Usefulness of basic renal function tests in the management of hydronephrosis. / Utilidad de las pruebas básicas de función renal en el manejo de la hidronefrosis.

OBJECTIVE: Nowadays, the algorithms for the study of hydronephrosis in children include voiding cystourethrogram (VCUG) and diuretic renogram (DR) in all patients. Both are invasive, distressing, and associated with radiation risk. However, basic renal function tests (bRFTs) are not included. This study was designed to determine whether bRFTs may help avoid VCUG and/or DR in some children. METHODS: Retrospective review of hydronephrosis (≥20 mm renal pelvis) patient records over one year (n = 38) (pyeloureteral stenosis (PUS) n = 12; high-grade vesicoureteral reflux (VUR) n = 8; non-obstructive hydronephrosis (NOH) n = 18. Data from the three protocolized bRFTs (maximum urine osmolality after DDAVP (UOsm), albumin/creatinine ratio (Alb/Cr), and NAG/creatinine ratio (NAG/Cr), together with VCUG and DR, were analyzed. RESULTS: 38 hydronephrosis patients (pyeloureteral stenosis (PUS) n = 12; high grade vesicoureteral reflux (VUR) n = 8; non-obstructive hydronephrosis (NOH) n = 18. UOsm was decreased in 100% of VUR patients, 75% of PUS patients, and 16.7% of NOH patients. Alb/Cr ratio was increased in 62.5% of VUR patients, 8.3% of PUS patients, and 11.1% of NOH patients. NAG/Cr ratio was increased in 42.8% of VUR patients, 25% of PUS patients, and 6.7% of NOH patients. UOsm was decreased in most patients who required surgery (100% of VUR patients and 74% of PUS patients), but only in 11.1% of patients who did not (NOH group). CONCLUSIONS: These results suggest that bRFTs may be useful in delaying or avoiding VCUG in some hydronephrosis cases. UOsm is the most sensitive test. No child with (high grade) VUR had a normal UOsm. VCUG could have been avoided in 43% of our patients -with a normal UOsm- without missing any high grade VUR.

OBJETIVO: Actualmente, los algoritmos para estudiar hidronefrosis en niños, incluyen realizar cistografía miccional (CUMS) y renograma diurético (RD) a todos. Ambos son invasivos, molestos, y con riesgo de radiación. Contrariamente, las pruebas básicas de función renal (PFRb), no están incluidas. Este estudio se realizó para saber si las PFRb, pueden ayudarnos a evitar alguna CUMS y/o RD. METODOS: Análisis retrospectivo de todas las historias de niños con hidronefrosis (pelvis renal ≥20 mm) atendidos durante un año (n=38), [estenosis pieloureteral (EPU) n = 12; reflujo vesicoureteral (RVU) de alto grado n = 8; hidronefrosis no obstructiva (HNO) n = 18]. Analizamos las tres PFRb protocolizadas [osmolalidad urinaria máxima tras DDAVP (UOsm), albúmina/creatinina (Alb/Cr) y NAG/creatinina (NAG/Cr)], junto con CUMS y RD. RESULTADOS: UOsm estaba disminuida en 100% RVU, 75% EPU, 16,7% HNO. Alb/Cr estaba aumentado en 62,5% RVU, 8,3% EPU, 11,1% HNO. NAG/Cr estaba aumentado en 42,8% RVU, 25% EPU, 6,7% HNO. En relación a la necesidad de cirugía, UOsm estaba disminuida en la mayoría de pacientes intervenidos (100% con RVU y 74% con EPU), mientras solo en el 11% de pacientes sin cirugía (HNO). CONCLUSION: Estos resultados sugieren que las PFRb pueden ser útiles para retrasar o evitar CUMS en algunos niños con hidronefrosis. La UOsm es la PFRb más sensible. Ningún niño con RVU (de alto grado) mostró una UOsm normal. Se podrían haber evitado CUMS en el 43% de nuestros pacientes, con UOsm normal, sin haber perdido ningún diagnóstico de VUR (de alto grado).

