Risk factors for recurrence in pediatric urinary stone disease.

BACKGROUND: Children's urinary system stones may develop from environmental, metabolic, anatomical, and other causes. Our objective is to determine the recurrence and prognosis, demographic, clinical, and etiological characteristics of children with urolithiasis. METHODS: Medical records of patients were evaluated retrospectively. Patients' demographic data and medical history, serum/urine biochemical and metabolic analysis, blood gas analysis, stone analysis, imaging findings, and medical/surgical treatments were recorded. RESULTS: The study included 364 patients (male 187). Median age at diagnosis was 2.83 (IQR 0.83-8.08) years. The most common complaints were urinary tract infection (23%) and urine discoloration (12%). Sixty-two percent had a family history of stone disease. At least one metabolic disorder was found in 120 (88%) of 137 patients having all metabolic analyses: hypercalciuria was found in 45%, hypocitraturia in 39%, and hyperoxaluria in 37%. Anatomical abnormalities were detected in 18% of patients. Of 58 stones analyzed, 65.5% were calcium and 20.6% were cystine stones. Stone recurrence rate was 15% (55/364). Older age (> 5 years), family history of stone disease, stone size (≥ 5 mm), and urinary system anatomical abnormalities were significantly associated with stone recurrence (p = 0.027, p = 0.031, p < 0.001, and p < 0.001, respectively). In adjusted logistic regression analysis, stone size ≥ 5 mm (OR 4.85, 95% CI 2.53-9.3), presence of urinary system anatomical abnormalities (OR 2.89, 95% CI 1.44-5.78), and family history of stone disease (OR 2.41, 95% CI 1.19-4.86) had increased recurrence rate. CONCLUSIONS: All children with urolithiasis should be evaluated for factors affecting stone recurrence. Children at higher risk of recurrence need to be followed carefully.

Litiasis renal en niños / Renal lithiasis in children

Resumen Justificación y objetivo: La litiasis renal se debe a la precipitación de cristales por un desequilibrio en la orina entre sustancias promotoras y las sustancias inhibitorias. Es una patología con una prevalencia entre 2-10% en la población pediátrica, con una incidencia que ha aumentado en los últimos 25 años; razón por la cual este estudio pretende conocer la prevalencia, las manifestaciones clínicas y metabólicas de la litiasis renal en la población pediátrica del Hospital Nacional de Niños de Costa Rica. Métodos: Es un estudio retrospectivo, descriptivo y observacional, mediante la revisión de expedientes de pacientes menores a 18 años con el diagnóstico de litiasis renal, atendidos en el Hospital Nacional de Niños, en el periodo comprendido entre enero del año 2000 al 2018. Resultados: Se incluyeron un total de 106 pacientes. El 57,5% hombres, la edad promedio al diagnóstico de 6,6 ± 3,8 años; la frecuencia de casos se ha incrementado en 5,5 veces en los últimos 5 años. Factores de riesgo detectados: anormalidades del tracto urinario 22,6% y antecedentes familiares de litiasis 17,9%. El análisis metabólico mostró un gasto urinario bajo en el 74,3%, hiperfosfaturia en un 43,2%, hipomagnesuria 39,2% e hipercalciuria 37,8%. Etiologías determinadas: metabólica 54,7%, malformaciones de las vías urinarias 16% e idiopática en un 30,9%. La litotricia intracorpórea se aplicó en un 61,2%. La recidiva se observó en el 28,5% de los casos, se encontró relación entre la incidencia de recidiva con el tamaño del lito (p = 0,001) y el tratamiento quirúrgico. (p = 0,010). Conclusiones: Existe un aumento en la frecuencia de casos de litiasis pediátrica con una etiología multifactorial en el Hospital Nacional de Niños de Costa Rica.

