Hepatic Monoamine Oxidase Deficiency in Reye Syndrome

Faraj et al1 recently reported a positive correlation between plasma tyramine levels and the number of days in coma, for patients with biopsy-proven Reye's syndrome. They suggested that the mitochondrial injury might have a disruptive effect upon hepatic monoamine oxidase, with a subsequent decrease in clearance of tyramine. We have reached a similar conclusion on the possible role of tyramine in the development of the encephalopathy, based on the finding that the hepatic monoamine oxidase activity was reduced about 60% in stage V Reye's syndrome patients.