Hypogammaglobulinemia in children: a warning sign to look deeply?

This study investigated phenotypic and functional characteristics of lymphocytes in children with common variable immunodeficiency ( CVID ) and unclassified hypogammaglobulinemia ( UH ), as well as B‐cell subsets in non‐consanguineous parents. Blood samples of 30 children, CVID (n = 9), UH (n = 9), healthy donors HD (n = 12), and 19 adults (parents and controls) were labeled by a combination of surface markers to identify CD 4, CD 8 T‐cell and B‐cell subpopulations. T‐cell cytokine production in children was analyzed in vitro after stimulation with phytohemagglutinin ( PHA ) and tetanus toxoid. We observed low percentages of switched memory B cells in children with CVID , increase in total CD 4 + T‐cell counts, and high percentages of transitional B cells only in UH group. Analysis of T‐cell immunity showed that CVID children had decreased percentages of CD 8 + IFN ‐γ‐producing cells after stimulation with PHA and tetanus toxoid. Parent of children with CVID had low percentages of naive B cell and increased percentages of memory B cells in comparison with controls. These results suggest that (i) early combined immune defect in children with CVID and (ii) a possible familial B‐cell disturbance in pediatric CVID .