CD79A and chronic rhinosinusitis: The incidence of bacterial pneumonia in patients with PAD has been nearly halved (2) and the major risk factors—low IgA levels, combination of low IgA and IgM levels (3, 4), low IgG levels despite replacement IGRT, chronic sinusitis, bronchiectasis, and low number of class-switched memory B cells—are known, directing risk stratification, informing monitoring, and detecting early symptoms.