Sjögren’s syndrome

Sjögren’s syndrome is an autoimmune connective tissue disease characterized by dryness of the eyes and mouth and lymphocytic infiltrates in the salivary, lachrymal, and other exocrine glands. Its cause is not known, but the condition may be primary, where the disease exists on its own, or secondary, where it is associated with other rheumatic diseases, most commonly rheumatoid arthritis. It affects women more than men (ratio 9:1) and is the second commonest autoimmune rheumatic disease (after rheumatoid arthritis), but in many patients remains undiagnosed because symptoms are usually mild.

Clinical features—presentation is typically with a gritty sensation in the eyes (or other ocular symptoms) and dryness of the mouth. Constitutional symptoms such as fatigue are common. Other systemic manifestations include Raynaud’s phenomenon, purpura, arthralgia/arthritis, pleurisy, peripheral neuropathy, myelopathy, interstitial nephritis, and lymphoma.

Investigation and diagnosis—laboratory testing reveals raised immunoglobulin levels, rheumatoid factors of all isotypes (70% of cases), and autoantibodies against the cellular ribonucleoprotein antigens Ro (50–90%) and La (30–50%). Diagnosis should be based on the American/European Consensus criteria, which require the presence of four of the following six criteria: (1) ocular symptoms, (2) oral symptoms, (3) ocular signs, (4) oral signs, (5) positive labial biopsy, and (6) antibodies to Ro- and/or La (one or other of conditions 5 or 6 must be present).

Management—for most patients treatment is topical and symptomatic, with tear and saliva substitutes. Fatigue and arthralgia respond to hydroxychloroquine. Serious systemic complications are treated with steroids and cytotoxic drugs. There is increasing interest in the use of immunodulatory drugs, which may have potential to improve long-term outcomes.