Gulf War Illness vs MCAS: symptoms, biomarkers, trials and researchliterature-only comparison
A data-driven comparison of Gulf War Illness and Mast Cell Activation Syndrome (MCAS) built from the Open Source Medicine Foundation biomarker atlases, PubMed literature feeds, ClinicalTrials.gov registry extract and post-acute infection syndrome (PAIS) cohort database.
There is little direct research connecting GWI and MCAS; the comparison is offered because both involve immune dysregulation with a chronic multisystem phenotype, and because readers searching for one often ask about the other.
No biomarker atlas exists for MCAS, so the biomarker sections below are limited to the other condition. This page compares literature, trials, therapeutics and cohorts.
What each condition is
Gulf War Illness
Also known as: GWI, Gulf War Syndrome, Chronic Multisymptom Illness
Gulf War Illness is a chronic multisymptom condition affecting roughly a quarter to a third of the nearly 700,000 US and allied personnel deployed in the 1990-1991 Gulf War. It is defined by the Kansas or CDC criteria (fatigue, pain, cognitive and mood symptoms, gastrointestinal and respiratory complaints) rather than by a single exposure, though pyridostigmine bromide, pesticides and low-level nerve agents are the leading hypotheses. Unlike the other conditions compared here it has no infectious trigger, which makes its biomarker overlap with post-viral syndromes scientifically interesting.
Atlas scope: Inflammatory, autoimmune, metabolic, cholinergic, and exposure-related biomarker alterations in Gulf War Illness (GWI / chronic multisymptom illness) compared to healthy deployed and non-deployed Gulf War veterans.
OSMF resources: biomarker atlas · literature feed
Mast Cell Activation Syndrome
Also known as: Mast cell activation disorder
MCAS is characterised by episodic, multi-system symptoms (flushing, hives, gastrointestinal upset, wheeze, hypotension) caused by inappropriate release of mast-cell mediators, with laboratory evidence such as a rise in serum tryptase during an episode and a response to mast-cell-directed therapy. Diagnostic criteria remain contested between consensus groups. MCAS is frequently reported alongside POTS, hypermobility and post-infectious illness; OSMF follows it through a literature feed and clinical-trial registry rather than a dedicated biomarker atlas.
OSMF resources: literature feed
Side-by-side summary
| Measure | Gulf War Illness | MCAS |
|---|---|---|
| Biomarkers catalogued | 41 | No atlas |
| Biomarker categories covered | inflammatory (10), metabolic (8), exposure (7), autoimmune (5), neurological (4), functional (3), autonomic (2), ocular (2) | — |
| Markers with LOINC codes | 12 | — |
| Literature studies tracked | 75 | 75 |
| Most recent tracked study | 25 Jun 2026 | 10 Jul 2026 |
| Registered trials (all statuses) | 4 | 5 |
| Recruiting / not yet recruiting | 0 | 1 |
| Active, not recruiting | 0 | 0 |
| Completed | 4 | 1 |
| Terminated / withdrawn / suspended | 0 | 2 |
| Unknown status | 0 | 1 |
| Named cohorts in PAIS database | 0 | 0 |
| Therapeutic agents tracked | 10 | 11 |
Trial condition matching: Gulf War Illness uses keyword matching on registry condition and title fields; MCAS uses keyword matching on registry condition and title fields. Trials listing both conditions: 0.
Biomarkers catalogued for Gulf War Illness
MCAS has no OSMF biomarker atlas, so no shared-marker matching is possible. The Gulf War Illness atlas lists 41 markers; the 15 most relevant to this comparison are shown (autonomic, immune, inflammatory and vascular categories first).
- Heart rate variability (HRV) Decreased autonomic
- Orthostatic heart rate increment Increased autonomic
- C-Reactive Protein (CRP) Increased inflammatory
- Tumor Necrosis Factor-α (TNF-α) Increased inflammatory
- Interleukin-6 (IL-6) Increased inflammatory
- Interleukin-1β (IL-1β) Increased inflammatory
- Interleukin-8 (IL-8 / CXCL8) Increased inflammatory
- Neopterin Increased inflammatory
- sCD26 (soluble DPPIV) Mixed / conflicting inflammatory
- sCD14 Increased inflammatory
- Interferon-γ (IFN-γ) Increased inflammatory
- H3K9Ac (chromatin marker) Mixed / conflicting inflammatory
- Laser-induced blood spectra (LIBS) Mixed / conflicting functional
- 6-minute walk distance Decreased functional
- SF-36 physical component score Decreased functional
Browse the full Gulf War Illness atlas.
Overlapping therapeutics under investigation (0)
No therapeutic agent is currently tracked for both conditions. Gulf War Illness has 10 tracked agents and MCAS has 11; see the therapeutic agents index.
Recent research
Latest Gulf War Illness studies
Latest MCAS studies
Frequently asked questions
Can you have both Gulf War Illness and MCAS?
Yes. MCAS is a syndrome diagnosed on clinical criteria and can be diagnosed in someone who also has Gulf War Illness; 0 registered trials in the OSMF registry list both conditions, and no therapeutic agent is currently tracked for both.
How do the biomarker profiles differ?
OSMF does not maintain a biomarker atlas for MCAS, which is diagnosed by physiological or clinical criteria rather than a laboratory panel, so this is a literature-level comparison. Gulf War Illness has 41 catalogued markers across 8 categories (most often inflammatory, metabolic, exposure).
Which has more active clinical trials?
MCAS has more: 1 active or recruiting trials versus 0 for Gulf War Illness (registry snapshot 07 Oct 2026). Totals including completed, terminated and unknown-status studies are 4 for Gulf War Illness and 5 for MCAS. Condition matching for Gulf War Illness, MCAS relies on keyword matching of registry condition fields and may miss trials. Trial counts measure research attention, not treatment efficacy.
Which condition has more recent research?
OSMF tracks 75 recent PubMed-indexed studies for Gulf War Illness (latest 25 Jun 2026) and 75 for MCAS (latest 10 Jul 2026). The feeds hold a rolling window of recent publications, so they indicate current publication pace rather than lifetime output. See the Gulf War Illness feed and the MCAS feed for the full lists.
Are the same treatments being studied for both?
No therapeutic agent is currently tracked for both Gulf War Illness and MCAS in the OSMF trial registry or agent database. That reflects the small or non-overlapping evidence base rather than proof that treatments differ.
Which has larger research cohorts?
The PAIS cohort database lists 0 named cohorts for Gulf War Illness and 0 named cohorts for MCAS. Cohorts with stored biospecimens and open external access are the most useful for cross-condition biomarker validation.
Related comparisons
Cite this page
@misc{osmf_gulfwarillness_vs_mcas,
author = {Open Source Medicine Foundation},
title = {Gulf War Illness vs MCAS: symptoms, biomarkers, trials and research compared},
year = {2026},
howpublished = {\url{https://research.opensourcemed.info/compare/gulf-war-illness-vs-mcas.html}},
note = {Data as of 2026-10-07}
}Get OSMF research updates
New biomarker, trial and cohort data, summarised for patients and researchers.
Last updated 07 Oct 2026 (page build). Underlying data: literature feeds 09 Jul 2026 / 10 Jul 2026; trial registry 07 Oct 2026; atlases 29 Jun 2026 / n/a. Generated by scripts/build_compare_pages.py.