Objective and methods: To assess the clinical significance of CA19-9 in patients with interstitial pneumonia showing pathological nonspecific interstitial pneumonia (NSIP) pattern (IP/NSIP groups), we measured the levels of serum (n = 14) and bronchoalveolar lavage fluid (BALF, n = 10) CA19-9 in IP/NSIP groups.
Result: The serum levels of CA19-9 did not correlate with the serum levels of LDH, of KL-6, or of SP-D or with the intensity of chest Ga-67 scintigraphy. There were no significant differences between the serum CA19-9 levels before therapy and those after therapy in improving patients. The levels of CA19-9 in fibrotic NSIP groups (serum:n = 7, 138.3 + /- 79.6 U/ml BALF: n = 5, 845.8 + /- 334.2 U/ml) were significantly higher than those in cellular NSIP groups (serum: n = 7, 12.8 +/-2.1 U/ml, BALF: n = 5, 40.8 +/- 16.2 U/ml). Immunohistochemical stains of CA19-9 showed the strong positivity in the bronchiolar epitheliums located in severe fibrotic lesions and the mucus within the lumens of microscopic honeycomb. The serum levels of CA19-9 were increased in both worsening patients.
Conclusion: We speculated that the serum levels of CA19-9 may reflect the progression of lung fibrosis but not the disease activity in IP-NSIP groups.