Increase of proteinuria after conversion from calcineurin inhibitor to sirolimus-based treatment in kidney transplant patients with chronic allograft dysfunction.
BACKGROUND
Conversion from calcineurin inhibitor to sirolimus, rapamycin has become an option in patients with chronic allograft dysfunction (CAD). However, in many cases an increase of proteinuria has been observed. The aim was to characterize the course of this so far unexplained proteinuria after conversion.


METHODS
In 149 renal transplant patients from various Spanish centres, proteinuria and renal function were analysed 6 months before until 6 months after conversion. Patients were divided into three groups according to mean proteinuria before conversion (1:<or=300 mg/day; 2:>300-3500 mg/day; 3:>3.5 g/day).


RESULTS
Generally patients showed an increase of proteinuria from 864+/-1441 (0-12125) to 1541+/-1878 (0-10976) mg/day after conversion; P<0.001. Group 1: 145+/-92 vs 669+/-868 mg/day, P<0.001; group 2: 1041+/-799 vs 1995+/-2021 mg/day, P<0.001; group 3: 6205+/-3184 vs 4859+/-2122 mg/day, P=NS. Patients with an increase of proteinuria of >500 mg/day (n=60; 40%) had a higher serum creatinine before conversion compared with patients with no or moderate increase (2.5+/-0.8 vs 2.15+/-0.72 mg/dl; P=0.002). The group that experienced an increase>500 mg/day had a higher serum creatinine after conversion compared with the patients with no or moderate increase (2.8+/-1.0 vs 2.1+/-1.2; P<0.001). Of 64 patients, 19 in group 1 showed an increase>500 mg/day.


CONCLUSIONS
Conversion for CAD can be associated with an increase of proteinuria in patients with pre-existing renal damage; however, it preserves renal function in patients with better creatinine and proteinuria before conversion, and might not be of benefit if advanced loss of renal function and high proteinuria are already present before conversion.
Ruiz
Juan Carlos
JC
Department of Nephrology, Hospital Universitario Marques de Valdecilla, Avda. Valdecilla s/n., E-39008 Santander, Spain. ruizjc@humv.es
Campistol
Josep M
JM
Sánchez-Fructuoso
Ana
A
Rivera
Constantino
C
Oliver
Juan
J
Ramos
David
D
Campos
Begoña
B
Arias
Manuel
M
Diekmann
Fritz
F
D065095:Calcineurin Inhibitors; D016572:Cyclosporine / Q000627:therapeutic use; D005260:Female; D006084:Graft Rejection / Q000503:physiopathology / Q000517:prevention & control / Q000652:urine; D006801:Humans; D007166:Immunosuppressive Agents / Q000009:adverse effects* / Q000627:therapeutic use; D007677:Kidney Function Tests; D016030:Kidney Transplantation / Q000502:physiology; D008297:Male; D008875:Middle Aged; D011507:Proteinuria / Q000139:chemically induced* / Q000503:physiopathology*; D012189:Retrospective Studies; D020123:Sirolimus / Q000009:adverse effects* / Q000627:therapeutic use; D016559:Tacrolimus / Q000627:therapeutic use; D014184:Transplantation, Homologous
D065095:Calcineurin Inhibitors; D007166:Immunosuppressive Agents; D016572:Cyclosporine; D020123:Sirolimus; D016559:Tacrolimus