Urinary Clara Cell Protein in Kidney Transplant Patients: A Preliminary Study.

OBJECTIVE: The aim of this exploratory study was to analyze the urinary excretion of Clara cell protein (CC16), a new marker of proximal tubular dysfunction (PTD), in kidney transplantation (KT). MATERIALS AND METHODS: Urinary concentrations of CC16, ß2-microglobulin (ß2m), and N-acetyl-glucosaminidase (NAG) were measured in 50 KT patients (72% men; mean age 50.4 ± 12.4 years; diabetes in 24%; duration of KT 4.3 ± 3.1 years) and 10 healthy controls (6 men; mean age 33.6 ± 13.4 years). RESULTS: Urinary levels of ß2m, NAG, and CC16 were significantly higher in KT patients than in controls: ß2m: 0.77 (interquartile range [IQ] 0.22 to 4.62) g/g vs 0.069 (IQ 0.05 to 0.10) g/g; NAG: 3.16 (IQ 2.09 to 5.33) U/g vs 1.73 (IQ 1.25 to 2.07) U/g; CC16: 26.01 (IQ 8.62 to 123.3) g/g vs 2.51 (IQ 0.83 to 7.18) g/g (P < .001). Elevated levels of ß2m, NAG, and CC16 were found in 81%, 28%, and 71% of KT patients, respectively. Urinary levels of ß2m, NAG, and CC16 significantly increase as glomerular filtration rate (GFR) decreases. Interestingly, in patients with GFR >60 mL/min, we still found high levels of ß2m, NAG, and CC16 in 77%, 13%, and 52%, respectively. Diabetic subjects had significant higher levels of the 3 markers compared with nondiabetic subjects, without differences in albumin excretion or GFR. CC16 showed a positive correlation with urinary albumin (r = 0.42, P < .001), NAG (r = 0.352, P < .05), and ß2m (r = 0.75, P < .001). CONCLUSION: PTD is highly prevalent in KT patients. This is the first study that analyzes CC16 in KT patients, showing that the urinary excretion of this protein is significantly increased in this population. Further studies are needed to examine the clinical value of CC16 in KT patients.

[The way we were. On the centenary of the first Spanish Congress of Paediatrics in Palma de Mallorca (1914-2014)]. / Tal como éramos. En el centenario del Primer Congreso Español de Pediatría de Palma de Mallorca (1914-2014).

Between the 19th and 25th April 1914, the First Spanish Congress of Paediatrics was held in Palma de Mallorca under the slogan "Protect the Children". The specialty had broken away a few years earlier from its secular connection with Obstetrics and Gynaecology, both in its teaching aspect as well as regarding healthcare. With the newly created Chairs in Childhood Diseases, in a way this Congress meant the coming-of age and debut int society of paediatrics in our country. Prof. Martínez Vargas, a university professor in Barcelona, was the Chairman, and soul of the congress. There was a need to face a very high rate of infant mortality. The Congress responded to that social and sanitary/health demand with the participation of over three hundred pediatricians, including foreign representatives from Belgium, France, Russia and Latin America. The activities were divided into four sections: Childcare, Child Medicine, Surgery and Health, and accredited lecturers gave master classes on the most pressing issues of child pathology of the time. One hundred years on, what we are today is the fruit gathered by those who preceded us. Some were brilliant figures in paediatrics and others, the majority, anonymous paediatricians. They dedicated their lives, their science and their best smile to child care. The way we were and the way we are. With legitimate pride and satisfaction, it is an honour for the Group on the History of Paediatrics and AEP Documentation to celebrate this centennial commemoration in the framework of the Annals of Paediatrics.

[Consensus document: recommendations for the use of equations to estimate glomerular filtration rate in children]. / Documento de consenso: recomendaciones sobre la utilización de ecuaciones para la estimación del filtrado glomerular en niños.

