Endotoxemia in Psoriasis

Abstract

To the Editor.— We have been able to detect circulating endotoxin in six of 11 patients with psoriasis. Our interest in the possibility of endotoxemia in psoriasis followed recent demonstrations of alterations in levels of alternative complement pathway components¹ and of circulating IgA immune complexes in psoriasis.² Endotoxin and immune IgA complexes each activate the alternative complement pathway.^3,4 Informed consent was obtained from 11 patients with psoriasis. Blood was drawn from each patient with a pyrogen-free syringe. The skin site for venipuncture was a sterilized antecubital fossa free of active psoriatic plaques. Endotoxin was measured by the Limulus lysate test on heparinized plasma following extraction by the chloroform method.⁵ A positive test result was indicated by firm clot formation after incubation at 37 °C for four hours. A weakly positive test result was indicated by a weak soft gel after four hours. Each test was matched