3000460
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Smith and Smith/RNP (ENA) Antibodies, IgG

SMITH_RNP
Example Reports
Negative
Positive

Ordering Recommendation

Useful for confirming a diagnosis of systemic lupus erythematosus (SLE) or mixed connective tissue disease (MCTD) following a positive ANA result. Antibodies may be useful in the differential diagnosis of other systemic autoimmune rheumatic diseases such as systemic sclerosis, Sjögren syndrome, polymyositis, dermatomyositis, and overlap syndromes.

New York DOH Approval Status

This test is New York state approved.

Specimen Required

Patient Preparation
Collect

Serum Separator Tube (SST).

Specimen Preparation

Separate 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 month (avoid repeated freeze/thaw cycles)

Methodology

Semi-Quantitative Enzyme-Linked Immunosorbent Assay/Semi-Quantitative Multiplex Bead Assay

Performed

Sun-Sat

Reported

1-3 days

Reference Interval

Test Number
 Components
 Reference Interval
  Smith/RNP (ENA) Ab, IgG 19 Units or less
  Smith (ENA) Antibody, IgG 40 AU/mL or less

Interpretive Data




Components Interpretation
Smith/RNP (ENA) Antibody, IgG 19 Units or less: Negative
20-39 Units: Weak Positive
40-80 Units: Moderate Positive
81 Units or greater: Strong Positive
Smith (ENA) Antibody, IgG 29 AU/mL or less: Negative
30-40 AU/mL: Equivocal
41 AU/mL or greater: Positive

Compliance Category

FDA

Note

Hotline History

View Hotline History

 

Hotline History

Date of Change
Test Name Change
Methodology
Performance/Reported Schedule
Specimen Requirements
Reference Interval
Interpretive Data
Note
CPT Code
Component Change
Other Interface Change
New Test
Inactive
02/21/2023
X
N/A

CPT Codes

86235 x2

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Components

Component Test Code* Component Chart Name LOINC
0050085 Smith (ENA) Antibody, IgG 18323-6
0050470 Smith/RNP (ENA) Ab, IgG 33983-8
* 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.

Aliases

  • Anti-Sm
  • Anti-Smith (ENA) Antibody
  • Sm antibody IgG
  • Sm/RNP
  • Sm/RNP Antibody
Smith and Smith/RNP (ENA) Antibodies, IgG