MCQ – 4827

Correct Answer � D Explanation

Ans.D. Glycogen depletion

Histology of the liver on Reye’s syndrome:

• Histology of the liver shows diffuse microvesicular steatosis (fatty vacuolization) with minimal inflammatory changes.

• Glycogen is virtually absent from the hepatocytes in a biopsy specimen.

• Mitochondria are large pleomorphic and have decreased matricial density on electron microscopy.

• The kidney changes include swelling and fatty degeneration of proximal tubules.

• Astrocyte edema and loss of neurons in the brain.

Reye’s syndrome

• It is an acute self-limiting metabolic insult of diverse etiology resulting in generalized mitochondrial dysfunction due to inhibition of fatty acid 8 oxidation.

• Salicylates or viral infection can precipitate this metabolic impairment.

• The pathogenesis is thought to be damage to mitochondria caused by salicylate metabolite or some other toxin or chemical in the setting of viral infection.

• The reasons for mitochondrial dysfunction are unknown. No toxic factor has yet been conclusively identified but studies have suggested an etiological link among Reye’s syndrome.

• The activities of hepatic mitochondrial enzymes including ornithine transcarbamylase, carbamoyl phosphate synthetase, and pyruvate dehydrogenase are reduced often to less than half their normal values.

• Mitochondrial dysfunction leads to elevated short-chain fatty acids and leads directly to cerebral edema.

• It is prudent to avoid the use of aspirin as an antipyretic in pediatric patients with influenza or varicella.

Clinical manifestations:-

• Classic Reye’s syndrome exhibits a stereotypic biphasic course.

• It usually occurs in a previously healthy child.

• A prodromal febrile illness, an upper respiratory tract infection, or chickenpox is followed by an interval in which the child has seemingly recovered.

• The abrupt onset of protracted vomiting then occurs usually within 5-7 days after the onset of the viral illness.

• Delirium, combative behavior, and stupor may occur simultaneously within a few hours after the onset of vomiting.

• Neurological symptoms may rapidly progress to seizures, coma, and death; focal neurological signs are absent.

Laboratory features:-

• There is an explosive release from the liver and muscle of enzymes such as aminotransferases, creatine kinase, and lactic dehydrogenase.

• The activity of the mitochondrial enzyme serum glutamate dehydrogenase is greatly increased.

• The Serum Ammonia level is increased.

• The prothrombin time is mild to moderately increased.