Intrinsic Factor Blocking Antibody

Message
Sendout, Mayo test code: IFBA


Test Code
LAB857


Alias/See Also
Anti Intrinsic Factor
IF Blocking
Type 1 Intrinsic Factor Antibody
Intrinsic Factor Blocking Antibody
IFBA


CPT Codes
86340

Preferred Specimen
1.0 mL of serum from a gold serum gel tube


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.

Minimum Volume
0.5 mL


Other Acceptable Specimens
Red tube


Instructions
Centrifuge and aliquot serum into a plastic vial.


Transport Container
Plastic vial


Transport Temperature
Refrigerated


Specimen Stability
Refrigerated (preferred): 14 days
Frozen: 14 days


Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)
Hemolysis: Mild OK; Gross reject
Lipemia: Mild OK; Gross OK


Methodology
Immunoenzymatic Assay

FDA Status
Approved

Setup Schedule
Monday through Friday


Report Available
1-3 days


Limitations
Patients who have received a vitamin B12 injection or radiolabeled vitamin B12 injection within the previous 2 weeks may have high serum vitamin B12 levels, which can interfere with this assay leading to falsely elevated results.
 
Some patients with other autoimmune diseases may have positive intrinsic factor blocking antibody (IFBA) assays without suffering from pernicious anemia (PA). This is reported particularly in patients with autoimmune thyroid disease or type I diabetes mellitus. In the validation of this assay, 24 individuals with these autoimmune endocrine diseases were tested and all were IFBA negative. However, 5 of 15 of patients with rheumatoid arthritis were IFBA positive during the validation of this assay. The literature suggests such individuals may, in fact, be at risk of later development of PA.
 
Since this is a competitive binding assay, the risk of heterophile antibody interference is low. During validation, 24 human antimouse antibody positive specimens and 25 specimens with other heterophile antibodies were tested and all were IFBA negative. However, if the clinical picture does not agree with the IFBA test result, the laboratory should be consulted for advice.


Reference Range
Included with report


Clinical Significance
Confirming the diagnosis of pernicious anemia


Performing Laboratory
Mayo Clinic Laboratories, Rochester, Minnesota

Additional Information
Intrinsic Factor Blocking Antibody, Serum


The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.