Stem Cell Transplantation • Brief Report

Severe combined immunodeficiencies (SCID) are commonly fatal early in life. Adequate diagnosis and rapid institution of treatment, such as allogeneic stem cell transplanta-tion (SCT), is essential. Several studies demonstrated that reconstitution of B-cell func-tion after SCT is better in B-positive SCID than in B-negative SCID. We demonstrate that B-cell reconstitution in a B-negative SCID patient due to an Artemis mutation required the elimination of the autologous precursor-B-cells in bone marrow, probably to create physical space in the precursor-B-cell niches. Apparently, occupation of the precursor-B-cell niches is a potential dominant factor influencing repopulation of a functional B-cell compartment in B-negative SCID