Bleomycin-induced changes in the carbon monoxide transfer factor of the lungs and its components

To study subclinical pulmonary toxicity of bleomycin we measured the single-breath carbon monoxide transfer factor (TLCO) and its components, pulmonary capillary blood volume (Vc), diffusing capacity of the alveolar-capillary membrane (Dm), and vital capacity (VC) in a homogenous group of 18 patients with testicular nonseminomatous germ cell tumor treated with bleomycin, vinblastine, and cis-diammine-dichloroplatinum (DDP). The most prominent finding was a substantial decrease in Vc (p less than 0.001) with only minor, though significant, changes in the other parameters. No recovery of pulmonary function had taken place 4 months after the last dose of bleomycin. The importance of correcting TLCO for hemoglobin concentration is shown. We conclude that vascular damage may be an important feature of subclinical pulmonary injury caused by bleomycin given in combination with vinblastine and DDP. In the postbleomycin phase, other forms of potentially lung-toxic treatment should be instituted with care.