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International Society for Peritoneal Dialysis. Baxter Health Care. Fresenius Medical Care, Germany. Ipsen. Medical Faculty of University of Cologne. Marga and Walter Boll-Foundation. Federal Ministry of Education & Research (BMBF): 01GM1515. European Rare Kidney Disease Reference Network (ERKNet).

We study versions of limit models adapted to the context of metric abstract elementary classes. Under categoricity and superstability-like assumptions, we generalize some theorems from [7, 15-17]. We prove criteria for existence and uniqueness of limit models in the metric context.

Activated PI3Kδ syndrome (APDS) Type I results from gain-of-function mutations in PIK3CD, which encodes the p110δ subunit of PI3Kδ. Abnormal actin dynamics have been hypothesized to contribute to the lymphopenia associated with this disease but have not been studied in patients with APDS. We report a patient with APDS who had widespread necrotic skin lesions that were responsive specifically to immunosuppressive therapy. EBV-transformed lymphoblastoid cells (EBV-LCLs) from patients with APDS exhibit increased polymerized actin and increased apoptosis, suggesting a contribution of impaired actin dynamics to this disease.

We broaden the framework of metric abstract elementary classes (mAECs) in several essential ways, chiefly by allowing the metric to take values in a well-behaved quantale. As a proof of concept we show that the result of Boney and Zambrano on (metric) tameness under a large cardinal assumption holds in this more general context. We briefly consider a further generalization to partial metric spaces, and hint at connections to classes of fuzzy structures, and structures on sheaves.

ResumoObjetivoComparar os resultados funcionais, após o tratamento artroscópico, das lesões parciais isoladas do tendão supra‐espinal dos tipos bursal e articular nos graus alto e baixo.MétodosForam avaliados 64 pacientes com lesões parciais isoladas do tendão supra‐espinal. Seguimento médio de 76 meses (29 a 193). A média de idade foi de 59 anos (36 a 82). O lado dominante foi acometido em 44 pacientes (68,8%). Observadas 35 lesões bursais (54,7%) e 29 articulares (45,3%). Usamos a classificação de Ellman e caracterizamos as lesões como baixo e alto grau quando acometiam menos ou mais de 50% de sua espessura, respectivamente. Foi feito desbridamento em 15 pacientes (23,5%), reparo sem completar a lesão em 11 (17%) e reparo após completar a lesão em 38 (59,5%). A avaliação clínica funcional dos pacientes foi feita com o uso dos escores de Constant & Murley e UCLA.ResultadosA média dos escores de Constant dos pacientes com lesão bursal foi de 82,64±6,98 (59,3 a 99) e com lesão articular foi de 83,57±7,58 (66 a 95), enquanto que a média do UCLA nas lesões bursais foi de 33,37±2,85 (21 a 35) e nas lesões articulares foi de 32,83±2,95 (22 a 35).ConclusãoO tratamento videoartroscópico das lesões parciais do manguito rotador apresenta resultados bons/excelentes quando as lesões de baixo grau são desbridadas e as lesões de alto grau são completadas e reparadas. Esses resultados se mantêm em longo prazo, com alto índice de satisfação e poucas complicações.AbstractObjectiveTo compare the functional results from high and low‐grade isolated partial lesions of the supraspinatus tendon of bursal and articular types, after arthroscopic treatment.MethodsSixty‐four patients with isolated partial lesions of the supraspinatus tendon were evaluated. The mean length of follow‐up was 76 months (range: 29 to 193). The mean age was 59 years (range: 36 to 82). The dominant side was affected in 44 patients (68.8%). There were 35 bursal lesions (54.7%) and 29 articular lesions (45.3%). We used the Ellman classification and characterized the lesions as low or high‐grade according to whether they affected less than or more than 50% of the tendon thickness, respectively. Debridement was performed in 15 patients (23.5%), repair without completing the lesion in 11 (17%) and repair after completing the lesion in 38 (59.5%). The functional assessments on the patients were done using the Constant & Murley and UCLA scores.ResultsThe mean Constant & Murley score among the patients with bursal lesions was 82.64±6.98 (range: 59.3 to 99) and among those with articular lesions, 83.57±7.58 (range: 66 to 95), while the mean UCLA score in the bursal lesions was 33.37±2.85 (range: 21 to 35) and in the articular lesions, 32.83±2.95 (range: 22 to 35).ConclusionVideoarthroscopic treatment of partial lesions of the rotator cuff presents good or excellent results when the low‐grade lesions are debrided and the high‐grade lesions are completed and repaired. These results are maintained over the long term, with a high satisfaction rate and few complications.

