Abstract
A patient with total villous atrophy of the small intestine, associated with selective IgA deficiency, presented after an acute febrile illness. Gluten-free diet and other standard treatments were without benefit. Studies revealed that T cell function, serum antibody production, delayed hypersensitivity, mixed leucocyte reaction, antibody-dependent and cell-mediated cellular cytotoxicity, and general immune responsiveness seemed intact. However, IgA could not be detected in serum, tissues, or external secretions and, cultured with poke weed mitogen, the patient's B cells failed to produce IgA. In addition, the patient's cells suppressed IgA production by control cells co-cultured in the presence of mitogen. Indirect immunofluorescent studies revealed in his serum an IgG-class organ-specific antibody which bound to villus cells in control intestine, obtained from normal and diseased subjects, but not to cells in the patient's diseased mucosa. After low dose cyclophosphamide therapy, IgA remained absent but suppressor activity disappeared, intestinal villi regenerated fully, cellular cytotoxicity was reduced, and the antibody titer in serum slowly declined. The antibody bound strikingly to mature cells in the patient's regenerated villi, on indirect but not direct immunofluorescence. These unique findings suggest an autoimmune aetiology. No such antibodies were found in other IgA-deficient subjects.
