CD40LG and common variable immunodeficiency: Mean IgG, IgA and IgM seric concentrations at diagnosis were significantly lower in the CVID group (IgG: 3.0 ± 1.7 vs 5.4 ± 0.6 g/L, p<0.0001; IgA: 0.4 ± 0.5 vs 1.0 ± 0.5 g/L, p<0.0004; IgM: 0.6 ± 0.8 vs 0.8 ± 0.5 g/L, p=0.02) as well as the number of switched memory B-cells (6.7 ± 8.2 vs 23.6 ± 18.3.106/L, p=0.007).