renal function in pediatric patients with allogeneic hematopoietic progenitor cell transplantation Patients with hematopoietic stem cell transplantation can develop some degree of renal failure. The aim of this descriptive study is to evaluate markers of kidney injury in pediatric patients undergoing allogeneic hematopoietic stem cell transplantation between 1991 and 2011. patients and method: A descriptive study of pediatric patients with allogeneic transplant of hematopoietic precursors between 1991 and 2011. The patients were between 1 month and 18 years of age at the time of the study and had at least 6 months of follow up. Clinical and nutritional history, continuous blood pressure monitoring (ABPM), urine tests, proteinuria, creatinine and renal and bladder ultrasonography imaging were evaluated. results: During this period 65 patients were transplanted, of which 13 patients were included. 46% (n = 6) showed diverse degrees of renal compromise defined by altered renal parenchymal echogenicity, clinic or masked hypertension and/or microalbuminuria. Conclusion: In this clinical group, almost half of the patients patients had some degree of renal injury in their evolution. We consider essential to assess the renal function in the follow-up of these patients. (Key words: Kidney failure, hematopoietic cell transplantation, hypertension, renal fuction). Rev Chil Pediatr 2014; 85 (6): 701-707

We study notions of independence appropriate for a stability theory of metric abstract elementary classes (for short, MAECs). We build on previous notions used in the discrete case, and adapt definitions to the metric case. In particular, we study notions that behave well under superstability-like assumptions. Also, under uniqueness of limit models, we study domination, orthogonality and parallelism of Galois types in MAECs.

In this paper, we study a stability transfer theorem in d-tame metric abstract elementary classes, in a similar way as in 2, but using superstability-like assumptions which involves a new independence notion (ζ*-independence) instead of ℵ0-locality.

This prospective, comparative trial investigated the impact on mean change in height standard deviation score (SDS), acute rejection rate, and renal function of early steroid withdrawal in 96 recipients with 5 years of follow-up. Recipients under basiliximab induction and steroid withdrawal (SW: TAC/MMF; n = 55) were compared with a matched steroid control group (SC: TAC/MMF/STEROID, n = 41). SW received steroids until Day 6, SC decreased to 10 mg/m2 within 2 months post-transplant. Five years after SW, the longitudinal growth (SDS) gain was 1.4 ± 0.4 vs. 1.1 ± 0.3 for SC group (p < 0.02). Height benefits in prepubertal and pubertal status in both groups were demonstrated in the delta growth trends (mixed model; p < 0.01). Biopsy-proven acute rejection in SW was 11% and 17.5%, SC (p: ns). Mean eGFR (ml/min/1.73 m2) at 5 years post-transplant was SW 80.6 ± 27.8 vs. 82.6 ± 25.1 for SC (p: ns). The death-censored graft survival rate at 1 and 5 years was 99 and 90% for SW; 98 and 96% for SC (p = ns). PTLD incidence in SW 3.3 vs. 2.5% in SC (p: ns). Five years post-transplant, early steroid withdrawal showed positive impacts on growth, stable renal function without increased acute rejection risk, and PTLD incidence.

