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HelpTest Code LY27B; SQ: HLAB27 HLA-B27, Blood
Reporting Name
HLA-B27, BUseful For
Assisting in the diagnostic process of ankylosing spondylitis, juvenile rheumatoid arthritis, and reactive arthritis
Performing Laboratory
Mayo Clinic Laboratories in Rochester
Specimen Type
Whole Blood EDTAOrdering Guidance
This test is best used alone if a particular disease, such as ankylosing spondylitis, is under consideration.
Orders received for both this test and 1LRR / Human Leukocyte Antigens (HLA) Class I Typing Low Resolution, Recipient, Blood or 1DIS / Human Leukocyte Antigens (HLA) A-B-C Disease Association Typing Low Resolution, Blood (which provides data on all HLA Class I low-resolution antigens, including B27) will be questioned due to test overlap.
Shipping Instructions
Specimen must arrive within 96 hours of collection.
Specimen Required
Container/Tube: Lavender top (EDTA)
Specimen Volume: 6 mL
Collection Instructions: Send whole blood specimen in original tube. Do not aliquot.
Specimen Minimum Volume
1 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Whole Blood EDTA | Ambient | 4 days |
Reference Values
An interpretive report will be provided.
Day(s) Performed
Monday through Saturday
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
86812
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| LY27B | HLA-B27, B | 26028-1 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| LY27 | HLA-B27 Result | 26028-1 |
| B27C | Interpretation | 96625-9 |
Clinical Information
This major histocompatibility coded class I antigen is associated with ankylosing spondylitis, juvenile rheumatoid arthritis, and reactive arthritis. The mechanism of the association is not understood but probably is that of linkage disequilibrium.
There is an increased prevalence of human leukocyte antigen (HLA)-B27 in certain rheumatic diseases, particularly ankylosing spondylitis.
Studies have demonstrated that the HLA-B*27:06 allele, which is present in a small percentage of individuals of Asian ethnicity, may not be associated with ankylosing spondylitis.
Interpretation
Approximately 8% of the normal population carries the human leukocyte antigen (HLA)-B27.
HLA-B27 is present in approximately 89% of patients with ankylosing spondylitis, 79% of patients with reactive arthritis, and 42% of patients with juvenile rheumatoid arthritis. However, lacking other data, it is not diagnostic for these disorders.
Method Description
Anti- human leukocyte antigens (HLA) fluorescein isothiocyanate/CD3 phycoerythrin monoclonal antibody reagent is added to human whole blood. The fluorochrome-labeled antibodies bind specifically to leukocyte surface antigens. The stained specimens are treated with lysing solution to lyse red blood cells, then washed and fixed prior to flow cytometric analysis. The flow cytometer is set up using BD 7 Color Setup beads and CS and T beads with FacsDIVA software and HLA-B27 calibration beads with the HLA-B27 software. The HLA-B27 software first identifies, on a forward scatter (FSC) versus fluorescence 2 (FL2) dot plot, the cluster of events with a uniformly bright CD3-positive signal (T-lymphocytes). During analysis, the median fluorescence intensity of the anti-HLA-B27 FITC signal is calculated for the events included in the FSC/FL2 gate. Specimens with a median fluorescence 1 channel result greater than or equal to the decision marker are considered HLA-B27 positive. Specimens with a median channel result lower than the decision marker are considered HLA-B27 negative. This decision marker is encoded in the suffix of the reagent lot number listed on the vial label.(Package insert: BD HLA-B27 Test Kit. BD Biosciences; 01/2018)
Reject Due To
All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.Method Name
Flow Cytometry
Forms
If not ordering electronically, complete, print, and send a General Request (T239) with the specimen.