Association of severe inflammatory polyarthritis in primary Sjögren's syndrome: clinical, serologic, and HLA analysis.

Objective: To evaluate the clinical, serologic, and MHC class II antigen characteristics of a group of patients with primary Sjögren's syndrome (SS) and severe arthritis.

Methods: A case-control study comparing 35 patients with primary SS: 17 with inflammatory arthritis, 18 without arthritis.

Results: All patients fulfilled criteria for primary SS.