The appearance of the K/DOQI guidelines in 2002 on the definition, evaluation and staging of chronic kidney disease (CKD) have led to a major change in how to assess renal function in adults and children. These guidelines, recently updated, recommended that the study of renal function is based, not only on measuring the serum creatinine concentration, but this must be accompanied by the estimation of glomerular filtration rate (GFR) obtained by an equation. However, the implementation of this recommendation in the clinical laboratory reports in the paediatric population has been negligible. Numerous studies have appeared in recent years on the importance of screening and monitoring of patients with CKD, the emergence of new equations for estimating GFR, and advances in clinical laboratories regarding the methods for measuring plasma creatinine and cystatin C, determined by the collaboration between the departments of paediatrics and clinical laboratories to establish recommendations based on the best scientific evidence on the use of equations to estimate GFR in this population. The purpose of this document is to provide recommendations on the evaluation of renal function and the use of equations to estimate GFR in children from birth to 18 years of age. The recipients of these recommendations are paediatricians, nephrologists, clinical biochemistry, clinical analysts, and all health professionals involved in the study and evaluation of renal function in this group of patients.

[Malformation syndromes in the spanish literature: The first descriptions]. / Bibliografía española de algunos síndromes malformativos. Las primeras descripciones.

INTRODUCTION: Malformation or dysmorphic syndromes are conditions that are defined by the combination of a set of major and minor malformations that generally have a genetic origin. We investigated the early Spanish descriptions of a large number of sydromes. MATERIAL AND METHODS: We started the study from the definition in a classic treatise on the subject. Among the 60 selected syndromes studied, at least two articles of each syndrome among those published in Spain and for the first time were listed in the Spanish Medical Index. For years prior to 1970, it expanded The search was expanded to PubMed, for the years before 1970. RESULTS: We collected 64 articles that referred to 58 syndromes. Four articles were written during the first half of the twentieth century. Almost half of the works (n=30) appeared in the 1970's. The papers were published in ten Spanish pediatric, nine Spanish non-pediatric, three pediatric non-Spanish and two non-Spanish non-pediatric Journals. The Journals with the most articles published were Anales de Pediatría y Revista Española de Pediatría. The hospitals where the articles originate more often were Hospital La Paz, Madrid and Hospital Clinic, Barcelona. The rest of the works were written in 30 pediatric hospitals and two more in non-Spanish hospitals. The number of authors increased with the passage of time. CONCLUSIONS: Although there were potential limitations, we have identified what may be the first descriptions of 58 syndromes, among the 60 chosen initially.

[Should a cystography be performed on all breastfeeding infants with mild to moderate dilatation of the urinary tract? Renal function tests can help to answer this question]. / ¿Debe realizarse una cistografía a todos los lactantes con dilatación leve y moderada de las vías urinarias? Las pruebas de función renal pueden ayudar a responder a esta pregunta.

INTRODUCTION: Pyelectasis can be defined as mild to moderate dilatation of the urinary tract and is diagnosed by means of an ultrasound scan (0.5-2cm transverse diameter in the initial ultrasound performed after birth). There is some disagreement about whether cystography should be indicated as standard practice. The aim of this study was to establish if renal function tests are useful in determining which cases of mild to moderate dilatation of the urinary tract do not require an initial cystography. PATIENTS AND METHODS: The study was conducted on 79 infants (57 males, 22 females) with pyelectasis. Seventy-three were diagnosed in utero and 6 after birth. All infants underwent at least one cystography and one desmopressin urine concentration test before one year of age. RESULTS: Compared to infants without vesicoureteral reflux (VUR) (n=68), infants with VUR (n=11; two with Grade I, three with Grade II, five with Grade III, two with Grade IV) showed a significantly lower (P=.006) maximum urine osmolality and a significantly higher microalbumin/creatinine ratio (P<.001) and NAG/creatinine ratio (P=.003). The negative predictive value of the first two tests was 93%. Sensitivity of the maximum urine osmolality to detect VUR was 72.7% (specificity 63.2%). Sensitivity of the microalbumin/creatinine ratio to detect VUR was 62.5% (specificity 75%). The positive probability ratio (PR) was 1.29 for the NAG/creatinine ratio, 2.03 for the maximum urine osmolality and 2.5 for the microalbumin/creatinine ratio. The negative PR was 0.95 for the NAG/creatinine ratio, 0.43 for the maximum urine osmolality and 0.5 for the microalbumin/creatinine ratio. CONCLUSIONS: Pyelectasis is a benign condition. Only 2 patients required pharmacological intervention (prophylactic treatment for VUR Grade IV patients). Initially at least, cystography should not be indicated in cases of microalbuminuria and/or normal urine concentrations.

