E2 ModerateModerate confidencePEM not requiredCase-ControlPeer-reviewedReviewed
Standard · 3 min
Hematologic and urinary excretion anomalies in patients with chronic fatigue syndrome.
Niblett, Suzanne H, King, Katrina E, Dunstan, R Hugh et al. · Experimental biology and medicine (Maywood, N.J.) · 2007 · DOI
Quick Summary
Researchers compared blood and urine samples from 100 people with ME/CFS and 82 healthy controls to look for abnormalities. While standard blood tests appeared normal, closer examination found subtle differences in blood cell counts and patterns in how patients' bodies were processing and excreting amino acids (building blocks of protein) and other compounds in their urine.
Why It Matters
This study provides objective laboratory evidence of physiological differences in ME/CFS patients, potentially supporting the biological basis of the condition beyond subjective symptoms. Identifying specific metabolic anomalies could eventually help develop diagnostic markers and guide targeted treatment approaches.
Observed Findings
Decreased red cell distribution width in CFS patients
Increased mean platelet volume and neutrophil counts in CFS patients
Elevated neutrophil-lymphocyte ratio in CFS patients
Reduced overnight urine output and amino acid excretion in CFS patients
Decreased urinary excretion of specific amino acids (asparagine, phenylalanine, branched-chain amino acids) and succinic acid; increased 3-methylhistidine and tyrosine
Inferred Conclusions
CFS patients exhibit measurable alterations in hematologic parameters despite normal standard clinical blood tests
Disturbed amino acid and organic acid metabolism or handling occurs in CFS, evidenced by abnormal urinary excretion patterns
Physiologic homeostasis is altered in CFS patients, suggesting underlying metabolic dysfunction
Remaining Questions
Are these urinary and blood anomalies state markers (active during illness) or trait markers (persistent features)?
Do these metabolic changes reflect primary metabolic dysfunction or secondary consequences of reduced activity and physiologic stress?
What This Study Does Not Prove
This study does not prove that the observed abnormalities cause ME/CFS or explain the fatigue mechanism—they may be consequences rather than causes. The cross-sectional design cannot establish whether these changes precede illness onset or persist long-term. The findings require replication and functional validation to determine clinical significance.
About the PEM badge: “PEM required” means post-exertional malaise was an explicit required diagnostic criterion for participant inclusion in this study — not that PEM was studied, observed, or discussed. Studies using criteria that do not require PEM (e.g. Fukuda, Oxford) are tagged “PEM not required”. How the atlas works →
Contribute
Private, reviewed by a human. Not a public comment thread.