Quick Facts
- Sample: Whole Blood
- Fasting: No special preparation is required.
- Turnaround: 2-4 business days. May take longer based on weather, holiday, or lab delays.
What This Test Measures
The Red Blood Cell (RBC) Antigen Typing: Fya/Fyb Blood Test detects whether the Fya and Fyb antigens are present or absent on your red blood cells. These are the two antigens tested, and the result is a qualitative one, reporting presence or absence for each antigen. Nothing is calculated.
This test uses a whole blood sample. The Fya and Fyb antigens belong to the Duffy blood group, so the results may help a healthcare provider assess Duffy blood group compatibility. The test identifies antigens only and does not evaluate any other blood group system.
Benefits
- Identifies whether Fya and Fyb antigens are present on your red blood cells.
- Provides Duffy blood group antigen information for Fya and Fyb.
- Helps identify potential antigen incompatibilities for blood transfusions.
- May help a provider assess hemolytic disease risk when maternal antibody is known.
- Can support antigen typing for donors prior to bone marrow, tissue, organ, or blood donation.
Who Is This Test For?
- Fathers whose red blood cells may need typing for antigens matching a maternal antibody.
- Bone marrow donors who need red cell antigen typing before donation.
- Tissue or organ donors who need red cell antigen typing before donation.
- Blood donors who need red cell antigen typing before donation.
- People whose providers need Duffy blood group compatibility information for transfusion planning.
How It Works
- Order Your Test Online
- Visit a Local Lab
- Get Results Online
FAQ
1. What is the purpose of this test?
This test detects the presence or absence of the Fya and Fyb antigens on your red blood cells. It may help a healthcare provider evaluate Duffy blood group compatibility and identify potential antigen incompatibilities relevant to blood transfusions. When typing paternal red cells for an antigen that matches a maternal antibody. It does not diagnose a condition on its own.
2. What does this test measure?
The result is qualitative, not a concentration, ratio, or titer, and no values are calculated. It uses a whole blood sample. The Fya and Fyb antigens belong to the Duffy blood group, and the test does not include other blood group antigens or related tests.
3. Who would benefit from this test, and when should I order it?
This test may be useful when a healthcare provider has identified a maternal antibody and wants the paternal red cells typed for the corresponding antigen. It may also be useful before bone marrow, tissue, organ, or blood donation, or when Duffy blood group compatibility information is needed for transfusion planning. Testing a prenatal patient for red cell antigens is generally not indicated. This test does not replace medical evaluation.
4. Do I need to fast before this test?
No special preparation is required.
5. How quickly will I get results?
2-4 business days. May take longer based on weather, holiday, or lab delays.
6. How do I interpret the results?
Your results show whether the Fya and Fyb antigens are present or absent on your red blood cells. What this means depends on your clinical context, such as the reason for testing, your medical history, and any known maternal antibody. Potent cold agglutinins, a positive direct antiglobulin test, and in some cases bacteremia may interfere with interpretation. Your healthcare provider can explain what your results mean for you.
Disclaimer: Reference ranges may vary by laboratory. Listed ranges are general guidelines and may differ from those used by the performing lab. Always consult your healthcare provider for interpretation.
7. What should I do if my results are abnormal?
Review your results with a qualified healthcare provider. A single result does not provide a complete clinical conclusion. Your provider will determine whether any additional evaluation is appropriate.
8. How often should I get tested?
Testing frequency should be as directed by your healthcare provider. It depends on the reason the test was ordered, such as donation or transfusion planning, and your provider can advise whether repeat testing is needed.
Pre-test preparation
No special preparation is required.
