Antiserum treatment of gram-negative bacteremia.

In order to lower the mortality rate from gram-negative bacteremia, 136 patients were treated with human antiserum against core glycolipid, or with control nonimmune human serum, in a double-blind clinical trial. The antiserum was prepared by immunizing healthy young men with a vaccine composed of heat killed cells of the J5 mutant of E. coli 0111 B4. Since the core glycolipid in this mutant is not encumbered with "O" side chains, it can stimulate antibody against the core glycolipid possessed in common by the different species of gram-negative bacteria responsible for lethal bacteremia in patients. No serious reactions occurred in over 300 men receiving this vaccine, and the J5 antiserum gave striking broad-spectrum protection against experimental gram-negative bacteremia and endotoxemia. When human J5 antiserum was administered to seriously ill bacteremic patients, the mortality rate was virtually cut in half, as compared to controls. The death rate from gram-negative bacteremia was 14% in patients treated with J5 antiserum, and 26% in those given nonimmune control human serum. Among patients in profound gram-negative bacteremic shock, the recovery rate rose from 29% in controls to 82% in those treated with J5 antiserum (p = 0.02). On the basis of these encouraging results we propose to treat more bacteremic patients with J5 antiserum, because larger groups are needed to establish the full significance of the initial findings.