Causes of Chronic Granulomatous Disease (CGD)
In Chronic granulomatous disease the white cells of the body or phagocytic cells are unable to kill certain bacteria and fungi. This situation arises due to a defect in nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activity. NADPH oxidase is a membrane bound enzyme complex that takes part in the generation of superoxides or anti-oxidants. Superoxides kill bacteria and fungi. Phagocytes (cells that engulf and digest debris and invading microorganisms) from patients with CGD can migrate normally to sites of infection, ingest infecting microbes and even dump digestive enzymes and other antimicrobial substances into the phagosome. But they lack the enzymatic system required to produce oxidants which are required to kill microbes.
Hence CGD patients are susceptible to infections with a special subset of bacteria and fungi, especially the ones that require hydrogen peroxide for control.
CGD patients are immune to most viruses and to some kinds of bacteria and fungi; hence they are necessarily not infected all the time.
