Human serum amine oxidase. Enzyme activity in severely burnt patients and in patients with cancer.

During a study of serum amine oxidase (SAO) levels in patients with fibrotic disease processes, 127 patients (100 adults and 27 children) with moderate to severe burns were investigated. Of these, 55 adults and 20 children, classified as severe, had enzyme levels of 2.7 +/- 0.3 and 4.6 +/- 0.9 McEwen Units (McE.U) (mean +/- S.E.) respectively, which, compared with those for normal healthy adults (18.3 +/- 0.6 McE.U), gave a difference of striking significance (t=21.05 for 130 d.f., and t=10.33 for 95 d.f., respectively). Subsequently, 125 patients with proven cancer were studied. 52 percent of the untreated and 41 percent of the treated showed remarkably low enzyme activity. The mean of the group of untreated patients was 9.6 +/- 1.1 McE.U, that of the treated 11.6 +/- 1.0 McE.U, and that of the entire group 10.7 +/- 0.7 McE.U. The difference between these values and normal activity is highly significant (p less than 10(-6)). Sequential SAO estimations on severly burnt patients and those with cancer established the time course of enzyme activity in these patients. Our observations suggest that estimation of SAO activity may be useful not only for the classification, monitoring and prognosis of severe burns, but also in the diagnosis of cancer and the evaluation of its treatment.