Intrinsic Factor Blocking Antibody Test
This test measures blocking antibody to intrinsic factor in a blood sample, an antibody Quest associates with pernicious anemia.
About this test
Intrinsic factor is a substance produced by cells in the stomach lining that binds vitamin B12 (cyanocobalamin) so the body can absorb it. This test measures blocking antibody that interferes with that action.
Because the antibody is present in only about half of pernicious anemia cases, a negative result does not rule the condition out on its own. The test is run on a 1 mL serum sample using an immunoassay method, and Quest lists it under the additional name IF-Blocking Antibody.
Who might consider this test?
- People who talk with their clinician about this test are often being evaluated for pernicious anemia or unexplained vitamin B12 deficiency.
Test details
| Collection | Quest patient service center |
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Quest resources
Additional details
What this test looks at
The test reports the presence of blocking antibody to intrinsic factor in a 1 mL serum sample, analyzed by immunoassay. Quest ties this antibody specifically to pernicious anemia rather than to vitamin B12 deficiency in general.
This test isn't part of the Celio Health store at the moment, so it can't be ordered or requested here. The test menu lists everything that can.
Laboratory results should always be interpreted by a licensed clinician who knows your health history. This page is information about a test, not medical advice.
Frequently asked questions
What does this test measure?
It measures blocking antibody to intrinsic factor, a substance the stomach lining produces to help the body absorb vitamin B12.
How is the sample collected?
The test uses a 1 mL serum sample from a routine blood draw.
Do I need to prepare for this test?
No preparation instructions are listed for this test, though people follow any instructions their ordering clinician provides.
What condition is this antibody linked to?
Quest associates intrinsic factor blocking antibody with pernicious anemia, a condition linked to impaired intrinsic factor function and vitamin B12 absorption.
Does a negative result rule out pernicious anemia?
No. Quest notes the antibody is observed in only about half of people who develop pernicious anemia, so a negative result does not rule the condition out on its own.