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IPLab:Lab 5:α1 Antitrypsin Deficiency

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File:IPLab5Antitrypsin12.jpg|This is a high-power photomicrograph of liver stained with periodic-acid Schiff's (PAS) stain. This demonstrates the PAS-positive granules of defective alpha 1-antitrypsin that accumulate in the Golgi of hepatocytes (arrows).
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== Study Questions ==
* <spoiler text="What is the genetic defect and pattern of inheritance in alpha1-antitrypsin deficiency?">Alpha 1-antitrypsin deficiency is an autosomal recessive disorder caused by mutations in the protease inhibitor locus of chromosome 14. In the mutations that lead to a deficiency of the enzyme, the protein is transcribed but there is abnormal folding of the protein, thus it cannot be processed by the endoplasmic reticulum of hepatocytes. The protein, therefore, accumulates in the endoplasmic reticulum forming PAS-positive granules.</spoiler>
* <spoiler text="What is the pathogenesis of emphysema in patients with alpha 1-antitrypsin deficiency?">Alpha 1-antitrypsin is the major antiprotease and is responsible for inhibiting neutrophil elastase that can cause destruction of the alveolar wall. With alpha1-antitrypsin deficiency, neutrophil elastase goes unchecked and tissue damage ensues.</spoiler>
* <spoiler text="What role does smoking play in the development of emphysema in patients with alpha 1-antitrypsin deficiency?">Smoking increases the numbers of neutrophils in the lung and accentuates the release of elastase from these neutrophils. With a deficiency of alpha 1-antitrypsin there is marked tissue damage.</spoiler>
* <spoiler text="Is hepatic cirrhosis common in patients with alpha1-antitrypsin deficiency and what is the pathogenesis of the cirrhosis?">The abnormal alpha 1-antitrypsin protein accumulates in hepatocytes of all patients with this abnormality but only 8 to 20% develop cirrhosis. The exact mechanism for hepatic cirrhosis in patients with alpha1-antitrypsin deficiency is not well understood.</spoiler>
{{IPLab 5}}
[[Category: IPLab:Lab 5]]
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