Systemic sclerosis-associated Sjögren's syndrome and relationship to the limited cutaneous subtype: results of a prospective study of sicca syndrome in 133 consecutive patients.

OBJECTIVE To determine the prevalence of sicca symptoms and Sjögren's syndrome (SS) in a 2-center prospective series of patients with systemic sclerosis (SSc), using the American-European Consensus Group criteria for SS. METHODS Consecutive SSc patients hospitalized for followup care were evaluated for sicca symptoms. When the initial clinical evaluation yielded positive findings, a labial salivary gland biopsy was performed; histologic analysis evaluated focal lymphocytic sialadenitis and/or glandular fibrosis. Computed tomography and respiratory function tests were used to assess pulmonary fibrosis. RESULTS We included 133 SSc patients (mean +/- SD age 55 +/- 13 years; mean +/- SD disease duration 6.5 +/- 6 years). Eighty-one patients had limited cutaneous SSc (lcSSc). Ninety-one patients (68%) had sicca syndrome. Histologic analysis revealed fibrotic involvement in 50 of these 91 patients, but labial salivary gland fibrosis was not associated with any organ involvement we evaluated. Nineteen of the 133 patients (14%) had SS. In this subgroup, lcSSc was present at a significantly higher frequency (18 of 19 patients) than in the remaining patients with sicca syndrome (39 of 72 patients) and the patients without sicca syndrome (24 of 42 patients). This subgroup also had a significantly higher frequency of anticentromere antibodies (18 of 19 patients) than did the remaining patients with sicca syndrome (19 of 72 patients) and the patients without sicca syndrome (5 of 42 patients). In addition, this subgroup had a significantly lower prevalence of pulmonary fibrosis (2 of 19 patients) than did the remaining patients with sicca syndrome (29 of 72 patients) and the patients without sicca syndrome (19 of 42 patients). CONCLUSION There was a 68% prevalence of sicca syndrome in this prospective series of SSc patients. Sicca syndrome was related primarily to glandular fibrosis, the hallmark of SSc. The prevalence of secondary SS, as defined by the American-European Consensus Group criteria, was 14% and was markedly associated with lcSSc. We believe that lcSSc should be regarded as a specific autoimmune subgroup of SSc.