Abstract Background and aim: Renal lithiasis is due to the precipitation of crystals due to an imbalance in the urine between promoter substances and inhibitory substances. It is a pathology with a prevalence between 2-10% in the pediatric population, with an incidence that is increasing in the last 25 years, because of that, this study pretend to know the prevalence, the clinical and metabolic, manifestation of the renal lithiasis in the pediatric population. Methods: It is a retrospective, descriptive and observational study, by reviewing records of patients under 18 years of age with a diagnosis of renal lithiasis, treated at the Hospital Nacional de Niños, in the period of 2000 to 2018. Results: A total of 106 patients were included, 57,5% men, the average age at diagnosis of 6,6+- 3,8 years, the frequency of cases has increased 5,5 times in the last 5 years. Risk factors detected: urinary trac abnormalities 22,6% and family history of nephrolithiasis 17,9%. The metabolic analysis showed a low urinary flow rate in 74,3%, hyperphosphaturia in 43,2%, hypomagnesuria 39,2% and hypercalciuria 37,8%. Etiologies determined: metabolic 54,7%, malformations of the urinary trac 16% and idiopathic in 30,9%. Intracorporeal lithotripsy was applied in 61,2%. Recurrence was observe in 28,5 % of cases, a relationship was found between the incidence of recurrence with the size of litho (p= 0.001) and surgical treatment (p= 0.01). Conclusions: There is a significant increase in the incidence of pediatric lithiasis cases with a multifactorial etiology.

A survey of hypercalciuria during chemotherapy in acute lymphoblastic leukemia.

BACKGROUND: Urolithiasis is an extremely rare complication in childhood acute lymphoblastic leukemia (ALL), and some reports have implicated corticosteroids during chemotherapy as a risk factor for it. However, only a few reports have analyzed urinary electrolytes in this context. METHODS: We retrospectively analyzed 55 patients with ALL who underwent chemotherapy between October 2007 and January 2019. Their median age was 9.3 years (range, 0.3-24.0 years) with 30 males and 25 females. Lineages were B-cell precursor ALL (BCP-ALL) in 42 patients, T-cell in nine and others in four patients. All patients received chemotherapy based on the Berlin-Frankfurt-Münster regimen. RESULTS: Forty-nine out of the 55 ALL patients exhibited hypercalciuria at least once during chemotherapy. Moreover, 36 patients with BCP-ALL, who were receiving identical Berlin-Frankfurt-Münster-based regimens, exhibited significantly high urinary calcium excretion immediately following high-dose glucocorticoid administration. Among the 55 ALL patients, urolithiasis was observed in one patient, a 6-year-old boy with BCP-ALL who developed urolithiasis at reinduction chemotherapy just after cessation of high-dose dexamethasone administration. CONCLUSIONS: Nearly 90% of the ALL patients studied developed hypercalciuria during chemotherapy in strong association with corticosteroid administration.

Aspectos clínicos, epidemiológicos y terapéuticos en niños y adolescentes con hipercalciuria idiopática / Clinical, epidemiological and therapeutic aspects in children and adolescents with idiopathic hypercalciuria

Introducción: La hipercalciuria idiopática es un trastorno metabólico frecuente y poco reconocido, cuyo curso clínico depende en gran medida de cambios en los hábitos dietéticos desde la infancia. Objetivo: Caracterizar a niños y adolescentes con hipercalciuria idiopática según variables clínicas, epidemiológicas y terapéuticas. Métodos: Se realizó una investigación observacional, longitudinal y prospectiva de 44 pacientes con hipercalciuria idiopática, atendidos en el Servicio de Miscelánea del Hospital Pediátrico Docente Sur Antonio María Béguez César de Santiago de Cuba, desde enero de 2014 hasta diciembre de 2015. Resultados: Las formas sintomáticas de la enfermedad resultaron ser las más frecuentes (68,2 %); asimismo, predominó el sexo masculino (72,7 %) y el promedio de edad fue de 7,2 ± 4 años. Existió asociación estadística entre las edades preescolar y escolar en cuanto al diagnóstico de hipercalciuria idiopática. La hematuria macroscópica recurrente fue el síntoma más usual en la mayoría de los casos (59,1 %); en tanto, 25,0 % de los pacientes presentó litiasis renal y el tratamiento no farmacológico a base de líquidos y dieta se relacionó con una evolución satisfactoria en 68,2 % de los afectados, a pesar de que el restante 31,8 % necesitó tratamiento medicamentoso. Conclusiones: Las características clínicas y epidemiológicas de los pacientes con hipercalciuria idiopática de esta casuística no difirieron de las registradas a nivel mundial, considerando que este trastorno metabólico es relativamente frecuente en los servicios de pediatría.

