Atypical presentation of Pearson syndrome in an infant with suspected myelodysplastic syndrome.

BACKGROUND: Anemia exhibits complex causation mechanisms and genetic heterogeneity. Some cases result in poor outcomes with multisystemic dysfunction, including renal tubulopathy. Early diagnosis is crucial to improve management. CASE-DIAGNOSIS/TREATMENT: A 21-month-old female patient was admitted with severe anemia. Persistent neutropenia and dysplastic signs suggested myelodysplastic syndrome, but targeted gene panel results were negative. After multiple transfusions, spontaneous hematologic recovery was observed. At 4 years old, she presented failure to thrive, renal Fanconi syndrome, and severe metabolic acidosis. Differential diagnosis included Pearson syndrome (PS), a life-threatening condition associated with mitochondrial DNA (mtDNA), featuring anemia and pancreatic insufficiency. Further analysis revealed a ~ 7.5 kb mtDNA deletion. Until the age of 5, supportive care has been provided, without pancreatic insufficiency. CONCLUSIONS: This PS case highlights the importance of genetic testing, even in the absence of typical features. Understanding the nature of mitochondrial disorders enables treatment tailoring and counseling about the prognosis.

Síndrome nefrótico idiopático: recomendaciones de la Rama de Nefrología de la Sociedad Chilena de Pediatría. Parte 2 / Idiopathic Nephrotic Syndrome: recommendations of the Nephrology Branch of the Chilean Society of Pediatrics. Part two

El síndrome nefrótico idiopático es la glomerulopatía más frecuente en la infancia, afecta a 1-3/100 mil niños menores de 16 años y se presenta con más frecuencia entre los 2 y 10 años. Su causa es desconocida, y la mayoría de las veces responde a corticoides, con buen pronóstico a largo plazo. El síndrome nefrótico corticorresistente representa un 10-20% de los síndromes nefróticos idiopáticos en pediatría. Tiene mal pronóstico, y su manejo constituye un desafío terapéutico significativo. La mitad de los pacientes evoluciona a insuficiencia renal crónica terminal en un plazo de 5 años, estando expuestos además a las complicaciones secundarias a un síndrome nefrótico persistente y a efectos adversos de la terapia inmunosupresora. El objetivo fundamental del tratamiento es conseguir una remisión completa, pero una remisión parcial se asocia a una mejor sobrevida renal que la falta de respuesta. Este documento surgió de un esfuerzo colaborativo de la Rama de Nefrología de la Sociedad Chilena de Pediatría con el objetivo de ayudar a los pediatras y nefrólogos infantiles en el tratamiento del síndrome nefrótico idiopático en pediatría. En esta segunda parte, se discute el manejo del síndrome nefrótico corticorresistente, así como de las terapias no específicas.

Idiopathic nephrotic syndrome is the most common glomerular disease in childhood, affecting 1 to 3 per 100,000 children under the age of 16. It most commonly occurs in ages between 2 and 10. Its cause is unknown, and its histology corresponds to minimal change disease in 90% of cases, or focal segmental glomerulosclerosis. Steroid-resistant nephrotic syndrome represents 10-20% of idiopathic nephrotic syndrome in pediatrics. It has a poor prognosis, and its management is a significant therapeutic challenge. Half of patients evolve to end-stage renal disease within 5 years, and are additionally exposed to complications secondary to persistent NS and to the adverse effects of immunosuppressive therapy. The primary goal of treatment is to achieve complete remission, but even a partial remission is associated with a better renal survival than the lack of response. This paper is the result of the collaborative effort of the Nephrology Branch of the Chilean Society of Pediatrics with aims at helping pediatricians and pediatric nephrologists to treat pediatric idiopathic nephrotic syndrome. In this second part, handling of steroid-resistant nephrotic syndrome as well as nonspecific therapies are discussed.

[Idiopathic Nephrotic Syndrome: recommendations of the Nephrology Branch of the Chilean Society of Pediatrics. Part two]. / Síndrome nefrótico idiopático: recomendaciones de la Rama de Nefrología de la Sociedad Chilena de Pediatría. Parte 2.

