Genetic Defects that Predispose to Serious Viral Infections.

Viral immunity is a complex, multistep process involving both the innate and adaptive immune systems. Genetic defects in the immune system known as primary immune deficiency disorders (PIDDs) can result in viral infections that are severe, recurrent, or recalcitrant to therapy. These infections can lead to respiratory tract disease and pneumonitis, skin disease, and disseminated viral syndromes that affect multiple organs and even the brain. This review will provide a brief overview of immunity to viruses, an overview of PIDDs that result in significant viral susceptibility, as well as a diagnostic approach to these infections with a focus on defects that are severe and may require intensivist care.