Test ID: LY27B
HLA-B27, Blood
Secondary ID 
A test code used for billing and in test definitions created prior to November 2011
NY State Approved Indicates the status of NY State approval and if the test is orderable for NY State clients.
Useful For Suggests clinical disorders or settings where the test may be helpful
Assisting in the diagnostic process of ankylosing spondylitis, juvenile rheumatoid arthritis, and Reiter’s syndrome
Method Name A short description of the method used to perform the test
Flow Cytometry
Reporting Name A shorter/abbreviated version of the Published Name for a test; an abbreviated test name
Aliases Lists additional common names for a test, as an aid in searching
Histocompatibility Antigen
Human Leukocyte Antigen
Leukocyte Antigens
LY27
Spondylitis
W-27 (HLA-B27)
Specimen Type Describes the specimen type needed for testing
Specimen Required Defines the optimal specimen. This field describes the type of specimen required to perform the test and the preferred volume to complete testing. The volume allows automated processing, fastest throughput and, when indicated, repeat or reflex testing.
Specimen must arrive within 96 hours of draw.
Container/Tube: Lavender top (EDTA)
Specimen Volume: 6 mL
Collection Instructions: Do not transfer blood to other containers.
Specimen Minimum Volume Defines the amount of specimen required to perform an assay once, including instrument and container dead space. Submitting the minimum specimen volume makes it impossible to repeat the test or perform confirmatory or perform reflex testing. In some situations, a minimum specimen volume may result in a QNS (quantity not sufficient) result, requiring a second specimen to be collected.
Reject Due To Identifies specimen types and conditions that may cause the specimen to be rejected
| Hemolysis | NA |
| Lipemia | NA |
| Icterus | NA |
| Other | NA |
Specimen Stability Information Provides a description of the temperatures required to transport a specimen to the laboratory. Alternate acceptable temperature(s) are also included.
| Specimen Type | Temperature | Time |
|---|---|---|
| Whole Blood EDTA | Ambient | 4 days |
Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
This major histocompatibility coded class I antigen is associated with ankylosing spondylitis, juvenile rheumatoid arthritis, and Reiter’s syndrome. The mechanism of the association is not understood but probably is that of linkage disequilibrium.
There is an increased prevalence of HLA-B27 in certain rheumatic diseases, particularly ankylosing spondylitis.
Reference Values Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.
An interpretive report will be provided.
Interpretation Provides information to assist in interpretation of the test results
Approximately 8% of the normal population carries the HLA-B27 antigen.
HLA-B27 is present in approximately 89% of patients with ankylosing spondylitis, 79% of patients with Reiter's syndrome, and 42% of patients with juvenile rheumatoid arthritis. However, lacking other data, it is not diagnostic for these disorders.
Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances
Orders received for SSO1/84472 HLA/SSO Class I Molecular Phenotype, Blood or DISI/89185 HLA Class I Molecular Typing Disease Association (which provides data on all HLA Class I low-resolution antigens, including B27) and LY27B/9648 HLA-B27, Blood will be questioned due to test overlap. This HLA-B27 test is best used alone if a particular disease such as ankylosing spondylitis is under consideration.
Extreme temperature changes during shipping may alter the specimen making it unacceptable for testing.
Clinical Reference Provides recommendations for further in-depth reading of a clinical nature
1. Brewerton DA, Hart FD, Nicholls A, et al: Ankylosing spondylitis and HLA-27. Lancet 1973;1:904-907
2. Albrecht J, Muller HA: HLA-B27 typing by use of flow cytofluorometry. Clin Chem 1987;33:1619-1623
Method Description Describes how the test is performed and provides a method-specific reference
Anti-HLA fluorescein isothiocyanate (FITC)/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 caliBRITE beads with Autocomp 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: HLA-B27 Test Kit. Becton-Dickinson, San Jose, CA)
Day(s) and Time(s) Test Performed Outlines the days and times the test is performed. This field reflects the day and time the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time required before the test is performed. Some tests are listed as continuously performed, which means assays are performed several times during the day.
Monday through Friday; 7:30-to 5:00 p.m.
Saturday; 10:00 a.m.-6:00 p.m
Analytic Time Defines the amount of time it takes the laboratory to setup and perform the test. This is defined in number of days. The shortest interval of time expressed is "same day/1 day," which means the results may be available the same day that the sample is received in the testing laboratory. One day means results are available 1 day after the sample is received in the laboratory.
Maximum Laboratory Time Defines the maximum time from specimen receipt at Mayo Medical Laboratories until the release of the test result
Specimen Retention Time Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded
Performing Laboratory Location The location of the laboratory that performs the test
Test Classification Provides information regarding the medical device classification for laboratory test kits and reagents. Tests may be classified as cleared or approved by the US Food and Drug Administration (FDA) and used per manufacturer's instructions, or as products that do not undergo full FDA review and approval, and are then labeled as an Analyte Specific Reagent (ASR), Investigation Use Only (IUO) product, or a Research Use Only (RUO) product.
CPT Code Information Provides guidance in determining the appropriate Current Procedural Terminology (CPT) code(s) information for each test or profile. The listed CPT codes reflect Mayo Medical Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.
86812
LOINC® Code Information Provides guidance in determining the Logical Observation Identifiers Names and Codes (LOINC) values for the result codes returned for this test or profile.
| Result ID | Reporting Name | LOINC Code |
|---|---|---|
| LY27 | HLA-B27 Result | 4821-5 |
| B27C | Interpretation | In Process |
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