Antinuclear and Precipitating Auto-antibodies in Sjogren's Syndrome

Abstract

Tests for antinuclear antibodies were performed by the indirect fluorescent technique in 42 patients with Sjogren''s syndrome. Eighteen had rheumatoid arthritis (Group A), 2 had probable rheumatoid arthritis (Group B), 3 had progressive systemic sclerosis (Group C), 3 had polymyositis (Group D), and 16 had the sicca syndrome alone (Group E). Of the 42 patients, 28 (67%) had positive antinuclear factor tests, the incidence and titer of the antibodies being greater in patients of Group E than in Group A. There was a direct relationship between the presence of antinuclear factor and parotid enlargement indicated by history or examination, and a direct relation between the titers of antinuclear factor and the gamma globulin levels. Study of the morphological pattern of nuclear fluorescence showed that the prevalence of "homogeneous" antibody, was the same in Groups A and E, but that "speckled" antinuclear antibody was more common in Group E. With the exception of 1 patient with "probable" rheumatoid arthritis (Group B), antinucleolar antibody was found exclusively in patients of Group E. "Membranous" antinuclear antibody (anti-DNA) was not detected in any of the sera. All patients with positive L. E. -cell tests had high titer "homogeneous" antinuclear antibody, but the converse did not hold. Precipitating auto-antibodies reacting with saline extracts of various human tissues were detected by an agar diffusion Ouchter-Iony plate method in eighteen of the 42 patients (43%). Three distinct precipitating auto-antibodies were found (anti-SjD, anti-SjT, and anti-Lup). As with the antinuclear antibodies, the incidence and titer of the precipitating auto-antibodies were higher in Group E than Group A.