Semi-quantitative analysis of immunoglobulins and complement fractions 3 and 4 in the jejunal mucosa in coeliac disease and in food allergy in childhood. Immunohistochemical study by light and electron microscopy.

Immunoglobulins A, M, G and E and complement fractions 3 and 4 in jejunal biopsy specimens of 14 children were stained by the peroxidase-labelled antibody technique and studied in light and electron microscopy. In addition, cryostat sections were stained with FITC-conjugated anti-C3,-C4 and -IgE sera. Five patients had coeliac disease, three intestinal cow's milk or rye allergy, three eczema due to food allergy, and in three patients, who served as controls, intestinal and immunological diseases were excluded. This study showed that increased amounts of IgA and IgM both in coeliac disease and in food allergy are produced by the plasma cells in the lamina propria of the jejunum and are secreted into the gut through the epithelial cells in a similar manner as in the morphologically normal intestine. The amount of IgG produced locally or derived from serum, was increased in coeliac disease. IgE-producing cells were rare in all patients. No deposits of complement were seen in the basement membranes or epithelial cells.