Ordering RecommendationRecommendations when to order or not order the test. May include related or preferred tests.
Useful in the differential diagnosis of connective tissue diseases with or without myopathy.
MnemonicUnique test identifier.
RNP
MethodologyProcess(es) used to perform the test.
Semi-Quantitative Multiplex Bead Assay
PerformedDays of the week the test is performed.
Sun-Sat
ReportedExpected turnaround time for a result, beginning when ARUP has received the specimen.
1-2 days
New York DOH Approval StatusIndicates test has been approved by the New York State Department of Health.
This test is New York DOH approved.
Specimen Required
Patient Preparation
Collect
Serum separator tube.
Specimen Preparation
Separate serum from cells ASAP or within 2 hours of collection. Transfer 1 mL serum to an ARUP Standard Transport Tube. (Min: 0.2 mL)
Storage/Transport Temperature
Refrigerated.
Unacceptable Conditions
Plasma or other body fluids. Contaminated, hemolyzed, or severely lipemic specimens.
Remarks
Stability
After separation from cells: Ambient: 48 hours; Refrigerated: 2 weeks; Frozen: 1 year (avoid repeated freeze/thaw cycles)
Reference IntervalNormal range/expected value(s) for a specific disease state. May also include abnormal ranges.
29 AU/mL or less
Negative
30-40 AU/mL
Equivocal
41 AU/mL or greater
Positive
Interpretive DataBackground information for test. May include disease information, patient result explanation, recommendations, details of testing, associated diseases, explanation of possible patient results.
Smith/RNP antibodies are frequently seen in patients with mixed connective tissue disease (MCTD) and are also associated with other systemic autoimmune rheumatic diseases (SARDs) such as systemic lupus erythematosus (SLE), systemic sclerosis, and myositis. Antibodies targeting the Smith/RNP antigenic complex also recognize Smith antigens, therefore, the Smith antibody response must be considered when interpreting these results.
Compliance Category
FDA
NoteAdditional information related to the test.
Purified Smith/RNP antigen is used in this assay. U1RNP IgG antibodies detected using immunoassays that employ recombinant U1-70K, A, and C proteins may yield discrepant results.
CPT CodesThe American Medical Association Current Procedural Terminology (CPT) codes published in ARUP's Laboratory Test Directory are provided for informational purposes only. The codes reflect our interpretation of CPT coding requirements based upon AMA guidelines published annually. CPT codes are provided only as guidance to assist clients with billing. ARUP strongly recommends that clients confirm CPT codes with their Medicare administrative contractor, as requirements may differ. CPT coding is the sole responsibility of the billing party. ARUP Laboratories assumes no responsibility for billing errors due to reliance on the CPT codes published.
* 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.
AliasesOther names that describe the test. Synonyms.