E2 ModeratePreliminaryPEM not requiredCross-SectionalPeer-reviewedMachine draft
Serum neopterin and somatization in women with chemical intolerance, depressives, and normals.
Bell, I R, Patarca, R, Baldwin, C M et al. · Neuropsychobiology · 1998 · DOI
Quick Summary
This study looked at a marker in the blood called neopterin, which may indicate immune system activation, in women with chemical sensitivity (difficulty tolerating everyday chemicals at low levels), women with depression, and healthy women. The researchers found that neopterin levels themselves were similar across groups, but in women with chemical sensitivity, higher neopterin levels were linked with more physical symptoms—a connection not seen in the other groups.
Why It Matters
ME/CFS often co-occurs with chemical sensitivity and multiple unexplained physical symptoms. This study provides preliminary evidence that immune activation (measured by neopterin) may be biologically linked to symptom burden in chemically sensitive patients, potentially supporting the biological basis of these conditions rather than attributing them solely to psychological factors.
Observed Findings
- Resting serum neopterin levels at 4 p.m. did not differ significantly between women with chemical intolerance, depressed women without chemical intolerance, and healthy controls.
- Women with chemical intolerance showed strong positive correlations between neopterin levels and all somatization scales measured.
- Women with depression and healthy controls did not show these neopterin-somatization correlations.
- Women with chemical intolerance reported high levels of affective (mood-related) distress.
Inferred Conclusions
- Neopterin may serve as a biological marker of immune activation specifically linked to somatic symptom expression in chemical intolerance.
- Chemical intolerance may represent a distinct biological subtype of polysymptomatic conditions, separable from depression based on the neopterin-somatization relationship.
- Both immunological and possibly neurogenic mechanisms may underlie the multiple somatic symptoms in chemical intolerance.
Remaining Questions
- Does neopterin elevation cause somatization, or does somatization cause neopterin elevation, or is there a third factor driving both?
- How do these findings relate to other cytokines and immune markers in chemically sensitive patients?
What This Study Does Not Prove
This study does not prove that neopterin causes somatic symptoms, only that they are correlated in the CI group. The small sample sizes and cross-sectional design prevent conclusions about causality or temporal relationships. Additionally, the similar baseline neopterin levels across groups suggests that neopterin alone cannot distinguish chemical sensitivity from depression or health.
Tags
Symptom:PainFatigueSensory Sensitivity
Biomarker:Blood Biomarker
Method Flag:Weak Case DefinitionSmall SampleExploratory OnlyMixed Cohort
Metadata
- DOI
- 10.1159/000026511
- PMID
- 9701717
- Review status
- Machine draft
- Evidence level
- Single-study or moderate support from human research
- Last updated
- 8 April 2026
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 →
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