Cellular immunity to intrinsic factor in pernicious anemia.

Cellular immunity to hog intrinsic factor was detected by a modified agarose-leukocyte migration test in 18 patients with pernicious amemia. Lymphocytes from 17 out of 18 patients with pernicious anemia gave positive responses to a concentrate of hog intrinsic factor; the intrinsic factor present in 1 mg. of this concentrate bound 128 ng. of vatamin B12. Six patients with atrophic gastritis, 7 with regional enteritis, and 9 out of 10 healthy adults did not respond to this preparation. No correlation existed between the presence of serum autoantibodies to intrinsic factor and in vitro lymphocyte responsiveness to intrinsic factor. The results demonstrate that cellular immunity to intrinsic factor concentrates is present in the majority of patients with pernicious anemia.