CD40LG and common variable immunodeficiency: In our CVID cohort, two-isotype hypogammaglobulinaemia (IgG, IgA) was detected in 34.4% (n = 22) of patients and three-isotype hypogammaglobulinaemia (IgG, IgA, IgM) was detected in 65.6% (n = 42) of patients.