Hematologic and immunologic studies in dogs given nitrogen mustard (hn3).

Hematologic and immunosuppressive effects of single doses of nitrogen mustard (HN3) were evaluated in 20 dogs. HN3 caused profound depression of peripheral blood counts in all animals. Recovery of total white blood cell counts in dogs surviving the acute gastrointestinal toxicity of HN3 was complete by day 15. Recovery of platelet and lymphocyte counts to initial levels took a more prolonged course. Granulopoietic progenitor cells (CFU-C) in the bone marrow were assayed by an in vitro culture system. Concentrations of CFU-C were markedly decreased one day after HN3-treatment, but showed at near-lethal doses rapid restoration to normal values within 4 to 7 days. Cellular immune function of HN3-treated dogs was impaired for prolonged periods as indicated by the reduced capacity of canine lymphocytes to proliferate in vitro in response to stimulation with mitogens. Humoral immune function was similarly affected as determined by the depressed and delayed antibody formation against an intravenous challenge with sheep red blood cell. In conclusion, our results suggest a different effect of HN3 on lymphoid and myeloid precursor cells.