Brain AbscessMETABCES-PoCNCT07479225
Circulating Cell-Free DNA for Brain Abscess Diagnosis: A Pilot Study
A study testing Plasma Microbial Cell-Free DNA Metagenomic Sequencing in people with Brain Abscess, run by University Hospital, Grenoble at 2 sites in France.
Trial summary
Brain abscess is a severe intracranial infection associated with significant morbidity and mortality. Standard management combines neurosurgical intervention, when feasible, with prolonged intravenous antibiotic therapy. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Brain Abscess
- What is being tested?
- Plasma Microbial Cell-Free DNA Metagenomic Sequencing
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 15 participants
- Where
- 2 sitesFrance
- Study dates
- 1 Apr 2026to 31 Mar 2028
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Participant ≥ 18 years of age.
- Participant presenting with a brain abscess requiring neurosurgical
- Signed Informed Consent
- Covered by health insurance
Who cannot join
- Participant in exclusion period for another study
- Participant referred to in articles L1121-5 to L1121-8 of the CSP (corresponding to all protected persons : pregnant woman, parturient, breastfeeding mother, person deprived of liberty by judicial or administrative decision, persons undergoing psychiatric care under articles L.3212-1 and L.3213-1 who do not fall under article L.1121-8, persons admitted to a healthcare or social institution for purposes other than research, minors, person under legal protection or unable to express consent).
- Staff members with a hierarchical relationship to the principal investigator
Trial locations and contacts
2 sites in 1 country. Contact the study team or a site near you to ask about taking part.
France2 sites
CHU de Grenoble Alpes, Laboratoire de bactériologie
Grenoble
Yvan Caspar, PharmD; PhD, 04 76 76 63 12, YCaspar@chu-grenoble.fr
CHU de Grenoble Alpes, Service de réanimation neurochirurgicale
Grenoble
Clotilde Schilte, MD, 04 76 76 66 88, CSchilte@chu-grenoble.fr
About this study
Official title: Assessment of Circulating Cell-Free DNA for the Microbiological Diagnosis of Brain Abscesses: A Pilot Proof-of-Concept Study
Brain abscess is a severe intracranial infection associated with significant morbidity and mortality. Standard management combines neurosurgical intervention, when feasible, with prolonged intravenous antibiotic therapy. Neurosurgical procedures, such as surgical drainage or stereotactic aspiration, play a key role in reducing intracranial pressure, decreasing the infectious burden, and obtaining samples for microbiological identification.
However, neurosurgical intervention is not always possible due to technical limitations or patien related contrindications. In these situations, microbiological documentation becomes particularly challenging. Conventional diagnostic methods have limited sensitivity, with blood cultures and lumbar puncture yielding positive results in only about 25% of brain abscess cases.
Recent advances in infectious disease diagnostics have introduced metagenomic approaches that may improve pathogen detection. Studies have shown that metagenomic analysis of operative samples can provide more comprehensive microbiological documentation than conventional culture-based methods. In addition, next-generation sequencing (NGS) of circulating microbial cell-free DNA in blood enables the detection of short microbial DNA fragments with a short half-life, reflecting active infection. This technology has already demonstrated promising results in clinical situations where microbiological documentation is difficult, such as febrile neutropenia. The present study aims to evaluate the performance of this approach in patients with brain abscess.
Read the detailed description
Brain abscess is a rare but severe intracranial infection, with an estimated incidence of approximately 0.8 cases per 100,000 individuals and a reported mortality rate ranging from 10% to 20%. Current management relies on a combination of neurosurgical intervention and prolonged intravenous antimicrobial therapy. When feasible, surgical drainage or stereotactic aspiration is performed to reduce intracranial pressure, decrease the infectious burden, and obtain biological samples for microbiological identification of the causative pathogen, enabling targeted antimicrobial treatment.
However, neurosurgical intervention is not always feasible. Technical factors such as small abscess size or deep anatomical location may prevent access to the lesion, and some patients may present contraindications to neurosurgical procedures. In these situations, microbiological documentation becomes particularly challenging. Conventional diagnostic methods, including blood cultures and cerebrospinal fluid analysis, have limited sensitivity in brain abscess and frequently fail to identify the causative pathogen.
Recent advances in molecular diagnostics have led to the development of metagenomic sequencing approaches for pathogen detection. Metagenomic analysis enables the unbiased identification of microbial DNA directly from clinical samples and may provide broader pathogen detection than traditional culture-based techniques. In neurosurgical infections, metagenomic sequencing performed on operative samples has shown promising results and may improve microbiological documentation compared with standard diagnostic methods.
In parallel, sequencing of circulating microbial cell-free DNA (cfDNA) in peripheral blood using next-generation sequencing represents an innovative and minimally invasive diagnostic approach. This technology detects short fragments of microbial DNA released into the bloodstream during active infection and may provide clinically relevant diagnostic information.
This study aims to evaluate the diagnostic performance of circulating microbial cfDNA metagenomic sequencing in patients with brain abscess and to compare its performance with metagenomic sequencing and conventional microbiological cultures performed on intraoperative samples when available.
