Test Overview
Test Methodology

Multiplex Flow Immunoassay

Test Usage

Antibodies to the Sm antigen represent a highly specific marker for SLE, but only occur in 25 - 35% of patients with the disease. Antibodies to RNP occur in 30 - 40% of patients with SLE, but are not specific for SLE. Antibodies to RNP are present in nearly all patients with Mixed Connective Tissue Disease (MCTD), and are specific for this disorder when all other antibodies are negative. The Sm and RNP antigens are closely associated, part of a protein and small nuclear RNA complex. The Bioplex 2200 ANA screen test system has beads coated with affinity purified Sm, with recombinant antigens RNP-68 and RNP-A, and a separate bead coated with Sm/RNP combined purified antigen.

Reference Range *

Negative

Test Details
Days Set Up
Monday - Friday
Analytic Time

1 day

Soft Order Code
SMRN
MiChart Code
Extractable Nuclear Antibodies, Sm and RnP
Synonyms
  • Smith Antibody
  • Anti-SmRNP
  • Anti-Sm (Smith)
  • RNP Antibody
  • SmRNP Antibody
  • U1RNP Antibody
  • SMRN
  • ANTI-SmRNP
  • ANTI-RNP
  • RNP
  • ANTI-SM
  • SMITH
  • Sm (Smith) Antibody
  • SMRNP
  • ENA (ANTI-Sm/SmRNP/RNP)
  • ENA 3 Antibody Panel
  • Anti-RNP (Ribonucleoprotein)
  • EXTRACTABLE NUCLEAR ANTIBODY
Laboratory
Chemical Pathology
Section
Immunopathology
Specimen Requirements
Collection Instructions

Collect specimen in SST tube. Centrifuge, aliquot serum into a plastic vial and refrigerate.

Alternate Specimen
Red top tube.
Yellow Top Tube
Normal Volume
0.5 mL serum
Minimum Volume
0.25 mL serum
Additional Information

Panel includes Smith (Sm) Antibody, SmRNP Antibody, and RNP Antibody. Smith and RNP Antibodies may also be ordered individually.

Billing
CPT Code
86235 x3
Fee Code
20571 SMRN, 30932 RNP, 30933 SMITH
LOINC
Z260-0 SMRN, 31627-3 SMITH, 31628-1 SMRNP, 8091-1 RNP
NY State Approved
No