Introduction: The idiopathic hypercalciuria is a frequent and not very recognized metabolic disorder which clinical course depends in great extent on changes in the dietary habits from the childhood. Objective: To characterize children and adolescents with idiopathic hypercalciuria according to the clinical, epidemiological and therapeutic variables. Methods: An observational, longitudinal and prospective investigation was carried out in 44 patients with idiopathic hypercalciuria, assisted in the Miscellaneous Service of Antonio María Béguez Cesar Southern Teaching Children Hospital in Santiago de Cuba, from January, 2014 to December, 2015. Results: The symptomatic forms of the disease were the most frequent (68.2 %); also, the male sex prevailed (72.7 %) and the average age was 7.2 ± 4 years. Statistical association existed among the preschool and school ages as for the diagnosis of idiopathic hypercalciuria. The recurrent macroscopic hematuria was the most usual symptom in the majority of cases (59.1 %); as long as, the 25.0 % of patients presented renal lithiasis and the diet and liquids-based non pharmacological treatment was associated with a satisfactory evolution in 68.2 % of the affected patients, although the remaining 31.8 % needed drugs treatment. Conclusions: The clinical and epidemiological characteristics of patients with idiopathic hypercalciuria of this case material didn't differ from the ones registered worldwide, taking into account that this metabolic disorder is relatively frequent in pediatric services.

Predictive and prognostic value of magnesium serum level in FOLFIRI plus cetuximab or bevacizumab treated patients with stage IV colorectal cancer: results from the FIRE-3 (AIO KRK-0306) study.

Magnesium wasting is a frequent side effect of epidermal growth factor receptor (EGFR)-antibody treatment as magnesium-absorption mechanisms are dependent on EGFR signaling. EGFR-inhibition results in decreased renal reabsorption. There is evidence that hypomagnesemia during cetuximab treatment correlates with response. The prognostic role of hypomagnesemia during bevacizumab treatment has not been studied yet. Here, we evaluate the prognostic value of hypomagnesemia in patients with metastatic colorectal cancer treated with FOLFIRI plus cetuximab or bevacizumab as first-line therapy. A total of 391 of 752 patients of the firstline irinotecan study population had magnesium levels measured at baseline and for the first three cycles (6 weeks) of treatment. Of those, 240 had Rat Sarkoma wildtype tumors. Overall hypomagnesemia was more common in the cetuximab compared to the bevacizumab arm (80 vs. 43%, P < 0.005). During therapy, magnesium showed a time-dependent decrease to 80% of baseline in the cetuximab and to 89% in the bevacizumab arm. Whereas magnesium continued to decrease over time in the cetuximab-treated patients, it remained stable in the bevacizumab-treated. Overall response rate (ORR) was associated with higher magnesium at week 6 (20.9 vs. 79.1%, P = 0.041). Bevacizumab-treated patients with magnesium levels below the median value at week 6 had a significantly longer progression-free survival (PFS; 11.7 vs. 9.9 months, P = 0.034; hazard ratio 0.73) and a trend towards longer overall survival (OS) (29.6 vs. 23.2 months, P = 0.089; hazard ratio 0.77). Hypomagnesemia at predefined time points and magnesium nadir had no significant effect on ORR, OS and PFS in the cetuximab arm. Our data show different magnesium kinetics in patients with metastatic colorectal cancer treated with cetuximab or bevacizumab. For patients treated with cetuximab, hypomagnesemia did not have an impact on response and survival. Hypomagnesemia might have a prognostic value in bevacizumab treatment.

Autosomal dominant hypocalcaemia: identification of two novel variants of CASR gene.

Autosomal dominant hypocalcaemia is a rare aetiology of hypocalcaemia, caused by gain-of-function mutations of the calcium-sensing receptor (CASR) gene. We present two cases of two asymptomatic women (50-year-old-case 1 and 25-year-old-case 2), referred to our endocrinology department for investigation of hypocalcaemia, hyperphosphatemia and inappropriately low parathormone. Both patients had relatives with the same laboratorial findings. At diagnosis, both patients presented basal ganglia calcifications. Genetic analysis was performed, identifying two novel heterozygous CASR variants: c.2269G>A (p.Glu757Lys) and c.2086C>G (p.Leu696Val), respectively, for case 1 and case 2. Affected individuals started oral calcium and vitamin D analogues, aiming to a low-normal calcium level. They remain under observation and are asymptomatic.

