a1 Antitrysin deficiency is associated with all except-
Correct Answer: Renal disease
Description: Ref:Textbook of pathology (harsh mohan)6th edition, page no.479 Protease-antiprotease . Alpha-1-antitrypsin (a1-AT), also called a1-protease inhibitor (a-1-Pi), is a glycoprotein that forms the normal constituent of the a1globulin fraction of the plasma proteins on serum electrophoresis. The single gene locus that codes for a-1-AT is located on the long arm of chromosome 15. It is normally synthesised in the liver and is distributed in the circulating blood, tissue fluids and macrophages. The normal function of a1-AT is to inhibit proteases and hence its name a1protease inhibitor. The proteases (mainly elastases) are derived from neutrophils. Neutrophil elastase has the capability of digesting lung parenchyma but is inhibited from doing so by anti-elastase effect of a1-AT. There are several known alleles of a1-AT which have an autosomal codominant inheritance pattern and are classified as normal (PiMM), deficient (PiZZ), null type (Pi null null) having no detectable level, and dysfunctional (PiSS) type having about half the normal level. The most common abnormal phenotype in classic a1-AT deficiency is homozygous state PiZZ resulting from a single amino acid substitution Glu-Lys which causes spontaneous polymerisation of a1-AT and inhibits its release from the liver. The remaining material of a1-AT in the liver causes hepatic cirrhosis . Clinically significant deficiency is also associated with homozygous Pi null null and heterozygous Pi nullZ. The heterozygote pattern of PiMZ has intermediate levels which is not sufficient to produce clinical deficiency, but heterozygote individuals who smoke heavily have higher risk of developing emphysema. The a1-AT deficiency develops in adults and causes pulmonary emphysema in smokers as well as in nonsmokers, though the smokers become symptomatic about 15 years earlier than non-smokers. The other organ showing effects of a1-AT deficiency is the liver which may develop obstructive jaundice early in infancy, and cirrhosis and hepatoma late in adulthood.It also causes chronic pancreatitis .
Category:
Pathology
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