Peritoneal equilibration test (PET) is a common technique used in children to evaluate peritoneal membrane transport capacity and adequate the dialysis regimen. Considering that this is a laborious test, a shortened version has been proposed. Our goal was to evaluate the concordance between the 2-h (short) and 4-h (classical) PET values to determine whether the short PET could be used in the clinical setting. Eighty-one PET corresponding to 81 peritoneal dialysis patients from two pediatric nephrology centers were retrospectively analyzed. Peritoneal transport capacity was evaluated using the dialysate to plasma ratio (D/P) of creatinine and the ratio of dialysate glucose to baseline dialysate glucose (D/D(0)) at 2 and 4 h. The mean [+/- standard deviation (SD)] creatinine D/P ratio at 2 and 4 h were 0.41 +/- 0.13 and 0.66 +/- 0.17, respectively, and the mean (+/- SD) D/D(0) glucose were 0.64 +/- 0.11 and 0.39 +/- 0.12 at the same times. Applying McNemar chi(2) test to evaluate the association between the categories obtained at 2 and 4 h, we found no relationship between the 2- and 4-h PET for both D/P and D/D(0) (p0.05). These results suggest that the use of this abbreviated test is probably not reliable for estimating the transport capacity of the peritoneal membrane in the pediatric population.

OBJECTIVE: To compare the functional results from high and low-grade isolated partial lesions of the supraspinatus tendon of bursal and articular types, after arthroscopic treatment.METHODS: Sixty-four patients with isolated partial lesions of the supraspinatus tendon were evaluated. The mean length of follow-up was 76 months (range: 29-193). The mean age was 59 years (range: 36-82). The dominant side was affected in 44 patients (68.8%). There were 35 bursal lesions (54.7%) and 29 articular lesions (45.3%). We used the Ellman classification and characterized the lesions as low or high-grade according to whether they affected less than or more than 50% of the tendon thickness, respectively. Debridement was performed in 15 patients (23.5%), repair without completing the lesion in 11 (17%) and repair after completing the lesion in 38 (59.5%). The functional assessments on the patients were done using the Constant & Murley and UCLA scores.RESULTS: The mean Constant & Murley score among the patients with bursal lesions was 82.64 ± 6.98 (range: 59.3-99) and among those with articular lesions, 83.57 ± 7.58 (range: 66-95), while the mean UCLA score in the bursal lesions was 33.37 ± 2.85 (range: 21-35) and in the articular lesions, 32.83 ± 2.95 (range: 22-35).CONCLUSION: Videoarthroscopic treatment of partial lesions of the rotator cuff presents good or excellent results when the low-grade lesions are debrided and the high-grade lesions are completed and repaired. These results are maintained over the long term, with a high satisfaction rate and few complications. OBJETIVO: Comparar os resultados funcionais, após o tratamento artroscópico, das lesões parciais isoladas do tendão supra-espinal dos tipos bursal e articular nos graus alto e baixo.MÉTODOS: Foram avaliados 64 pacientes com lesões parciais isoladas do tendão supra-espinal. Seguimento médio de 76 meses (29 a 193). A média de idade foi de 59 anos (36 a 82). O lado dominante foi acometido em 44 pacientes (68,8%). Observadas 35 lesões bursais (54,7%) e 29 articulares (45,3%). Usamos a classificação de Ellman e caracterizamos as lesões como baixo e alto grau quando acometiam menos ou mais de 50% de sua espessura, respectivamente. Foi feito desbridamento em 15 pacientes (23,5%), reparo sem completar a lesão em 11 (17%) e reparo após completar a lesão em 38 (59,5%). A avaliação clínica funcional dos pacientes foi feita com o uso dos escores de Constant & Murley e UCLA.RESULTADOS: A média dos escores de Constant dos pacientes com lesão bursal foi de 82,64 ± 6,98 (59,3 a 99) e com lesão articular foi de 83,57 ± 7,58 (66 a 95), enquanto que a média do UCLA nas lesões bursais foi de 33,37 ± 2,85 (21 a 35) e nas lesões articulares foi de 32,83 ± 2,95 (22 a 35).CONCLUSÃO: O tratamento videoartroscópico das lesões parciais do manguito rotador apresenta resultados bons/excelentes quando as lesões de baixo grau são desbridadas e as lesões de alto grau são completadas e reparadas. Esses resultados se mantêm em longo prazo, com alto índice de satisfação e poucas complicações.

