[Hypovitaminosis D in pediatric patients on renal replacement therapy]. / Hipovitaminosis D en pacientes pediátricos en terapia de sustitución renal.

BACKGROUND: Hypovitaminosis D has a high prevalence among patients with chronic kidney disease (CKD). AIM: To determine the prevalence of 25 hydroxy vitamin D (25(OH) D) insufficiency and deficiency in pediatric patients on dialysis and kidney transplantation. MATERIAL AND METHODS: Serum calcium and phosphorus, parathormone (PTH), alkaline phosphatases and 25 (OH)D were measured in 13 children on hemodialysis (HD), 18 on peritoneal dialysis (PD) and 53 that received an allograft (Tx), aged 9.8 ± 4.6 years (51% females). RESULTS: Fifty four percent of patients had height Z score less than -1.88. Patients on HD had the lowest values. The average time of replacement therapy was 2.9 ± 2.8 years. Mean 25(OH)D levels in all was 18.7 ± 10.7ng/ml (HD: 21 ± 16.8, PD: 18.9 ± 8.5, Tx: 18.1 ± 9.72 ng/ml). Eighty eight percent of patients had levels below 30 ng/ml. Mean of serum calcium was 9.5 ± 0.64 mg/dl, serum phosphorus 5.03 ± 1.02 mg/dl, calcium-phosphorus product 48 ± 11.8 mg/dl and alkaline phosphatases 300.5 ± 171.3 IU/L. Average PTH values in dialyzed and Tx patients were 724.6 ± 640.5 and 107.7 ± 56.2 pg/ml, respectively (p < 0.001). A positive correlation between 25 (OH) D and calcium levels among PD patients was observed (r = 0.490, p = 0.04). CONCLUSIONS: Hypovitaminosis D is highly prevalent among children on renal substitution therapy, regardless of the type of therapy used and the stage of renal failure.

Intraperitoneal calcitriol in infants on peritoneal dialysis.

BACKGROUND: Calcitriol has long been used as the main therapy in renal osteodystrophy, but the efficacy of the oral route is not always as high as expected. OBJECTIVE: To asses the safety and efficacy of intraperitoneal calcitriol in infants undergoing peritoneal dialysis (PD). PATIENTS AND METHODS: PD patients on oral calcitriol therapy, with serum parathyroid hormone (PTH) >1000 pg/mL during the previous 3 months of treatment, were switched to intraperitoneal calcitriol therapy, 1 microg twice per week. Dose was increased to 1 microg three times per week if PTH remained >1000 pg/mL, and was later readjusted. Target PTH was 200-300 pg/mL according DOQI guidelines. STATISTICS: All results are expressed as mean +/- SE. The Wilcoxon signed rank test was used to evaluate differences in measurements for each pair of values. The confidence interval for differences between population medians was 96.9%. A p value less than 0.05 was considered significant. RESULTS: Six male children, mean age 17 +/- 3.86 months, completed a 12-month follow-up. Mean pretreatment PTH was 1654 +/- 209 pg/mL. Mean PTH at months 0, 3, 6, 9, and 12 was 1448 +/- 439*, 1277 +/- 723, 910 +/- 704, 582 +/- 282*, and 465 +/- 224* pg/mL, respectively (*p < 0.05). Twelve hypercalcemic and 10 hyperphosphatemic episodes were successfully treated. CONCLUSION: Infants on PD who fail to respond to oral calcitriol therapy can be safely treated with intraperitoneal administration of active vitamin D.

Early steroid withdrawal in pediatric renal transplant on newer immunosuppressive drugs.

Steroids have been a cornerstone in renal transplant immunosuppression. New immunosuppressive drugs have led to protocols using early steroid withdrawal or complete avoidance. A prospective protocol in 23 pediatric renal transplant (ages 2-14 yr) who received decreasing steroid doses stopping at day 7 post-Tx, FK, and MMF were compared with a CsA, AZT, historically matched steroid-based control group. Basiliximab was used in two doses. Anthropometric, biochemical variables, AR rates, and CMV infection were evaluated and compared using Student's t-test and regression analysis. A better growth pattern was seen in steroid withdrawal group. GFR rate and serum glucose were similar in both groups. Total serum cholesterol levels were significantly lower in steroid withdrawal group. The incidence of AR at 12 months was 4.3% in steroid withdrawal group vs. 8.6% in steroid-based group (p = ns). No difference in CMV infection was observed. Hemoglobin levels were low during the first months in both groups; reached normal values after six months. SBP became higher at 12 months in steroid-based group. Patient and graft survival was 98% in both groups at one-yr post-transplant. Early steroid withdrawal was efficacious, safe, and did not increase risk of rejection, preserving optimal growth, renal function, and reducing cardiovascular risk factors.

