Patients with Persistent Polyclonal B-Cell Lymphocytosis Share the Symptomatic Criteria of Systemic Exertion Intolerance Disease.
Morizot, Romain, de Korwin, Jean-Dominique, Feugier, Pierre et al. · Journal of clinical medicine · 2021 · DOI
Quick Summary
Researchers studied a rare blood condition called persistent polyclonal B-cell lymphocytosis (PPBL) and found that most patients with PPBL experience symptoms very similar to ME/CFS, including severe fatigue that doesn't improve with rest, worsening after physical activity, sleep problems, and difficulty thinking clearly. Out of 39 patients surveyed, 72% met the official criteria for ME/CFS, and nearly all reported chronic fatigue lasting more than 6 months. This finding suggests these two conditions may share common underlying features, though more research is needed to understand why.
Why It Matters
This study provides evidence that ME/CFS-like symptoms are prevalent in another rare condition, which could help clinicians recognize ME/CFS in underdiagnosed populations and may offer clues about shared biological mechanisms underlying post-exertional malaise and cognitive dysfunction. Understanding symptom overlap across conditions could advance biomarker research and improve diagnostic accuracy for ME/CFS.
Observed Findings
72% (28/39) of PPBL patients met full SEID diagnostic criteria
92% (36/39) reported severe chronic fatigue lasting more than 6 months
82% (32/39) experienced post-exertional malaise
77% (30/39) reported unrefreshing sleep; 72% (28/39) had cognitive impairment
33% (13/39) had concurrent inflammatory or autoimmune conditions
Inferred Conclusions
PPBL patients frequently present with a constellation of symptoms meeting SEID criteria, suggesting potential shared pathophysiological mechanisms between the two conditions
Post-exertional malaise and cognitive dysfunction are prominent features in PPBL similar to ME/CFS
Clinician education about PPBL symptom recognition is needed to improve diagnostic assessment and patient outcomes
Remaining Questions
What are the underlying biological mechanisms connecting PPBL and SEID symptoms?
Does treating PPBL improve the associated ME/CFS-like symptoms, and if so, what does this reveal about causality?
How do PPBL patients compare to matched controls and documented ME/CFS cohorts on objective measures of post-exertional malaise and immune function?
What This Study Does Not Prove
This study does not prove that PPBL causes ME/CFS or vice versa, nor does it establish a causal relationship between the two conditions. The lack of a control group means we cannot determine whether these symptoms are uniquely common in PPBL or represent baseline prevalence in similar populations. Additionally, patient self-reporting without objective confirmation of symptom severity limits conclusions about actual disease burden.