Prophylactic and therapeutic effects of a monoclonal antibody to tumor necrosis factor-alpha in experimental gram-negative shock.

A monoclonal antibody to recombinant murine tumor necrosis factor-alpha (TNF alpha), TN3-19.12, was used to explore pathogenetic mechanisms and therapeutic strategies in gram-negative shock. In mice receiving an LD90 dose of Escherichia coli O111, TN3-19.12 prevented death if given 1.5 h before or 30 min after challenge. Less protection was conferred if the antibody was given 2.5 h after challenge. In control mice receiving an irrelevant antibody, L2-3D9, TNF alpha levels rose (less than or equal to 185.1 +/- 26.1 ng/ml) by 90 min and had returned to baseline by 5 h. Mice receiving TN3-19.12 did not have this response. TN3-19.12 was of limited benefit in mice receiving Pseudomonas aeruginosa but had no protective effect in cyclophosphamide-treated mice receiving Klebsiella pneumoniae. In L2-3D9-treated mice, TNF alpha levels were elevated to 61.8 +/- 27.9 and 49.7 +/- 5.1 ng/ml by 90 min in the two models, respectively. TNF alpha levels in TN3-19.12-treated mice in these two models were very low (3.9-5.5 ng/ml). TNF alpha is a mediator in gram-negative shock; antibody to TNF alpha can be of value in prophylaxis and treatment, but its clinical use remains to be established.