Lung in Cellular Immunodeficiencies

The lung is a very complex organ, devoted to the oxygen supply to the whole body. The essential role of the respiratory system forces lung microenvironment to a continuous contact with air and with the external world. Lung epithelium and lung connective tissue are protected by an articulated and pervasive immune system, which fights the external microbial and toxic threats while preserving respiratory function and blood oxygenation. The balance between microbial clearance and preservation of tissue function is of pivotal importance because not only microbial growth but also immunopathology in this organ can be a serious threat to the whole organism survival. Primary immunodeficiencies (PID) can be associated with a wide range of systemic and lung complications (see Table 12.1); lung complications (see Table 12.2) in PID can be broadly divided in infections and chronic complications. In this chapter, we review the main clinical and epidemiological features associated with lung involvement in PID.