Patients with hematopoietic stem cell transplantation can develop some degree of renal failure. The aim of this descriptive study is to evaluate markers of kidney injury in pediatric patients undergoing allogeneic hematopoietic stem cell transplantation between 1991 and 2011.A descriptive study of pediatric patients with allogeneic transplant of hematopoietic precursors between 1991 and 2011. The patients were between 1 month and 18 years of age at the time of the study and had at least 6 months of follow up. Clinical and nutritional history, continuous blood pressure monitoring (ABPM), urine tests, proteinuria, creatinine and renal and bladder ultrasonography imaging were evaluated.During this period 65 patients were transplanted, of which 13 patients were included. 46% (n = 6) showed diverse degrees of renal compromise defined by altered renal parenchymal echogenicity, clinic or masked hypertension and/or microalbuminuria.In this clinical group, almost half of the patients patients had some degree of renal injury in their evolution. We consider essential to assess the renal function in the follow-up of these patients.

BACKGROUND Parathyroid hormone (PTH)-independent hypercalcemia in patients with chronic kidney failure is a rare and poor understood entity. CASE REPORT We report the case of an infant with stage III chronic kidney failure secondary to multicystic dysplastic kidney disease, who presented at 3 months of life with severe hypercalcemia, suppressed PTH, and elevated PTH-related peptide. Malignancy was discarded, and the patient was treated twice with bisphosphonates with an initial partial response. During follow-up, the calcium levels descended. To date, he has maintained normal serum calcium level for 1 year after discharge. CONCLUSIONS The presence of PTH-related peptide may play a role in hypercalcemia associated to multicystic dysplastic kidney disease possibly by the overproduction of this peptide in the kidney.

La infección urinaria (ITU) es una de las patologías infecciosas más frecuentes en pediatría. Tradicionalmente se ha considerado como marcador de probables anormalidades anatómicas y funcionales de la vía urinaria, por lo cual, en las últimas décadas todos los niños que presentaban una ITU eran sometidos a estudio por imágenes en busca de cicatrices renales o anormalidades de la vía urinaria. El objetivo de este artículo es actualizar los conceptos sobre el estudio y tratamiento de pacientes pediátricos que presentan una ITU febril. El estudio por imágenes es incómodo para los pacientes, estresante para los padres y las evidencias actuales para continuar realizándolo son limitadas por lo cual debe ser selectivo en orden de focalizar en los pacientes que puedan beneficiarse con cirugías urológicas correctoras o tratamientos médicos adecuados. Estas pautas están basadas en las guías NICE de ITU e intentan demostrar que uno de los pilares más importantes para evitar secuelas renales es el diagnóstico y tratamiento oportuno de las ITU febriles.

The C7 reservoir, located in Casanare Basin, not only exhibits serious formation consolidation problems, but the producing zone is also close to the oil/water contact. Most of the workover interventions have been focused on sand- and water-production issues. A solution developed to obtain hydrocarbon production that combines sand-control and water-control techniques, without additional services to clean the sand or change the production pump, is presented in this paper.Numerous methods for this purpose exist in the industry, such as mechanical sand control methods, chemical treatments, and combinations of both. These are typically applied according to best practices with consideration of the associated costs.The sand-control technique presented in this paper has been applied for three consecutive years in the area of Casanare, Colombia and has proven to be successful. This technique consists of pumping linear gel at high rates to place the proppant into the formation; in some cases, up to 40 sacks/ft (experiences in other regions mention 3.5 sacks/ft). In some cases, because of the proximity of the water, it was decided not to fracture to prevent the influx of water.To increase the amount of proppant placed in the formation, a combination of two techniques, which have each proven to be successful individually, has been implemented. These techniques are: (1) use of a relative permeability modifier (RPM) to control the water influx and (2) high-rate pumping of linear gel to place proppant.The combination of the RPM treatment and sand-control technologies designed for each particular area has set a new standard for sand-control operations in the area.

