Last Updated: June 17, 2026
By: Brian Karr · Co-Founder & Chief Inspection Officer, We Inspect
To test for CIRS, you need specific inflammatory biomarkers that standard lab panels don’t include — C4a, TGF-β1, MMP-9, MSH, and VIP — plus HLA-DR genetic testing. Most doctors haven’t ordered these before. This guide covers the exact panel to request, what each marker reveals, and what to do once you have results.
CIRS (Chronic Inflammatory Response Syndrome) is a multi-system inflammatory condition triggered by biotoxins produced in water-damaged buildings. It’s not detectable on standard bloodwork because the affected systems — complement activation, neuropeptide production, inflammatory cytokines — require specialized testing most labs don’t run by default.
Most people with CIRS spend months, sometimes years, being told their tests look fine. The frustration is legitimate. Standard blood panels aren’t measuring what CIRS disrupts. A CBC and metabolic panel can be completely normal while C4a is running at three times its ceiling and MSH has nearly disappeared from the bloodstream. The tests aren’t wrong. They’re just not looking at the right systems. Knowing which markers to request, and why each one matters, is the first step toward getting a diagnosis that reflects what your body is actually experiencing.
Key Takeaways
- Standard blood panels (CBC, CMP, thyroid) don’t test the complement, neuropeptide, or inflammatory pathways disrupted by CIRS — a specialized panel is required
- The core CIRS panel includes C4a, TGF-β1, MMP-9, MSH, VIP, VEGF, and HLA-DR genetic typing
- CIRS is confirmed by a pattern across multiple systems — not a single out-of-range marker
- C4a testing must be sent to National Jewish Health in Denver for results interpretable under the CIRS reference range
- Positive biomarker results show what your body is doing; they don’t tell you where the exposure is coming from
Why Standard Tests Miss CIRS Entirely
Standard bloodwork was designed to screen for the conditions doctors see most often. Kidney function. Thyroid output. Anemia. Blood sugar. CIRS doesn’t register on any of those.
A 2024 systematic review in Annals of Medicine and Surgery found that CIRS is commonly misdiagnosed as ME/CFS, fibromyalgia, or depression — in part because it affects up to 25% of the population yet requires specialty biomarker testing that falls outside routine protocols, tests most primary care physicians have never ordered.1
I hear the same story almost every week on consultation calls. A woman in Phoenix told me last month that she had seen nine specialists over three years, and every standard panel came back normal. “I feel like somebody poisoned me,” she said, “but every doctor looks at my bloodwork and says I’m fine.” That’s the pattern I hear on nearly every CIRS call. The tests weren’t wrong. They were looking in the wrong place.
CIRS disrupts the complement cascade, suppresses key neuropeptides, and drives multi-system inflammation through biological pathways that a CBC and metabolic panel were never designed to detect. To find the signal, you have to measure the right channels.
The CIRS Biomarker Panel: What to Request
The Shoemaker Protocol — the only published CIRS treatment framework with documented evidence of normalizing biomarkers, not just managing symptoms1 — uses a specific set of laboratory markers to establish the CIRS pattern. Request each of these by name. Many labs require separate physician authorization for each individual test.
Elevated Inflammatory Markers: C4a, TGF-β1, and MMP-9
These three markers are typically elevated in CIRS and reflect distinct aspects of immune dysregulation:
| Marker | Normal Range | Role in CIRS |
|---|---|---|
| C4a | < 2,830 ng/mL (National Jewish Health) | Complement activation marker; elevated in sustained biotoxin response. Often reaches 10,000–20,000+ ng/mL in active CIRS. |
| TGF-β1 | < 2,380 pg/mL | Drives fibrotic and pro-inflammatory signaling. Values of 20,000–50,000 pg/mL are not unusual in active CIRS. |
| MMP-9 | < 332 ng/mL | Reflects active systemic inflammation; associated with the neurological symptoms — memory loss, brain fog, word retrieval difficulty — seen in chronic mold illness.2 |
One critical requirement for C4a: it must be processed at National Jewish Health in Denver. Standard commercial labs (Quest, LabCorp) use a different assay methodology with different reference ranges. Results from those labs cannot be reliably interpreted using the CIRS reference range of under 2,830 ng/mL. If your doctor orders it through a routine lab, the result may look normal even when it isn’t — or may look flagged when the CIRS-specific context is what matters.
