How to Manage Kidney Transplant Recipients: Deciding Between Glomerular Filtration Rate-Estimating Equations, Creatinine Clearance and Albumin-Creatinine Ratio, or Albumin Excretion.

OBJECTIVES: Management of renal transplant recipients involves measuring glomerular filtration rate and albuminuria; however, data are conflicting on the use of estimating equations or creatinine clearance and albumin-creatinine ratio in early morning urine or albumin excretion in 24-hour urine. We aimed to determine the performance of creatinine clearance and 3 estimated creatinine-based formulas and compare the usefulness of albumin-creatinine ratio related to albumin excretion in kidney transplant patients. MATERIALS AND METHODS: This cross-sectional study examined 300 consecutive kidney transplant patients. Serum creatinine was measured with Cobas-8000 and albumin-creatinine ratio, and albumin excretion was measured with Cobas-C311 (Roche Diagnostics, Hitachi, Tokyo, Japan). We quantified bias and percent bias, Bland-Altman results, and concordances in the classification of chronic kidney disease between formulas and creatinine clearance. We also conducted linear regression analyses of all parameters and for cutoffs of 30 and 300 mg/24 hours and determined the ability of albumin-creatinine ratio to predict abnormal albumin excretion (receiver operator characteristic curve analysis). RESULTS: Bias (mL/min/1.73 m2), percent bias, and concordances between creatinine clearance and Cockcroft-Gault, Modification of Diet in Renal Disease, and Chronic Kidney Disease Epidemiology Colla-boration formulas in the classification of chronic kidney disease were as follows: 15.89, 20.91%, and 0.35; 20.52, 27.89%, and 0.21; and 18.24, 25.39%, and 0.27, respectively. Regression analyses showed a weak but significantly linear relationship for the cutoff values (P < .001). Receiver operator characteristic curve analyses showed areas under the curve of 0.957 and 0.997 at cutoffs of 30 and 300 mg/24 hours. In our patients, the cutoffs were 27 mg/g (88.38% sensitivity, 92.16% specificity) and 238 mg/g (80.00% sensitivity, 97.45% specificity). CONCLUSIONS: We suggest using estimating equations and albumin-creatinine ratio with caution. In routine management of patients with successive stable revisions, we recommended using the Cockcroft-Gault or Chronic Kidney Disease Epidemiology Collaboration formulas and albumin-creatinine ratio.

Effect of paricalcitol on mineral bone metabolism in kidney transplant recipients with secondary hyperparathyroidism.

INTRODUCTION: Secondary hyperparathyroidism is highly prevalent in kidney transplant recipients, and commonly results in hypercalcaemia; an association to osteopenia and bone fractures has also been observed. Paricalcitol has proved effective to control secondary hyperparathyroidism in chronic kidney disease in both dialysed and non-dialysed patients, with a low hypercalcaemia incidence. Currently available experience on paricalcitol use in kidney transplant recipients is scarce. Our main aim was to show the effect of paricalcitol on mineral bone metabolism in kidney transplant recipients with secondary hyperparathyroidism. MATERIAL AND METHODS: A retrospective multicentre study in kidney transplant recipients aged>18 years with a 12-month or longer post-transplantation course, stable renal function, having received paricalcitol for more than 12 months, with available clinical follow-up for a 24-month period. RESULTS: A total of 69 patients with a 120 ± 92-month post-transplantation course were included. Baseline creatinine was 2.2 ± 0.9 mg/dl y GFR-MDRD was 36 ± 20 ml/min/1.73 m(2). Paricalcitol doses were gradually increased during the study: baseline 3.8 ± 1.9 µg/week, 12 months 5.2 ± 2.4 µg/week; 24 months 6.0 ± 2.9 µg/week (P<.001). Serum PTH levels showed a significant fast decline: baseline 288 ± 152 pg/ml; 6 months 226 ± 184 pg/ml; 12 months 207 ± 120; 24 months 193 ± 119 pg/ml (P<.001). Reduction from baseline PTH was ≥30% in 42.4% of patients at 12 months y in 65.2% of patients at 24 months. Alkaline phosphatase showed a significant decrease in first 6 months followed by a plateau: baseline 92 ± 50 IU/l; 6 months 85 ± 36 IU/l, 12 months 81 ± 39 IU/l (P<.001). Overall, no changes were observed in serum calcium and phosphorus, and in urine calcium excretion. PTH decline was larger in patients with higher baseline levels. Patients with lower baseline calcium levels showed significantly increased levels (mean increase was 0.5-0.6 mg/dl) but still within normal range, whereas patients with baseline calcium>10mg/dl showed gradually decreasing levels. Fifteen (21.7%) patients had received prior calcitriol therapy. When shifted to paricalcitol, such patients required paricalcitol doses significantly larger than those not having received calcitriol. Paricalcitol was used concomitantly to cinacalcet in 11 patients with significant PTH reductions being achieved; clinical course was similar to other patients and paricalcitol doses were also similar. CONCLUSIONS: Paricalcitol is an effective therapy for secondary hyperparathyroidism in kidney transplant recipients. Overall, no significant changes were observed in calcium and phosphorus levels or urinary excretion. Patients having previously received calcitriol required higher paricalcitol doses. When used in patients receiving cinacalcet, paricalcitol results in a significant PTH fall, with paricalcitol doses being similar to those used in patients not receiving cinacalcet.