Idiopathic nephrotic syndrome is the most common glomerular disease in childhood, affecting 1 to 3 per 100,000 children under the age of 16. It most commonly occurs in ages between 2 and 10. Its cause is unknown, and its histology corresponds to minimal change disease in 90% of cases, or focal segmental glomerulosclerosis. Steroid-resistant nephrotic syndrome represents 10-20% of idiopathic nephrotic syndrome in pediatrics. It has a poor prognosis, and its management is a significant therapeutic challenge. Half of patients evolve to end-stage renal disease within 5 years, and are additionally exposed to complications secondary to persistent NS and to the adverse effects of immunosuppressive therapy. The primary goal of treatment is to achieve complete remission, but even a partial remission is associated with a better renal survival than the lack of response. This paper is the result of the collaborative effort of the Nephrology Branch of the Chilean Society of Pediatrics with aims at helping pediatricians and pediatric nephrologists to treat pediatric idiopathic nephrotic syndrome. In this second part, handling of steroid-resistant nephrotic syndrome as well as nonspecific therapies are discussed.

[Idiopathic Nephrotic Syndrome: recommendations of the Nephrology Branch of the Chilean Society of Pediatrics. Part One]. / Síndrome nefrótico idiopático: recomendaciones de la Rama de Nefrología de la Sociedad Chilena de Pediatría. Parte 1.

Idiopathic nephrotic syndrome is the most common glomerular disease in childhood, affecting 1 to 3 per 100,000 children under the age of 16. It most commonly occurs in ages between 2 and 10. Its cause is unknown and its histology corresponds to minimal change disease in 90% of cases, or focal segmental glomerulosclerosis. 80 to 90% of cases respond to steroids (steroid-sensitive nephrotic syndrome) with good prognosis and long-term preservation of renal function over time. 70% of patients with SSNS have one or more relapses in their evolution, and of these, 50% behave as frequent relapsing or steroid-dependent, a group that concentrate the risk of steroid toxicity. Patients with steroid-resistant nephrotic syndrome have a poor prognosis and 50% of them evolve to end-stage renal disease. The goal of therapy is to induce and maintain remission of the disease, reducing the risk secondary to proteinuria while minimizing the adverse effects of treatments, especially with prolonged use of corticosteroids. This paper is the result of the collaborative effort of the Nephrology Branch of the Chilean Society of Pediatrics with aims at helping pediatricians and pediatric nephrologists to treat pediatric SNI. In this first part, recommendations of steroid-sensitive nephrotic syndrome are discussed.

Management of anemia in children receiving chronic peritoneal dialysis.

Little information exists regarding the efficacy, modifiers, and outcomes of anemia management in children with CKD or ESRD. We assessed practices, effectors, and outcomes of anemia management in 1394 pediatric patients undergoing peritoneal dialysis (PD) who were prospectively followed in 30 countries. We noted that 25% of patients had hemoglobin levels below target (<10 g/dl or <9.5 g/dl in children older or younger than 2 years, respectively), with significant regional variation; levels were highest in North America and Europe and lowest in Asia and Turkey. Low hemoglobin levels were associated with low urine output, low serum albumin, high parathyroid hormone, high ferritin, and the use of bioincompatible PD fluid. Erythropoiesis-stimulating agents (ESAs) were prescribed to 92% of patients, and neither the type of ESA nor the dosing interval appeared to affect efficacy. The weekly ESA dose inversely correlated with age when scaled to weight but did not correlate with age when normalized to body surface area. ESA sensitivity was positively associated with residual diuresis and serum albumin and inversely associated with serum parathyroid hormone and ferritin. The prevalence of hypertension and left ventricular hypertrophy increased with the degree of anemia. Patient survival was positively associated with achieved hemoglobin and serum albumin and was inversely associated with ESA dose. In conclusion, control of anemia in children receiving long-term PD varies by region. ESA requirements are independent of age when dose is scaled to body surface area, and ESA resistance is associated with inflammation, fluid retention, and hyperparathyroidism. Anemia and high ESA dose requirements independently predict mortality.

The plasma permeability factor in nephrotic syndrome: indirect evidence in pediatric peritoneal dialysis.

