Chronic granulomatous disease primarily affects which type of cell?

Chronic granulomatous disease (CGD) predominantly affects phagocytes, specifically neutrophils and macrophages, which are key players in the immune system responsible for engulfing and destroying pathogens. In CGD, these phagocytes have a defect in their ability to produce reactive oxygen species due to a deficiency in the NADPH oxidase enzyme complex. This impairment limits their effectiveness in killing bacteria and fungi, making individuals with CGD more susceptible to infections, particularly from catalase-positive organisms.

Phagocytes typically generate reactive oxygen species as part of the respiratory burst that occurs after they engulf pathogens. The inability to produce these substances leads to the formation of granulomas—clusters of immune cells that form when the immune response is unable to clear infections or foreign substances effectively.

While lymphocytes, erythrocytes, and platelets play vital roles in the body's overall immune function, oxygen-dependent killing mechanisms primarily involve phagocytes. Therefore, the correct focus on phagocytes in relation to chronic granulomatous disease highlights the specific genetic and functional deficits that characterize this condition.