URINARY-EXCRETION OF APO(A) IN PATIENTS AFTER KIDNEY-TRANSPLANTATION

Background. Increased plasma Lipoprotein (a) (Lp(a)) levels are strong ly associated with premature cardiovascular disease and stroke. The ki dney is purported to play an important role in apo(a) catabolism. Ther efore we investigated plasma Lp(a) levels in relation to kidney functi on and urinary apo(a) excretion.Methods. One hundred and sixteen kidne y transplant patients with normal or impaired renal function and 109 a ge- and sex-matched healthy controls were investigated. Plasma Lp(a) a nd urinary apo(a) levels were determined immunochemically and all othe r parameters were determined by routine laboratory methods. Results. T ransplant recipients were found to have significantly elevated total c holesterol and LDL-C values, but equal HDL-C values compared to contro ls. Plasma Lp(a) values were higher and urinary apo(a) excretion was l ower in transplant recipients compared to controls, independent of ren al function. When the patient group was subdivided into 'normal' and ' impaired creatinine clearance', only the latter group secreted less ap o(a) than normal controls. Conclusion. These data suggest that urinary apo(a) excretion is reduced in transplant recipients with impaired ex cretory graft function, which may contribute to the elevation of plasm a Lp(a) levels in these patients.