Persistent post-enteritis diarrhoea

Cow's milk protein induced changes in the expression of HLA-DR antigens on colonic epithelial cells

BACKGROUND

Normal colonic epithelial cells do not express HLA-DR antigens unless they become inflamed. It is possible that colonic epithelial cells may function as antigen-presenting cells once HLA-DR is induced by infection or inflammation.

OBJECTIVE

The aim of this study was to investigate whether cow's milk protein (CMP) is capable of inducing changes in HLA-DR expression on colonic epithelial cells, providing indirect evidence that CMP may activate cell-mediated immune mechanisms within intestinal mucosa.

METHODS

HLA-DR expression was evaluated by flow cytometry on cultured human colonic epithelial cell line (HT-29) before and after treatment with bacterial lipopolysaccharide (LPS) or recombinant gamma interferon (IFN-gamma). Untreated and LPS- or IFN-gamma-treated HT-29 cells were then cultured in the presence of CMP. The changes in epithelial HLA-DR expression induced by CMP on untreated and LPS- or IFN-gamma-treated HT-29 cells were examined.

RESULTS

Untreated HT-29 cells expressed very little HLA-DR molecule. Bacterial LPS or IFN-gamma induced a significant HLA-DR expression on HT-29 cells. When untreated HT-29 cells were cultured in the presence of CMP, there was little induction of HLA-DR expression. Culture of LPS- or IFN-gamma-treated HT-29 cells in the presence of CMP induced a significant increase in HLA-DR expression, which was much greater than on HT-29 cells treated with bacterial LPS or IFN-gamma only.

CONCLUSIONS

Our results suggest that CMP initiates an immune response in the intestinal mucosa and may be responsible for the activation of cell-mediated immunity after enteric infection or inflammation.

Chronic diarrhea

The differential diagnosis of chronic diarrhea varies markedly with age. In infants, it is usually a problem with formula intolerance. Because there is up to a 50% crossover intolerance between milk and soy, the infant should be given an extensively hydrolyzed formula. If such intervention is delayed, he or she may develop intractable diarrhea of infancy. Most affected toddlers have either irritable colon of infancy or protracted viral enteritis with low-grade mucosal injury and are consuming hypertonic feedings. In either case, institution of a high-fat, low-carbohydrate diet that includes whole milk often results in significant improvement. Dietary lactose rarely is a problem. A likely cause of diarrhea among children and adolescents is inflammatory bowel disease. With the exception of toddlers, chronic diarrhea suggests the presence of significant organic disease.

Milk protein enteropathy after acute infectious gastroenteritis: experimental and clinical observations

Animal models of allergic gastroenteropathy have defined both morphologic and physiologic changes that accompany the immune-mediated reaction to a dietary protein. In such models a broadening of the allergic response to other dietary proteins present in the gastrointestinal tract may occur during the localized anaphylactic reaction. The characteristic histologic intestinal findings of food protein-induced enteropathy may develop in selected infants with protracted diarrhea after infectious enteritis. Mechanisms underlying the induction of this response remain to be explained, but they may in part be similar to the broadening of the hypersensitivity response seen in experimental models of allergic enteropathy.

Postenteritis enteropathy in infancy. A prospective study of 10 patients with special reference to growth pattern, long-term outcome and incidence

Ten patients, who developed postenteritis enteropathy with chronic diarrhoea, failure to thrive and small intestinal mucosal damage after an episode of acute gastroenteritis, were studied prospectively. All patients experienced severe growth retardation. Maximum deviation of height and weight from mean values of age-correlated normal children were -1.7 and -3.1 SD (median values), respectively, as compared to -0.1 and 0 SD before onset of the illness. One child died after 14 months of illness. The long-term outcome was satisfactory for the 9 surviving children. For these children, treatment with an elemental diet (in some cases supplemented initially with parenteral nutrition) and later a lactose-free diet lead to resolution of diarrhoea within periods ranging from 0.5 to 10 months. The phase of catch-up growth lasted from 4 to 36 months, resulting in final height and weight deviating -0.6 and -0.8 SD (median values), respectively, from normal mean values. Attempt to predict duration of diarrhoea or length of catch-up growth phase by means of age, weight before illness, characteristics of small intestinal biopsy or maximum deviation of height or weight were unsuccessful. The incidence of postenteritis enteropathy for children of North European ethnic origin was estimated to be 7.6/1,000,000 children below 7 years of age/year, corresponding to 1.2/1,000 children hospitalized for acute gastroenteritis.

Plasma zinc levels in children with chronic diarrhoea

We measured the plasma zinc concentration in a group of children with chronic diarrhoea. Fifteen patients with untreated coeliac disease had a mean plasma zinc level significantly lower than that of healthy children (69 micrograms/dl vs 96 micrograms/dl). In patients with chronic post-enteritic diarrhoea (n = 70) the mean plasma zinc level was in the normal range (100 micrograms/dl). The latter result suggests that our country a secondary zinc deficiency is not a feature of chronic post-enteritic diarrhoea.