Predictive value of SS-B precipitating antibodies in Sjoögren's syndrome.

As part of a screening programme several patients were identified with antibodies to the nuclear antigen SS-B. Fifteen were examined and 11 found to have Sjögren's syndrome, though this had not been suspected by most of the referring physicians. In contrast, among a group of 17 patients with overt Sjögren's syndrome, most of whom also had rheumatoid arthritis, only one had antibodies to SS-B. Patients presenting with polyarthralgia found to be SS-B positive may be likely to develop Sjögren's syndrome but unlikely to develop rheumatoid arthritis. The detection of SS-B antibodies may antedate clinical evidence of Sjögren's syndrome by months or even years. These results emphasise the clinical heterogeneity of Sjögren's syndrome.