Host-microbiota relationship in the pathophysiology of aseptic abscess syndrome: protocol for a multicentre case-control study (ABSCESSBIOT)

Introduction Aseptic abscess (AA) syndrome is a rare disease whose pathophysiology is unknown. It is often associated with inflammatory bowel disease and characterised by sterile inflammation with collections of neutrophils affecting several organs, especially the spleen. Microbiota are known to influence local and systemic immune responses, and both gut and oral microbiota perturbations have been reported in diseases associated with AA syndrome. However, interactions between these factors have never been studied in AA syndrome. The purpose of this translational case-control study (ABSCESSBIOT) is to investigate gut and/or oral microbiota in patients with AA syndrome compared with healthy controls. Moreover, microbiota associated metabolites quantification and Treg/Th17 balance characterisation will give a mechanistic insight on how microbiota may be involved in the pathophysiology of AA syndrome.Methods and analysis This French multicentre case control study including 30 French centres (University hospital or regional hospital) aims to prospectively enrol 30 patients with AA syndrome with 30 matched controls and to analyse microbiota profiling (in stools and saliva), microbial metabolites quantification in stools and circulating CD4(+) T cell populations.Ethics and dissemination This study protocol was reviewed and approved by an independent French regional review board (n degrees 2017- A03499-44, Comit & eacute; de Protection des Personnes Ile de France 1) on 10 October 2022, and declared to the competent French authority (Agence Nationale de S & eacute;curit & eacute; du M & eacute;dicament et des produits de sant & eacute;, France). Oral and written informed consent will be obtained from each included patient and the control participant. Study results will be reported to the scientific community at conferences and in peer-reviewed scientific journals.