What is the pathophysiology of Chronic Granulomatous disease?

Chronic granulomatous disease (CGD) has a defective NADPH oxidase activity and decreased oxidative burst with recurrent infection and granuloma formation. ROS are synthesized the NADPH oxidase (phagocyte oxidase) pathway and are released from neutrophils and macrophages that are activated by microbes, immune complexes, cytokines, and a variety of other inflammatory stimuli. There is production of microbicidal reactive oxygen species within phagocytic vesicles The final step in the microbial killing is due to reactive oxygen species called as respiratory burst. chronic granulomatous disease is an example of deficient intracellular killing due to absent NADPH oxidase. ref:-basic pathology robbins 9th ed , page 49,54