Background Besides ocular and oral dryness, fatigue is a prominent symptom in patients with primary Sjögren's syndrome (pSS).

Objectives To investigate the importance of fatigue in relation to other symptoms and to evaluate the effect of rituximab treatment on fatigue in pSS patients with active disease.

Methods The present analysis was based on data from our follow-up study of treatment with rituximab.(1) Twenty-eight pSS patients were treated with rituximab (1000 mg at days 1 and 15) and evaluated for 60 weeks. Subjective symptoms of dryness, physical fatigue, and limb pain were scored on a scale of 0–10 according to the ESSPRI. Mental fatigue was also scored on a scale of 0–10. Patients were asked to rank their symptoms of dryness, physical fatigue, pain, and mental fatigue in order of importance; from most to least eligible for improvement. In addition, the importance for improvement of each symptom was scored on a scale of 0–10. Fatigue was assessed in more detail with the Multidimensional Fatigue Inventory (MFI). Systemic disease activity was assessed with the ESSDAI.

Results At baseline, 24 of the 28 (86%) pSS patients reported physical fatigue as most eligible for improvement, followed by pain and dryness. Mental fatigue was ranked as least eligible for improvement by 50% of the patients. However, for all these 4 domains, patients found it very important to get rid of their symptoms, reflected by median scores of importance of 8 or higher. The highest scores were given for physical fatigue (median 10, IQR 9–10).

Rituximab treatment resulted in a significant improvement in all clinical assessments. At 16 and 24 weeks of follow-up, physical fatigue showed 31% and 25% improvement in median values at group level, pain 36 and 29%, dryness 29% and 36%, and mental fatigue 36% and 9%, respectively. Regarding MFI domains, most improvement was reported in general (25% and 25%) and physical (19% and 16%) fatigue. In comparison, systemic disease activity assessed with ESSDAI improved 73% at group level. At 60 weeks of follow-up, all clinical assessments had returned to baseline values.

Before rituximab treatment, 18% of the patients had physical fatigue score <5, representing patient-acceptable symptom state (PASS). At 16–24 weeks, this proportion of patients increased to 21–36%. The proportion of patients with low disease activity according to ESSDAI increased from 29% at baseline to 75–79% at 16–24 weeks.

Conclusions Fatigue is a very important symptom in pSS patients with active disease, which particularly concerns physical fatigue. Rituximab treatment resulted in a significant improvement of all patient-reported symptoms. However, the large majority of patients still experienced physical fatigue above the cut-off value for the PASS. Therefore, clinical attention for this prominent symptom is warranted in future clinical trials in pSS.

1. Meiners et al. Ann Rheum Dis. 2012;71(8):1297–302.

Disclosure of Interest None declared