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Infantile jejunal mucosa in infection and malnutrition
Insights
Malnutrition and giardiasis in children significantly impair small intestinal immunity, reducing IgA-producing cells and secretory component. This immune deficiency contributes to refractory diarrhea and growth retardation.
Area of Science:
- Pediatric Gastroenterology
- Immunology
- Nutritional Science
Background:
- Refractory diarrhea and malnutrition are significant health issues in children.
- Small intestinal mucosal integrity and immune function are crucial for nutrient absorption and overall health.
Purpose of the Study:
- To investigate the small intestinal mucosal and immunological changes in malnourished children with refractory diarrhea.
- To assess the impact of malnutrition and giardiasis on immune cell populations and enzyme activity in the small intestine.
Main Methods:
- Peroral upper small intestinal biopsy was performed on 19 children (16 with refractory diarrhea, 3 malnourished).
- Histological examination assessed mucosal atrophy and villous height.
- Immunohistochemistry identified IgA-producing cells and secretory component.
- Enzyme histochemistry evaluated leucine aminopeptidase, alkaline phosphatase, and acid phosphatase activity.
Main Results:
- Eighteen children showed mucosal atrophy and reduced villous height.
- Mononuclear inflammatory cells were reduced compared to well-nourished controls but increased compared to normal adults.
- IgA-producing cells and secretory component were significantly reduced, especially in malnourished children with giardiasis.
- Reduced acid phosphatase activity was observed in all malnourished groups.
Conclusions:
- Malnutrition, particularly when complicated by giardiasis, severely impacts small intestinal mucosal immunity in children.
- Reduced IgA and secretory component may contribute to the pathogenesis of refractory diarrhea and growth failure.
- Further research is needed to understand the long-term consequences and potential therapeutic interventions.
Abstract:
Sixteen children with refractory diarrhea and three malnourished children who had frequent episodes of acute gastroenteritis but little diarrhea at the time of hospital admission, were studied by peroral upper small intestinal biopsy. Six children were adequately nourished; five children weighed 62 to 79% of expected weight and eight weighed less than 60% of expected weight. Two of the malnourished children had giardiasis. Pathogenic bacteria were found in only one case. Varying degrees of mucosal atrophy with reduction of mean villous height were seen in 18 cases. The concentration of mononuclear inflammatory cells and plasma cells was about half that seen in well-nourished children with severe nongastrointestinal infections. The concentration of mononuclear cells in the lamina propria was about twice that seen in normal adults. The proportions of IgA-producing cells and cells that stained for secretory component were significantly reduced, as compared with normal adult control values. This reduction was most striking in children with malnutrition complicated by giardiasis. Enzyme histochemical studies were performed for leucine aminopeptidase, alkaline phosphatase and acid phosphatase. There was a tendency for considerably reduced acid phosphatase activity in all clinical groups (kwashiorkor, marasmic kwashiorkor and marasmus) of growth-retarded infants.