Common variable immunodeficiency (CVID) refers to primary hypogammaglobulinemia with unknown pathogenesis. Although there is evidence for intrinsic B cell defects in some CVID patient groups, various abnormalities in cytokine production by T cells in CVID patients are frequently observed. Here, we demonstrate a relationship in the production of pro-inflammatory Th1 cytokines and regulatory B cells producing IL-10 between CVID patients and healthy controls. We describe CD19(+)CD24(hi)CD38(hi)IL-10(+) regulatory B cells generated after T cell stimulation of human peripheral blood lymphocytes ex vivo are able to suppress IFN-γ(+)TNF-α(+) producing CD4(+) T cells. This process is impaired in CVID patients, who present with both low numbers of CD19(+)CD24(hi)CD38(hi)IL-10(+) B cells and increased numbers of IFN-γ(+)TNF-α(+)CD4(+) T cells. Disruption of the regulatory B cell response to T cell stimulation explains the excessive T cell activation regarded as an immunoregulatory abnormality that is a frequent finding in CVID patients.

Centre for Rheumatology Research Division of Medicine University College London 5 University Street London WC1E 6JF UK

CLIP Childhood Leukemia Investigation Prague Department of Pediatric Hematology and Oncology 2nd Medical Faculty Charles University Prague University Hospital Motol Prague Czech Republic

Department of Clinical Immunology and Allergy St Anne's Faculty Hospital and Faculty of Medicine Masaryk University Brno Czech Republic

References provided by Crossref.org

Common Variable Immunodeficiency patients with a phenotypic profile of immunosenescence present with thrombocytopenia