Immunologic Studies With Intrinsic Factor in Man*

In Vitro Assay for Human Intrinsic Factor*

“…Potent rabbit antisera to hog intrinsic factor concentrate (37) and to human stomach mucosa 3 inhibited the B12 uptake mediated by hog intrinsic factor concentrate and by human gastric juice (Table IX). Cross-reactivity with heterologous antigen was exhibited by both antisera (Table IX).…”

Precipitating Serum Antibodies to Intrinsic Factor in Pernicious Anemia

“…Experimental results suggesting the existence of hog IF antibodies in p.a. patients on oral IF therapy have earlier been reported (17,20), whereas other workers have not been able to confirm this (4, 15,18). The discrepancy in the results may be explained by differences in the techniques used.…”

Separation and Immunologic Characterization of Hog Intrinsic Factor in Comparison with Human Intrinsic Factor

“…O n the other hand, serum antibodies to human IF in p. a. patients do not cause refractoriness either to human or to hog IF. Those antibodies to IF could be shown to suppress the B,,-absorption only if the I F is given orally, mixed with the antibody-containing serum, in a so-called in vivo inhibition test, in which they cross-react with hog I F (8, Another hypothesis on the refractoriness to oral hog IF has been presented by Kaplan et al (21). They immunized two p. a. patients by injections of a purified hog IF-concentrate.…”