26th February 2025

Investigations in Sjögren’s syndrome

Over 70% have a positive ANA, and anti-Ro (SS-A) and La (SS-B) antibodies are common, with anti-Ro being the most specific. Rheumatoid factor can be positive, and patients can be misdiagnosed as having rheumatoid arthritis.

Schirmer’s test can be performed in clinic: a piece of filter paper is slipped under the eyelid and left for 5 minutes; if <5 mm of the paper is wet after 5 minutes, this suggests impaired tear secretion. Other investigations include measurement of saliva production and labial gland biopsy, which can help in diagnosis of antibody-negative patients.