[Diffuse immunological lung damage due to heterologous anti-thymocyte serum]

Heterologous anti-rat-thymocyte-serum produces an acute hemorrhagic pulmonary lesion. Pneumotoxicity is dependant upon complement since preparatory C' - depletion protects the experimental animal from its letal properties. Absorption of serum with finely dispersed homologous tissue suspensions of lung and thymus is eliminative of toxicity while prophylactic administration of histamin antagonists seems to be non-influential in the genesis of the pulmonary lesions.