This pilot study is designed to provide proof-of-concept data on the diagnostic performance of circulating microbial cfDNA sequencing in brain abscess. The results may help define the role of this diagnostic approach in improving microbiological documentation and guiding targeted antimicrobial therapy, particularly when neurosurgical sampling is not feasible.
- Conditions
- Brain Abscess
- Being tested
- Plasma Microbial Cell-Free DNA Metagenomic Sequencing
- Keywords
- Brain Abscess, Cell-Free DNA, Metagenomics
- Medical subject headings
- Brain Abscess
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Plasma Microbial Cell-Free DNA Metagenomic SequencingDiagnostic test
A 20 mL peripheral blood sample will be collected prior to neurosurgical intervention for metagenomic next-generation sequencing (mNGS) analysis of circulating microbial cell-free DNA. Results will be compared with metagenomic analysis and conventional culture of intraoperative brain abscess specimens, which serve as the reference standard for microbiological identification.
| Study group | Role | What they receive |
|---|---|---|
| Metagenomic Diagnostic Evaluation | Experimental | Not described Receives: Diagnostic Test: Plasma Microbial Cell-Free DNA Metagenomic Sequencing |
What is being measured
The primary outcome is the main question the study is designed to answer.
Blood and Brain Abscess Metagenomic Concordance
Comparison of bacterial species identified by metagenomic next-generation sequencing of cell-free DNA (cfDNA) from blood samples versus metagenomic analysis of per-operative brain abscess samples.
Measured: Day 0
Secondary outcomes (3)
Metagenomic Next-Generation Sequencing vs. Culture Concordance
Evaluation of bacterial species identification using metagenomic next-generation sequencing compared to gold-standard culture techniques on per-operative brain abscess samples.
Measured: Day 0
Plasma Cell-Free DNA vs. Abscess Culture Correlation
Comparison of bacterial species identified by metagenomic analysis of circulating cell-free DNA (cfDNA) from blood samples versus species identified by conventional culture of per-operative brain abscess samples.
Measured: Day 0
Potential Clinical Impact on Antimicrobial Treatment
Assessment of potential therapeutic modifications or antibiotic optimization induced by metagenomic next-generation sequencing results compared to standard culture-based diagnosis.
Measured: At 1 Month
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted18 Mar 2026
- Study start1 Apr 2026 (estimated)
- Primary completion31 Mar 2028 (estimated)
- Study completion31 Mar 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Brain AbscessStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Diagnosis
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 15 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University Hospital, Grenoble
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07479225
- Sponsor's protocol ID
- 38RC24.0243
- Acronym
- METABCES-PoC
- Status last verified
- Mar 2026
- First submitted
- 12 Mar 2026
- Last updated
- 18 Mar 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 18 Mar 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Assessment of Circulating Cell-Free DNA for the Microbiological Diagnosis of Brain Abscesses: A Pilot Proof-of-Concept Study
- ClinicalTrials.gov ID
- NCT07479225
- Acronym / sponsor ID
- METABCES-PoC / 38RC24.0243
- Conditions
- Brain Abscess
- Keywords
- Brain Abscess, Cell-Free DNA, Metagenomics
- Study type
- Interventional
- Recruitment status
- Not yet recruiting
- Enrolment
- 15 participants (estimated)
- Lead sponsor
- University Hospital, GrenobleUniversity, hospital or other
- Study start
- 1 Apr 2026 (estimated)
- Primary completion
- 31 Mar 2028 (estimated)
- Study completion
- 31 Mar 2028 (estimated)
- First posted
- 18 Mar 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Brain abscess is a severe intracranial infection associated with significant morbidity and mortality. Standard management combines neurosurgical intervention, when feasible, with prolonged intravenous antibiotic therapy. Neurosurgical procedures, such as surgical drainage or stereotactic aspiration, play a key role in reducing intracranial pressure, decreasing the infectious burden, and obtaining samples for microbiological identification.
However, neurosurgical intervention is not always possible due to technical limitations or patien related contrindications. In these situations, microbiological documentation becomes particularly challenging. Conventional diagnostic methods have limited sensitivity, with blood cultures and lumbar puncture yielding positive results in only about 25% of brain abscess cases.
Recent advances in infectious disease diagnostics have introduced metagenomic approaches that may improve pathogen detection. Studies have shown that metagenomic analysis of operative samples can provide more comprehensive microbiological documentation than conventional culture-based methods. In addition, next-generation sequencing (NGS) of circulating microbial cell-free DNA in blood enables the detection of short microbial DNA fragments with a short half-life, reflecting active infection. This technology has already demonstrated promising results in clinical situations where microbiological documentation is difficult, such as febrile neutropenia. The present study aims to evaluate the performance of this approach in patients with brain abscess.
Detailed description
Brain abscess is a rare but severe intracranial infection, with an estimated incidence of approximately 0.8 cases per 100,000 individuals and a reported mortality rate ranging from 10% to 20%. Current management relies on a combination of neurosurgical intervention and prolonged intravenous antimicrobial therapy. When feasible, surgical drainage or stereotactic aspiration is performed to reduce intracranial pressure, decrease the infectious burden, and obtain biological samples for microbiological identification of the causative pathogen, enabling targeted antimicrobial treatment.
