Comparisons of Fibrinolysis and Blood Coagulation in Melanesians and Caucasians

SUMMARY Investigations carried out in Port Moresby, Territory of Papua and New Guinea, on blood coagulation and fibrinolysis are described. Significant differences (P < 0.01) were found when comparing Melanesians with Caucasians, in that the former show decreased plasmin inhibition, increased and accelerated plasminogen activation and prolonged prothrombin times. Total plasminogen levels are similar in the two ethnic groups compared. The possible roles of liver disease and vitamin K deficiency in the causation of prolonged prothrombin times in Melanesians merit further study. It is concluded from the results that compared to Caucasian males resident in the Tropics, Melanesian males have a less labile or more potent plasminogen activator system, and also a relative lack of anti‐plasmin. These differences might account for the increased incidence of hyperplasminaemia in the indigenous population, and possibly are relevant to their comparative freedom from atheromatous and thrombo‐embolic occlusive vascular disease.