Lipoprotein lipase and postheparin esterase activity in primary hyperlipoproteinaemia type IV and V.

In a study of the aetiopathogenesis of primary hyperlipoproteinaemias, which has not yet been elucidated, we paid attention to the heparin-activated lipolytic enzymes. Lipoprotein lipase (LPL) and postheparin esterase (PHE) activity was determined in 35 patients with primary hyperlipoproteinaemia (HLP) type IV (average age 50 years), 28 with type V (average age 48 years) and 2 with type III (57 and 62 years). Since PHE activity is correlated to sex and in women also to age, these factors had to be taken into account. The average activity values for the given enzymes in the patients group did not differ from the results in the control group. From these enzymes activities we tried to analyse the findings in individual cases in which the values were lower or higher than the control group range. The low PHE activity in some patients with type IV and V was evidently secondary and due to hepatobiliary disorder (most frequently liver steatosis). The simultaneous elevation of LPL and PHE activity in type IV and V patients with a high serum lipoprotein concentration shows that the response of patients with extreme HLP to heparin is more pronounced. The low PHE activity in type III (tested in only 2 patients) could possibly indicate the liver disorder on which this metabolic disease may be based.