SIGNIFICANCE OF GLOMERULAR DEPOSITION OF APOLIPOPROTEIN (A) IN VARIOUS GLOMERULOPATHIES

Apolipoprotein (a) [apo(a)] may interfere with the fibrinolytic system because of its structural similarity to plasminogen. In the present s tudy, we evaluated the effect of glomerular deposition of apo(a) on co agulation and fibrinolysis in patients with glomerular diseases. Twent y-four patients (13 males and 11 females) with various glomerulopathie s were studied. We examined renal biopsy specimens for the presence of apo(a), and investigated the relationship between the glomerular depo sition of apo(a) and coagulation and fibrinolysis within the glomeruli . The patients who exhibited the deposition of apo(a) (group A) had a significantly higher incidence of deposition of apo B-100 and low-dens ity lipoprotein (LDL) receptor, and a significantly lower incidence of deposition of plasmin-az-plasmin inhibitor complexes (PIG) and tissue -type plasminogen activator than did patients without apo(a) depositio n (group B). Patients in group A had a significantly higher level of s erum total cholesterol and lipoprotein (a) than did patients in group B. Plasma levels of PIC and D-dimer in group A were significantly lowe r than those in group B. The plasma level of thrombin-antithrombin III complexes in group A was significantly higher than that in group B. T hese findings suggest that glomerular apo(a) deposition plays a part i n coagulation and fibrinolysis within the glomeruli in patients with g lomerular diseases.