From 2004, OBS'CEREVANCE is a national real-world prospective clinical cohort of patients with auto-immune cytopenia of pediatric-onset : Immune thrombocytopenia (ITP), Autoimmune Hemolytic anemia (AIHA), or Evans syndrome (all bi or tri cytopenias). Thanks to the collaboration of the 30 French pediatric hematologic centers, this cohort supports all of the Rare Disease Centre CEREVANCE (Centre de Référence National des Cytopénies Auto-Immunes de l'Enfant) missions for care, education and research. Specifically, this original unbiased database allows to describe the long-term health of adult patients, to identify the heterogenous genetic underlying pathophysiologic contexts, and to study the benefit-risk balance of treatments, including the growing development of targeted therapies.

Immune thrombocytopenic purpura (ITP) and autoimmune hemolytic anemia (AHAI) are rare childhood diseases that involve autoimmune destruction of platelets and erythrocytes respectively.

They may be associated with an even rarer entity, Evans syndrome (ES). These three conditions are referred to as autoimmune cytopenias (AIC).

In association with CAI, patients may present with various immunopathological (IM) manifestations such as lymphoproliferation, autoimmune autoimmune/autoinflammatory organ diseases that may be absent at the time of at the time of diagnosis of CAI and develop during follow-up.

Since 2004, the CEREVANCE reference center for childhood autoimmune CEREVANCE has been coordinating a national prospective cohort of patients with pediatric-onset CAI including over 1900 patients (data 05/2023).

Thanks to the collaboration of the 30 French pediatric hematologic centers, this cohort supports all of the Rare Disease Centre CEREVANCE (Centre de Référence National des Cytopénies Auto-Immunes de l'Enfant) missions for care, education and research. Specifically, this original unbiased database allows to describe the long-term health of adult patients, to identify the heterogenous genetic underlying pathophysiologic contexts, and to study the benefit-risk balance of treatments, including the growing development of targeted therapies.

Inclusion Criteria:

• Diagnosis of ITP, AIHA, Evans Syndrome
• Onset before the age of 18

Exclusion Criteria:

• Opposition of legal representative or to data collection

Each of the 30 hemato-immunologic pediatric unit in France guaranties the prospective in real time inclusion in the cohort of all the children diagnosed in their unit, before 18 years old, with ITP, AIHA or Evans syndrome diagnosis, whatever the date of diagnosis at the date of inclusion.

This observational cohort is prospective from the day of initial diagnosis of the auto-immune cytopenia The pediatricians from this rare disease CEREVANCE national network follow national guidelines for evaluation and treatment (PNDS 2009, 2017)