Review Question - QID 100827

The reaction catalyzed by myeloperoxidase results in the characteristic green-colored sputum that is often found in respiratory infections.

Myeloperoxidase is a peroxidase enzyme that is found in the azurophilic granules of neutrophils. The enzyme participates in the respiratory burst reaction and produces hypochlorous acid from hydrogen peroxide and a chloride anion. It oxidizes tyrosine to tyrosyl using hydrogen peroxide as the oxidizing agent. Both of these products are cytotoxic and are used by the neutrophil to ward off invading bacterial infection. Myeloperoxidase deficiency results in an immunodeficient state where patents are at increased risk for the development of Candida albicans infections.

Knutson and Braun review the diagnosis and management of acute bronchitis. They state that sputum color can vary from clear, green, yellow and blood tinged. They assert that green colored sputum is not the most specific indicator for bacterial infections since the green colored is generated by the body's own leukocytes.

Altiner et al. performed a cross-sectional study attempting to answer the question of whether patient's with green colored sputum have a bacterial infection and should be prescribed antibiotics. They found that in patients with no underlying lung disease and a productive cough, colored sputum was not a specific indicator for underlying bacterial infection and the needed for antibiotics.

Illustration A is an image of a neutrophil and their azurophilic granules.

Incorrect answers:
Answer 2 & 4: Cough and fever are often the result of a systemic inflammatory response found when a patient is sick. It is often the result of leukotriene release.
Answer 3: Usually secondary to a pneumococcal pneumonia infection.
Answer 5: Tachypnea is a physiologic response secondary to increased hypercarbia or hypoxemia, and is often secondary to lung pathology.