2001 Volume 41 Issue 6 Pages 649-651
Objective: We quantitatively measured thymidine phosphorylase (TP) activity of normal (non-tumor-bearing) lungtissues in non-small lung cancer, and investigated the relationships with various clinical backgrounds.
Methods: Both normal lung tissues and tumor tissues were obtained from 39 patients with primary lung cancer undergoinga pulmonary lobectomy. The tissue TP activity was quantitatively measured with a sandwich enzyme immunoassay.
Results: The mean value of TP activity in tumor tissues was significantly higher than that in normal lung tissues (226U/mg protein vs. 46U/mg protein, p<;0.0001). TP activity of normal lung tissues varied from 10U/mg protein to 136U/mg protein, and was high in male patients (male; 56.1U/mg protein vs. female; 29.3U/mg protein, p=0.001), heavysmokers (Brinkmann Index (BI) =600 or >600; 57.9U/mg protein vs. BI<600; 31.7U/mg protein, p=0.001) or presenceof interstitial changes on chest CT (positive; 63.0U/mg protein vs. negative; 36.2, p=0.002). In 8 of 9 patients, in whominterstitial inflammation (infiltration of chronic inflammatory cells) was histologically identified, the TP level of normallung tissues was higher than 50U/mg protein. The high level of TP activity might be attributed to some active inflammatorycells in the interstitium and reflect the presence of interstitial inflammation. We are now investigating the usefulnessof TP activity of lung tissues as a marker of activity of interstitial pneumonia.
