Autoantibody to U3 Nucleolar Ribonucleoprotein (Fibrillarin) In Patients with Systemic Sclerosis

Authors

  • Yutaka Okano MD,

    Corresponding author
    1. Division of Rheumatology and Clinical Immunology, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania.
    • Department of Medicine, 985 Scaife Hall, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261
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  • Virginia D. Steen MD,

    1. Division of Rheumatology and Clinical Immunology, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania.
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  • Thomas A. Medsger Jr. MD

    1. Division of Rheumatology and Clinical Immunology, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania.
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Abstract

To determine the clinical significance of serum antibodies to the U3 small nuclear ribonucleoprotein particle ([U3]snRNP), we studied sera from 416 patients with systemic sclerosis (SSc) and 264 controls, using immunofluorescence and immunoprecipitation assays. The presence of serum anti-(U3)snRNP was highly specific to SSc, was found more frequently in blacks, and was associated with skeletal muscle disease and primary pulmonary arterial hypertension. These antibodies may identify one or more unusual clinical subsets of SSc.

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