The analysis of serological profiles of antibodies against specific EBV antigens such as EA (early antigen), VCA (viral-capsid antigen), and EBNA-1 (Epstein–Barr virus nuclear antigen 1) in classes IgA, IgM, and IgG showed EBV reactivation in 60% of patients with CLL and 57.69% of patients with CVID. This evidence concerns the gene CD79A and common variable immunodeficiency.