Plasma Limulus gelation assay in infants and children: correlation with gram negative bacterial infection and evidence for "intestinal endotoxemia".

Plasma limulus gelation assays for gram negative bacterial endotoxemia were performed in 103 infants and children with evaluable clinical findings. A strong association between gram negative infection and positive assays was found, provided patients with gastrointestinal disorders were considered separately. Ten of 11 patients (91%) with gram negative bacteremia (p less than .001 compared with controls) and five of 10 (50%) with focal gram negative bacterial infections (p = .002) had a positive assay. Only 1/22 (5%) of those classified as having other forms of infection-like illness with negative cultures, and none of 20 considered to have neither infection nor gastrointestinal disturbances had a positive assay. However, 8/24 (33%) of those with major gastrointestinal disturbances had a positive test (p = .003). This association supports the possibility that endotoxins produced by indigenous gram negative bacteria in the gut may reach the circulation during states of intestinal disturbance (intestinal endotoxemia). Individual cases suggest several different possible mechanisms which could account for such an occurrence. Rigorous proof of this concept must await the development of confirmatory methodology.