Hypouricemia and tubular transport of uric acid.

Hypouricemia is defined when a serum urate concentration is less than or equal 2.0mg/dl. Differential diagnosis is made by fractional uric acid excretion with the identification of urate transporters and intracellular proteins involved in the tubular transport of uric acid. This review examines current knowledge on uric acid tubular transport and the various clinical situations of hypouricemia.

[Are simple renal cysts another manifestation of prelithiasis in infancy?]. / ¿Los quistes renales simples son otra forma de manifestación de prelitiasis en la infancia?

Simple renal cysts are uncommon lesions in paediatric patients. In the absence of hypokalaemia or an increase in the production of NH+, the cause of simple renal cysts is unknown. Hepler, in 1930, suggested that they may be caused by a tubular obstruction. We prospectively studied the presence of hypercalciuria or hypocitraturia as well as the family history of urolithiasis in a group of children diagnosed sonographically with simple renal cysts. The average age of the 22 patients (12M, 10F) was 6.04 +/- 2.9 years at the time of diagnosis. The ultrasound examination had been requested due to urinary tract infection, abdominal pain, haematuria or other disorders. The cysts were slightly more frequent on the left side (54.5%). All were located in the upper kidney pole. 14 patients were found to have hypercalciuria and/or hypocitraturia (hypercalciuria n = 11, 50%). Thirteen families had history of renal stones. The metabolic abnormalities associated with calculi in children and/or family history of stones were present in 19 families (86.3%). Our hypothesis is that both entities, renal cysts, and genetic predisposition to kidney stones, are related.

[Infant metabolic alkalosis of dietetic origin]. / Alcalosis metabólica de origen dietético en un lactante.

Cases of metabolic alkalosis are divided into susceptible or resistant to treatment with sodium chloride, depending on the response to it. The resistant cases present with high urinary excretion of chloride, and are secondary to tubular disease or use of diuretics. Included among the sensitive cases are, vomiting, cystic fibrosis and low intake. Two infants were fed with "almond milk" and showed clinical symptoms of dehydration and failure to thrive. Hypochloraemic and hypokalaemic metabolic alkasosis was seen in both cases, which responded satisfactorily to water and electrolyte replacement. After ruling out vomiting, ingestion of drugs, tubular disease, and cystic fibrosis, the diagnosis was low intake, due to poor contribution of Na+ and Cl(-) provided by the "almond milk". This deficit induces an increase in proximal tubular reabsorption of H(-)CO3 and in parts of the distal nephron, an increase in reabsorption of Na+ and Cl(-) which are exchanged with K+ and H+, which can give rise to a hypochloraemic alkalosis and hypokalaemia. Secondary hypothyroidism was found in one case, apparently due to the lack of iodine in the almond milk, and disorders of the myelination characterized by optic neuritis and hearing loss. These disorders were resolved when feeding with human formula was established.

[Celebrating fifty years of percutaneous renal biopsies in Spain]. / En el cincuentenario de las primeras biopsias renales percutáneas realizadas en España.

