HIGH PLASMA-CONCENTRATION OF MYELOPEROXIDASE IN CIRRHOSIS - A POSSIBLE MARKER OF HYPERSPLENISM

Plasma myeloperoxidase levels in patients with cirrhosis were compared with those in patients with chronic hepatitis and healthy controls by means of a specific radioimmunoassay for myeloperoxidase. The mean co ncentration of plasma myeloperoxidase in cirrhotic patients (309.1 +/- 17.2 ng/ml, n = 41) was markedly higher than that in chronic hepatiti s patients (222.6 +/- 17.2 ng/ml, n = 21) (p < 0.01) and normal contro ls (219.5 +/- 5.7 ng/ml, n = 50) (p < 0.01). Plasma myeloperoxidase sh owed good negative correlations with neutrocyte count (r = -0.32, p < 0.01), thrombocyte count (r = - 0.40, p < 0.01), red blood cell count (r = - 0.32, p < 0.01), serum albumin (r = - 0.35, p < 0.01), and chol inesterase (r = - 0.32, p < 0.02) and positive correlations with serum alkaline phosphatase (r = 0.49; p < 0.01) and lactate dehydrogenase ( r = 0.31, p < 0.01) in patients with cirrhosis or chronic hepatitis. A mong lactate dehydrogenase isozymes, a good positive correlation was s een between plasma myeloperoxidase and lactate dehydrogenase-2 (r = 0. 40, p < 0.01) and lactate dehydrogenase-1 (r = 0.03, p < 0.02). Plasma myeloperoxidase was significantly higher in the cirrhotic and chronic hepatitis patients with splenomegaly (34 1.1 +/- 19.4 ng/ml, n = 31) than in those without splenomegaly (217.4 +/- 12.2 ng/ml, n = 29) (p < 0.01). We also examined the difference between plasma levels of myelo peroxidase in the portal and peripheral blood. In the patients with no nhepatic disease, we found a significant, portalsystemic difference (p ortal myeloperoxidase, 221.5 +/- 19.7 ng/ml; vs. systemic myeloperoxid ase, 179.1 +/- 10.8 ng/ml; n = 15) (p < 0.01), whereas there was no su ch difference in the cirrhotic patients (portal myeloperoxidase, 281.5 +/- 15.2 ng/ml vs. systemic myeloperoxidase, 268.0 +/- 28.2 ng/ml; n = 7). A significantly high concentration of plasma myeloperoxidase was evident in the case of esophageal varices, which is a sign of portals ystemic shunting in human beings. The results of our study imply that the release of myeloperoxidase from destroyed neutrocytes, in addition to its decreased hepatic clearance, are responsible for the high conc entrations of plasma myeloperoxidase in cirrhotic patients. Therefore measurement of plasma myeloperoxidase may be useful in assessing hyper splenic function in liver disease.