Elevated serum hepatocyte growth factor/scatter factor levels in inflammatory lung disease

Hepatocyte growth factor/scatter factor (HGF/SF) plays an important role in tissue repair in liver and renal damage. The clinical significance of this growth factor in these diseases has also been reported. The lung is one of the major sources of HGF/SF; because of this, we investigated serum HGF/SF levels in 26 patients with inflammatory lung disease (15 with interstitial pneumonitis [IP], 11 with bacterial pneumonia [BP]) by enzyme-linked immunosorbent assay. As controls, we measured HGF/SF in the serum of 13 stable outpatients with chronic respiratory failure. All patients had no significant liver or renal dysfunction. Serum HGF/SF levels were significantly elevated in patients with IP (1.16 +/- 0.22 ng/ml) or BP (0.96 +/- 0.27 ng/ml) compared with those in the control subjects (0.29 +/- 0.03 ng/ml, both p < 0.01). Serum HGF/SF levels in 14 healthy subjects were also studied, and the results (0.30 +/- 0.02 ng/ml) were not remarkably different from those of the control subjects. There were no significant correlations between serum HGF/SF levels and C-reactive protein and lactate dehydrogenase. Serum HGF/SF levels in the surviving patients rapidly decreased with treatment, but they did not change in the patients who ultimately died. Our results demonstrate the clinical significance of serum HGF/SF level as a useful indicator of prognosis in inflammatory lung disease.