[Type III procollagen N-terminal peptide (P-III-P, prolyl hydroxylase (PH), and laminin P1 levels in serum and BALF of radiotherapy patients].

The etiology of pulmonary fibrosis remains unclear, and at present there are no definite biochemical markers of its activity. We measured serum and BALF levels of type III procollagen N-terminal peptide (P-III-P), prolyl hydroxylase (PH), and laminin P1 in patients who had undergone radiotherapy for malignant neoplasms, and investigated their value as biochemical markers in a model of pulmonary fibrosis. The following results were obtained: 1) Patients with abnormal liver function had significantly higher serum P-III-P levels and showed a tendency to have higher serum PH levels. If P-III-P or PH are to be used as markers of pulmonary fibrosis, the effect of liver function must be taken into consideration; however, no significant difference was detected with respect to laminin P1 levels. 2) Serum P-III-P levels were significantly elevated by radiotherapy. 3) Laminin P1 levels rose in a similar manner to P-III-P levels after radiotherapy, but no significant change was detected. 4) In most cases, the levels of all markers in BALF were below the threshold of detection, nevertheless all three markers were elevated in a patient who developed diffuse radiation pneumonitis during radiotherapy. Increases in the lymphocyte count were found in BALF of this patient. 5) BALF hyaluronic acid levels were negative in the 3 cases assayed. 6) A significant correlation between P-III-P and laminin P1 in serum was shown, but no significant correlations could be found between the other combinations of markers in serum. Thus it appears that serum P-III-P and laminin P1 are valid biochemical markers of pulmonary fibrosis.(ABSTRACT TRUNCATED AT 250 WORDS)