Hipovitaminosis D en pacientes pediátricos en terapia de sustitución renal / Hypovitaminosis D in pediatric patients on renal replacement therapy

Background: Hypovitaminosis D has a high prevalence among patients with chronic kidney disease (CKD). Aim: To determine the prevalence of 25 hydroxy vitamin D (25(OH) D) insufficiency and deficiency in pediatric patients on dialysis and kidney transplantation. Material and Methods: Serum calcium and phosphorus, parathormone (PTH), alkaline phosphatases and 25 (OH)D were measured in 13 children on hemodialysis (HD), 18 on peritoneal dialysis (PD) and 53 that received an allograft (Tx), aged 9.8 ± 4.6 years (51 percent females). Results: Fifty four percent of patients had height Z score less than -1.88. Patients on HD had the lowest values. The average time of replacement therapy was 2.9 ± 2.8 years. Mean 25(OH)D levels in all was 18.7 ± 10.7ng/ml (HD: 21 ± 16.8, PD: 18.9 ± 8.5, Tx: 18.1 ± 9.72 ng/ml). Eighty eight percent of patients had levels below 30 ng/ml. Mean of serum calcium was 9.5 ± 0.64 mg/dl, serum phosphorus 5.03 ± 1.02 mg/dl, calcium-phosphorus product 48 ± 11.8 mg/dl and alkaline phosphatases 300.5 ± 171.3 IU/L. Average PTH values in dialyzed and Tx patients were 724.6 ± 640.5 and 107.7 ± 56.2 pg/ml, respectively (p < 0.001). A positive correlation between 25 (OH) D and calcium levels among PD patients was observed (r = 0.490, p = 0.04). Conclusions: Hypovitaminosis D is highly prevalent among children on renal substitution therapy, regardless of the type of therapy used and the stage of renal failure.

Trasplante renal en pediatría: una década de experiencia multicéntrica / Pediatric renal transplant: a decade of experience

El transplante renal en pediatría representa la modalidad óptima de manejo de la insuficiencia renal crónica, ya que permite recuperar en diversos grados las severas complicaciones propias de la uremia, especialmente el retraso del crecimiento. Objetivo: Evaluar los resultados del transplante renal pediátrico en 3 centros hospitalarios del país, en un período de 10 años (1989-1999). Pacientes y Métodos: Evaluación retrospectiva de los transplantes renales en base a un protocolo común, efectuados en los hospitales Exequiel González Cortes, Luis Calvo Mackenna y San Juan de Dios, entre julio de 1989 y julio 1999. Se analizaron 3 grupos de variables: un primer grupo de tipo descriptivo para variables demográficas; un segundo grupo para analizar el crecimiento desde el período de recién nacido hasta el último año de seguimiento, y un tercer grupo que analizó aspectos con relación al transplante, en especial la inmunosupresión, las complicaciones y la función del injerto por períodos anuales. Las variables continuas fueron expresadas como promedio ñ desviación estándar, el crecimiento como puntaje Z, la función renal se graficó como el inverso de creatinina en plasma, y al igual que la evaluación del rechazo agudo en relación al tipo de donante vivo o cadáver, se analizó con la prueba de chi² de Pearson. El análisis de la función renal en relación a los tiempos de isquemia tibia y fría se evaluó por el test t de Student, y la sobrevida a 1,3 y 5 años para el injerto y pacientes se estudio por la curva de Kaplan Meier. Se consideró significativo un p < 5 por ciento. Resultados: se analizaron 98 transplantes en 92 pacientes, edad 10,9 ñ 3,2 años, rango 2 a 17; las 3 patologías más importantes causantes de la insuficiencia renal que llevo al transplante fueron la nefropatía del reflujo, las displasias o hipoplasias renales, y la glomerulonefritis crónica. El crecimiento mostró una caída de un Z -0,6 al nacer a -2,14 al inicio de la diálisis (p <0,05), y a -2,57 al momento del transplante (p < 0,05). A los 3 años postrasplante el Z fue de -2,38, y a los 5 años -2,93. La sobrevida actuarial de los pacientes a 1 , 3 y 5 años fue de 97,8 / 95,2 y 92,6 respectivamente para los transplantes donante vivo, y de 92,6 / 92,6 y 92,6 en los mismos plazos para los transplantes donate cadáver. La sobrevida del injerto fue de 89, 78 y 71 por ciento a 1 , 3 y 5 años para donate vivo, y de 84, 76 y 70 por ciento respectivamente para donante cadáver