Combined Immunodeficiencies Clinical Trial
Official title:
Hematopoietic Stem Cells Transplantation in Children With Combined Immunodeficiency (CID): Selective Depletion of Naive Cells From the Graft
The purpose of this study is to evaluate selective depletion of naïve CD45RA+ T cells from allogenic peripheral blood stem cell graft in children transplanted for combined immune deficiency. The aims of this procedure are to prevent graft versus host disease (GVHD) while preserving anti-infectious response from donor memory T lymphocytes.
Combined immunodeficiencies (CIDs) are an heterogeneous group of primitive immunodeficiency
(PID), which affect T cells development, function or both. These inherited conditions can
only be cured by allogeneic hematopoietic stem cell transplantation (HSCT). These procedures
have a high risk of morbidity and mortality such a graft versus host disease (GVHD),
rejection of the graft and serious infections, especially in this population of children with
PID. GVHD is more frequent and severe if the donor is not an identical sibling and/or
presents an HLA-mismatch. GVHD requires high immunosuppression as prevention and treatment,
and therefore impedes immunity against infections.
In vitro and animal models suggest that GVHD is mediated by naïve T cells. The aim of this
study is to decrease the rate and severity of GVHD after selective depletion of naïve CD45RA+
T cells from allogeneic hematopoietic stem cell grafts in patients with CIDs with high risk
of severe GVHD, and to preserve immunity against pathogens in a population with high
vulnerability to infections.
The project aims is, first, to show improvement of rejection-free and GVH-free survival 12
months post-transplant, and secondly, to show the decrease of viral infection, and assess
immune reconstitution kinetic and quality and specific antiviral responses, after a
engraftment with naïve cell depleted allograft.
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