Renal manifestations of sarcoidosis: from accurate diagnosis to specific treatment

ABSTRACT Sarcoidosis is a multisystem granulomatous disease characterized by epithelioid noncaseating granulomas associated with clinical and radiologic findings. The cause of this disease is still uncertain. Sarcoidosis affects mostly lungs and lymph nodes and is not usually considered a urological disease, therefore, this etiology may be overlooked in several urological disorders, such as hypercalcemia, hypercalciuria and nephrolithiasis. It affects all races and genders. This review aims to describe the urological manifestations of sarcoidosis and to elucidate how the disease may affect the management of numerous urological conditions.

Educational review: role of the pediatric nephrologists in the work-up and management of kidney stones.

BACKGROUND: The incidence of nephrolithiasis in children and adolescents is increasing and appears to double every 10 years. The most important role of the pediatric nephrologist is to diagnose and modify various metabolic and non-metabolic risk factors, as well as prevent long-term complications especially in the case of recurrent nephrolithiasis. OBJECTIVE: The purpose of this review is to summarize the existing literature on the etiology and management of pediatric nephrolithiasis. RESULTS: The incidence of kidney stones is increasing; dietary and environmental factors are probably the main causes for this increased incidence. In most pediatric patients, the etiology for the kidney stones can be identified. Metabolic factors, such as hypercalciuria and hypocitraturia, urinary tract infection, and urinary stasis, constitute leading causes. Herein, we review the etiologies, diagnostic work-up, and treatment options for the most prevalent causes of kidney stones. The detrimental effects of excessive dietary sodium, reduced fluid intake, and the benefits of plant-based over animal-based protein consumption on urinary crystal formation are discussed. We also review the long-term complications. CONCLUSIONS: Pediatric nephrologists have an important role in the diagnostic work-up and prevention of recurring nephrolithiasis.

Renal manifestations of sarcoidosis: from accurate diagnosis to specific treatment.

Sarcoidosis is a multisystem granulomatous disease characterized by epithelioid noncaseating granulomas associated with clinical and radiologic findings. The cause of this disease is still uncertain. Sarcoidosis affects mostly lungs and lymph nodes and is not usually considered a urological disease, therefore, this etiology may be overlooked in several urological disorders, such as hypercalcemia, hypercalciuria and nephrolithiasis. It affects all races and genders. This review aims to describe the urological manifestations of sarcoidosis and to elucidate how the disease may affect the management of numerous urological conditions.

Riñón en esponja y litiasis renal / Sponge kidney and renal lithiasis

Introducción: El riñón en esponja es una malformación renal, de los túbulos colectores, que se suele asociar a nefrocalcinosis o acidosis tubular distal. La asociación con la litiasis renal se observa entre un 4-20%. Objetivo: El objetivo de nuestro trabajo fue describir factores de riesgo bioquímicos para litiasis renales, en pacientes con riñón en esponja. Material y métodos: Se realizó un estudio retrospectivo, observacional de corte, entre los años 2000 y 2017 en donde se estudiaron 37 pacientes con riñón en esponja y litiasis renal (26 mujeres y 11 hombres) de 37.3 ± 13.2 años. El diagnóstico de riñón en esponja se hizo mediante urograma excretor. Resultados: Fue observada nefrocalcinosis en el 95%. El diagnóstico bioquímico más frecuente fue la hipercalciuria idiopática que como única y asociada alteración se observó en el 59.4%. La hiperuricosuria fue el segundo diagnóstico encontrado en el 32.4% (única y asociada) seguido por la, hipocitraturia, hipomagnesuria y el pHu persistentemente ácido. En los hombres llamó la atención que un 46.2% no presentaron alteración bioquímica. Conclusiones: En conclusión se destaca la asociación relativamente frecuente de riñón en esponja y litiasis renal. La hipercalciuria idiopática fue la alteración metabólica más frecuente como causa de litogénesis, seguida por la hiperuricosuria, similar a lo descripto en la literatura, aunque en menor proporción. Otras alteraciones, como la hipocitraturia, hipomagnesuria y pHu persistentemente ácido también deben ser consideradas en el estudio de estos pacientes.

