Ethylene dibromide: evidence of systemic and immunologic toxicity without impairment of in vivo host defenses.

Ethylene dibromide was administered intragastrically on 14 consecutive days to B6C3F1 female mice. Host resistance was not altered after challenge with B16F10 tumor cells, Listeria monocytogenes, influenza, or Herpes simplex viruses. In contrast, decreases were seen in relative thymus and spleen weights, red blood cells, hemoglobin, hematocrit, and in alveolar macrophage, natural killer cell, T-cell, and mixed lymphocyte culture responses. Increases occurred in relative kidney and liver weights, cholesterol, peripheral neutrophils, resident peritoneal exudate cells (with increased phagocytosis) and plaque-forming cells. There was little difference between the dose that caused immune modulation and that which produced significant toxicity.