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HelpTest ID: SSAB SS-A and SS-B Antibodies, IgG, Serum
Reporting Name
SSA/SSBUseful For
Evaluating patients with signs and symptoms of a connective tissue disease in whom the test for antinuclear antibodies is positive, especially those with signs and symptoms consistent with Sjogren syndrome or lupus erythematosus
This test is not useful in patients without demonstrable antinuclear antibodies.
Clinical Information
Sjogren syndrome (SS)A (Ro), SSB (La), ribonucleoprotein (RNP), and Smith (Sm) proteins are autoantigens commonly referred to as extractable nuclear antigens (ENA). Antibodies to ENA are common in patients with connective tissue diseases (systemic rheumatic diseases).
SSA or Ro is composed of protein antigens of 52 kD and 60 kD combined with cytoplasmic RNA species. SSA antibodies occur in patients with several different connective tissue diseases including Sjogren syndrome, an autoimmune disease that involves primarily the salivary and lachrymal glands (up to 90% of cases); systemic lupus erythematosus (SLE) (40%-60% of cases); and rheumatoid arthritis. SSA antibodies are associated with childhood SLE, neonatal SLE, and with congenital heart block in infants born to mothers with SLE.(1,2) SSA antibodies have also been reported to be associated with features of extraglandular inflammation in patients with SLE including vasculitis, purpura, cytopenias, and adenopathy.
SSB or La is composed of a 48-kD protein combined with RNA species. SSB antibodies are found primarily in patients with Sjogren syndrome or SLE, where they occur with frequencies of approximately 60% and 15%, respectively.(1,2) SSB antibodies occur only infrequently in the absence of SSA antibodies.
See Connective Tissue Disease Cascade (CTDC) in Special Instructions.
Interpretation
A positive result for SSA (Ro) or SSB (La) antibodies is consistent with connective tissue disease, including Sjogren syndrome, lupus erythematosus (LE), or rheumatoid arthritis.
A positive result for SSA antibodies in a woman with LE prior to delivery indicates an increased risk of congenital heart block in the neonate.
Profile Information
| Test ID | Reporting Name | Available Separately | Always Performed |
|---|---|---|---|
| SSA | SS-A/Ro Ab, IgG, S | Yes | Yes |
| SSB | SS-B/La Ab, IgG, S | Yes | Yes |
Testing Algorithm
See Connective Tissue Disease Cascade (CTDC) in Special Instructions.
Analytic Time
Same day/1 dayDay(s) and Time(s) Performed
Monday through Saturday; 4 p.m.
Clinical Reference
1. Homburger H, Larsen S: Detection of specific antibodies. In: Rich R, Fleisher T, Schwartz B, et al, eds. Clinical Immunology: Principles and Practice. Mosby-Year Book; 1996:2096-2109
2. Kotzin B, West S: Systemic lupus erythematosus. In: Rich R, Fleisher T, Shearer E, et al, eds. Clinical Immunology Principles and Practice. 2nd ed. Mosby-Year Book; 2001:60.1-60.24
3. Rifai N, Horvath AR, Wittwer CT, eds: Tietz Textbook of Clinical Chemistry and Molecular Diagnostics. 6th ed. Elsevier; 2018
Method Name
Multiplex Flow Immunoassay
Specimen Type
SerumSpecimen Required
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 | Special Container |
|---|---|---|---|
| Serum | Refrigerated (preferred) | 21 days | |
| Frozen | 21 days |
Special Instructions
Reference Values
SS-A/Ro ANTIBODIES, IgG
<1.0 U (negative)
≥1.0 U (positive)
Reference values apply to all ages.
SS-B/La ANTIBODIES, IgG
<1.0 U (negative)
≥1.0 (positive)
Reference values apply to all ages.
Test Classification
This test has been cleared, approved or is exempt 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 x 2
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| SSAB | SSA/SSB | 87555-9 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| SSA | SS-A/Ro Ab, IgG, S | 33610-7 |
| SSB | SS-B/La Ab, IgG, S | 33613-1 |
mml-Behavioral, mml-Epilepsy, mml-Headache, mml-Movement-Disorders, mml-Demyelinating-Diseases, mml-Neuroimmunology, mml-Neuromuscular, mml-Autonomic, mml-Pediatric, mml-Spinal-Cord, mml-Neuro-ophthalmology