Introduction: Sponge kidney is a renal malformation of the collecting tubules, which is usually associated with nephrocalcinosis or distal tubular acidosis. The association with renal lithiasis is observed between 4-20%. Objective: The aim of our work was to describe the biochemical risk factors of renal lithiasis in patients with sponge kidney. Methods: A retrospective, observational, cross-sectional study was conducted between 2000 and 2017, in which 37 patients with sponge kidney and renal lithiasis (26 women and 11 men), aged 37.3 ± 13.2 years, were studied. The diagnosis of sponge kidney was made by excretory urography. Results: Nephrocalcinosis was observed in 95% of patients. The most frequent biochemical diagnosis was idiopathic hypercalciuria, which was observed, as a single and associated alteration, in 59.4% of cases. Hyperuricosuria was the second diagnosis found in 32.4% (single and associated) followed by hypocitraturia, hypomagnesuria and persistently acid pHu. Surprisingly, 46.2% of men presented no biochemical alteration. Conclusions: Our findings highlight the relatively frequent association of sponge kidney and renal lithiasis. Idiopathic hypercalciuria was the most common metabolic alteration as the cause of lithogenesis, followed by hyperuricosuria, similar to that described in the literature, but to a lesser extent. Other alterations, such as hypocitraturia, hypomagnesuria and persistently acid pHu, should also be considered in the study of these patients.

Urinary abnormalities in children and adolescents with Wilson disease before and during treatment with d-penicillamine.

BACKGROUND AND AIM: Renal abnormalities can occur at any time point during the course of Wilson disease (WD). We aimed to fill a literature gap in this respect by studying urinary abnormalities in children and adolescents with WD. METHODS: This study included 60 children with WD presenting to the Pediatric Hepatology Unit, Cairo University. The following data were retrieved from the patients' files including age, sex, liver function tests, serum ceruloplasmin, 24-h urinary copper, serum creatinine, blood urea nitrogen, urinalysis, urinary albumin/creatinine ratio, urinary calcium/creatinine ratio, urinary ß2-microglobulin, liver and renal biopsy results when available. RESULTS: All studied cases had no symptoms related to renal involvement. Microscopic hematuria was detected in 11% and 12% at baseline and within 5 years of therapy, respectively. Moderate microalbuminuria was detected in 34%, 50%, and 33% at baseline, within 5 years and > 5 years after therapy, respectively. Hypercalciuria was detected in 23% at baseline, 34% in those patients treated for up to 5 years and 37.5% > 5 years of therapy. Age and international normalized ratio were significantly higher in patients with high calcium/creatinine ratio compared with those with normal values at initial evaluation. Frequency of elevated urinary ß2-microglobulin was 36%, 36%, and 37% in patients at baseline, up to 5 years and > 5 years of therapy, respectively. CONCLUSION: Asymptomatic urinary abnormalities are present in patients with WD at any time point of the disease and during treatment with d-penicillamine. They have to be searched for, as early intervention may prevent progression to renal insufficiency.

Hypomagnesaemia is absent in children with autosomal dominant polycystic kidney disease.

BACKGROUND: Hypomagnesaemia is present in 40-50% of children with autosomal dominant renal cysts and diabetes syndrome (RCAD). On the contrary, the prevalence of hypomagnesaemia in children with autosomal dominant polycystic kidney disease (ADPKD) has never been examined. We aimed to investigate whether hypomagnesaemia is present in children with polycystic kidney diseases. METHODS: Children with cystic kidney diseases were investigated in a cross-sectional study. Serum concentrations of magnesium (S-Mg) and fractional excretion of magnesium (FE-Mg) were tested. Fifty-four children with ADPKD ( n = 26), autosomal recessive polycystic kidney disease (ARPKD) ( n = 16) and RCAD ( n = 12) with median age of 11.2 (0.6-18.6) years were investigated. RESULTS: Hypomagnesaemia (S-Mg < 0.7 mmol/L) was detected in none of the children with ADPKD/ARPKD and in eight children (67%) with RCAD. Median S-Mg in children with ADPKD/ARPKD was significantly higher than in children with RCAD (0.89 vs. 0.65 mmol/L, P < 0.01). The FE-Mg was increased in 23% of patients with ADPKD/ARPKD (all had chronic kidney disease stages 2-4) and in 63% of patients with RCAD, where it significantly correlated with estimated glomerular filtration rate (r = -0.87, P < 0.01). CONCLUSIONS: Hypomagnesaemia is absent in children with ADPKD or ARPKD and could serve as a marker for differential diagnostics between ADPKD, ARPKD and RCAD in children with cystic kidney diseases of unknown origin where molecular genetic testing is lacking. However, while hypomagnesaemia, in the absence of diuretics, appears to rule out ADPKD and ARPKD, normomagnesaemia does not rule out RCAD at least in those aged <3 years.

