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HelpTest Code RNP RNP/SmRNP Antibodies
Useful For
Diagnosis and prognosis of rheumatoid arthritis. A seropositive rheumatoid arthritis generally has a more favorable prognosis than seronegative form. This "rheumatoid factor" is not specific for rheumatoid arthritis; it also appears in serum from patients with Connective Tissue Disease, chronic inflammatory and infectious diseases, pulmonary fibrosis, liver disease and acute viral infections.
See the Mixed Connective Tissue Disease Panel Algorithm for suggested testing strategy.
Synonyms/Keywords
SMRNP, ENA, Extractable Nuclear Antibodies, RNP
Specimen Requirements
| Fasting Required | Specimen Type | Preferred Container/Tube | Acceptable Container/Tube | Specimen Volume | Specimen Minimum Volume (allows for 1 repeat) |
Pediatric Minimum Volume (no repeat) |
|---|---|---|---|---|---|---|
| No | Serum | Red Top Tube (RTT) or Serum Separator Tube (SST) | 1.0 mL | 0.5 mL | 0.5 mL |
Collection/Processing Instructions
Separate serum from cells within 2 hours of collection.
Specimen Stability Information
| Specimen Type | Temperature | Time |
|---|---|---|
| Serum | Refrigerated | 7 days |
| Frozen | 3 months |
Rejection Criteria
| Gross Lipemia |
| Gross Hemolysis |
| Heat inactivated samples |
Test Components
RNP and SmRNP Antibodies
Interpretations
Positive result(s) support diagnosis of mixed connective tissue disease, which resembles SLE but is not accompanied by renal involvement.
Reference Range Information
| Performing Location | Reference Range |
|---|---|
| Marshfield |
Negative 13 IU/mL Analytical measuring range is 0.2-8.0 AI (Antibody Index) |
Marshfield Labs Performing Department
Marshfield Labs Immunodiagnostics
Performing Information
| Performing Location | Day(s) Test Performed | Analytical Time | Methodology/Instrumentation |
|---|---|---|---|
| Marshfield | Monday through Friday | 1 day | Multiplex Flow Immunoassay/ Bio-Rad BioPlex 2200 |
CPT Codes
| CPT | Modifier (if needed) |
Quantity | Description | Comments |
|---|---|---|---|---|
| 86235 | 2 | Antibody to extractable nuclear antigen |
Outreach CPT Codes
| CPT | Modifier (if needed) |
Quantity | Description | Comments |
|---|---|---|---|---|
| 86235 | 2 | Antibody to extractable nuclear antigen |
Ordering Applications
| Ordering Application | Description |
|---|---|
| Cerner | Rheumatoid Factor, IgM |