An observational study in Eosinophilia and Hypereosinophilic Syndrome, sponsored by University Hospital, Lille. Recruiting at 1 site in France. Per ClinicalTrials.gov, last updated 2026-02-20.
Sponsored by University Hospital, Lille · Observational
Unexplained chronic hypereosinophilia (HE) and hypereosinophilic syndromes (HES) are heterogeneous regarding the organ involvements (heart, lungs, skin, .. or none), the evolutionary profiles, the response to treatments.
Underlying mechanisms are largely unknown and may associate genetic predisposing factors (germinal ? somatic?), environmental factors (alimentation, tobacco use, hormones, infections, ..) The COHESion study aims to study all clinical and biological characteristics of HE/HES patients and their evolutionary profiles, with a focus on genetic factors and the mechanisms supporting transitory or persistant chronic HE/HES (in absence of any well identified extrinsic trigger like drugs, parasitosis, ..)
There is currently no data on the natural history of unexplained chronic hypereosinophilia (HE) and hypereosinophilic syndromes (HES). Clinical practice shows that HE/SHE patients can present 4 evolutionary profiles:
A. a single flare-up of their disease, with favourable evolution spontaneously or under corticosteroid therapy, without further recurrence B. recurrent flare-ups with a variable free interval of several months to several years, with or without persistent eosinophilia between flare-ups C. a chronic disease requiring the continuation of a substantive treatment D. chronic asymptomatic HE for years: the mechanisms involved in the occurrence of possible organ damage are unknown
The primary objective of the study is to describe the frequency of the different clinical manifestations during the diagnostic and follow-up of the hypereosinophilic syndrome (HES). The primary endpoint is the frequency of the different clinical manifestations and/or organs damage related to eosinophilia.
66 studies on the registry are indexed under Eosinophilia; 14 are open to participants now.
This study's planned enrollment of 600 is above the median of 225 across 24 observational studies indexed under Eosinophilia.
Browse Eosinophilia studies →University Hospital, Lille is the lead sponsor of 625 studies on the registry; 141 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Patients with Hypereosinophilia and Hypereosinophilic Syndromes
Exclusion Criteria:
patient with eosinophilia and/or hypereosinophilic syndrome
Biological: Biological sample
Additional blood samples for biobanking
Frequency of the different clinical manifestations at time of diagnosis and during follow-up of the hypereosinophilic syndrome (HES)
The primary objective of the study is to describe the frequency of the different clinical manifestations at diagnosis and during follow-up of the hypereosinophilic syndrome (HES/HE). The primary endpoint is the frequency of the different clinical manifestations and/or organs damage related to hypereosinophilia.
Time frame: 10 years
Frequency of the evolutionary profiles
Frequency of the different evolutionary profiles.
Time frame: 10 years
Frequency of complications depending of the type of HES
Frequency of complications (organ damages) depending on the type of HES (idiopathic, reactive, clonal…).
Time frame: 10 years
Frequency of organ damage profiles before and after 18 years old.
Describe the characteristics of pediatrics HE/HES vs adult HE/HES.
Time frame: 10 years
Frequency of clinical complications profiles before and after 18 years old.
Clinical characteristics of pediatrics HE/HES vs adult HE/HES.
Time frame: 10 years
Frequency of HLA alleles and variants / mutations on other genes of HE/HES
Predisposing factors in HE/HES by various genomic approaches
Time frame: 10 years
Serum biomarkers
to explore Potential predisposing factors in HE/HES: serum markers predictive of interest in eosinophilopoiesis (IL5), tissue homing (eotaxins, etc.)
Time frame: 10 years
Difference in Membrane activation markers of HE patients (asymptomatic) versus SHE (symptomatic).
Predisposing factors in HE/HES by various genomic approaches
Time frame: 10 years
Difference in Eosinophilic gene expression profiles of HE patients (asymptomatic) versus SHE (symptomatic).
Predisposing factors in HE/HES by various genomic approaches
Time frame: 10 years
Plan to share: No
Eligibility is decided by the study team. Share this record with your doctor or contact the team directly.
Contact study teamGet an email when the registry record changes — status, dates, results — or when someone posts here.
Sign in to followQuestions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.
Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.
Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.
University Hospital, Lille