Test ID RIB Ribosome P Antibodies, IgG, Serum
Reporting Name
Ribosome P Ab, IgG, SUseful For
As an adjunct in the evaluation of patients with lupus erythematosus (LE)
Aids in the differential diagnosis of neuropsychiatric symptoms in patients with LE
Testing Algorithm
See Connective Tissue Disease Cascade (CTDC) in Special Instructions.
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
<1.0 U (negative)
≥1.0 U (positive)
Reference values apply to all ages.
Day(s) and Time(s) Performed
Monday through Saturday; 4 p.m.
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
83516
LOINC Code Information
Test ID | Test Order Name | Order LOINC Value |
---|---|---|
RIB | Ribosome P Ab, IgG, S | 53892-6 |
Result ID | Test Result Name | Result LOINC Value |
---|---|---|
RIB | Ribosome P Ab, IgG, S | 53892-6 |
Clinical Information
The 80S mammalian ribosome is composed of approximately equal amounts of protein and RNA. The larger 60S subunit contains 3 acidic phosphoproteins, PO, P1, and P2 with molecular masses of 38 kDa, 19 kDa, and 17 kDa, respectively. The major immunoreactive epitope of these 3 autoantigens is found within 22 consecutive amino acids of the carboxy terminus of these 3 highly conserved proteins.
It has been known for some time that sera from some patients with lupus erythematosus (LE) react with ribosomal protein antigens. Studies performed with synthetic peptide antigens revealed that reactivity detected by immunoprecipitation and by immunofluorescence methods in sera from LE patients was directed at the above mentioned epitope. Antibodies to ribosome P proteins are considered highly specific for LE, and have been reported in patients with central nervous system (CNS) involvement and so called "lupus psychosis." The reported frequency of antibodies to ribosome P protein autoantigens in patients with LE is approximately 12%.
Since patients with LE may manifest signs and symptoms of CNS diseases including neuropsychiatric symptoms, the presence of antibodies to ribosome P protein may be useful in the differential diagnosis of such patients. Other causes of CNS symptoms in patients with LE include thrombosis with or without antibodies to phospholipid antigens and iatrogenic effects from treatment with corticosteroid drugs.
Interpretation
A positive result is consistent with the diagnosis of lupus erythematosus, and may indicate the presence of central nervous system involvement.
Clinical Reference
1. Bonfa E, Golombek SJ, Kaufman LD, et al: Association between lupus psychosis and anti-ribosomal P protein antibodies. N Engl J Med 1987;317:265-271
2. Bonfa E, Elkon KB: Clinical and serologic associations of the anti-ribosomal P protein antibody. Arthritis Rheum 1986;29:981-985
Analytic Time
Same day/1 dayMethod Name
Multiplex Flow Immunoassay