E3 PreliminaryPreliminaryPEM ✓Case-ControlPeer-reviewedMachine draft
A case of post-COVID-19 myalgic encephalomyelitis/chronic fatigue syndrome characterized by post-exertional malaise and low serum acylcarnitine level.
Jinushi, Ryuhei, Nishiguchi, Sho, Masuda, Sakue et al. · Clinical case reports · 2023 · DOI
Quick Summary
This study describes a patient who developed ME/CFS after recovering from COVID-19. The researchers found that this patient had lower-than-normal levels of acylcarnitine, a substance the body uses to produce energy. The study reviews existing research on how COVID-19 can lead to ME/CFS, a condition that causes severe fatigue and symptoms that worsen after physical activity.
Why It Matters
This research is important because ME/CFS is difficult to diagnose and lacks established blood tests, making any potential biomarker valuable for patients seeking confirmation of their condition. The connection between COVID-19 and ME/CFS development is increasingly recognized clinically, and identifying metabolic abnormalities like low acylcarnitine may help explain the underlying mechanism of post-exertional malaise.
Observed Findings
- Patient presented with post-exertional malaise following COVID-19 recovery
- Serum acylcarnitine levels were lower than normal reference ranges
- Symptoms consistent with ME/CFS diagnostic criteria were documented
- Literature review confirmed increased ME/CFS diagnoses in post-COVID-19 populations
Inferred Conclusions
- Post-COVID-19 ME/CFS may involve metabolic dysfunction affecting energy production pathways
- Low serum acylcarnitine could serve as a potential biomarker for investigating ME/CFS in post-viral contexts
- Clinical recognition of ME/CFS as a COVID-19 sequela is warranted given accumulating case evidence
Remaining Questions
- Is low acylcarnitine present in most post-COVID-19 ME/CFS patients, or was this an individual variation?
- Does acylcarnitine supplementation improve symptoms or energy metabolism in affected patients?
- What mechanisms cause acylcarnitine depletion following SARS-CoV-2 infection?
- Are other metabolic biomarkers similarly dysregulated in post-viral ME/CFS?
What This Study Does Not Prove
This case report cannot prove that low acylcarnitine causes ME/CFS or that it occurs in all post-COVID-19 ME/CFS patients—it describes only one individual. The study does not establish whether reduced acylcarnitine is a reliable diagnostic marker or whether it is specific to post-viral ME/CFS versus other conditions. Causation cannot be inferred from a single case observation.
Tags
Symptom:Post-Exertional MalaiseFatigue
Biomarker:MetabolomicsBlood Biomarker
Phenotype:Infection-TriggeredLong COVID Overlap
Method Flag:No ControlsSmall SampleExploratory Only
Metadata
- DOI
- 10.1002/ccr3.6930
- PMID
- 36789311
- Review status
- Machine draft
- Evidence level
- Early hypothesis, preprint, editorial, or weak support
- Last updated
- 8 April 2026