Volume 69 - 2006 - Fasc.1 - Symposium
Diagnosis small bowel malabsorption syndromes in adults
Patients with malabsorption represent a small proportion of presentations with chronic diarrhea. In spite of some progress, the last twenty years were not very innovating in malabsorption inves- tigations. Supporting history may direct investigations toward either the small bowel or pancreas. Serological testing for celiac disease will determine most cases without invasive investigation, but individuals suspected to have small bowel malabsorption, despite negative celiac serology, should have endoscopic distal duo- denal biopsies taken to exclude other rare forms of small bowel enteropathy. This strategy has largely supplanted many older tests of small bowel function. (Acta gastroenterol. belg., 2006, 69, 31-37).
Food allergy : a challenge for the clinician
Adverse reactions to food resulting in gastrointestinal symp- toms and due to immunologic reactions (allergy) are discussed : their pathogenesis, the prevalence of food allergens and the clini- cal digestive expressions of food allergy in children and adults are reviewed. In IgE-mediated food allergy, the usefulness of the bio- logical available tests is considered, mainly CAP tests, for pro- ceeding to the diagnosis and the monitoring of the allergic disease. Finally, the best actual diagnostic tools in food allergy are considered (clinical history, skin tests, biological tests and food oral challenges), with their limitations and indications. (Acta gastroenterol. belg., 2006, 69, 38-42).
Sensitivity and specificity of food specific IgE and IgG determinations for the diagnosis of food allergy
Among the methods currently used to demonstrate a sensitiza- tion to foods the measurement of food specific IgE antibodies (sIgE) is the most practical but not the most accurate. The "sensi- tivity" of food sIgE determinations is, for example, suboptimal with unstable allergens in fruits and vegetables that are involved in the (birch) pollen-related immediate oral allergy syndromes. In this particular syndrome the history is often conclusive and can be substantiated by skin prick tests with fresh foods. The "sensitivi- ty" of sIgE tests is much better when sIgE are directed to stable plant or animal food allergens which often cause non-immediate generalized reactions. Foods, usually, contain many different (glyco)proteinic allergens of which some are stable and others not. The "sensitivity" of the sIgE test with a particular food, therefore, varies according to the type of allergen that is recognized by the patient. The "specificity" of sIgE tests with foods is affected by the existence of homologous food allergens which induce cross-reac- tive IgE that may or may not be clinically relevant. While variable, clinical cross-reactivity is more common among botanically-relat- ed fruits, among different nuts, among mammalian foods and among seafood than among cereals, grains and legumes. The "specificity" of food sIgE tests is much better when sIgE are directed to unique non-cross-reactive food allergens. Unfortunately, neither the presence of food sIgE nor its level are predictive of clinical reactivity. The identification of individual allergens in foods and the characterization of the relevant IgE binding sites in these allergens might lead to the development of tests that only measure sIgE to clinical relevant food allergens. (Acta gastroenterol. belg., 2006, 69, 43-48).
Role of the pathologist in the differential diagnosis of malabsorption
Histological examination of small intestinal biopsies is an essen- tial step in the assessment of malabsorption syndromes. Multiples biopsies should be taken in the proximal jejunum or distal duo- denum and correctly oriented. Histological evaluation has to be systematic considering villous architecture, inflammation and specific diagnostic elements. In celiac disease, even with the development of serology tests, the biopsy remains useful to follow the patient and to detect potential complications. (Acta gastro- enterol. belg., 2006, 69, 49-51).
Clinical implication of immunohistochemical markers
The role of the pathologist is to establish accurate diagnosis more and more with the help of complementary techniques. At present immunohistochemical expression of some diagnostic and prognostic factors may possibly predict the response to specific therapies. We focus here on the expression of three of these markers : epidermal growth factor receptor which overexpression is correlated with aggressive tumoral behaviour and with the pos- sibility of a targeted therapy, cytokeratins 7 and 20 with their diagnostic implication in carcinomatous differentiation, and we close this review with the identification of markers related to hereditary non-polyposis colorectal cancer involving microsatellite instability. (Acta gastroenterol. belg., 2006, 69, 52-54).
Hepatic intra-arterial injection of Yttrium-loaded microspheres for Liver Metastasis secondary to colorectal cancer : Best soups are sometimes made from old recipies
Colorectal cancer is a severe disease with a significant incidence in western world.
In the curse of disease, about 40% of patients will eventually develop metastases to the liver. The majority of them will never be candidate for curative surgical management.
For those patients, systemic or intra-hepatic chemotherapy is the treatment's cornerstone. Unfortunately, despite evident improvements and apparition of several active new agents, no hope of cure emerges on the agenda for now.
Hepatic intra-arterial injections of radioactive devices have since a long time drawn interest from the medical community.
An anti-tumoural activity has been demonstrated with Yttrium- loaded microspheres injected in the hepatic artery for several liver neoplasms including metastases from colorectal cancer. We lack however the results of large randomized phase III trials to define clearly the place of those interventional therapies in the manage- ment of colorectal cancer metastatic to the liver. (Acta gastro- enterol. belg., 2006, 69, 55-58).
