INCREASED RELEASE OF PLATELET-DERIVED GROWTH-FACTOR FROM PLATELETS INCHRONIC LIVER-DISEASE

The concentrations of platelet-derived growth factor in serum in 7 hea lthy controls (61 +/- 9 years; mean +/- SD) and 10 patients (62 +/- 8 years) with chronic liver disease (chronic hepatitis and/or liver cirr hosis) were compared. The plasma concentration of platelet-derived gro wth factor was below the detection limit (< 0.45 mu g/l) in all the su bjects studied. The peripheral blood platelet count in patients with c hronic liver disease was significantly lower than that in control subj ects. However, the concentration of platelet-derived growth factor in serum, which was assumed to be released from platelet, was similar in patients with chronic liver disease and control subjects. These result s indicate that the mean amount of platelet-derived growth factor rele ased from the same number (10(9)) of platelets, calculated from the se rum platelet-derived growth factor concentration and the peripheral bl ood platelet count, in patients with chronic liver disease (33 +/- 11 ng/10(9) platelets) was significantly (p < 0.01) higher than that in c ontrol subjects (14 +/- 5 ng/10(9) platelets). Moreover, the amount of platelet-derived growth factor released from 10(9) platelets inversel y correlated with the serum concentration of pseudocholinesterase acti vity (r = -0.65, p < 0.01), and correlated positively (r = 0.91, p < 0 .01) with the percent retention of indocyanine green in serum, in all subjects studied. These findings suggest that the amount of platelet-d erived growth factor releasable from platelets of patients with chroni c liver disease is higher than that in normal subjects and that it cor relates with the severity of the disease. Platelet-derived growth fact or released from platelets may be involved in the pathophysiology of c hronic liver diseases as a local factor.