September is Sepsis Awareness Month in the United States, and this year the spotlight includes a wave of new blood biomarker research. Sepsis is the body’s extreme, life-threatening reaction to an infection, and speed of diagnosis has always been the biggest obstacle to survival. A newer blood marker called presepsin is now showing, in a 2026 multicenter study, that it can outperform the traditional infection panel at flagging sepsis early and predicting risk. At the same time, French hospitals have just begun testing a rapid blood biomarker in the emergency room as part of a national program. Neither development changes how sepsis is diagnosed today, but both point to where blood testing for this condition is heading, and to why understanding your own lab panel matters.
What sepsis is, and why minutes matter
Sepsis develops when the immune system’s response to an infection, rather than the infection itself, starts damaging the body’s own tissues and organs. It can follow something as ordinary as a urinary tract infection, a chest infection, or an infected wound. Left unrecognized, sepsis can progress to septic shock, organ failure, and death within hours. Public health agencies describe it as a medical emergency that demands the same urgency as a heart attack or a stroke, which is part of why the condition has its own awareness month.
The challenge is that early sepsis symptoms are vague. Confusion, a fast heart rate, clammy skin, or simply feeling much sicker than the underlying infection would suggest can all be early clues, and they overlap with dozens of other conditions. That is exactly the gap that blood testing is meant to close.
How doctors currently test for suspected sepsis
When a clinician suspects sepsis, blood work is ordered immediately, usually alongside blood cultures to identify the responsible bacteria or fungus. A standard panel typically checks your white blood cell count for signs the immune system is mobilizing, along with inflammation and organ-stress markers.
- A complete blood count reviews your white blood cell count and other cell lines for signs of infection or bone marrow stress.
- An inflammation panel measures elevated CRP levels, since C-reactive protein rises quickly when the body is fighting an infection.
- An infection-specific marker tracks procalcitonin blood levels, which tend to rise more specifically with bacterial infection than CRP does.
- A metabolic panel checks lactate, a marker of how well tissues are getting oxygen; a high lactate level is one of the strongest single warning signs of developing septic shock.
None of these markers are diagnostic on their own. Clinicians combine them with vital signs, symptoms, and clinical scoring tools to decide how urgently a patient needs treatment.
Latest scientific advances in sepsis blood testing
A 2026 prospective study across two intensive care units compared presepsin against procalcitonin, CRP, and interleukin markers in 184 patients, including those with confirmed sepsis and septic shock. Presepsin, a fragment released when immune cells called monocytes engulf bacterial material, distinguished sepsis from a simple lung infection more accurately than any of the older markers, and it was the only biomarker that independently predicted 30-day survival, according to PubMed (DOI: 10.1016/j.cca.2026.121204). In plain terms: a single blood marker flagged both who had sepsis and who was at the highest risk of dying from it, better than the combination of tests used today.
Separately, French emergency departments have started a real-world evaluation of a different approach. Two Paris-area hospitals affiliated with Assistance Publique-Hôpitaux de Paris are now combining a bedside clinical score with a blood biomarker called Nu.Q NETs, which measures a byproduct of a process neutrophils use to trap invading bacteria. The goal is to return a result within about an hour so emergency teams can route patients faster, an approach summarized on the hospital network’s own project page (aphp.fr). Researchers are also mapping other neutrophil-related markers in the laboratory, though those remain experimental and are not yet used in patient care.
What this means for you: none of these markers has replaced the standard sepsis panel yet, and a single elevated or normal result should never be interpreted alone. But if your lab report shows procalcitonin, lactate, or an inflammation marker, this research explains why your care team is watching those specific numbers so closely.
Comparing the main sepsis-related blood markers
| Markör | Vad det återspeglar | Role in sepsis workup |
|---|---|---|
| Antal vita blodkroppar | Immune system activation | Routine, first-line |
| CRP | Allmän inflammation | Routine, first-line |
| Prokalcitonin | Likely bacterial infection | Widely used, more specific |
| Laktat | Tissue oxygen delivery | Key severity and shock indicator |
| Presepsin | Monocyte response to bacteria | Emerging, not yet routine |
Varningstecken som kräver akut vård
Sepsis can escalate within hours, so timing matters more than certainty. Seek emergency care immediately if an infection is accompanied by any of the following.
- Confusion, slurred speech, or extreme sleepiness
- A very fast heart rate or fast, shallow breathing
- Clammy or mottled skin, or a fever with shivering
- Not urinating for a full day
- Feeling far sicker than the original infection would explain
These are the same signs public health campaigns summarize as knowing the risks, spotting the signs, and acting fast.
Making sense of your own results
If you or a family member has recently had blood drawn during an infection scare, the report can list unfamiliar abbreviations under time pressure, at exactly the moment it is hardest to focus on them. AI DiagMe reviews values like white blood cell count, CRP, procalcitonin, and lactate against your history and explains what each one is doing in your specific case, in plain language, so you can have a clearer conversation with your care team.
Ordlista
- Sepsis: the body’s extreme, potentially life-threatening response to an infection.
- Septic shock: a severe stage of sepsis with dangerously low blood pressure.
- Procalcitonin: a blood protein that rises mainly with bacterial infection.
- Presepsin: an emerging blood marker released by immune cells responding to bacteria.
- Lactate: a chemical that builds up in blood when tissues are short of oxygen.
- NETs (neutrophil extracellular traps): web-like structures immune cells release to trap bacteria, now being studied as a sepsis marker.
Vanliga frågor
Can a single blood test confirm sepsis? No single marker confirms sepsis on its own. Diagnosis combines blood tests, vital signs, symptoms, and clinical judgment.
Is presepsin available for routine testing? Not yet widely. It remains a research and specialty-lab marker rather than a standard emergency department test in most hospitals.
Why does lactate matter so much in suspected sepsis? A rising lactate level signals that tissues are not getting enough oxygen, which is one of the clearest warning signs of progression toward septic shock.
Who is most at risk of sepsis? Adults 65 and older, infants, pregnant women, and people with chronic conditions such as diabetes, cancer, or kidney disease face higher risk.
Does a normal white blood cell count rule out sepsis? No. Some people with sepsis, especially older adults, can have a normal or even low white blood cell count, which is why several markers are checked together.
Källor
- CDC – About Sepsis
- MedlinePlus (NIH) – Sepsis
- Mayo Clinic – Sepsis, Symptoms and Causes
- According to PubMed: Allam et al., “Presepsin outperforms conventional biomarkers for Sepsis diagnosis and 30-day mortality prediction,” Clinica Chimica Acta, 2026. DOI: 10.1016/j.cca.2026.121204
- Assistance Publique-Hôpitaux de Paris – DETECSEPS project launch
Other articles worth reading
- Learn how clinicians interpret your antalet vita blodkroppar.
- Understand what drives elevated CRP-värden.
- Review how doctors use the infektionsmarkören prokalcitonin.
- See how specialists read lactate dehydrogenase test results.
Förstå dina labresultat med AI DiagMe
Whether you are watching a routine panel or trying to make sense of results from an infection scare, AI DiagMe explains your blood, urine, and stool test values in plain language, reviewed by our medical team. Explore AI DiagMe to get a clear, personalized read on your own results.
