Ventricular aneurysms and blunt chest trauma.

Pulmonary injury due to allergy (hypersensitivity) or direct drug toxicity has been described in association with a number of drugs. Nitrofurantoin3 and perhaps methotrexate* may cause a true hypersensitivity type of lung injury. Eosinophilia is often present and it has been postulated that antigen-antibody complexes are involved in triggering cellular damage. In contrast, interstitial pneurnonitis and fibrosis has been described in association with the use of hexamethonium5 and busulfan.6 These drug effects are most likely due to direct pulmonary toxicity. Although sometimes characterized as "hypersensitivity" reactions, there is no direct evidence that immunologic mechanisms are involved. The clinical and histologic findings in our patient lack the hallmarks usually associated with allergic pulmonary reactions and more closely resemble pulmonary toxicity of the direct type ascribed to hexamethonium and busulfan. Shimosato et al,7 in the Japanese literature have postulated that bleomycin acts directly upon pulmonary vascular endothelium, alveolar epithelium and ground substance causing increased vascular permeability which leads to intra-alveolar and interstitial edema as an intermediate step in pulmonary fibrosis. Our imrnunofluorescence observations tend to support this hypothesis since they can be interpreted as showing transudation and/or exudation of plasma proteins. They do not support the idea that this was a true "hypersensitivity" reaction which might be expected to show the presence of complement.