What is the primary defect leading to the inability to produce hydroxy-halide radicals?

What is the primary defect leading to the inability to produce hydroxy-halide radicals?

• A. Myeloperoxidase deficiency
• B. Lactate dehydrogenase deficiency
• C. Glucose-6-phosphate dehydrogenase deficiency
• D. Chronic granulomatous disease

Answer: (A)

The primary defect leading to the inability to produce hydroxy-halide radicals is myeloperoxidase deficiency. Myeloperoxidase (MPO) is an enzyme found in neutrophils that plays a crucial role in the body's immune response. It catalyzes the reaction of hydrogen peroxide with chloride ions to produce hypochlorous acid, a potent antimicrobial substance that helps kill bacteria and other pathogens. In individuals with myeloperoxidase deficiency, there is a reduced or absent function of this enzyme. As a result, neutrophils are less effective at producing reactive oxygen species and hydroxy-halide radicals, which are essential for the destruction of pathogens during the immune response. This deficiency can lead to increased susceptibility to infections, particularly from catalase-positive organisms, as these bacteria can neutralize hydrogen peroxide, thus avoiding destruction by neutrophils. Chronic granulomatous disease, on the other hand, is caused by defects in the NADPH oxidase complex, leading to an inability to produce reactive oxygen species, rather than specifically affecting the conversion of hydrogen peroxide to hypochlorous acid. Lactate dehydrogenase deficiency and glucose-6-phosphate dehydrogenase deficiency are related to metabolic pathways that do not directly involve

The primary defect leading to the inability to produce hydroxy-halide radicals is myeloperoxidase deficiency. Myeloperoxidase (MPO) is an enzyme found in neutrophils that plays a crucial role in the body's immune response. It catalyzes the reaction of hydrogen peroxide with chloride ions to produce hypochlorous acid, a potent antimicrobial substance that helps kill bacteria and other pathogens.

In individuals with myeloperoxidase deficiency, there is a reduced or absent function of this enzyme. As a result, neutrophils are less effective at producing reactive oxygen species and hydroxy-halide radicals, which are essential for the destruction of pathogens during the immune response. This deficiency can lead to increased susceptibility to infections, particularly from catalase-positive organisms, as these bacteria can neutralize hydrogen peroxide, thus avoiding destruction by neutrophils.

Chronic granulomatous disease, on the other hand, is caused by defects in the NADPH oxidase complex, leading to an inability to produce reactive oxygen species, rather than specifically affecting the conversion of hydrogen peroxide to hypochlorous acid. Lactate dehydrogenase deficiency and glucose-6-phosphate dehydrogenase deficiency are related to metabolic pathways that do not directly involve