Suppressed Neuropeptides: MSH, VIP, and VEGF
These markers are typically low in CIRS. Each depletion has a distinct downstream effect:
| Marker | Normal Range | What Depletion Causes |
|---|---|---|
| MSH | 35–81 pg/mL | Governs immune tolerance, mucosal integrity, sleep cycles, and pain sensitivity. Very low MSH explains chronic sinus congestion, disrupted sleep, and sensitivity to medications at doses others tolerate easily. |
| VIP | 23–63 pg/mL | Regulates pulmonary circulation, cognitive clarity, and inflammatory resolution. RNA-Seq genomic analysis identified VIP depletion as part of a distinct measurable signature in CIRS, alongside the molecular hypometabolism underlying CIRS-related fatigue.3 |
| VEGF | > 31 pg/mL | Supports tissue perfusion. Low VEGF contributes to exercise intolerance and the deep fatigue that sleep doesn’t improve. |
HLA-DR Genetic Testing
Not everyone exposed to a water-damaged building develops CIRS. The determining factor is genetics. A 2025 review confirmed that HLA susceptibility haplotypes prevent biotoxin elimination, creating a sustained immune activation state that compounds with ongoing exposure — approximately 24–25% of the general population carries variants that make effective biotoxin clearance impossible through normal immune channels.4
A 2024 study in Mycotoxin Research documented four cases where identical mold exposure produced dramatically different health outcomes depending entirely on HLA haplotype — two people in the same home, same contamination, completely different trajectories.5 HLA-DR testing is available through major reference labs; request “HLA-DR typing” with a note asking for the CIRS-relevant susceptibility haplotypes.
How to Read Your CIRS Results
A single abnormal value is not diagnostic. CIRS shows up as a pattern across multiple systems — elevated complement, elevated TGF-β1, and suppressed neuropeptides together. An isolated elevated C4a could indicate other conditions entirely. The combination is what tells the story.
A 2018 review in AIMS Allergy and Immunology described CIRS as involving both Th2 and Th17 immune polarization alongside neurogenic inflammation — a multi-system dysregulation that requires multi-system evidence to confirm and that produces overlapping symptoms with ME/CFS, fibromyalgia, and autoimmune conditions.6 Interpreting CIRS labs requires a practitioner who knows the pattern, not just a comparison of individual values to the reference range printed on the lab report.
If your panel shows elevated C4a, TGF-β1, and MMP-9 alongside depressed MSH and VIP, that tells you something clinically meaningful: your body is actively struggling to clear a biotoxin load it can’t eliminate on its own. What it doesn’t tell you is where that load is coming from. That requires a separate investigation entirely. For a deeper look at how CIRS affects multiple body systems, see What Is CIRS? Chronic Inflammatory Response Syndrome Explained.
Why Environmental Testing Has to Come First
This is where CIRS treatment most often stalls. Biomarker testing confirms what the immune system is doing. It cannot identify the source of the biotoxin exposure driving that response. That requires environmental investigation — and getting it right matters more than getting it fast.
A 2013 review in The Scientific World Journal documented that 27 of 28 mold-illness patients returned to full function after treatment — but only after the exposure source was eliminated from their environment.7 Patients who remained in contaminated spaces while pursuing treatment made limited progress. Continued exposure sustains the inflammatory state the treatment is trying to resolve. The biology doesn’t allow for exceptions to this sequence.
The source is rarely where people expect. It’s not usually visible surface mold on a bathroom ceiling. It’s inside walls, behind flooring, in HVAC components, or in spaces that were water-damaged and sealed over. We Inspect’s Exposure Mapping™ process targets source-level identification — locating where active mold growth is occurring inside the building structure, not just measuring what’s drifted into the air.
Your biomarker panel tells you whether your body is in the CIRS pattern. Source-level environmental testing tells you whether your home is the reason. Both pieces of information are required. For more on why the environmental step can’t wait, see our detailed guide on CIRS Treatment: Why Finding the Source Has to Come First.
And if you’re still building your understanding of CIRS before diving into testing, the 17 Signs of Mold Illness: The Complete CIRS Guide covers the full clinical picture.
Key Takeaways
- Standard blood panels (CBC, CMP, thyroid) don’t test the complement, neuropeptide, or inflammatory pathways disrupted by CIRS — a specialized panel is required
- The core CIRS panel: C4a (send to National Jewish Health in Denver), TGF-β1, MMP-9 (elevated in CIRS), MSH, VIP, VEGF (suppressed in CIRS), and HLA-DR genetic typing
- CIRS is a pattern diagnosis — multiple abnormal values across different systems, not a single flagged marker
- HLA-DR testing reveals genetic susceptibility; roughly 1 in 4 people cannot clear biotoxins through normal immune pathways
- Positive biomarkers confirm the body’s response — environmental source testing identifies what’s driving it and must run in parallel with any treatment protocol
CIRS is diagnosable. The tests exist, the clinical framework is established, and the path forward is documented. Most people who’ve spent years being told nothing is wrong simply had the wrong tests ordered. Getting the right biomarker panel — and pairing it with a thorough environmental investigation — is what changes the trajectory from managed symptoms to actual recovery.
