Lipoprotein Lp(a) in lipoprotein spectrum indentified by Lipoprint LDL system.

OBJECTIVE: Identification of lipoprotein subfractions in lipoprotein profile by Lipoprint LDL system, where a lipoprotein(a), an independent risk factor for the development of cardiovascular disease, migrates with. The concentration of lipoprotein(a) in serum over 0.3 g/l increases the risk of athero-thrombosis and a brain stroke. The persons with increased levels of lipoprotein(a) and contemporarily increased cholesterol level in serum, are at increased risk of the inception of cardiovascular or cerebrovascular event even 3-times.

PATIENTS AND METHODS: In a general group of subjects with increased serum concentration of lipoprotein(a) a lipoprotein profile analysis was performed. The general group of subjects was divided into two groups: subgroup with the lipoprotein(a) concentration in the range between 0.3-0.8 g/l and a subgroup with the lipoprotein(a) concentration over 0.8 g/l, to learn if the lipoprotein(a) particles of different serum concentration and different size do not migrate in different positions of the lipoprotein spectrum. For the analysis of serum lipoproteins an innovated electrophoresis method on polyacrylamide gel (PAG) - Lipoprint LDL system USA, was used. Lipids: a total cholesterol and triglycerides in serum were analysed by an enzymatic method CHOD PAP (Roche Diagnostics, FRG), lipoprotein(a) was analysed by an immuno-nephelometric method (Roche Diagnostics, FRG).

RESULTS: In the Lipoprint LDL system using a polyacrylamide gel (PAG) for the lipoprotein separation, lipoprotein(a) migrates in the position IDL2-IDL3. In the band of IDL2 a high Lp(a) values can be identified, when the increment of IDL2 subfraction is over the value of 0.015 g/l, i.e. 15 mg/dl (reference range for IDL2) and when the increment of IDL3 subfraction is over the value of 25 mg/dl, i.e. 0.025 g/l (reference range for IDL3).

CONCLUSIONS: A clear contribution of new method is: identification of the lipoprotein subpopulations where the lipoprotein(a) migrates with different migration position for the mild increased lipoprotein(a) concentration and high lipoprotein(a) concentration in serum was not confirmed.