Effect of B-cell Depletion in Patients With Primary Sjögren's Syndrome

The primary purpose of the study is to determine whether B-cell depletion with Rituximab has an effect on the oral, ocular and general disease manifestations in patients with primary Sjögren´s syndrome, that is, an effect on the symptoms of oral and ocular dryness, improvement of the glandular function and a beneficial effect on the general symptoms such as fatigue. The secondary purpose of the study is the investigate the underlying autoimmune and pathophysiological mechanisms in Sjögren´s syndrome.