The aim of this study was to determine the frequency of renal abnormalities in HIV positive children hospitalized in one pediatric hospital in Chile.a cross sectional study was performed during April 2007.A total of 18 patients were evaluated, ten male and eight female ranging in age from 4 to 19 years. The average age at the time of HIV diagnosis and nephrologic evaluations were 2,69 and 10,7 years respectively. All patients had acquired HIV infection by vertical transmission. Uriñe samples of two children had microalbuminuria; two had monosymptomatic hematuria, and ten had ¿squamous? cells. Hypercalciuria was detected in one patient, renal lithiasis in another and two patients had abnormal renal ultrasonography. All 19 patients had normal blood pressures. Overall 7 patients (39%) had a renal abnormality.The relatively high incidence of renal abnormalities in our series support the need for a nation-wide screening program to assess the incidence of renal impairment in pediatric HIV positive patients.

El objetivo de este estudio fue evaluar la función renal de pacientes infectados con virus de inmuno-deficiencia humana (VIH) que se controlan en un hospital pediátrico chileno. Método: estudio de corte transversal. Resultados: Se evaluaron 18 pacientes, 10 varones y 8 mujeres; edad: entre 4 y 19 años, la edad promedio al diagnóstico de la infección por VIH y al momento de la evaluación fue 2,69 y 10,7 años, respectivamente. Todos nuestros pacientes adquirieron la infección vía vertical. Dos presentaron microalbuminuria y dos hematuria monosintomática. En 10 (55%) se encontraron células descamativas, en uno hiper-calciuria y en otro litiasis renal. Todos tuvieron presión arterial normal. La ecotomograña renal fue anormal en dos. Se han descrito varias anormalidades renales en pacientes con infección por VIH; en nuestro estudio, 7 pacientes (39%) tuvieron alteraciones en los exámenes de laboratorio. Conclusión: La alta frecuencia de afectación renal encontrada en pacientes pediátricos con infección por VIH hace necesario plantear un tamizaje nacional para determinar la incidencia de nefropatía asociada en nuestros pacientes.

Background: Hemolytic-uremic syndrome (HUS) is characterized by acute renal failure, microangiopathic hemolytic anemia and thrombocytopenia. Aim: To describe the characteñstics ofpatients with the diagnosis ofHUS in Chile, and to identify the most reliable early predictors oímorbidity and moñality. Material and methods: The clinical records ofpatients with HUS aged less than 15 years, attended between January 1990 and December 2003 in 15 hospitals, were reviewed. Demographic, clinical, biochemical, hematological parameters, morbidity and mortality were analyzed. Results: A cohort of 587 patients aged 2 to 8 years, 48% males, was analyzed. Ninety two percent had diarrhea. At the moment of diagnosis, anuria was observed in 39% of the patients, hypertension in 45% and seizures in 17%. Forty two percent required renal replacement therapy (RRT) and perítoneal dialysis was used in the majoríty of cases (78%). The most frequently isolated etiological agentwas Escherichia coli. Mortality rate was 2.9% in the acute phase of the disease and there was a positive correlation between mortality and anuria, seizures, white blood cell count (WCC) >20.000/mm³ and requirements of renal replacement therapy (p 20.000/mm³, seizures and hypertension. Conclusions: The present study emphasizes important clinical and epidemiological aspeets ofHUSin a Chilean pediatricpopulation.

