Possible pathogenic role of endotoxin in Reye's syndrome.

Evidence of circulating endotoxin was sought in children with Reye's syndrome, on the thesis that severe hepatic failure is likely to result in loss of capacity to detoxify intestinal endotoxins entering the circulation. A modification of the Limulus assay was used to demonstrate high levels of endotoxin-like activity (E.L.A.) in nine comatose patients with Reye's syndrome and in one of the two non-comatose patients. The symptom-free sibling of one patient had raised liver enzymes and a negative Limulus test. Plasma E.L.A. correlated significantly with degree of electroencephalographic disturbance early in the course of the illness. E.L.A. was also found in both of two cerebrospinal fluids evaluated. Preliminary in-vitro characterisation of this substance indicated that it resembled endotoxin derived from anaerobic intestinal bacteria. Intestinally derived endotoxin could be one factor in the pathogenesis of encephalopathy and other features of Reye's syndrome.