Urinary proteome in inherited nephrolithiasis.

In the last decades, proteomics has been largely applied to the Nephrology field, with the double aim to (1) elucidate the biological processes underlying renal diseases; (2) identify disease-specific biomarkers, predictor factors of therapeutic efficacy and prognostic factors of disease progression. Kidney stone disease, and in particular, inherited nephrolithiasis (INL) are not an exception. Given the multifactorial origin of these disorders, the combination of genomics and proteomics studies may complement each other, with the final objective to give a global and comprehensive mechanistic view. In this review, we summarize the results of recent proteomic studies which have expanded our knowledge about INL, focusing the attention on monogenic forms of nephrolithiasis (cystinuria, Dent's disease, Bartter syndrome, distal renal tubular acidosis and primary hyperoxaluria), on polygenic hypercalciuria and on medullary sponge kidney disease.

Respuesta de la calciuria a suplementos de vitamina D / Calcium response to vitamin D supplementation

Múltiples estudios muestran la importancia de mantener niveles suficientes de vitamina D para prevenir varias enfermedades crónicas. Sin embargo, la suplementación de vitamina D sobre la calciuria es controvertida. El objetivo de este trabajo prospectivo, intervencionista, fue evaluar la respuesta de la calciuria en mujeres con hipercalciuria y normocalciuria, luego de conseguir niveles adecuados de 25 OH D. Se estudiaron 63 mujeres con hipercalciuria idiopática (9 con litiasis renal) y 50 mujeres normocalciúricas. Ambos grupos presentaron déficit/insuficiencia de 25 OH D y fueron suplementadas con vitamina D2 o D3 semanales o vitamina D3 en dosis de 100 000 UI mensuales. A todas se les midió la calciuria basal y final al alcanzar el valor de 25 OH D deseado (> 30 ng/dl). No observamos cambios significativos en los valores de la calciuria inicial y final en las que recibieron vitamina D2 o D3 semanal ni en las que recibieron dosis mensuales. Sin embargo, un subgrupo de mujeres: 19% (n = 12) de las hipercalciúricas y 12% (n = 6) de las normocalciúricas (con vitamina D semanal) aumentaron la calciuria en forma significativa. Mientras que, con dosis mensuales, un 40% (n = 4/10) de las hipercalciúricas y 44% (n = 4/9) de las hipercalciúricas con litiasis renal aumentaron la calciuria. En conclusión, niveles adecuados de 25 OH D son seguros en la mayoría de las pacientes. En aquellas que requieren dosis de carga mensuales podrían observarse aumentos de la calciuria en forma significativa con riesgo de formar cálculos renales o perder masa ósea, cuando están genéticamente predispuestas.

Several studies show the importance of serum vitamin D sufficient levels to prevent multiple chronic diseases. However, vitamin D supplementation and its effects on urine calcium excretion remain controversial. The objective of this prospective and interventional study was to evaluate urine calcium excretion in women with normal calciuria or hypercalciuria, once serum vitamin D sufficiency was achieved. We studied 63 women with idiopathic hypercalciuria, (9 with renal lithiasis) and 50 normocalciuric women. Both groups had serum vitamin D levels low (deficiency or insufficiency). Baseline urine calcium excretion was measured before being supplemented with vitamin D2 or D3 weekly or vitamin D3 100.000 IU monthly. Once serum vitamin D levels were corrected achieving at least 30 ng/ml, a second urine calcium excretion was obtained. Although in the whole sample we did not observe significant changes in urine calcium excretion according to the way of supplementation, some of those with weekly supplementation had significant higher urine calcium excretion, 19% (n = 12) of hypercalciuric women and 12% (n = 6) of the normocalciuric group. Monthly doses, also showed higher urine calcium excretion in 40% of hypercalciuric women (n = 4/10) and in 44% (n = 4/9) of the renal lithiasis hypercalciuric patients. In conclusion, different ways of vitamin D supplementation and adequate serum levels are safe in most patients, although it should be taken into account a subgroup, mainly with monthly loading doses, that could increase the calciuria significantly eventually rising renal lithiasis risk or bone mass loss, if genetically predisposed.

