Lipoprotein (a) test

Lp (a)

About the parameter

Lp(a) is similar to low-density lipoprotein (LDL) in lipid composition but differs in protein profile. The structural component of Lp(a) distinguishing it from LDL and implicating it in the coronary disease process is apolipoprotein(a) [apo(a)], a highly glycosylated protein attached by disulfide bond to apolipoprotein B100 (apo B100). Apo(a) has a high degree of structural homology with plasminogen that is a key zymogen of the coagulation cascade.

The similarity of structural components of Lp(a) to LDL and to plasminogen suggests that Lp(a) may be associated with atherosclerosis and/or thrombosis. Although there is a lack of consistency in the conclusions of the studies about the contributory role of Lp(a) to coronary heart disease, it is widely accepted that Lp(a) is an important risk factor that may contribute to coronary artery disease independently or cooperatively with other risk factors.

While the wide differences in Lp(a) levels seen among individuals are largely due to hereditary factors, the identification of individuals at risk through diagnostic screening should nevertheless be useful in alerting them to the need to eliminate or control other high risk factors when possible. Lp(a) values should be interpreted in conjunction with clinical evaluation and other lipoprotein tests when assessing atherosclerotic cardiovascular disease in specific populations.