Efecto de paricalcitol sobre el metabolismo mineralóseo en pacientes trasplantados renales con hiperparatiroidismo secundario / Effect of paricalcitol on mineral bone metabolism in kidney transplant recipients with secondary hyperparathyroidism

Introducción: El hiperparatiroidismo secundario es muy prevalente en pacientes trasplantados renales. Cursa con frecuencia con hipercalcemia y se ha asociado al desarrollo de osteopenia y fracturas óseas. El paricalcitol ha mostrado su eficacia en el control del hiperparatiroidismo secundario en la enfermedad renal crónica con y sin diálisis, con una baja incidencia de hipercalcemia. La experiencia con paricalcitol en trasplantados renales es muy escasa. El objetivo de este trabajo fue mostrar el efecto sobre el metabolismo mineralóseo del paricalcitol en trasplantados renales con hiperparatiroidismo secundario. Material y métodos: Estudio retrospectivo multicéntrico con trasplantados renales de más de 18 años de edad y más de 12 meses de evolución postrasplante, con función renal estable, que hayan sido tratados con paricalcitol durante más de 12 meses, con seguimiento clínico hasta los 24 meses de tratamiento. Resultados: Se incluyó a 69 pacientes, con 120±92 meses postrasplante, con creatinina inicial de 2,2±0,9mg/dl y FG-MDRD 36±20ml/min/1,73 m2. La dosis de paricalcitol se incrementó progresivamente durante el estudio: basal 3,8±1,9μg/semana, 12 meses 5,2±2,4μg/semana; 24 meses 6,0±2,9μg/semana (p<0,001). Los niveles séricos de PTH descendieron de forma rápida y significativa: basal 288±152 pg/ml; 6 meses 226±184 pg/ml; 12 meses 207±120; 24 meses 193±119 pg/ml (p<0,001). Observamos una reducción sobre PTH basal ≥30% en el 42,4% de los pacientes a los 12 meses y en el 65,2% de los pacientes a los 24 meses. La fosfatasa alcalina descendió también significativamente en los 6 primeros meses para luego estabilizarse: basal 92±50 UI/l; 6 meses 85±36 UI/l, 12 meses 81±39 UI/l (p<0,001). Globalmente no hubo modificaciones en el calcio o fósforo séricos ni en la excreción urinaria de calcio. La reducción de PTH fue más importante en trasplantados con niveles séricos más elevados de partida. Observamos que los pacientes con calcio basal más bajo mostraron un incremento significativo de sus cifras de 0,5-0,6 mg/dl en promedio aunque manteniéndose en rango de normalidad, mientras que pacientes con calcio basal > 10 mg/dl mostraron una reducción progresiva de sus cifras. Quince (21,7%) pacientes seguían tratamiento previo con calcitriol y al cambiarlos a paricalcitol precisaron dosis significativamente mayores que los pacientes que no habían recibido calcitriol. El paricalcitol fue asociado a cinacalcet en 11 pacientes, con reducciones significativas de PTH, con evolución similar al resto de la población y con dosis de paricalcitol también similares. Conclusiones: Paricalcitol es eficaz en el tratamiento del hiperparatiroidismo secundario de trasplantados renales. Globalmente no observamos modificaciones significativas de los niveles de calcio ni de fósforo, ni en su excreción urinaria. Los pacientes en tratamiento previo con calcitriol precisaron dosis mayores de paricalcitol. Cuando el paricalcitol se administra a pacientes tratados con cinacalcet, se observa un descenso significativo de la PTH con dosis de paricalcitol similar a pacientes sin cinacalcet (AU)

