Jejunal mucosa after leukemia treatment in children. Increase of crypt mitotic activity, decrease of intraepithelial lymphocytes and IgA-cells.

Nine children with acute lymphoblastic leukemia in remission were studied at the end of their three years' maintenance therapy. In the jejunal biopsy specimens significantly fewer intraepithelial lymphocytes and IgA-cells were observed in the patients than in the controls. However, the crypts were deeper than normal, and the mitotic activity of the crypt cells was markedly increased in all of the patients. Three children presented with decreased epithelial disaccharidase activities. One had abnormal D-xylose test and two abnormal lactose tolerance test. Although weight gain did not differ from the normal, height increase was retarded in all but one of the patients. We conclude that leukemia treatment leads to changes in the intestinal mucosa that might in part contribute to impairment of growth in the patients and to suppression of mucosal immunity in their jejunum.