However, neurosurgical intervention is not always feasible. Technical factors such as small abscess size or deep anatomical location may prevent access to the lesion, and some patients may present contraindications to neurosurgical procedures. In these situations, microbiological documentation becomes particularly challenging. Conventional diagnostic methods, including blood cultures and cerebrospinal fluid analysis, have limited sensitivity in brain abscess and frequently fail to identify the causative pathogen.
Recent advances in molecular diagnostics have led to the development of metagenomic sequencing approaches for pathogen detection. Metagenomic analysis enables the unbiased identification of microbial DNA directly from clinical samples and may provide broader pathogen detection than traditional culture-based techniques. In neurosurgical infections, metagenomic sequencing performed on operative samples has shown promising results and may improve microbiological documentation compared with standard diagnostic methods.
In parallel, sequencing of circulating microbial cell-free DNA (cfDNA) in peripheral blood using next-generation sequencing represents an innovative and minimally invasive diagnostic approach. This technology detects short fragments of microbial DNA released into the bloodstream during active infection and may provide clinically relevant diagnostic information.
This study aims to evaluate the diagnostic performance of circulating microbial cfDNA metagenomic sequencing in patients with brain abscess and to compare its performance with metagenomic sequencing and conventional microbiological cultures performed on intraoperative samples when available.
This pilot study is designed to provide proof-of-concept data on the diagnostic performance of circulating microbial cfDNA sequencing in brain abscess. The results may help define the role of this diagnostic approach in improving microbiological documentation and guiding targeted antimicrobial therapy, particularly when neurosurgical sampling is not feasible.
Study design
- Primary purpose
- Diagnosis
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Metagenomic Diagnostic Evaluation | Experimental | Diagnostic Test: Plasma Microbial Cell-Free DNA Metagenomic Sequencing |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (4 listed)
- Participant ≥ 18 years of age.
- Participant presenting with a brain abscess requiring neurosurgical
- Signed Informed Consent
- Covered by health insurance
Key exclusion criteria (3 listed)
- Participant in exclusion period for another study
- Participant referred to in articles L1121-5 to L1121-8 of the CSP (corresponding to all protected persons : pregnant woman, parturient, breastfeeding mother, person deprived of liberty by judicial or administrative decision, persons undergoing psychiatric care under articles L.3212-1 and L.3213-1 who do not fall under article L.1121-8, persons admitted to a healthcare or social institution for purposes other than research, minors, person under legal protection or unable to express consent).
- Staff members with a hierarchical relationship to the principal investigator
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Plasma Microbial Cell-Free DNA Metagenomic SequencingA 20 mL peripheral blood sample will be collected prior to neurosurgical intervention for metagenomic next-generation sequencing (mNGS) analysis of circulating microbial cell-free DNA. Results will be compared with metagenomic analysis and conventional culture of intraoperative brain abscess specimens, which serve as the reference standard for microbiological identification. | Diagnostic test | Metagenomic Diagnostic Evaluation |
Primary outcome
Blood and Brain Abscess Metagenomic Concordance
Time frame: Day 0
Comparison of bacterial species identified by metagenomic next-generation sequencing of cell-free DNA (cfDNA) from blood samples versus metagenomic analysis of per-operative brain abscess samples.
3 secondary outcomes
Metagenomic Next-Generation Sequencing vs. Culture Concordance
Time frame: Day 0
Plasma Cell-Free DNA vs. Abscess Culture Correlation
Time frame: Day 0
Potential Clinical Impact on Antimicrobial Treatment
Time frame: At 1 Month
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 18 Mar 2026.
Related trials for Brain Abscess
RecruitingObservational study
Study of a Cohort of Non-HIV Immunocompromised Patients With Toxoplasmosis at the Strasbourg University Hospital
Cerebral Toxoplasmosis
RecruitingObservational study
Clearance of Intracranial Blood Products by Continuous Irrigation With the IRRAflow System
Intracranial Hemorrhage, Ventriculitis
RecruitingObservational study
Cognitive Function and Fatigue After Brain Abscess
Brain Abscess, Fatigue
RecruitingPhase 4
Partial Oral Antibiotic Treatment for Bacterial Brain Abscess
Brain Abscess, Cerebral Abscess
RecruitingObservational study
Fosfomycin I.v. for Treatment of Severely Infected Patients
Bacterial Infections, Bone Diseases, Infectious
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
2 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Plasma Microbial Cell-Free DNA Metagenomic Sequencing in people with Brain Abscess, run by University Hospital, Grenoble at 2 sites in France.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 3 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: opening soon, as of the sponsor's last update on 18 Mar 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 2 sites in France. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Marion LE MARECHAL, MD,PhD (04 76 76 52 91, MLemarechal@chu-grenoble.fr), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Blood and Brain Abscess Metagenomic Concordance (time frame: Day 0). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 18 Mar 2026.