BACKGROUND: Nephrotic syndrome (NS) in children has been associated with a systemic circulating permeability factor. Therefore, once peritoneal dialysis (PD) has been started, peritoneal protein losses should be higher in the nephrotic than in the non-nephrotic population. OBJECTIVE: We compared peritoneal protein losses in children with and without NS on PD. METHODS: Our retrospective 4-year study analyzed Hispanic patients with NS under PD. Data at dialysis entry and 6 months later were compared. Nutritional support was given according to recommended dietary allowances and recommendations from the Kidney Disease Outcomes Quality Initiative. Clinical and biochemical data were obtained, and 24-hour dialysate and urine samples were collected to measure protein losses. Dialysis dose (Kt/V), daily protein intake (DPI), normalized protein equivalent of nitrogen appearance (nPNA), peritoneal equilibration test (PET), and peritonitis rate were determined. All measurements took place at least 4 weeks after resolution of a peritonitis episode. All patients received automated PD using a HomeChoice PD System cycler (Baxter Healthcare Corporation, Deerfield, IL, USA), with an exchange volume of 1100 mL/m(2) and a dextrose concentration of 1.5% - 2.5%. A control group of non-NS children on PD matched by age and sex were also studied. Data are reported as mean ± standard deviation. Differences between groups were calculated using the Mann-Whitney U-test, and p < 0.05 was considered significant. RESULTS: Each study group consisted of 10 patients [NS patients: 4 boys, mean age of 7.3 ± 4.1 years; control patients: 6 boys, mean age of 7.2 ± 4.7 years (p = nonsignificant)]. In the group with NS, 8 patients were diagnosed by biopsy as having focal segmental glomerulosclerosis, and 2 as having minimal-change disease. At study entry, patients with NS had hourly urinary protein losses of 398 ± 313 mg/m(2) and daily peritoneal protein losses of 3.4 ± 1.9 g/m(2), compared with 29.9 ± 31 mg/m(2) and 1.5 ± 1.1 g/m(2) respectively in the control group (p < 0.05). The same statistical difference was found 6 months later. We observed no statistical differences in PET results, daily exchange volume, and mean dextrose concentration of dialysate. Similarly, no significant between-group differences were observed for Kt/V, DPI, nPNA, and biochemical parameters. CONCLUSIONS: Hispanic children with NS on PD show higher peritoneal protein losses than do their control counterparts. Such differences could be secondary to increased peritoneal permeability caused by a systemic permeability factor.

The short peritoneal equilibration test in pediatric peritoneal dialysis.

The peritoneal equilibration test (PET) is the gold standard method for defining peritoneal membrane permeability and for prescribing peritoneal dialysis (PD) therapy on an individual basis. However, it is laborious, consumes nursing time, and requires many hours to be performed. Therefore, several authors have attempted to validate a short PET protocol, with controversial results. To evaluate the concordance between the 2-h (short) and 4-h (classical) peritoneal equilibrium test, a prospective observational protocol was applied in three PD centers (Mexico, Chile, and Uruguay) between July 1, 2008 and July 31 2009. PET protocol: the night prior to the test, each patient received five exchanges, 1 h each, at the same glucose concentration as previously used. Afterwards, a 2.5% glucose dialysis solution was used for a dwell time of 4 h. Exchange fill volume was 1,100 ml/m2 body surface area. The next morning, the 4-h dwell was drained, and Dianeal 2.5% was infused. Three dialysate samples at 0, 2, and 4 h were obtained. A single blood sample was obtained at 120 min. Creatinine D/P and glucose D/D0 ratios were calculated at hours 0, 2, and 4. Patients were categorized as low, low average, high average, or high transporters according creat D/P and gluc D/D0 results. Pearson and Kappa test were used for numerical and categorical correlations, respectively, and p<0.05 was considered significant. Eighty-seven PET studies were evaluated in 74 patients, 33 males, age 11.1+/-5.05 years old. A positive linear correlation of 92% between 2 and 4-h creat D/P and 80% between 2 and 4-h gluc D/D0 (p<0.001) was founded. The Kappa test showed a significant concordance between creat D/P and gluc D/D0 categories at 2 and 4 h (p<0.001). When analyzing cut-off-value categories, creat D/P was founded to be lower and gluc D/D0 higher than other experiences. This multicentric prospective study strongly suggests that PET obtained at 2 h and 4 h, based on either creatinine or glucose transport, provides identical characterization of peritoneal membrane transport capacity in PD children.