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Test ID SSB SS-B/La Antibodies, IgG, Serum

Useful For

Evaluating patients with signs and symptoms of a connective tissue disease in whom the test for antinuclear antibodies is positive

Testing Algorithm

See Connective Tissue Disease Cascade (CTDC) in Special Instructions.

Method Name

Multiplex Flow Immunoassay

Reporting Name

SS-B/La Ab, IgG, S

Specimen Type

Serum

Container/Tube:

Preferred: Serum gel

Acceptable: Red top

Specimen Volume: 0.5 mL

Specimen Minimum Volume

0.35 mL

Specimen Stability Information

Specimen Type Temperature Time
Serum Refrigerated (preferred) 21 days
  Frozen  21 days

Clinical Information

SS-B/La is an extractable nuclear antigen (ENA) composed of a 48-kD protein combined with RNA species. SS-B/La antibodies are found primarily in patients with Sjogren’s syndrome or lupus erythematosus (LE), where they occur with frequencies of approximately 60% and 15%, respectively.(1,2) SS-B/La antibodies occur only infrequently in the absence of SS-A/Ro antibodies.

 

SS-B/La is 1 of 4 autoantigens commonly referred to as extractable nuclear antigens (ENAs). The other ENAs are SS-A/Ro, RNP, and Sm. Each ENA is composed of 1 or more proteins associated with cytoplasmic or small nuclear RNA species (snRNP) ranging in size from 80 to 350 nucleotides. Antibodies to ENAs are common in patients with connective tissue diseases (systemic rheumatic diseases) including LE, mixed connective tissue disease, Sjogren's syndrome, scleroderma (systemic sclerosis), and polymyositis/dermatomyositis.

 

See Connective Tissue Disease Cascade (CTDC) in Special Instructions and Optimized Laboratory Testing for Connective Tissue Diseases in Primary Care: The Mayo Connective Tissue Diseases Cascade in Publications.

Reference Values

<1.0 U (negative)

≥1.0 U (positive)

Reference values apply to all ages.

Cautions

Testing for SS-B/La antibodies is not useful in patients without demonstrable antinuclear antibodies.

Day(s) Performed

Monday through Saturday; 4 p.m.

Report Available

1 day

Performing Laboratory

Mayo Medical Laboratories in Rochester

Test Classification

This test has been cleared or approved by the U.S. 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

86235

NY State Approved

Yes