Measurement of hepatocyte growth factor in serum and plasma

To investigate whether serum or plasma should he used for the measurement o f blood hepatocyte growth factor, the levels were compared in 28 normal sub jects and 30 patients who had undergone surgery. The serum level was signif icantly higher than the plasma level. The serum and plasma hepatocyte growt h factor levels differed markedly depending on the subjects, although overa ll there was a significant correlation between levels (r=0.862, P=0.0001). In serum obtained by the clotting of platelet- or leukocyte-containing plas ma with thrombin, hepatocyte growth factor increased in proportion to the n umber of leukocytes. The difference between serum and plasma hepatocyte gro wth factor levels also correlated with the number of leukocytes in the pati ents (r=0.642, P=0.0004). Such a correlation was not observed for platelets . These findings suggest that the serum hepatocyte growth factor level does not strictly reflect the in vivo blood Level, due to the release from leuk ocytes during sample preparation (i.e., blood clotting) and that plasma is more suitable for assay of blood hepatocyte growth factor.