Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) and fibromyalgia: PR3-versus MPO-ANCA-associated vasculitis, an exploratory cross-sectional study.
van Eeden, Charmaine, Mohazab, Naima, Redmond, Desiree et al. · Lancet regional health. Americas · 2023 · DOI
Quick Summary
This study looked at fatigue in people with ANCA-vasculitis (a type of blood vessel inflammation) and found that over half met the diagnostic criteria for ME/CFS. The researchers discovered that the type of vasculitis matters: people with MPO-ANCA had fatigue patterns more similar to fibromyalgia, while those with PR3-ANCA had fatigue linked to inflammation markers. This suggests different types of vasculitis may cause fatigue through different biological mechanisms.
Why It Matters
This research highlights an important but understudied overlap between ME/CFS and vasculitis, suggesting that some patients diagnosed with vasculitis may actually have ME/CFS or comorbid conditions. Understanding that different disease mechanisms (inflammatory vs non-inflammatory) may drive fatigue in different patient subgroups could lead to more targeted, effective treatments tailored to the underlying cause rather than symptom similarity alone.
Observed Findings
51.9% (27/52) of AAV patients met diagnostic criteria for ME/CFS, with 37% of those having comorbid fibromyalgia
Fatigue rates and symptom patterns were higher in MPO-ANCA patients compared to PR3-ANCA patients
MPO-ANCA patients' fatigue symptoms were more similar to fibromyalgia controls
In PR3-ANCA patients, fatigue was associated with inflammatory markers (CRP) and disease activity (BVAS)
Cognitive dysfunction, depression, anxiety, and sleep disturbances were assessed as contributing factors to fatigue
Inferred Conclusions
A substantial proportion of AAV patients experience debilitating fatigue meeting ME/CFS diagnostic criteria, indicating significant disease burden beyond traditional vasculitis assessments
PR3- and MPO-ANCA serotypes have distinct fatigue etiologies: PR3-ANCA is inflammation-driven while MPO-ANCA appears more similar to fibromyalgia-related fatigue mechanisms
Clinical treatment strategies for AAV-related fatigue should consider ANCA serotype, as different underlying pathophysiology may require different therapeutic approaches
Fatigue in AAV warrants dedicated clinical recognition and investigation separate from general vasculitis disease activity measures
Remaining Questions
What This Study Does Not Prove
This study does not prove that ANCA-vasculitis causes ME/CFS or vice versa—it only shows they frequently co-occur. The cross-sectional design cannot establish causality or determine whether fatigue develops before, during, or after vasculitis diagnosis. The findings are exploratory in a relatively small cohort and require validation in larger, prospective studies before generalizing to all ME/CFS and vasculitis populations.
What are the specific biological mechanisms underlying fatigue in MPO-ANCA patients that make it phenotypically similar to fibromyalgia?
Do AAV patients with ME/CFS have worse long-term outcomes or quality of life compared to those with fatigue alone, and does serotype predict prognosis?
Can this serotype-based fatigue distinction be prospectively validated in a larger, multicenter cohort with longitudinal follow-up?
What targeted treatment strategies (immunosuppressive vs symptomatic management) are most effective for fatigue in PR3- versus MPO-ANCA patients?