Índice calcio-creatinina en una muestra matutina de orina para la estimación de hipercalciuria asociada con hematuria no glomerular observada en las edades infanto-juveniles / Calcium-creatinine ratio in a morning urine sample for the estimation of hypercalciuria associated with non-glomerular hematuria observed in children and adolescents

Resumen Introducción: La hipercalciuria suele revelarse durante el diagnóstico diferencial de la hematuria que acompaña a la litiasis renal. La exactitud diagnóstica de la excreción urinaria de calcio puede afectarse por las insuficiencias asociadas con la colección de orina de 24 horas. En este estudio se evaluó la utilidad diagnóstica del índice calcio/creatinina (ICaCre) en la estimación de la hipercalciuria asociada con hematuria y litiasis renal. Método: Se calculó el ICaCre de las concentraciones urinarias de calcio (mmol/l) y creatinina (µmol/l) en una alícuota de colección de 24 horas de orina en 169 niños y adolescentes atendidos por hematuria no glomerular (HNG) o litiasis renal (LR). La calciuria de 24 horas > 4.0 mg/kg en 24 horas se distribuyó según la presencia de HNG o LR. Resultados: El ICaCre promedio fue de 0.2 ± 0.1 mg/mg. La excreción urinaria de calcio estimada del ICaCre fue significativamente superior a la obtenida en colección de orina de 24 horas (p < 0.05). Los métodos de determinación de la calciuria concordaron en la frecuencia de hipercalciuria (ICaCre 39.5% vs. colección de 24 horas 32.1%; p > 0.05). Según la presencia de HNG o LR, la hipercalciuria se distribuyó de la siguiente manera: no HNG + no LR: 59%; no HNG + LR: 60% (diferencia: +1.0%); HNG + no LR: 68.2% (diferencia: +9.2%); HNG + LR: 73.3% (diferencia: +14.4%). Conclusiones: El ICaCre para estimar la excreción urinaria de calcio puede ser efectivo en el estudio de la hipercalciuria asociada con HNG y LR.

Abstract Background: Hypercalciuria might be revealed during the differential diagnosis of hematuria accompanying renal lithiasis (RL). In spite of this, diagnostic accuracy of calcium urinary excretion might be affected by incomplete 24-hour urine collections. In the present study, the diagnostic utility of calcium/creatinine (ICaCre) index for determining hypercalciuria associated with non-glomerular hematuria (NGH) and RL was assessed. Method: ICaCre (mg/mg) index was calculated from calcium (mmol/l) and creatinine (µmol/l) concentrations in an aliquot from a 24-hour urine collection in 169 children and adolescents with NGH or RL. Calciuria values > 4.0 mg/kg in 24 hours were distributed according to the presence of NGH or RL. Results: Mean ICaCre index was 0.2 ± 0.1 mg/mg. Calciuria values estimated from ICaCre were statistically higher to those from 24-hour urine collection (p < 0.05). The frequency of hypercalciuria was independent from the measurement method (estimated from ICaCre 39.5% vs. 24 h collection 32.1%; p > 0.05). Hypercalciuria distribution was as follows: no NGH + no RL: 59.0%; no NGH + RL: 60.0% (∆ = +1.0%); NGH + no RL: 68.2% (∆ = +9.2%); NGH + RL: 73.3% (∆ = +14.4%). Conclusions: The use of ICaCre index for determining calcium urine excretion might be effective in the study of hypercalciuria associated with NGH and RL.

[Calcium response to vitamin D supplementation]. / Respuesta de la calciuria a suplementos de vitamina D.

Several studies show the importance of serum vitamin D sufficient levels to prevent multiple chronic diseases. However, vitamin D supplementation and its effects on urine calcium excretion remain controversial. The objective of this prospective and interventional study was to evaluate urine calcium excretion in women with normal calciuria or hypercalciuria, once serum vitamin D sufficiency was achieved. We studied 63 women with idiopathic hypercalciuria, (9 with renal lithiasis) and 50 normocalciuric women. Both groups had serum vitamin D levels low (deficiency or insufficiency). Baseline urine calcium excretion was measured before being supplemented with vitamin D2 or D3 weekly or vitamin D3 100.000 IU monthly. Once serum vitamin D levels were corrected achieving at least 30 ng/ml, a second urine calcium excretion was obtained. Although in the whole sample we did not observe significant changes in urine calcium excretion according to the way of supplementation, some of those with weekly supplementation had significant higher urine calcium excretion, 19% (n = 12) of hypercalciuric women and 12% (n = 6) of the normocalciuric group. Monthly doses, also showed higher urine calcium excretion in 40% of hypercalciuric women (n = 4/10) and in 44% (n = 4/9) of the renal lithiasis hypercalciuric patients. In conclusion, different ways of vitamin D supplementation and adequate serum levels are safe in most patients, although it should be taken into account a subgroup, mainly with monthly loading doses, that could increase the calciuria significantly eventually rising renal lithiasis risk or bone mass loss, if genetically predisposed.

