the score and the number of intraepithelial gamma/delta+ positive T lymphocytes. The serum IgA AGA levels were significantly correlated with the duodenal biopsy score, the number of intraepithelial gamma/delta+ T lymphocytes, and the number of CD3+ intraepithelial T lymphocytes. Most patients had no, or only mild, gastrointestinal symptoms. Of the 14 patients with biopsy scores > or = 1, seven had severe psoriasis and five moderately severe psoriasis, whereas only two had mild psoriasis. There was no relationship between the duodenal score and haemoglobin, folate, whole blood selenium or serum zinc levels. Some of these patients improve on a gluten-free diet, but it is still too early to draw any definite conclusions concerning the type of relationship between the skin lesions, the increased number of intraepithelial lymphocytes in the duodenal mucosa and gluten hypersensitivity.