Bronchiectasis: The hidden side of common variable immunodeficiency – Case report

immunoglobulin (Ig) G level less than SD below age-appropriate references for 2 measurements more than 3weeks apart unless the level is very low (<100-300 mg/dL depending on age);

no secondary causes of hypogammaglobulinemia.

poor antibody responses to vaccination;

greater than 4 years of age;

either a low IgA or IgM;

decrease of IgA is required;

low switched memory B cells (less than 70% of age-related normal value) can be used instead of measurement of antibody response to vaccine;

no evidence of profound T cell deficiency;

a clinical manifestation of disease such as an increased susceptibility to infection, autoimmune manifestations, granulomatous disease, or unexplained polyclonal lymphoproliferation, or an affected family member with antibody deficiency