The first renal biopsies, made as much in adults as in children, were surgical. They were made to patients who were under renal decapsulation with the intention to reduce the kidney pressure, especially in cases of nephrotic syndrome. In 1944, Nils Alwall initiated the accomplishment of percutaneous kidney biopsies by means of a needle and aspiration at the University of Lund (Sweden), although his experience was published in 1952. The first article that had by subject the practice of a percutaneous renal biopsy was written in 1950 by a Cuban doctor, Antonino Pérez Ara, and published in a local journal with little diffusion. The first work that appeared in a Spanish journal (1953) about the practice of the percutaneus renal biopsies was not signed by any Spanish group but by members of the Hospital "Calixto García" of the University of The Havana, Cuba. The first article published in Spain regarding to this subject, saw the light in 1958, now 50 years ago, in the Revista Clínica Española. The two first signers were Alfonso de la Peña Pineda and Vicente Gilsanz García, professors of the Medicine Faculty of Madrid. Later, the practice of the percutaneous renal biopsy became general in other Spanish hospitals.

[Multicystic kidney disease in a segment of horseshoe kidney: an uncommon combination of malformations]. / Displasia renal multiquística en un segmento de un riñón ''en herradura'': una asociación de malformaciones poco usual.

Multicystic dysplasia is the most common type of renal cystic disease, and it is one of the most common causes of an abdominal mass in infants. The contralateral system is also frequently abnormal. The most commonly associated anomalies are contralateral ureteropelvic junction obstruction and contralateral vesicoureteral reflux. In a few cases, multicystic dysplasia involves a horseshoe kidney or one pole of a duplex kidney. We present a female patient diagnosed with this condition at 9 years old, when she was being studied due to recurrent abdominal pain. The renal function was normal.

[Reduced nocturnal systolic blood pressure dip in obese children]. / Pérdida de la reducción de la presión arterial sistólica nocturna en el niño obeso.

UNLABELLED: Ambulatory blood pressure monitoring (ABPM) allows evaluation not only of casual daytime elevations of blood pressure (BP) but also alterations in the 24-hour circadian patterns of BP. The aim of the present study was to assess 24-hour BP patterns in a population of obese children who were referred to our outpatient clinic, in relation to the degree of obesity, body fat distribution and insulin resistance, and considering other cardiovascular risk factors. METHODS: Office and ambulatory BP measurements, and fasting serum glucose, insulin and HOMA determinations were obtained in 119 obese children (7-15 years old). Urinary albumin excretion was measured in the first morning urine. The extend of obesity was quantified using body mass index z score adjusted by age and gender. RESULTS: The prevalence of office hypertension in only one set of blood pressure measurements was 47%. This value was not confirmed on further separate occasions. The prevalence of global ambulatory hypertension was 36%. Diurnal systolic hypertension was found in 14%, while 39 patients (33%) had nocturnal systolic hypertension. Twenty five of them (64%) were only hypertensive at nightime and the rest (n = 14), were also hypertensive during the day. Only 4 patients were exclusively systolic hypertensive at daytime (table III). None of the patients were exclusively diastolic at day or nighttime. Of the total 119 subjects 47% non systolic dippers. This abnormal BP pattern was associated with the degree of obesity (p < 0.001) and insulinresistance (HOMA values; p < 0.001). The anthropometric and metabolic characteristics of the population studied are shown in table I and II respectively. The correlations coefficients and regression analysis between anthropometric and metabolic parameters are shown in table IV and V. CONCLUSION: Reduced nocturnal systolic blood pressure dip and nightime systolic hypertension were the most frequent forms of hypertension in our cohort of severe obese children. These alterations in the 24-hour circadian patterns of BP were related to the degree of obesity and insulin resistance.

[Psychopathology associated with idiopathic nephrotic syndrome in the pediatric age group]. / Psicopatología del síndrome nefrótico idiopático en la edad pediátrica.

