Clinical aspects of primary and secondary Sjögren’s syndrome

Summary Sjögren's syndrome (SS) is a rheumatic autoimmune disease of salivary and lacrimal gland. The disease has a heterogenous character, therefore multiple organ manifestations can occur next to dryness, fatigue and pain. The most common manifestations of the disease are dryness of the mouth and eyes, the sicca symptoms. In our study, we investigated the occurrence of sicca symptoms and secondary SS in patients with rheumatoid arthritis (RA). Patients with higher disease activity of RA had more often sicca complaints and secondary SS. We showed that the presence of and changes in organ involvement of SS can be studied with ESSDAI, a systemic disease activity score. Furthermore, joint involvement can be assessed in more detail by DAS-28 score. In this thesis, the diagnosis and treatment of SS in elderly patients was discussed. It is known that 5-10% of SS patients develop lymphomas. We found that serum levels of free light chains can be suitable as biomarker for systemic disease activity and MALT lymphoma in SS patients. Finally, an overview was given of different treatments of sicca complaints and extraglandular disease manifestations. Most patients experience fatigue as most important symptom. Treatment with rituximab resulted in significant improvement of physical fatigue, but the majority of patients still experienced a substantial level of fatigue. The findings from this thesis give an overview of clinical manifestations, biomarkers and effect of the treatment and can tribute to monitoring and treatment of SS patients in daily clinical practice.