Introduction: Secondary hyperparathyroidism is highly prevalent in kidney transplant recipients, and commonly results in hypercalcaemia; an association to osteopenia and bone fractures has also been observed. Paricalcitol has proved effective to control secondary hyperparathyroidism in chronic kidney disease in both dialysed and non-dialysed patients, with a low hypercalcaemia incidence. Currently available experience on paricalcitol use in kidney transplant recipients is scarce. Our main aim was to show the effect of paricalcitol on mineral bone metabolism in kidney transplant recipients with secondary hyperparathyroidism. Material and methods: A retrospective multicentre study in kidney transplant recipients aged > 18 years with a 12-month or longer post-transplantation course, stable renal function, having received paricalcitol for more than 12 months, with available clinical follow-up for a 24-month period. Results: A total of 69 patients with a 120 ± 92-month post-transplantation course were included. Baseline creatinine was 2.2 ± 0.9 mg/dl y GFR-MDRD was 36 ± 20 ml/min/1.73m2. Paricalcitol doses were gradually increased during the study: baseline 3.8 ± 1.9 g/week, 12 months 5.2 ± 2.4 g/week; 24 months 6.0 ± 2.9 g/week (P<.001). Serum PTH levels showed a significant fast decline: baseline 288 ± 152 pg/ml; 6 months 226 ± 184 pg/ml; 12 months 207 ± 120; 24 months 193 ± 119 pg/ml (P<.001). Reduction from baseline PTH was ≥30% in 42.4% of patients at 12 months y in 65.2% of patients at 24 months. Alkaline phosphatase showed a significant decrease in first 6 months followed by a plateau: baseline 92 ± 50 IU/l; 6 months 85 ± 36 IU/l, 12 months 81 ± 39 IU/l (P<.001). Overall, no changes were observed in serum calcium and phosphorus, and in urine calcium excretion. PTH decline was larger in patients with higher baseline levels. Patients with lower baseline calcium levels showed significantly increased levels (mean increase was 0.5-0.6 mg/dl) but still within normal range, whereas patients with baseline calcium > 10 mg/dl showed gradually decreasing levels. Fifteen (21.7%) patients had received prior calcitriol therapy. When shifted to paricalcitol, such patients required paricalcitol doses significantly larger than those not having received calcitriol. Paricalcitol was used concomitantly to cinacalcet in 11 patients with significant PTH reductions being achieved; clinical course was similar to other patients and paricalcitol doses were also similar. Conclusions: Paricalcitol is an effective therapy for secondary hyperparathyroidism in kidney transplant recipients. Overall, no significant changes were observed in calcium and phosphorus levels or urinary excretion. Patients having previously received calcitriol required higher paricalcitol doses. When used in patients receiving cinacalcet, paricalcitol results in a significant PTH fall, with paricalcitol doses being similar to those used in patients not receiving cinacalcet (AU)