AIM: To analyze the influence of several variables in the genesis of psychological morbidity in children with idiopathic nephrotic syndrome (INS) as compared with healthy controls. METHODS: The Strengths and Difficulties Questionnaire (SDQ) was administered to children with INS (n = 23) and a control group of healthy children (n = 38). The SDQ is a well-known screening instrument for psychological/psychiatric morbidity in childhood. The questionnaire consists of five scales that evaluate emotional symptoms, behavioral problems, hyperactivity, peer problems and prosocial behavior. The total score is calculated by adding all the subscales except the prosocial behavior scale. In children with INS, type of treatment, sex, steroid dose, disease stage, disease duration, and prognosis (number of relapses/disease stage) were also noted. RESULTS: Statistically significant differences were found in two of the scales (emotional symptoms and peer problems), as well as in the total score in children with INS as compared with the control group (p < 0.05). A positive correlation was found between disease duration and total score in the INS group. CONCLUSIONS: Emotional and behavioral problems were more frequent in children with INS. The only variable related to the severity of the symptoms studied in these children was disease duration.

[Inhaled corticosteroid therapy and bone metabolism in asthmatic children]. / Glucocorticoides inhalados y metabolismo óseo en niños asmáticos.

OBJECTIVE: To explore the association between inhaled corticosteroids (ICS) therapy and bone metabolism. PATIENTS AND METHODS: The sample was composed of 151 children, aged between 1 and 17 years. There were 71 asthmatics treated with ICS for at least 6 months (group 1), 44 asthmatics treated occasionally with ICS during exacerbations (group 2), and 36 healthy children (group 3). Bone mineral density (BMD) and markers of bone formation and resorption were measured. These measures, as well as other related factors, were compared among groups. Regression models for osteopenia and BMD were used with the group as the independent variable adjusted by factors with differences between groups. A two-tailed level of p < 0.05 was used in all tests. RESULTS: No differences in BMD were found between groups 1 and 2 but significant differences were found between groups 1 and 3 (p = 0.003). No differences were found in markers of bone formation and resorption among the groups. No association was found between BMD and the type, daily dose or accumulated dose of ICS. Group 1 showed an osteopenia odds ratio relative to group 3 of 2.94 (95 % CI: 1.49-5.78) and an average reduction of BMD of 0.50 (95 % CI: 0.32-0.68) was found from group 3 to 2 and from group 2 to 1. In group 1, markers of bone resorption significantly increased in asthmatics with osteopenia compared with those without osteopenia. CONCLUSIONS: ICS treatment in asthmatic children seems to affect BMD. Markers of bone formation and resorption are unaffected. Osteopenia in these children could also be related to other factors that increase bone resorption.

Molecular analysis of the CLCN5 gene in Dent's disease: first mutation identified in a patient from South America.

BACKGROUND: Dent's disease is a rare renal tubular disorder characterized by low-molecular weight proteinuria, hypercalciuria, nephrocalcinosis, nephrolithiasis, rickets and eventual renal failure. The selective loss of low-molecular weight proteins points to a defect of the proximal tubule, where filtered proteins are normally reabsorbed by endocytosis. The disease tends to present in childhood or early adult life, and males are more severely affected than females. The disease is caused by mutations in CLCN5 or OCRL1, both on the X chromosome, which code for the chloride/proton exchange transporter ClC-5 and the phosphatidylinositol-4,5-biphosphate-5-phosphatase, respectively. METHODS: Mutational analysis of CLCN5 gene from 4 unrelated patients diagnosed with Dent's disease and their relatives, 3 from Spain and 1 from Bolivia, was performed by PCR and automatic DNA sequencing. RESULTS: In the current study, we report the identification of 4 mutations in CLCN5 of 1 family from Bolivia and 3 families from Spain. Two of the mutations are novel and consist of 1 nonsense mutation, Y502X, and 1 missense mutation, L225P, affecting ClC-5alpha-helix F, one of the helices involved in formation of the chloride selectivity filter. CONCLUSIONS: Our results add to the expanding spectrum of mutations in CLCN5. This is the first report of a CLCN5 mutation in a Dent's disease patient of South American origin.