Intrinsic Factor Blocking Antibody, Serum
Reporting Name
Intrinsic Factor Blocking Ab, SClinical System Name: Miscellaneous Test
Useful For
Confirming the diagnosis of pernicious anemia
Ordering Guidance
For a comprehensive workup of patients with suspected pernicious anemia, order ACASM / Pernicious Anemia Cascade, Serum, which initiates testing with measurement of vitamin B12. Depending of the vitamin B12 concentration, testing for intrinsic factor blocking antibody, gastrin, and methylmalonic acid may be added.
Specimen Required
Patient Preparation:
1. Patient should be fasting for 8 hours.
2. This test should not be performed on patients who have received a vitamin B12 injection or radiolabeled vitamin B12 injection within the previous 2 weeks.
Collection Container/Tube:
Preferred: Serum gel
Acceptable: Red top
Submission Container/Tube: Plastic vial
Specimen Volume: 1 mL
Collection Instructions: Centrifuge and aliquot serum into a plastic vial.
Specimen Type
SerumSpecimen Minimum Volume
0.5 mL
Specimen Stability Information
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
Serum | Refrigerated (preferred) | 14 days | |
Frozen | 14 days |
Day(s) Performed
Monday through Friday
TAT: 3 - 5 days
Performing Laboratory
Mayo Clinic Laboratories in RochesterMethod Name
Immunoenzymatic Assay
Method Description
The Access Intrinsic Factor (IF) Antibody assay is a competitive binding immunoenzymatic assay. The sample is added to a reaction vessel along with IF alkaline phosphatase conjugate and a protein blocking solution. IF antibody in the sample binds to the IF conjugate. After incubation in a reaction vessel, paramagnetic particles coated with a mouse monoclonal antibody, specific for the vitamin B12 binding site on IF, is added to the reaction. IF conjugate that has not been blocked by sample anti-IF binds to the monoclonal antibody on the solid phase. After an additional incubation, materials bound to the solid phase are held in a magnetic field, while unbound materials are washed away. Chemiluminescent substrate is added to the vessel and light generated by the reaction is measured with a luminometer. The light production is inversely proportional to the concentration of IF antibody in the sample expressed in AU/mL (antibody units/mL). The amount of analyte in the sample is determined from a stored calibration.(Package insert: Access Intrinsic Factor Ab. Beckman Coulter, Inc; 06/2020)
Reference Values
Negative
Test Classification
This test has been cleared, approved, or is exempt by the US Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.CPT Code Information
86340
LOINC Code Information
Test ID | Test Order Name | Order LOINC Value |
---|---|---|
IFBA | Intrinsic Factor Blocking Ab, S | 31444-3 |
Result ID | Test Result Name | Result LOINC Value |
---|---|---|
IFBLA | Intrinsic Factor Blocking Ab, S | 31444-3 |
CMT31 | Comment | 48767-8 |
Testing Algorithm
For more information, see Vitamin B12 Deficiency Evaluation.
Special Instructions
Report Available
1 day to 3 daysReject Due To
Gross hemolysis | Reject |
Gross lipemia | OK |