Kidney Calculi: Pathophysiology and as a Systemic Disorder.

The pathophysiology of urinary stone formation is complex, involving a combination of metabolic, genetic, and environmental factors. Over the past decades, remarkable advances have been emerged in the understanding of the pathogenesis, diagnosis, and treatment of calcium kidney calculi. For this review, both original and review articles were found via PubMed search on pathophysiology, diagnosis, and management of urinary calculi. These resources were integrated with the authors' knowledge of the field. Nephrolithiasis is suggested to be associated with systemic disorders, including chronic kidney insufficiency, hematologic malignancies, endocrine disorders, autoimmune diseases, inflammatory bowel diseases, bone loss and fractures, hypertension, type 2 diabetes mellitus, metabolic syndrome, and vascular diseases like coronary heart diseases and most recently ischemic strokes. This is changing the perspective of nephrolithiasis from an isolated disorder to a systemic disease that justifies further research in understanding the underlying mechanisms and elaborating diagnostic-therapeutic options.

Urolithiasis in the First 2 Months of Life.

INTRODUCTION: There is limited data about urolithiasis in young infants. We reviewed clinical, imaging, and biochemical data of urolithiasis in the first 2 months of life. MATERIALS AND METHODS: In an 11-year period, 77 of the 1172 children diagnosed with urolithiasis (6.8%) were 60 days old and younger (64.9% boys and 35.1% girls). Routine diagnostic assessments included urinalysis and urine culture; measurement of calcium, uric acid, oxalate, and creatinine in nonfasting random urine; measurement of blood urea nitrogen and serum creatinine, sodium, potassium, calcium, and phosphorus levels; and venous blood gasometry. Urinary calculi were diagnosed using tridimensional ultrasonography with 5-MHz, 7.5-Mhz, and 10-MHz probes. RESULTS: The most common symptom was irritability (37.6%). A family history of urinary calculi was documented in 49.4% of the patients. The calculi were 0.5 mm to 6 mm in length. Eight infants (10.4%) had urinary tract infection. Hypercalciuria was found in 21 of 62 patients (33.8%). There were no cases of hyperuricosuria, hyperoxaluria, or struvite calculus. Vesicoureteral reflux was reported in 9 of 20 patients who underwent voiding cystourethrography. Two-thirds of asymptomatic and 85% of symptomatic infants were diagnosed during summer and autumn, and the peaks of calculus visits were in September, October, and November. Of 43 infants (55.8%) who were followed up (Mean, 16.2 ± 15.2 months), none needed calculus removal interventions. CONCLUSIONS: Hypercalciuria is the most common urinary metabolic abnormality in young infants with urinary calculus. Infection was not an important factor for our cohort in the pathogenesis of the disease.

Renal assessment in teenage patients with cystic fibrosis - preliminary report.

BACKGROUND: Together with increasing life expectancy of patients with cystic fibrosis *CF*, there is a growing need to deal with unforeseen problems and complications. Among others renal dysfunction has become of great concern. AIM: Evaluation of renal function in CF children. MATERIAL AND METHODS: We performed cross-sectional study on a group of 11 teenage inpatients with CF. Physical examination, past medical history analysis, renal function measurements and analysis were conducted in all of them. Renal assessment included: serum cystatin C and creatinine levels, measured and estimated creatinine clearance, estimated cystatin C clearance, urine indicators of crystallization risk and renal ultrasonography. RESULTS: One patient had elevated serum cystatin C level and diminished McIsaac equation. Renal ultrasound revealed non-congenital anomaly in 1 case - it was nephrolithiasis. All the individuals had elevated at least 1 urine indicator of crystallization risk. CONCLUSION: There is a great need of good, standardized test of renal function in cystic fibrosis patients. The focus of research should turn towards finding a tool similar to faecal elastase, which is cheap, easy to perform, sensitive and specific, and can be used to confirm the diagnosis.