Arthritis & Rheumatism, Volume 62,
November 2010 Abstract Supplement

Abstracts of the American College of
Rheumatology/Association of Rheumatology Health Professionals
Annual Scientific Meeting
Atlanta, Georgia November 6-11, 2010.


Antinuclear Antibody Screening in Systemic Sclerosis.

Swistowski2,  Donna Rose, Saddic3,  Nicole, Shanmugam1,  Victoria K., Steen4,  Virginia D.

Georgetown University Division of Rheumatology, Immunology, and Allergy, Great Falls, VA
Georgetown University Division of Rheumatology, Immunology, and Allergy, Bethesda, MD
Georgetown University Hospital Department of Medicine
Georgetown University Medical Center, Washington, DC

Purpose:

Scleroderma specific antinuclear antibodies (SScAB) are helpful predictors of disease manifestations, clinical course and outcome in scleroderma. Historically, immunofluorescence (IF) antinuclear antibody (ANA) testing was the gold standard method for ANA detection, and the American College of Rheumatology continues to recommend IF for evaluation of ANA. Many commercial labs have recently adopted newer, automated, non-immunofluorescence methods (NEW ANAs), such as EIA (enzyme immunoassay) or immunobead methods to evaluate for the presence of antinuclear antibodies. These new techniques rely on a limited panel of autoantigens in the assay.

The purpose of this study was to evaluate ANAs and SScAB results performed through commercial labs, using both NEW ANA detection techniques and traditional IF, in a consecutive cohort of scleroderma patients seen in the Georgetown Scleroderma Clinic over a one year period.

Methods:

Between June 2008 and June 2009, 241 scleroderma patients were evaluated. Patient charts were reviewed for results of NEW ANA, IF-ANA, isolated nucleolar ANA pattern (NuANA), and the SScAB profile including anticentromere (ACA), anti-topoisomerase (Scl-70), U1 RNP, and RNA polymerase III (Pol III) antibodies.

Results:

The results of this study are summarized in table 1. NEW ANA results were available in 58 patients with 28 patients (48%) testing negative. Of these 28 patients, 22 had either positive IF-ANA or a SScAB recorded: IF-ANA only (n=7), NuANA (n=6), Pol III (n=7), SSB (n=1), U1 RNP (n=1). In the patients with a positive NEW ANA (n=30) the NEW ANA successfully detected all patients with ACA (n=4), Scl-70 (n=13), UI RNP (n=6), and SSA (n=1) antibodies. A positive NEW ANA additionally identified Pol III (n=1), NuANA with a + SSA (n=3), and nonspecific ANA (n=2). However, the NEW ANA failed to identify the NuANA, Pol III antibodies, and other IF-ANA patterns in a significant number of patients (20/22 vs. 6/30, p<0.0001).

The remaining 183 SSc patients did not have NEW ANA testing available. Of these patients, 156 (85%) had positive SScABs or an IF-ANA. ACA was present in 22.4%, Scl-70 in 25%, and U1 RNP in 9.6%. This accounts for 57% of patients who we predict would be identified with the NEW ANA assay. However, patients with other antibodies including Pol III (10.2%), NuANA (19.2%), and nonspecific ANA patterns (13.5%), account for 40% of the scleroderma patients in our population, and we predict these patients would not be identified using NEW ANA assays.

Conclusions:

Immunofluorescence ANA should be performed in all patients in whom there is clinical suspicion for scleroderma. Physicians should remain skeptical of negative ANAs in patients with clinical evidence of scleroderma.

Table 1. NEW ANA test results on 52 patients with corresponding ANA IF data or SScABs

ACANEW ANA Positive (n=30)NEW ANA Negative (n=22)
 40
Scl-70130
UI RNP61
SSA/SSB11 (+SSB)
NuANA3 (all+SSA)]20%6]20%
Pol III17
ANA IF27
*p<0.0001.

To cite this abstract, please use the following information:
Swistowski, Donna Rose, Saddic, Nicole, Shanmugam, Victoria K., Steen, Virginia D.; Antinuclear Antibody Screening in Systemic Sclerosis. [abstract]. Arthritis Rheum 2010;62 Suppl 10 :2197
DOI: 10.1002/art.29961

Abstract Supplement

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