Sialographic study in patients with and without antibodies to Sjögren's syndrome A (Ro).

Antibodies to Sjögren's syndrome A (SS-A) (Ro) antigen were detected in 13 of 16 (81%) patients with sicca alone and 18 of 34 (54%) patients with systemic lupus erythematosus (SLE). Antibodies to Sjögren's syndrome B (SS-B) (La, Ha) antigen were detected in 7 of 16 (44%) patients with sicca alone. These percentages were statistically higher than those in other types of connective tissue diseases. There were no direct correlations between titers of antibodies to SS-A (Ro) and severity of sialographic abnormalities in 35 patients with Sjögren's syndrome (SS). However comparison of a total of 20 sialograms obtained from patients with antibodies to SS-A (Ro) showed more advanced changes than in a total of 36 sialograms from patients without antibodies to SS-A (Ro) in systemic lupus erythematosus, mixed connective tissue disease, progressive systemic sclerosis and rheumatoid arthritis. These results suggested that antibody to SS-A (Ro) may be a good indicator of subclinical SS.