Clinical Research Directory

Long-term Psychological and Cognitive Evaluation of Children Treated With Allogeneic Hematopoietic Stem Cell Transplantation for Immunodeficiency

Primary immunodeficiencies (PIDs) are a large group of genetic diseases of the immune system with highly variable clinical presentations. Allogeneic hematopoietic stem cell transplantation (HSCT) is one of the treatments offered to some patients with PIDs. It is a curative but particularly demanding treatment, potentially life-threatening, requiring several months of hospitalization, prolonged limitations in social interactions for the patient, and impacting the entire family unit. The short-term complications of HSCT are numerous and well-known. However, few studies describe the long-term psychological and cognitive complications of HSCT, particularly in the context of PIDs. The few published studies in children concern patients transplanted for hematological malignancies, a context very different from that of primary immunodeficiencies. This study is a pilot research project focusing on the multidimensional assessment of the neurocognitive, psychological, and psychosocial functioning of children between 6 and 8 years old who have received allogeneic hematopoietic stem cell transplantation for primary immunodeficiency for at least 2 years. These stringent criteria aim to limit biases related to the diversity of ages at which care is provided.

Characterization of Autoreactive b Lymphocytes in Autoimmune Diseases and Immune Deficiencies

Autoimmune diseases (AID), whether systemic or organ-specific, affect approximately one in ten people, and their prevalence continues to increase. Many AIDs are linked to the emergence of autoreactive B cells (BCs) directed against components of the self. In healthy individuals, these autoreactive B cells are counter-selected or regulated before reaching the antibody-secreting cell compartment. However, in predisposed individuals, a breakdown in B cell tolerance can occur, leading to the formation of autoantibodies with devastating consequences, such as the emergence of systemic lupus erythematosus (SLE), rheumatoid arthritis, and vasculitis. B-cell depletion is often beneficial in these patients, but paradoxically, therapies targeting B cells are not always effective. Furthermore, B cell depletion via LB-specific antibodies (anti-CD20) or treatment with CD19 chimeric antigen receptor T cells (CAR T) leads to complete and prolonged depression of the entire B compartment without targeting the LB population responsible for the onset of the disease. To date, two pitfalls in studies of human autoreactive LBs often complicate the interpretation of results: i) the difficulty of identifying autoreactive LBs among all LBs, ii) demonstrating the pathogenicity of autoreactive B lymphocytes when they can be identified individually. We propose to quantify and phenotype these autoreactive/pathogenic B cells using high-throughput flow cytometry in several clinical situations.