Physical fatigue characterises patient experience of primary Sjögren's syndrome

Besides ocular and oral dryness, fatigue is a major symptom in patients with primary Sjögren's syndrome (pSS). Our aim was to investigate the importance of fatigue in relation to other symptoms experienced as well as to evaluate the effect of rituximab treatment on fatigue in pSS patients with active disease.

This analysis was based on data from our open-label rituximab study in 28 pSS patients. Symptoms of dryness, physical fatigue, pain, and mental fatigue were scored on 0-10 scales (according to ESSPRI). Systemic disease activity was assessed with ESSDAI.

At baseline, 24 (86%) patients rated physical fatigue as the complaint most eligible for improvement (median importance of 10), followed by pain, dryness, and mental fatigue. After rituximab treatment, physical fatigue showed maximum improvement of 2.5 points and 31% in median values at group level, and 10 (36%) patients reached physical fatigue score<5 representing patient-acceptable symptom state (PASS). In comparison, systemic disease activity improved 5.5 points and 73% at group level, and 22 (79%) patients reached ESSDAI<5 representing low disease activity. GEE analysis over time revealed that physical fatigue was significantly associated with absolute number of B cells, dryness and mental fatigue, but not with ESSDAI, IgG levels and IgM-RF.

Physical fatigue characterises patient experience of pSS. Rituximab treatment resulted in significant improvement of patient-reported symptoms. However, the large majority of patients still experienced physical fatigue at an unsatisfactory level, above the cut-off value for PASS. Therefore, attention for optimal management of this prominent symptom is warranted.