Serum lipolytic activity in Reye's syndrome.

High levels of the serum free fatty acids (FFA) are found in Reye's syndrome (RS). While this is attributed to enhanced adipose tissue lipolysis, the possibility that intravascular lipolysis could augment this process was investigated by measuring lipase activity in sera from RS and other subjects. Ordinarily, lipolytic activity is not detectable in serum from unheparinized subjects. Significant lipolytic activities ranging from 1-3 mumol/ml serum per hour were detected in sera from 5 of the 7 RS patients studied. Similar activities were also found in sera from two other subjects one of whom was a long-term survivor of RS and the other who had recurrent bouts of biliary obstruction and encephalopathy. Lipase activity was negligible in the serum from 2 other RS patients, 4 other long-term survivors of RS, 2 siblings, one RS parent and in 20 disease controls including patients with influenza, diabetic ketoacidosis and cerebral edema, meningitis and febrile infections with diarrhea and vomiting. None of these individuals had received heparin. An inverse relationship was found between LPL and hepatic lipase (HL) activities. Glucose levels tended to correlate directly with LPL and inversely with HL activity. The basis for the presence of LPL activity in RS sera is not known but the presence of serum lipase activity in unheparinized patients supports the notion that the TG in the circulating lipoprotein particles probably also serve as another source of FFA in the sera of RS patients.