Background: Hemolytic-uremic syndrome (HUS) is characterized by acute renal failure, microangiopathic hemolytic anemia and thrombocytopenia. Aim: To describe the characteñstics ofpatients with the diagnosis ofHUS in Chile, and to identify the most reliable early predictors oímorbidity and moñality. Material and methods: The clinical records ofpatients with HUS aged less than 15 years, attended between January 1990 and December 2003 in 15 hospitals, were reviewed. Demographic, clinical, biochemical, hematological parameters, morbidity and mortality were analyzed. Results: A cohort of 587 patients aged 2 to 8 years, 48% males, was analyzed. Ninety two percent had diarrhea. At the moment of diagnosis, anuria was observed in 39% of the patients, hypertension in 45% and seizures in 17%. Forty two percent required renal replacement therapy (RRT) and perítoneal dialysis was used in the majoríty of cases (78%). The most frequently isolated etiological agentwas Escherichia coli. Mortality rate was 2.9% in the acute phase of the disease and there was a positive correlation between mortality and anuria, seizures, white blood cell count (WCC) >20.000/mm³ and requirements of renal replacement therapy (p 20.000/mm³, seizures and hypertension. Conclusions: The present study emphasizes important clinical and epidemiological aspeets ofHUSin a Chilean pediatricpopulation.

Objetivo: Caracterizar la función tiroidea y la respuesta a test de TRH (thyroid releasing hormone), en niños con enfermedad renal crónica (ERC) leve (L), moderada (M), peritoneodiálisis (PD), hemodiálisis (HD) y trasplantados renales (TX). Pacientes y Método: Se estudiaron 46 pacientes con ERC (10 L, 10 M, 10PD,6HDy 10TX),9,3±3,7 años. Se midió t4t,t41,t3t, t31,TBGbasalytest de TRH(TSHa 0,30y60min). Se evaluó función renal, antropometría y se consignó tratamiento inmunosupresor (IS) en el grupo TX. Se utilizó anova para comparar los resultados entre los grupos y coeficiente de correlación para las variables estudiadas. Resultados: Los valores básales de hormonas tiroideas fueron normales en todos los grupos, sólo TSH fue significativamente mayor en L aunque dentro del rango normal (p < 0,01). La respuesta al test de TRH fue predominantemente prolongada en L, M, PD y HD y deficiente en TX; los 3 pacientes TX con tacrolimus, micofenolato y prednisona en días alternos tuvieron respuesta normal a diferencia del resto TX que recibían prednisona continua, ciclosporina y micofenolato. La prolongación de respuesta a TRH se correlacionó con creatininemia, BUN y clearance de creatinina (p < 0,01). Conclusiones: Los niveles de hormonas tiroideas básales se encuentran normales en todos los grupos de ERC. La respuesta a TRH fue predominantemente prolongada en L, M, PD y HD, demostrando un fenómeno adaptativo a nivel terciario del eje hipotálamo-hipofisis-tiroides. Los TX presentan una respuesta mayoritoriamente deficiente a TRH, sugerente de disfunción hipofisiaria, la que podría estar relacionada con el tipo de tratamiento inmunosupresor y al uso de corticoides en días continuos

