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ABSTRACT: Background
Adenosine deaminase (ADA) deficiency causes severe cellular and humoral immune defects and dysregulation because of metabolic toxicity. Alterations in B-cell development and function have been poorly studied. Enzyme replacement therapy (ERT) and hematopoietic stem cell (HSC) gene therapy (GT) are therapeutic options for patients lacking a suitable bone marrow (BM) transplant donor.Objective
We sought to study alterations in B-cell development in ADA-deficient patients and investigate the ability of ERT and HSC-GT to restore normal B-cell differentiation and function.Methods
Flow cytometry was used to characterize B-cell development in BM and the periphery. The percentage of gene-corrected B cells was measured by using quantitative PCR. B cells were assessed for their capacity to proliferate and release IgM after stimulation.Results
Despite the severe peripheral B-cell lymphopenia, patients with ADA-deficient severe combined immunodeficiency showed a partial block in central BM development. Treatment with ERT or HSC-GT reverted most BM alterations, but ERT led to immature B-cell expansion. In the periphery transitional B cells accumulated under ERT, and the defect in maturation persisted long-term. HSC-GT led to a progressive improvement in B-cell numbers and development, along with increased levels of gene correction. The strongest selective advantage for ADA-transduced cells occurred at the transition from immature to naive cells. B-cell proliferative responses and differentiation to immunoglobulin secreting IgM after B-cell receptor and Toll-like receptor triggering were severely impaired after ERT and improved significantly after HSC-GT.Conclusions
ADA-deficient patients show specific defects in B-cell development and functions that are differently corrected after ERT and HSC-GT.
SUBMITTER: Brigida I
PROVIDER: S-EPMC4489526 | biostudies-literature | 2014 Mar
REPOSITORIES: biostudies-literature
Brigida Immacolata I Sauer Aisha V AV Ferrua Francesca F Giannelli Stefania S Scaramuzza Samantha S Pistoia Valentina V Castiello Maria Carmina MC Barendregt Barbara H BH Cicalese Maria Pia MP Casiraghi Miriam M Brombin Chiara C Puck Jennifer J Müller Klaus K Notarangelo Lucia Dora LD Montin Davide D van Montfrans Joris M JM Roncarolo Maria Grazia MG Traggiai Elisabetta E van Dongen Jacques J M JJ van der Burg Mirjam M Aiuti Alessandro A
The Journal of allergy and clinical immunology 20140205 3
<h4>Background</h4>Adenosine deaminase (ADA) deficiency causes severe cellular and humoral immune defects and dysregulation because of metabolic toxicity. Alterations in B-cell development and function have been poorly studied. Enzyme replacement therapy (ERT) and hematopoietic stem cell (HSC) gene therapy (GT) are therapeutic options for patients lacking a suitable bone marrow (BM) transplant donor.<h4>Objective</h4>We sought to study alterations in B-cell development in ADA-deficient patients ...[more]