New Biomarker-based Strategy to Screen and Monitor for Activated Phosphoinositide 3-kinase δ Syndrome

Inclusion Criteria: Group 1: * Patients with genetic diagnosis of APDS type 1 or type 2 and planned to be treated by PI3Kδ selective inhibitor leniolisib * Primary immunodeficient patients with new disease-causing variants in the PIK3CD gene or PIK3R1 gene * Minimum age 12 years old * Patients or holders of parental authority do not oppose participation in this research. * Patients affiliated to a Health Insurance scheme or beneficiaries Group 2 : * Patients with genetic diagnosis of APDS type 1 or type 2 already treated by PI3Kδ selective inhibitor leniolisib in the last 2 years * Patients whose pre-treatment samples are available/analyzable * Minimum age 12 years old * Patients or holders of parental authority do not oppose participation in this research. * patients affiliated to a Health Insurance scheme or beneficiaries Exclusion Criteria: * Bone marrow transplantation * Refusal to participate to the study.