ResumenIntroducciónEl síndrome hemolítico urémico (SHU) se caracteriza por la presencia de anemia hemolítica microangiopática, trombocitopenia y afectación renal aguda. Es la principal causa de falla renal aguda en niños menores de 3 años. Un número variable de pacientes evoluciona con afectación renal a largo plazo con proteinuria, hipertensión arterial e insuficiencia renal crónica.ObjetivoEvaluar la afectación renal mediante el índice microalbuminuria/creatininuria en pacientes pediátricos con diagnóstico de SHU.Pacientes y MétodoEstudio descriptivo de cohorte concurrente que analizó la presencia de microalbuminuria en pacientes diagnosticados de SHU entre enero de 2001 y marzo de 2012, que evolucionaron sin hipertensión y con función renal normal (clearance mayor de 90ml/min medido por fórmula de Schwartz). Se evaluaron factores demográficos (edad, sexo), presentación clínica en el momento del diagnóstico, uso de antibióticos previo al ingreso y requerimiento de terapia de reemplazo renal.ResultadosSe estudiaron 24 pacientes, el 54% varones; la edad promedio en el momento del diagnóstico fue de 2 años; un 45% requirió diálisis peritoneal; un 33% evolucionó con microalbuminuria persistente; cuatro pacientes recibieron tratamiento antiproteinúrico con buena respuesta. El promedio de seguimiento fue de 6 años (rango: 6 meses a 11 años); todos los pacientes durante el seguimiento evolucionaron con creatinina plasmática normal.ConclusionesEn nuestro grupo, el porcentaje de microalbuminuria persistente en pacientes con diagnóstico previo de SHU fue similiar a lo descrito en la literatura; el tratamiento con antiproteinúricos podría retrasar el daño renal, pero es necesario realizar estudios prospectivos multicéntricos.AbstractIntroductionHemolytic uremic syndrome (HUS) is characterized by the presence of microangiopathic hemolytic anemia, thrombocytopenia, and acute kidney failure. It is the leading cause of acute kidney failure in children under 3 years of age. A variable number of patients develop proteinuria, hypertension, and chronic renal failure.ObjectiveTo evaluate the renal involvement in pediatric patients diagnosed with HUS using the microalbumin/creatinine ratio.Patients and MethodsDescriptive concurrent cohort study that analyzed the presence of microalbuminuria in patients diagnosed with HUS between January 2001 and March 2012, who evolved without hypertension and normal renal function (clearance greater than 90ml/min using Schwartz formula). Demographic factors (age, sex), clinical presentation at time of diagnosis, use of antibiotics prior to admission, and need for renal replacement therapy were evaluated.ResultsOf the 24 patients studied, 54% were male. The mean age at diagnosis was two years. Peritoneal dialysis was required in 45%, and 33% developed persistent microalbuminuria. Antiproteinuric treatment was introduce in 4 patients, with good response. The mean follow-up was 6 years (range 6 months to 11 years). The serum creatinine returned to normal in all patients during follow up.ConclusionsThe percentage of persistent microalbuminuria found in patients with a previous diagnosis of HUS was similar in our group to that described in the literature. Antiproteinuric treatment could delay kidney damage, but further multicenter prospective studies are necessary.

The mineral and bone disorder of chronic kidney disease remains a challenging complication in pediatric end-stage renal disease. Here, we assessed symptoms, risk factors and management of this disorder in 890 children and adolescents from 24 countries reported to the International Pediatric Peritoneal Dialysis Network Registry. Signs of this disease were most common in North American patients. The prevalence of hyperphosphatemia increased with age from 6% in young infants to 81% in adolescents. Serum parathyroid hormone (PTH) was outside the guideline targets in the majority of patients and associated with low calcium, high phosphorus, acidosis, dialysis vintage and female gender. Serum calcium was associated with dialytic calcium exposure, serum phosphorus with low residual renal function and pubertal status. PTH levels were highest in Latin America and lowest in Europe. Vitamin D and its active analogs were most frequently administered in Europe; calcium-free phosphate binders and cinacalcet in North America. Clinical and radiological symptoms markedly increased when PTH exceeded 300 pg/ml, the risk of hypercalcemia increased with levels below 100 pg/ml, and time-averaged PTH concentrations above 500 pg/ml were associated with impaired longitudinal growth. Hence, the symptoms and management of the mineral and bone disorder of chronic kidney disease in children on peritoneal dialysis showed substantial regional variation. Our findings support a PTH target range of 100-300 pg/ml in the pediatric age group. Kidney International (2010) 78, 1295-1304; doi:10.1038/ki.2010.316; published online 1 September 2010