[Immunologic defects in the lymphatic system of the intestinal mucosa in common variable immunodeficiency (CVID)...

The humoral immune system of the intestinal mucosa of patients with common variable immuno deficiency (CVID) syndrome was studied immunohistologically using antibodies against immunoglobulin (Ig) A1-2, M and G1-4, against the J chain and the secretory component. In 9/13 CVID-patients IgA-positive cells were totally absent whereas a total IgM-defect was found only in 3/14 patients. Considerable numbers of J chain-positive cells were present in all CVID-patients irrespective of the extent of the Ig-defect indicating the presence of early B-cells unable to differentiate and to produce Ig. There was a strong expression of the secretory component in the cytoplasm and at the surface of enterocytes even in those CVID-patients who were totally defective in IgA- and IgM-positive cells.