Alanine aminotransferase (ALAT, ALT, GPT)Clinical significance1) Physiologic changes in the catalytic concentration of ALT in serumThe catalytic activity of ALT is decreased in normal umbilical blood; the concentration gradually rises to reach maximal values on day 5 postnatally. 2) Pathologic changes in the catalytic concentration of ALT in serum A) Increased values of the catalytic concentration of ALT in serum are found in: • active cirrhosis, • acute extrahepatic biliary obstruction (ALT usually greatly exceeds AST), • acute hepatitis; considerable increase, which is relatively greater than AST increase; ALT level is also increased in jaundice-free episodes. • dermatomyositis, • hepatotoxic lesions, • infectious mononucleosis (highest ALT level in the second week, returning to normal ALT value in the fifth week of disease), • infectious or toxic hepatitis, • initial therapy with clofibrate, • myocardial infarction (smaller increase in comparison to AST), • obstructive jaundice, • primary or metastatic liver carcinoma, • progressive muscular dystrophy, • relapse of liver cirrhosis, • therapy with salicylates (plasma concentration >250 mg/L), • viral hepatitis. B) Decreased values of the catalytic concentration of ALT in serum are found in: • vitamin B6 deficiency |