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NIH Intramural ME/CFS Deep-Phenotyping Study (Walitt/Nath 2024)
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Flags: small sample — read the observations and design fields with these caveats in mind.
Design notes & limitations. The single most intensively measured ME/CFS cohort in existence. 17 ME/CFS participants (IOM 2015 criteria) and 21 matched healthy controls underwent an exhaustive multi-day protocol at the NIH Clinical Center including: 2-day CPET, tilt-table testing, brain MRI/MRS, fMRI, metabolomics, proteomics, immunophenotyping (flow cytometry, CyTOF, cytokine panels), stool microbiome, muscle biopsy with RNA-seq and mitochondrial respirometry, CSF lumbar puncture with proteomics and metabolomics, overnight polysomnography, and extensive neuropsychological testing. Despite the small N (~40), this is the highest-value Tier-1 cohort for physiologic and lab measures. The study found no consistent immunological signature discriminating cases from controls but documented significant effort preference and central motor activation differences. Placed under unknown-trigger as participants had both post-infectious and gradual onset. A contested study in the patient community due to the interpretation of the CPET and effort-preference findings; the database records the observations regardless of interpretive controversy.
Identity & trigger
- Cohort id
nih-intramural-me-cfs-2024- Aliases
- NIH ME/CFS intramural study, Walitt 2024, Nath NIH ME/CFS
- Outbreak / event
- n/r
- Pathogen
- Unknown / idiopathic trigger (Unknown)
- Exposure ascertainment
- not reported
Design
- Design
- Cross-sectional
- Denominator defined
- Yes
- Denominator method
- Extensively screened ME/CFS volunteers meeting IOM 2015 criteria plus matched healthy controls, recruited to the NIH Clinical Center for a multi-day inpatient deep-phenotyping protocol.
- Recruitment
- self referral
- Time zero
- Not applicable (cross-sectional deep-phenotyping with retrospective illness duration) (undefined)
- Control group
- Healthy convenience
Size & attrition
- Enrolled
- 57
- Analysed / enrolled
- 57/57 (100%)
- Max follow-up (months)
- 0
Biospecimens
- Specimens
- Yes
- Types
- serum, plasma, pbmc, whole_blood, csf, muscle_tissue, stool, saliva, urine
- Acute-phase specimens
- N/A
- Biobank
- active
- External access
- collaboration only
Harmonized estimate layer
Curation status: none · 0 estimate(s). Download core estimates
Observations (6)
Symptoms
measured, not reported Mean (SD)
- Measure
- Fatigue sym:fatigue
- As worded
- “SF-36 vitality subscale score”
- Population
- subgroup · denominator Assessed at timepoint · N=n=17
- Timing
- 0 mo (Unspecified) · ref Past 30 days
- Method
- Validated instrument · Short Form-36 Health Survey
- Comparator
- Healthy convenience: measured, not reported
- Comparability signature
- 45e46c69dc — measure sym:fatigue · Validated instrument · ref Past 30 days · denom Assessed at timepoint · Unspecified · Mean (SD)
- Provenance
- Walitt 2024, Supplementary Tables (SF-36 administered to all participants; individual scores extractable from supplementary data) · Manual · verified OSMF research-tracker (web-verified against source) on 2026-07-21
Extensive multi-omics sampling from all 57 participants: serum, plasma, PBMC, whole blood (flow cytometry, CyTOF, cytokine panels), CSF via lumbar puncture (proteomics, metabolomics), skeletal muscle biopsy (RNA-seq, mitochondrial respirometry), stool (microbiome), saliva, urine. Banked at NIH Clinical Center biorepository. Qualitative
- Measure
- Fatigue sym:fatigue
- As worded
- “Multi-omics biospecimen inventory: serum, plasma, PBMC, whole blood, CSF, muscle biopsy, stool, saliva, urine from all participants”
- Population
- whole cohort · denominator Assessed at timepoint · N=n=57
- Timing
- 0 mo (Unspecified) · ref not reported
- Method
- Lab assay
- Comparator
