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The presence of fibrillarin (U3-RNP) IgG antibodies in association with an ANA IFA nucleolar pattern is suggestive of systemic sclerosis (SSc). These antibodies in SSc are associated with distinct clinical features, such as younger age at disease onset and frequent internal organ involvement, including pulmonary hypertension, myositis, and renal disease. Fibrillarin antibodies are detected more frequently in African American patients with SSc compared to other ethnic groups. Strong correlation with ANA IFA results is recommended. In a multiethnic cohort of SSc patients, U3-RNP antibodies detected by immunoblot showed a high agreement with the immunoprecipitation assay.