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Consent Form Recommended
Ordering Recommendation

Not a diagnostic test for ankylosing spondylitis. May assist in the diagnosis of the condition only if other clinical signs and symptoms are present. Test should not be performed for prenatal diagnosis of ankylosing spondylitis because a positive result is not predictive for the disorder.

Mnemonic
HLAB27 PCR
Methodology

Polymerase Chain Reaction/Fluorescence Monitoring

Performed

Sun-Sat

Reported

3-7 days

New York DOH Approval Status
This test is New York DOH approved.
Specimen Required
Patient Preparation
Collect

Lavender (EDTA), pink (K2EDTA), or yellow (ACD Solution A or B).

Specimen Preparation

Do not freeze. Transport 3 mL whole blood. (Min: 1 mL)

Storage/Transport Temperature

Refrigerated.

Unacceptable Conditions

Plasma or serum; collection of specimen in sodium heparin tubes.

Remarks
Stability

Ambient: 72 hours; Refrigerated: 1 week; Frozen: Unacceptable

Reference Interval

Negative: The specimen is negative for HLA-B27.
Positive: The specimen is positive for HLA-B27.

Interpretive Data

Background Information for Ankylosing Spondylitis (HLA-B27) Genotyping:
Characteristics:
Ankylosing spondylitis (AS) is a chronic inflammatory disease that primarily causes pain and inflammation of the joints between the vertebrae of the spine and the sacroiliac joints. Inflammation and pain may occur in other parts of the body as well. HLA-B27 is strongly associated with ankylosing spondylitis (AS) as well as with Reiter syndrome, anterior uveitis, psoriatic arthritis, and inflammatory bowel disease.
Incidence:
Greater than 90 percent of patients with AS are HLA-B27 positive compared to 5-10 percent of the general population.
Penetrance:
Two to eight percent of individuals with HLA-B27 will develop AS.
Methodology:
Polymerase chain reaction (PCR) and fluorescent hybridization probes.
Analytical Sensitivity & Specificity:
99 percent
Limitations: Rare alleles present in less than 1 percent of most populations will not be detected. Diagnostic errors can occur due to rare sequence variations.

Compliance Category

Laboratory Developed Test (LDT)

Note
Hotline History
N/A
CPT Codes

81374

Components
Component Test Code* Component Chart Name LOINC
0050406 Ankylosing Spondylitis (HLAB27) 26043-0
2001317 Ankylosing Spondylitis (HLAB27) Specimen 31208-2
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.
Aliases
  • HLA B27 genotyping
  • HLA-B27
Ankylosing Spondylitis (HLA-B27) Genotyping