To understand how biotoxins from mold work at a biological level and why they produce this kind of multi-system illness, see Mold Biotoxin Illness: Understanding the Root Cause.
Next Steps
If you want to know what your home is actually doing to your body, we can find out. We Inspect uncovers hidden mold contamination, ranks what truly drives your exposure, and delivers a contractor-ready Remediation Recovery Blueprint designed to meaningfully reduce exposure so your body can heal — without wasting tens of thousands on unnecessary fixes that won’t move the needle. Get My Free Exposure Consultation
Frequently Asked Questions
What is the most important test to order when investigating CIRS?
No single marker is diagnostic, but C4a is often the first ordered because it’s highly sensitive to complement activation from biotoxin exposure. It must be sent to National Jewish Health in Denver — commercial lab assays use different methodology and reference ranges. Pair it with TGF-β1, MSH, VIP, MMP-9, and HLA-DR typing for a complete picture.
Can my regular doctor order CIRS biomarker testing?
Yes, most primary care and integrative medicine physicians can order the Shoemaker Protocol panel. The challenge is interpretation: many general practitioners aren’t familiar with what the pattern means. Ideally, work with a provider trained in CIRS — the International Society for Environmentally Acquired Illness (ISEAI) maintains a practitioner directory specifically for this.
Why does C4a testing need to go to National Jewish Health specifically?
C4a assays vary significantly by laboratory. National Jewish Health in Denver uses the specific methodology and reference range (under 2,830 ng/mL) that the Shoemaker Protocol was built around. Results from Quest, LabCorp, or hospital labs use different assay methods with different thresholds — those results cannot be reliably interpreted for CIRS without knowing which assay was used.
What does very low MSH mean if I’ve been exposed to mold?
MSH (melanocyte-stimulating hormone) governs immune tolerance, mucosal barrier integrity, pain modulation, and sleep architecture. In CIRS, MSH is frequently below 35 pg/mL. Very low MSH explains several hallmark symptoms: chronic sinus congestion that doesn’t resolve with antihistamines, disrupted sleep that worsens despite medication, and unusual sensitivity to drugs or supplements at doses most people tolerate normally.
If my CIRS biomarkers come back abnormal, what should I do next?
Two things need to happen in parallel: engage a CIRS-trained practitioner to guide the Shoemaker Protocol, and arrange source-level environmental testing of your home. The treatment protocol is well-documented — but research consistently shows that patients who remain in a contaminated environment during treatment make limited progress. Finding and removing the exposure source is step one.
References
- Dooley M, Vukelic A, Jim L. Chronic inflammatory response syndrome: a review of the evidence of clinical efficacy of treatment. Annals of Medicine and Surgery. 2024. doi:10.1097/MS9.0000000000002718
- Campbell A, Akpan A, Anyanwu E, Ehiri J, Jones J. The neurological significance of abnormal natural killer cell activity in chronic toxigenic mold exposures. TheScientificWorldJOURNAL. 2003;3:1128–1137. doi:10.1100/tsw.2003.98
- Shoemaker RC. RNA-Seq on patients with chronic inflammatory response syndrome (CIRS) treated with vasoactive intestinal peptide (VIP) shows a shift in metabolic state and innate immune functions that coincide with healing. Medical Research Archives. 2016;4(7). doi:10.18103/MRA.V4I7.862
- Rao TR, Sravya G, Kaushik T, Akshaya D. Chronic inflammatory response syndrome (CIRS): a review of diagnosis, immunological mechanisms and treatment challenges. International Journal of Creative and Systematic Research and Reviews. 2025;8(7). doi:10.47191/ijcsrr/v8-i7-09
- Saghir S, Ansari RA. HLA gene variations and mycotoxin toxicity: four case reports. Mycotoxin Research. 2024;40:57–68. doi:10.1007/s12550-023-00517-y
- Tuuminen T, Lohi J. Immunological and toxicological effects of bad indoor air to cause Dampness and Mold Hypersensitivity Syndrome. AIMS Allergy and Immunology. 2018;2(4):190. doi:10.3934/Allergy.2018.4.190
- Hope J. A review of the mechanism of injury and treatment approaches for illness resulting from exposure to water-damaged buildings, mold, and mycotoxins. The Scientific World Journal. 2013;2013:767482. doi:10.1155/2013/767482
This article is for informational purposes only and does not constitute professional medical advice. If you believe mold or other environmental hazards may be affecting your health, consult your healthcare provider.