Low marginal zone-like B lymphocytes and natural antibodies characterize skewed B-lymphocyte subpopulations in del22q11 DiGeorge patients
Abstract
Purpose: Patients with DiGeorge syndrome suffer from T-Iymphopenia.T-cells are important for the maturation and regulation of B-cell function. Our aim was to characterize the B-cell compartment in DiGeorge syndrome patients.
Methods: B-cell subset phenotypization using flow cytometry. Serum BAFF (B-cell activating factor) and serum anti-alpha-galactosyl IgM measurement using ELISA.
Serum IgG measurement using nephelometry. Results: We observed a significantly increased number of naive B-cells and decreased number of switched memory B-cells in DiGeorge patients.
Furthermore, we observed increased BAFF levels and a trend toward hypergammaglobulinemia later in life. Surprisingly, we detected a decrease in marginal zone-like (MZ-like) Bcells and natural antibodies in DiGeorge patients.
Conclusion: The maturation of B-cells is impaired in DiGeorge patients, with high naive and low switched memory B-cell numbers being observed. There is a clear trend toward hypergammaglobulinemia later in life, coupled with increased serum BAFF levels.
Surprisingly, the T-independent humoral response is also impaired, with low numbers of MZ-like B-cell and low levels of anti-alpha-galactosyl IgM natural antibodies being detected.