Endotoxemia in sudden infant death syndrome

Endotoxemia has been proposed as a significant cause of Sudden Infant Death Syndrome (SIDS). We examined postmortem sera from left and right heart samples of 21 SIDS cases (1989 definition) and 23 controls. The controls were < 1 year of age and had died suddenly and unexpectedly of infection, abuse, suffocation, blunt injury, or fire and smoke inhalation. Endotoxin was measured without knowledge of the clinical status by using a kinetic modification of the chromogenic limulus amoebocyte lysate assay. The SIDS cases had insignificant concentrations of endotoxin in serum, whereas some of the controls who experienced blunt injury, abuse, or severe infection exhibited moderately elevated concentrations. Postmortem interval and postmortem blood culture results did not materially affect endotoxin concentrations. Thus, we conclude that endotoxemia is not a substantial pathophysiologic event in SIDS.