Diagnosis of Sjögren syndrome
A diagnosis of Sjögren syndrome is strongly suggested by significant and persistent sicca symptoms (eg severe dry eyes necessitating the use of ocular lubricants several times a day), in association with positive investigations including:
- serum electrophoresis showing polyclonal hypergammaglobulinaemia
- positive antinuclear antibody (ANA) titre
- presence of antibodies to extractable nuclear antigens (ENAs)—Ro (SS-A) and La (SS-B); see Common tests and prevalence of specific autoantibodies associated with inflammatory connective tissue diseases.
For a discussion about the role of ANA testing in the diagnosis of inflammatory connective tissue diseases, see Antinuclear antibody testing for inflammatory connective tissue diseases.
A raised erythrocyte sedimentation rate (ESR), positive rheumatoid factor (RF)1, and anaemia of chronic disease are common findings in Sjögren syndrome.
Ocular abnormalities associated with Sjögren syndrome are confirmed by a Schirmer tear test to demonstrate reduced tear production (see this video for how to perform a Schirmer test for dry eyes) and slit-lamp examination (looking for keratitis).
The presence of lymphocytic infiltrate in the minor salivary glands on lip biopsy is diagnostic of Sjögren syndrome; however, lip biopsy is usually only undertaken by specialists to confirm the diagnosis of Sjögren syndrome in the absence of antibodies to Ro or La. Ultrasound scan of the salivary glands is useful in supporting the diagnosis and may reduce the need for biopsyInanc, 2019Baldini, 2018.