- no comparator
- Comparability signature
- cd81a10b2a — measure sym:fatigue · Lab assay · ref not reported · denom Assessed at timepoint · Unspecified · Qualitative
- Provenance
- Walitt 2024, Methods (full protocol description details all specimen types collected) · Manual · verified OSMF research-tracker (web-verified against source) on 2026-07-21
100% Proportion
- Measure
- Post-exertional malaise sym:post-exertional-malaise
- As worded
- “post-exertional malaise (IOM 2015 criterion: substantial worsening after exertion)”
- Population
- subgroup · denominator Assessed at timepoint · N=n=17
- Timing
- 0 mo (Unspecified) · ref Current
- Method
- Clinician-assessed
- Comparator
- no comparator
- Comparability signature
- 4ed459f3ea — measure sym:post-exertional-malaise · Clinician-assessed · ref Current · denom Assessed at timepoint · Unspecified · Proportion
- Provenance
- Walitt 2024 (IOM 2015 criteria require PEM; all 17 ME/CFS participants met IOM criteria, therefore all have PEM) · Manual · verified OSMF research-tracker (web-verified against source) on 2026-07-21
Case definitions
100% Proportion
- Measure
- Institute of Medicine / NAM ME/CFS criteria (IOM 2015) case-def:iom-me-cfs-2015
- As worded
- “met IOM 2015 (NAM) diagnostic criteria for ME/CFS”
- Population
- subgroup · denominator Assessed at timepoint · N=n=17
- Timing
- 0 mo (Unspecified) · ref Current
- Method
- Clinician-assessed
- Comparator
- no comparator
- Comparability signature
- 6204c177c9 — measure case-def:iom-me-cfs-2015 · Clinician-assessed · ref Current · denom Assessed at timepoint · Unspecified · Proportion
- Provenance
- Walitt 2024, Table 1 (17 ME/CFS participants met IOM 2015 criteria) · Manual · verified OSMF research-tracker (web-verified against source) on 2026-07-21
Physiologic / tissue
measured, not reported Paired change
- Measure
- 2-day CPET workload drop physio:cpet-workload-drop
- As worded
- “2-day CPET workload at ventilatory anaerobic threshold (VAT) — change from day 1 to day 2”
- Population
- subgroup · denominator Assessed at timepoint · N=measured, not reported
- Timing
- 0 mo (Unspecified) · ref N/A
- Method
- Physiologic test
- Comparator
- Healthy convenience: measured, not reported
- Comparability signature
- d40e179485 — measure physio:cpet-workload-drop · Physiologic test · ref N/A · denom Assessed at timepoint · Unspecified · Paired change
- Provenance
- Walitt 2024, Results (2-day CPET performed; day-1 to day-2 VAT workload change extractable from supplementary data) · Manual · verified OSMF research-tracker (web-verified against source) on 2026-07-21
measured, not reported Mean (SD)
- Measure
- Tilt-table haemodynamic response physio:tilt-table-drop
- As worded
- “tilt-table haemodynamic response (heart rate and blood pressure change from supine to 70° head-up tilt)”
- Population
- subgroup · denominator Assessed at timepoint · N=measured, not reported
- Timing
- 0 mo (Unspecified) · ref N/A
- Method
- Physiologic test
- Comparator
- Healthy convenience: measured, not reported
- Comparability signature
- 947165d23d — measure physio:tilt-table-drop · Physiologic test · ref N/A · denom Assessed at timepoint · Unspecified · Mean (SD)
- Provenance
- Walitt 2024, Methods (tilt-table testing was part of the protocol; haemodynamic parameters extractable from supplementary data) · Manual · verified OSMF research-tracker (web-verified against source) on 2026-07-21
Publications
- Walitt B, Singh K, LaMunion SR, et al. (2024). Deep phenotyping of post-infectious myalgic encephalomyelitis/chronic fatigue syndrome. Nature Communications. PMID 38358935 · DOI 10.1038/s41467-024-45107-3 primary
Provenance & verification
- Registration
- NCT02669212
- Funders
- National Institutes of Health Intramural Research Program (NINDS)
- Related cohorts
- none
- Symptom-inventory scope
- Comprehensive inventory
- Last verified
- 2026-07-21 — OSMF research-tracker (web-verified against source)