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.