← All cohorts · SARS-CoV-2 cohorts
Amsterdam Long COVID muscle-biopsy PEM cohort (Appelman)
source record (JSON) · schema v2.0.0 · CC BY 4.0
Design notes & limitations. Small longitudinal case-control study (25 long COVID patients with PEM vs 21 healthy controls) and the only cohort in this database with tissue-level objective measures: a two-day cardiopulmonary exercise test to induce post-exertional malaise, with skeletal muscle biopsies before and after. It documented exercise-induced myopathy, metabolic disturbance, and amyloid-containing deposits that worsened after PEM. Included for the objective-measures and PEM-assessment gap matrices rather than for symptom prevalence; not denominator-defined for prevalence estimation.
Identity & trigger
- Cohort id
appelman-2024-lc-muscle- Aliases
- Amsterdam UMC long COVID exercise/biopsy study
- Outbreak / event
- COVID-19 pandemic
- Pathogen
- SARS-CoV-2 (Virus)
- Exposure ascertainment
- Mixed
Design
- Design
- Case-control
- Denominator defined
- No
- Denominator method
- n/r
- Recruitment
- outpatient clinic
- Time zero
- Established long COVID with exertion-triggered post-exertional malaise; assessed before and after an exercise challenge (undefined)
- Control group
- Healthy convenience
Size & attrition
- Enrolled
- 46
- Analysed / enrolled
- 46/46 (100%)
- Max follow-up (months)
- n/r
Biospecimens
- Specimens
- Yes
- Types
- muscle_tissue, whole_blood, serum
- Acute-phase specimens
- No
- Biobank
- Unknown
- External access
- collaboration only
Observations (1)
Physiologic / tissue
Muscle biopsies after a two-day CPET-induced post-exertional malaise showed severe exercise-induced myopathy (atrophic fibres, focal necrosis), local and systemic metabolic disturbance, and amyloid-containing deposits; abnormalities were worse post-PEM than at baseline. No prevalence is reported — this is a mechanistic tissue finding. Qualitative
- Measure
- Skeletal muscle pathology (biopsy) physio:skeletal-muscle-pathology
- As worded
- “exercise-induced myopathy, metabolic disturbance and amyloid-containing deposits in skeletal muscle, worsening after post-exertional malaise”
- Population
- whole cohort · denominator Assessed at timepoint · N=n=25
- Timing
- None mo (Unspecified) · ref N/A
- Method
- Physiologic test
- Comparator
- Healthy convenience: measured, not reported
- Comparability signature
- 9219e1e245 — measure physio:skeletal-muscle-pathology · Physiologic test · ref N/A · denom Assessed at timepoint · Unspecified · Qualitative
- Provenance
- Abstract / Results (muscle biopsy pre/post exercise) · Manual · verified OSMF research-tracker (web-verified against source) on 2026-07-20
Publications
- Appelman B, Charlton BT, Goulding RP, et al. (2024). Muscle abnormalities worsen after post-exertional malaise in long COVID. Nature Communications. PMID 38177128 · DOI 10.1038/s41467-023-44432-3 primary
Provenance & verification
- Registration
- NCT05225688
- Funders
- Amsterdam UMC, Stichting Long COVID
- Related cohorts
- none
- Symptom-inventory scope
- Single domain
- Last verified
- 2026-07-20 — OSMF research-tracker (web-verified against source)