Plasma marinobufagenin immunoreactivity in patients with chronic kidney disease: a case control study

Experimental data have shown increased plasma levels of marinobufagenin in kidney failure. In this case-controlled retrospective analysis, we evaluated plasma marinobufagenin immunoreactivity in hemodialysis patients compared with subjects with normal kidney function. Sixty-eight adult hemodialysis patients with chronic kidney disease (34 females and 34 males) as well as 68 age-, gender-, and blood pressure-matched subjects without chronic kidney disease were enrolled. Patients on stable hemodialysis regimen for at least 3 mo before the study were included. Exclusion criteria were: age <18 yr, severe liver or heart insufficiency, and overhydration. Subjects without chronic kidney disease must have had an estimated glomerular filtration rate ≥60 ml·min^-1·1.72 m^-2 according to the Modification of Diet in Renal Disease formula. Plasma marinobufagenin immunoreactivity was significantly ( P < 0.001) higher in hemodialysis patients (1.66 ± 1.13 nmol/l) compared with subjects with normal kidney function (0.46 ± 0.23). In hemodialysis patients, plasma marinobufagenin immunoreactivity was higher in men compared with women. A significant positive correlation has been found between plasma marinobufagenin immunoreactivity and serum NT-proBNP, NT-proANP, or aldosterone concentrations in all analyzed subjects. In hemodialyzed patients with plasma marinobufagenin immunoreactivity above median value 5-yr, all-cause mortality was higher compared with those with plasma marinobufagenin concentration below median. We have shown that plasma marinobufagenin immunoreactivity is increased in patients with end-stage kidney failure treated with hemodialysis parallel to the increase in serum NT-proBNP, NT-proANP, and aldosterone concentrations. Higher marinobufagenin immunoreactivity has been associated with worse survival in hemodialyzed patients.