Role of Gut Microbiota in the Pathophysiology of Aseptic Abscesses

Study Overview
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Brief Summary
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Aseptic abscess syndrome (AA) is a rare entity characterized by the occurrence of deep abscesses with no germ found. Antibiotic therapy is ineffective and they are sensitive to anti-inflammatory treatment with corticosteroids. Gut microbiota is important for the development of the immune system. In Crohn's disease which is frequently associated with AA syndrome, dysbiosis is found but could also be involved in the immune response at a distance from the gut. Stool, blood, saliva and urine samples will be taken from the patients included and their controls in the centers where they are followed. These biological samples will be transported to Clermont Ferrand using the same procedure (transporter and dry ice) where the following analyses will be performed: microbiota on stool and saliva, short chain fatty acids on stool and lymphocyte study on blood.

Detailed Description
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Included patients will be adult patients meeting the diagnostic criteria for aseptic abscess syndrome described by André et al. Controls will be adults without aseptic abscess syndrome living in the same environment as the patients, whether related to the patient or not. Patients and controls must be able to provide informed consent and be affiliated with the French Social Security system.

Official Title
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Role of Gut Microbiota in the Pathophysiology of Aseptic Abscesses

Conditions
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Aseptic Abscess Syndrome

Intervention / Treatment
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* Other: Biological sample collection


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: For cases: adult patients meeting the diagnostic criteria for aseptic abscess syndrome described by André et al: Deep abscesses on radiological examination with neutrophilic features proven by pathological analysis of a surgical specimen or biopsy when performed Negative blood cultures, negative serological tests for bacteria, including always Yersinia enterocolitica, and, during surgery or aspiration, sterile pus (with standard cultures, BAAR and fungal tests) Failure of antibiotic therapy, when prescribed, after at least 2 weeks for conventional antibiotic therapy and at least 3 months for anti-tuberculosis treatment Rapid clinical improvement the day after the prescription of corticosteroids (at least 1/2 mg/kg prednisone or equivalent) followed by radiological improvement after 1 month of corticosteroids, sometimes in association with immunosuppressive treatments. For controls: adult person living in the same environment as the case to which it is matched. Adult person living in the same household or near the patient. For cases and controls: Ability to provide informed consent. Membership in the Social Security system. Exclusion Criteria: Pregnant women. Incapable patients Patients deprived of liberty Antibiotic therapy administered within 6 weeks prior to inclusion.

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Diagnostic
Allocation: Non-Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: All patients and their controls will have a sample of urine, stool, saliva and blood taken during a follow-up visit. Patients will not be specifically asked to take these samples, they will be taken during a follow-up visit, during which these samples are usually already taken.
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Patients<br>adult patients with aseptic abscess syndrome | Other: Biological sample collection<br>* All patients and their controls will be asked to provide a urine, stool, saliva and blood sample during a follow-up visit. Patients will not be specifically asked to take these samples, they will be taken during a follow-up visit, during which these samples are usually already taken.<br>|
| Experimental: control<br>control An adult person living in the same environment as the case. | Other: Biological sample collection<br>* All patients and their controls will be asked to provide a urine, stool, saliva and blood sample during a follow-up visit. Patients will not be specifically asked to take these samples, they will be taken during a follow-up visit, during which these samples are usually already taken.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Gut microbiota profiling (diversity) of patients with aseptic abscess syndrome and matched healthy controls | 16S rRNA gene sequencing technique and illumina MiSeq platform to investigate the difference of gut microbiota composition between patients with aseptic abscess syndrome and matched healthy controls. | day 1 | 
| Gut microbiota profiling (composition) of patients with aseptic abscess syndrome and matched healthy controls | 16S rRNA gene sequencing technique and illumina MiSeq platform to investigate the difference of gut microbiota diversity between patients with aseptic abscess syndrome and matched healthy controls. | day 1 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Th17/Treg Lymphocytes phenotyping | Th17/Treg Lymphocytes phenotyping of patients with aseptic abscesses compared to matched healthy controls. | day 1 | 
| Salivary microbiota profiling (composition) of patients with aseptic abscess syndrome and matched healthy controls | 16S rRNA gene sequencing technique and illumina MiSeq platform to investigate the difference of salivary microbiota composition between patients with aseptic abscess syndrome and matched healthy controls. | day 1 | 
| Salivary microbiota profiling (diversity) of patients with aseptic abscess syndrome and matched healthy controls | 16S rRNA gene sequencing technique and illumina MiSeq platform to investigate the difference of salivary microbiota diversity between patients with aseptic abscess syndrome and matched healthy controls. | day 1 | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Aseptic abscess syndrome, Comparative Study, Pathophysiology