Intrinsic Factor Blocking Antibody
Also known as: IF-Blocking Antibody
Use
Intrinsic Factor Blocking Antibody detects circulating autoantibodies that bind to intrinsic factor, interfering with vitamin B12 absorption and supporting the diagnosis of pernicious anemia, particularly when combined with megaloblastic anemia and low serum B12 levels. The test may be positive in other autoimmune disorders, though sensitivity is moderate (around 50%) while specificity is high. High serum vitamin B12 levels or recent B12 injections (within 1–2 weeks) can yield false-positive results.
Special Instructions
Not provided.
Limitations
High vitamin B12 concentrations in serum may interfere with the assay and cause false-positive results. Sensitivity is limited (~50%), so a negative result does not rule out pernicious anemia. Specificity is high, thus a positive result confirms the presence of intrinsic factor blocking antibodies; timing relative to B12 injection can affect accuracy.
Methodology
Immunoassay (Other)
Biomarkers
Intrinsic Factor Blocking Antibody
Other
Result Turnaround Time
1-3 days
Related Documents
For more information, please review the documents below
Specimen
Serum
Volume
1 mL
Minimum Volume
0.3 mL
Collection Instructions
Samples should not be collected from a patient who has received Vitamin B12 injection therapy within the past week
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 7 days |
| Refrigerated | 7 days |
| Frozen | 28 days |
Other tests from different labs that may be relevant