Test Catalog

Test Id : LY27B

HLA-B27, Blood

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 syndrome

Method Name
A short description of the method used to perform the test

Flow Cytometry

NY State Available
Indicates the status of NY State approval and if the test is orderable for NY State clients.


Reporting Name
Lists a shorter or abbreviated version of the Published Name for a test

HLA-B27, B

Lists additional common names for a test, as an aid in searching


Histocompatibility Antigen

Human Leukocyte Antigen

Leukocyte Antigens



W-27 (HLA-B27)

Specimen Type
Describes the specimen type validated for testing

Whole Blood EDTA

Ordering 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
Defines the optimal specimen required to perform the test and the preferred volume to complete testing

Container/Tube: Lavender top (EDTA)

Specimen Volume: 6 mL

Collection Instructions: Send whole blood specimen in original tube. Do not aliquot.


If not ordering electronically, complete, print, and send a General Request (T239) with the specimen.

Specimen Minimum Volume
Defines the amount of sample necessary to provide a clinically relevant result as determined by the Testing Laboratory

1 mL

Reject Due To
Identifies specimen types and conditions that may cause the specimen to be rejected

All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.

Specimen Stability Information
Provides a description of the temperatures required to transport a specimen to the performing laboratory, alternate acceptable temperatures are also included

Specimen Type Temperature Time Special Container
Whole Blood EDTA Ambient 4 days

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 syndrome

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 syndrome. 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 B*27:06 allele, which is present in a small percentage of individuals of Asian ethnicity, may not be associated with 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.

Provides information to assist in interpretation of the test results

Approximately 8% of the normal population carries the human leukocyte antigen (HLA)-B27 antigen.


HLA-B27 is present in approximately 89% of patients with ankylosing spondylitis, 79% of patients with Reiter syndrome, and 42% of patients with juvenile rheumatoid arthritis. However, lacking other data, it is not diagnostic for these disorders.

Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances

Extreme temperature changes during shipping may alter the specimen making it unacceptable for testing.

Clinical Reference
Recommendations for in-depth reading of a clinical nature

1. Profaizer T, Dibb K, Bethers H, et al: Comparison of next-generation sequencing-based human leukocyte antigen typing with clinical flow cytometry and allele-specific PCR melting assays for HLA-B27 genotyping. J Appl Lab Med. 2021 Sep 1;6(5):1221-1227. doi: 10.1093/jalm/jfab046

2. Skalska U, Kozakiewicz A, Maslinski W, Jurkowska M: HLA-B27 detection - comparison of genetic sequence-based method and flow cytometry assay. Reumatologia. 2015;53(2):74-78. doi: 10.5114/reum.2015.51506

3. Brewerton DA, Hart FD, Nicholls A, Caffrey M, James DC, Sturrock RD: Ankylosing spondylitis and HL-A27. Lancet. 1973 Apr 28;1(7809):904-907

4. Albrecht J, Muller HA: HLA-B27 typing by use of flow cytofluorometry. Clin Chem. 1987 Sep;33(9):1619-1623

Method Description
Describes how the test is performed and provides a method-specific reference

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)

PDF Report
Indicates whether the report includes an additional document with charts, images or other enriched information


Day(s) Performed
Outlines the days the test is performed. This field reflects the day that the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time before the test is performed. Some tests are listed as continuously performed, which means that assays are performed multiple times during the day.

Monday through Saturday

Report Available
The interval of time (receipt of sample at Mayo Clinic Laboratories to results available) taking into account standard setup days and weekends. The first day is the time that it typically takes for a result to be available. The last day is the time it might take, accounting for any necessary repeated testing.

2 to 6 days

Specimen Retention Time
Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded

7 days

Performing Laboratory Location
Indicates the location of the laboratory that performs the test


Several factors determine the fee charged to perform a test. Contact your U.S. or International Regional Manager for information about establishing a fee schedule or to learn more about resources to optimize test selection.

  • Authorized users can sign in to Test Prices for detailed fee information.
  • Clients without access to Test Prices can contact Customer Service 24 hours a day, seven days a week.
  • Prospective clients should contact their Regional Manager. For assistance, contact Customer Service.

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 instructions, or as products that do not undergo full FDA review and approval, and are then labeled as an Analyte Specific Reagent (ASR) product.

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
Provides guidance in determining the appropriate Current Procedural Terminology (CPT) code(s) information for each test or profile. The listed CPT codes reflect Mayo Clinic Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.

CPT codes are provided by the performing laboratory.


LOINC® Information
Provides guidance in determining the Logical Observation Identifiers Names and Codes (LOINC) values for the order and results codes of this test. LOINC values are provided by the performing laboratory.

Test Id Test Order Name Order LOINC Value
LY27B HLA-B27, B 26028-1
Result Id Test Result Name Result LOINC Value
Applies only to results expressed in units of measure originally reported by the performing laboratory. These values do not apply to results that are converted to other units of measure.
LY27 HLA-B27 Result 26028-1
B27C Interpretation 96625-9

Test Setup Resources

Setup Files
Test setup information contains test file definition details to support order and result interfacing between Mayo Clinic Laboratories and your Laboratory Information System.

Excel | Pdf

Sample Reports
Normal and Abnormal sample reports are provided as references for report appearance.

Normal Reports | Abnormal Reports

SI Sample Reports
International System (SI) of Unit reports are provided for a limited number of tests. These reports are intended for international account use and are only available through MayoLINK accounts that have been defined to receive them.

SI Normal Reports | SI Abnormal Reports