Survey for positive Limulus amoebocyte lysate test in plasma from humans and common research animals.

A survey for positive Limulus amoebocyte lysate tests was conducted on apparently healthy humans, mongrel dogs, rats, mice, rabbits, and squirrel monkeys. Only mongrel dog (45.8%) and human (32.8%) plasma samples gave positive tests. In dogs, a significant correlation between positive Limulus amoebocyte lysate tests and the presence of intestinal parasites was found. Positives found in human plasma samples were thought to be due to the presence of background levels of endotoxin or some possible mimicker substance found in the plasma after chloroform extraction. It was concluded that there was a need to distinguish between these positive Limulus tests and those which represent significant endotoxemia.