Study of functional and biochemical indicators of subclinical lung damage in bleomycin-treated patients.

In 30 patients affected by testicular non-seminomatous cancer we evaluated pulmonary function tests before and after bleomycin-including combination chemotherapy. We paid particular attention to changes in diffusing lung capacity ( D CO) and its two components, namely diffusing capacity of the alveolar-capillary membrane ( D m) and pulmonary capillary blood volume ( V c). In the same patients we also evaluated the behaviour of serum procollagen III aminopeptide (sP-III-P), assumed to be a biochemical equivalent to D m, and of serum angiotensin converting enzyme (S-ACE), assumed to be a biochemical equivalent to V c. We foundthat, after chemotherapy, patients showed a significant decline in several pulmonary function parameters, namely VC, TLC, and FEV 1 ( P P = 0·0351, P =0·0004, respectively), when compared to pre-treatment values. D CO was significantly impaired after chemotherapy ( P V c values showed a significant decline ( P =0·0002), whereas D m values were unchanged. Values of sP-III-P raised significantly after chemotherapy ( P = 0·003), whereas S-ACE activity did not show any significant variation. When we looked at relationships between functional and biochemical parameter variations, the only significant correlation we foundwas between D CO and S-ACE ( r 2 = 0·112; P D CO impairment is likely to occur because of a subclinical injury to pulmonary vessels, as suggested by V c decline. Although the occurrence of pulmonary interstitial fibrosis after chemotherapy was excluded by chest X-ray examination and by stable values of D m, sP-III-P elevation would suggest an accelerated type III collagen turnover in interstitial fibroblasts activated by bleomycin.