Hematopoietic Stem Cell Mobilization in Idiopathic CD4 Lymphocytopenia Patients and Healthy Controls for the Study of T Cell Maturation and Trafficking in Murine Models
- Conditions
- T-LymphocytopeniaIdiopathic CD4-Positive
- Interventions
- Registration Number
- NCT02015013
- Brief Summary
Idiopathic CD4 lymphocytopenia (ICL) is a rare syndrome defined by consistently low CD4 T cell counts (\<300/mm3) without evidence of HIV infection or other known immunodeficiency. Patients with ICL are at risk for opportunistic infections typically associated with HIV/AIDS such as disseminated cryptococcal infection and severe human papillomavirus-related dysplasia. More than 20 years since the description of ICL, its etiology, pathogenesis, and management remain unclear. In this study we propose to administer the combination of granulocyte colony stimulating factor (G-CSF) and plerixafor to ICL patients and healthy volunteers with the objective of harvesting mobilized CD34+ hematopoietic progenitor cells (HPCs) by apheresis for transfer into immunocompromised mice and for study with in vitro assays. The mice studies would serve to investigate thymic development, survival, and trafficking of the mobilized human cells within murine lymphoid and non-lymphoid organs.
HPCs are used for various therapies and there is an increasing use of agents that stimulate the bone marrow to produce progenitor cells and move them into the bloodstream where they may be harvested by apheresis. Not all patients respond to GCSF with vigorous HPC mobilization. The binding of chemokine receptor CXCR4 to stromal cell derived factor (SDF-1 or CXCL12) is an important interaction between a hematopoietic progenitor cell and its marrow environment. Plerixafor is a CXCR4 inhibitor which blocks binding to SDF-1 resulting in the release of hematopoietic progenitor cells (CD34+) into peripheral circulation. In pharmacodynamic studies of plerixafor in conjunction with G-CSF compared to G-CSF and placebo, a two-fold increase in CD34+ cell count was observed.
Due to the important role CXCR4 plays in immune cell trafficking and its potential role in the pathogenesis of ICL, we propose as a secondary objective to assess peripheral CD4 T cell and CD34+ hematopoietic progenitor cell numbers and functions in ICL patients compared to controls following G-CSF and plerixafor administration.
Study participants will be screened within 12 weeks prior to the study period. Eligible participants will receive G-CSF for 5 days with hospitalization on Day 4 for plerixafor injection followed by apheresis on Day 5. Participants will return for examinations and blood draws on Days 8 and 12.
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- Detailed Description
Idiopathic CD4 lymphocytopenia (ICL) is a rare syndrome defined by consistently low CD4 T cell counts (\<300/3microL) without evidence of HIV infection or other known immunodeficiency. Patients with ICL are at risk for opportunistic infections typically associated with HIV/AIDS such as disseminated cryptococcal infection and severe human papillomavirus-related dysplasia. More than 20 years since the description of ICL, its etiology, pathogenesis, and management remain unclear. In this study we propose to administer the combination of granulocyte colony stimulating factor (G-CSF) and plerixafor to ICL patients and healthy volunteers with the objective of harvesting mobilized CD34+ hematopoietic progenitor cells (HPCs) by apheresis for transfer into immunocompromised mice and for study with in vitro assays. The mice studies would serve to investigate thymic development, survival, and trafficking of the mobilized human cells within murine lymphoid and non-lymphoid organs.
HPCs are used for various therapies and there is an increasing use of agents that stimulate the bone marrow to produce progenitor cells and move them into the bloodstream where they may be harvested by apheresis. Not all patients respond to GCSF with vigorous HPC mobilization. The binding of chemokine receptor CXCR4 to stromal cell derived factor (SDF-1 or CXCL12) is an important interaction between a hematopoietic progenitor cell and its marrow environment. Plerixafor is a CXCR4 inhibitor which blocks binding to SDF-1 , resulting in the release of HPCs (CD34+) into peripheral circulation. In pharmacodynamic studies of plerixafor in conjunction with G-CSF compared to G-CSF and placebo, a two-fold increase in CD34+ cell count was observed.
Due to the important role CXCR4 plays in immune cell trafficking and its potential role in the pathogenesis of ICL, we propose as a secondary objective to assess peripheral CD4 T cell and CD34+ hematopoietic progenitor cell numbers and functions in ICL patients compared to controls following G-CSF and plerixafor administration.
Study participants will be screened within 12 weeks prior to the study period. Eligible participants will receive G-CSF for 5 days with hospitalization on Day 4 for plerixafor injection followed by apheresis or large volume blood draw (120 cc) on Day 5. Participants will return for examinations and blood draws on Days 8 and 12.
Recruitment & Eligibility
- Status
- RECRUITING
- Sex
- All
- Target Recruitment
- 40
Not provided
Not provided
Study & Design
- Study Type
- INTERVENTIONAL
- Study Design
- SINGLE_GROUP
- Arm && Interventions
Group Intervention Description Filgrastim Filgrastim ICL and healthy volunteers will be given 10 microgram/kg daily for 5 days administered according to a vial-based algorithm to reduce wastage and increase the G-CSF dose given to lighter-weight donors to improve CD34+ yields Plerixafor Plerixafor ICL and healthy volunteers will be given 0.24 mg/kg as a single dose (maximum dose: 40 mg) 11 hours prior to apheresis
- Primary Outcome Measures
Name Time Method To mobilize CD34+ HPCs in ICL patients and healthy volunteers for collection and transfer into immunocompromised mice to investigate thymic development, survival, and trafficking of these cells in murine lymphoid and non-lymphoid organs Throughout the study Collection of CD34+ cells from ICL patients and healthy volunteers to investigate thymic development, survival, and trafficking of these mobilized cells in the lymphoid and non lymphoid organs of mice.
- Secondary Outcome Measures
Name Time Method To assess peripheral CD4 T cell and CD34+ HPC numbers and functions in ICL subjects compared to controls following G CSF and plerixafor administration Throughout the study Collection of peripheral CD4 T cells and CD34+ HSCs for comparison of number and function of these cell types in ICL patients and healthy volunteers. The function of progenitor cells will be measured as multipotency.
Trial Locations
- Locations (1)
National Institutes of Health Clinical Center
🇺🇸Bethesda, Maryland, United States