Memory switched B cell percentage and not serum immunoglobulin concentration is associated with clinical complications in children and adults with specific antibody deficiency and common variable immunodeficiency.

Although idiopathic humoral immunodeficiencies are arbitrarily classified into specific antibody deficiency (SAD) or common variable immunodeficiency (CVID), this distinction does not accurately predict the risk of the bronchiectasis, one of the major long-term clinical complications in these patients. In this study, clinical complications were compared with laboratory markers of cellular and humoral immunity in fifty-five consecutive patients (27 children and 28 adults) attending regional immunology clinics in Manchester, United Kingdom. Reduced CD19(+)CD27(+)IgD(-) B cell percentage but not serum immunoglobulin levels or classification of patients into SAD and CVID was associated with a significantly higher prevalence of bronchiectasis (OR 0.

Total and serotype-specific pneumococcal antibody titres in children with normal and abnormal humoral immunity.

A heptavalent pneumococcal conjugate vaccine (PCV-7) protects children against invasive pneumococcal disease. The aim of this study was to evaluate immunoglobulin subclass and serotype-specific pneumococcal antibody responses to vaccination in children with a history of recurrent or severe bacterial infections. Pneumococcal IgG, IgG1, IgG2 titres were assayed by ELISA, and nine serotype concentrations measured using a nonaplex bead assay in 145 children investigated for recurrent or severe infections.