The normal values for intrinsic factor blocking antibodies are negative, and this range is unisex for all age groups.
The results of intrinsic factor antibody (IF antibody) tests are often taken into consideration with the results of other laboratory tests to help make a diagnosis.
When a person has a decreased vitamin B12 level and/or increased methylmalonic acid and homocysteine levels and has IF antibodies, then it is likely that the person has pernicious anemia.
A negative test result does not necessarily mean that a person does not have pernicious anemia. As many as half of those affected will not have IF antibodies. When they are not present, the health practitioner may order a parietal cell antibody test to help establish the diagnosis.
Parietal cell antibodies are not as specific as IF antibodies. They are present in about 90% of those with pernicious anemia but may also be present in a variety of other conditions and in up to 10% of the general population.