Brief CommunicationEvaluation of salivary gland protein 1 antibodies in patients with primary and secondary Sjogren's syndrome

- Antibodies anti-Ro, anti-La and anti-SP1 studied in Sjogren's syndrome
- Anti-SP1 in 19% of patients with primary SS lacking anti-Ro or anti-La
- Anti-SP1 in 50% of patients with RA and SS but only 8% of RA patients without SS
- Anti-Ro/anti-La was present in 40% of patients with RA and secondary SS.

Sjogren's syndrome (SS) has been associated with the expression of anti-Ro and anti-La antibodies. Anti-salivary gland protein 1 (SP1) antibodies have recently been identified in patients with SS.The current work involved a cross sectional study to determine whether anti-SP1 antibodies were identified in particular subgroups of patients with SS.The results of this study revealed that anti-SP1 antibodies were present in the sera of 52% of SS patients while anti-Ro/anti-La was present in 63% of patients. 19% of patients had anti-SP1 without anti-Ro/anti-La. Patients with SS and lymphoma expressed anti-Ro, anti-La and anti-SP1 together. In SS associated with RA, 50% had antibodies anti-SP1 while 40% had anti-Ro/anti-La.In conclusion, anti-SP1 antibodies are commonly seen in both primary and secondary SS and rarely in normal controls. Future studies are needed to determine the roles and timing of expression of anti-SP1 antibodies in Sjogren's syndrome.