043
Test #
SLE Panel (includes ANA, dsDNA, Ro, La, Sm, U1RNP, RNP70, Ribo P)
CPT Code(s) #
86038, 86039, 86255, 86225, 86235 x6
If Profile, Includes Tests:
N/A
Disease Name:
Systemic Connective Tissue Disease
Type of Study:
Serum Studies
Methodology:
Indirect Immunofluorescence (HEp-2) and Fluoroenzyme immunoassay (FEIA)
Substrate:
N/A
Reference Range:
ANA (Titer)
• Negative <40
dsDNA (IU/mL)
• Negative <10
• Equivocal 10-15
• Positive >10
Ro (SS-A) (U/mL)
• Negative <7
• Equivocal 7-10
• Positive >10
La (SS-B) (U/mL)
• Negative <7
• Equivocal 7-10
• Positive >10
Sm (Titer: U/mL)
• Negative <7
• Equivocal 7-10
• Positive >10
U1RNP (U/mL)
• Negative <5
• Equivocal 5-10
• Positive >10
RNP70 (U/mL)
• Negative <7
• Equivocal 7-10
• Positive >10
Ribo P (U/mL)
• Negative <7
• Equivocal 7-10
• Positive >10
Units:
Titer, Units
Schedule:
Assay performed once per week. Report availability is within one week from the time of specimen receipt.
Specimen Requirements:
Collect 5-10 ml of blood in a red top or serum separator tube. If possible, separate serum from clot and place into red capped tube provided with Beutner Laboratories collection kits. If separation facilities are not available, the blood can be sent in the tube used for collection.
Sample Stability:
Stable at ambient temperature during shipment. If sample is stored prior to shipment, it is stable refrigerated (2-8ºC) up to five days and frozen (-20ºC or lower) up to one year.
Clinical Relevance:
ANAs are a hallmark of SLE. Nearly all patients with SLE are ANA positive, with a titer of 1:80 giving a sensitivity of 98% and specificity of 75%. The American College of Rheumatology (ACR) recommends testing for specific autoantibodies when positive ANA titer and clinical suspicion of disease are present. Anti-double stranded DNA (dsDNA) antibodies have a high specificity (92% to 96%) and moderate sensitivity (57%-67%) for SLE. These antibodies constitute a criterion for SLE classification recommended by ACR and are associated with renal involvement (lupus nephritis). Although less common (sensitivity, 26% to 31%) antibodies to Sm antigen are highly specific (95% to 99%) for SLE. Detection of Sm is useful in patients with SLE but without anti dsDNA antibodies (15% of patients). Their presence at a high level at the onset of kidney disease in SLE is associated with poor prognosis. About 30%-40% of patients with SLE have Anti Ro/SSA and these correlate with photosensitivity, cutaneous vasculitis, and hematological disorders. Antibodies to La/SSB antigen are present in 10% of patients with SLE and are associated with lower prevalence of renal disease. Anti-ribosomal P antibodies are highly specific for SLE and are associated with neuropsychiatric manifestations. Anti RNP antibodies are found in patients with mixed connective tissue disease (MCTD). Clinical sensitivity in SLE is between 8% to 69% with specificity between 25% to 82%.
References:
Didier K, Bolko L, Giusti D, Toquet S, Robbins A, Antonicelli F, Servettaz A. Autoantibodies Associated With Connective Tissue Diseases: What Meaning for Clinicians? Front Immunol. 2018 Mar 26;9:541.
Jog NR, James JA. Biomarkers in connective tissue diseases. J Allergy Clin Immunol. 2017 Dec;140(6):1473-1483
