Systemic autoimmune rheumatic diseases (SARDs) such as systemic sclerosis (SSc, or scleroderma) and ANCA-associated vasculitis (AAV) are rare with annual incidences estimated at 1.4 (1.1–1.9) per 100.000 for SSc [Citation3] and 3–5 cases per 100,000 for AAV [Citation4,Citation5]. SSc is characterized by systemic immune dysregulation, vasculopathy, and/or fibrosis [Citation6].
ME/CFS, Systemic Sclerosis, and Vasculitides are unique diseases with vastly different presentations. However, their pathogenesis shares a multitude of inflammatory, immune, and metabolic perturbations. In particular, mitochondrial dysregulation, Th2 polarization, low IgG levels and reduced NK cell cytotoxicity have been highlighted in all three groups – suggesting that in patients with ME/CFS and SSc or vasculitis, common mechanisms may be present. Patients with these diseases also present with high levels of persistent, debilitating fatigue.
We have identified that patients with early SSc and AAV patients with fatigue fulfill the diagnostic criteria for ME/CFS. Although these patients cannot be diagnosed as having ME/CFS, the criteria surrounding the diagnosis of ME/CFS have been very well researched. Using ME/CFS criteria as a standardized approach to identifying persistent fatigue in SARDs may help streamline research, including the identification of potential biomarkers as well as improved treatment strategies.