Endotoxinemia in renal transplant recipients. In immunosuppressed renal transplant recipients a high incidence of endotoxinemia was found during chest or urinary tract infections. Although the endotoxinemia was protracted, indicating inability to eradicate the infection, yet in general the effects were benign and adverse renal damage was not seen. The Limulus gelation test has a positive contribution to make in the diagnosis of illness in transplant recipients.