Why is childhood urolithiasis increasing? Etiology, diagnosis and management: a single-center experience.

BACKGROUND: Globally, urolithiasis is becoming more and more common among children. We aimed to determine the etiology, and the diagnostic and therapeutic approaches in patients with urolithiasis. METHODS: This was a retrospective study which included all patients (aged 1 month-18 years) admitted to the pediatric nephrology clinic in Elazig Fethi Sekin City Hospital with urolithiasis between November 2019 and 2021. Only patients whose diagnosis of urolithiasis was confirmed by urinary ultrasonography were included in the study, while patients with chronic diseases (neurological diseases such as epilepsy, cerebral palsy, chronic bowel diseases, etc.) predisposing to kidney stone formation were not. Demographic characteristics, serum and urine biochemical parameters, urine metabolic and kidney stone metabolic and chemical analyses, urinary tract ultrasonography findings and treatment modalities were collected. RESULTS: One hundred ninety-seven patients (91 female and 106 male) were included in the study. Hypervitaminosis D was detected in 4 (2%) patients, suppressed parathyroid hormone in 12 (6%) and hypercalcemia in 27 (14%) patients. Metabolic screening showed hypercalciuria in 69 (35%) patients, hypocitraturia in 39 (20%), hyperoxaluria in 15 (8%) and cystinuria in 6 (3%) patients. Eighty three (42%) patients had a positive family history for kidney stones. One hundred eighteen (60%) patients received potassium citrate treatment, 71 (36%) were given hydration and diet recommendations without medical treatment, 6 (3%) received tiopronin treatment, and 2 (1%) patients were treated surgically. CONCLUSIONS: Our study suggests that Vitamin D supplementation at doses higher than 400 IU/day may be a risk factor for kidney stones in children. We observed that mothers tend not to give water to infants who are breastfed or formula-fed in the first year of life. K-citrate treatment can be a good option for prevention and dissolution of stones by alkalinization.

Cistinuria: la recurrencia de lo excepcional / Cystinuria: the recurrence of the exceptional

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[Modulation of the phenotypic expression in the patient with cystinuria: influence of therapeutic intervention and diet]. / Modulacion de la expresion fenotipica del paciente con cistinuria: influencia de la intervencion terapeutica y de la dieta.

OBJECTIVES: The final phenotype of patients with cystinuria depends on the absence or molecular defect, more or less acute, of the transport of cystine and dibasic aminoacids, and, also on environmental factors. The objective of this work is to study the effect of the modulation of some environmental factors (urinary pH, intake of liquids, pharmacological treatment and, specially, diet) on the final phenotype of the patient with cystinuria. METHODS: We study 45 patients with cystinuria (25 men and 20 women), 42 relatives (15 men and 27 women) and 90 unrelated controls. Anthropometric, clinical (personal and familiar history of urinary infections, colics and calculi expulsion), biochemical (microscopy analysis of urine and urinary aminoacids cuantification) and life style (diet and medical treatment) variables were obtained. Statistical analysis was performed using tests to compare means and frequencies and, also, logistic regression and multivariate analysis. RESULTS: Of the 45 patients with cystinuria, only 20% showed cystine cristalls in urine, the rest of the phenotypical manifestations of cystinuria were found with the same prevalence as in relatives and in the control group. 50% of the patients did not undergo any therapeutic intervention; of these, only 50% were effective. In patients with cystinuria, the presence of cystine cristalls was associated with a diet rich in meats and poor in milk products (p < 0.05). Meat consumption also tend to associate with a higher risk of urinary infections, meanwhile the stone expulsion showed a negative tendance with a diet rich in phytate. The elevate consumption of oranges and mandarins was the variable of the diet which was more associated with urinary aminoacids concentrations, specially with lower levels of lysine and arginine (p < 0.05). CONCLUSIONS: Some components of the diet, in addition to standard treatment, modulate the phenotypical manifestations of cystinuria.

Modulación de la expresión fenotípica del paciente con cistinuria: influencia de la intervención terapéutica y de la dieta / Modulation of the phenotypic expression in the patient with cystinuria: influence of therapeutic intervention and diet

OBJETIVOS: El fenotipo final del paciente con cistinuria depende, por una parte, de la ausencia o defecto molecular más o menos grave en el transporte de cistina y aminoácidos dibásicos; y por otra parte también de factores ambientales. El objetivo del presente estudio es conocer el efecto de la modulación de diversos factores ambientales (pH urinario, ingesta de líquido, tratamiento farmacológico y en especial la dieta) sobre el fenotipo final del paciente con cistinuria. METODOS: Se estudiaron 45 sujetos diagnosticados como pacientes con cistinuria (25 hombres y 20 mujeres), 42 individuos pertenecientes al árbol genealógico de estos pacientes con cistinuria (15 hombres y 27 mujeres) y 90 controles. Se obtuvieron datos antropométricos, clínicos (antecedentes personales y familiares de infecciones urinarias, cólicos, expulsión de cálculos y problemas renales), bioquímicos (análisis microscópico de orina y cuantificación de aminoácidos en orina) y estilo de vida (dieta y tratamiento recibido). El estudio estadístico incluyó, además de pruebas de comparación de frecuencias y de medias, regresión logística y análisis multivariante. RESULTADOS: De los 45 pacientes con cistinuria, sólo el 20% presentaban cristales de cistina en orina; el resto de manifestaciones fenotípicas de la enfermedad, se encontraron con la misma prevalencia que en el grupo de familiares y el grupo control. El 50% de los pacientes no estaban siguiendo ninguna pauta terapéutica, y de estos, solo en el 50% era efectivo. En pacientes con cistinuria, la presencia de cristales de cistina se asoció a una dieta rica en carnes y baja en productos lácteos (p<0,05). El consumo de carnes también tendía a asociarse a mayor riesgo de presentar infecciones urinarias, mientras que la expulsión de piedras mostró una tendencia negativa con una dieta rica en fitatos. El consumo elevado de naranjas y mandarinas fue la variable de la dieta que más se asoció con las concentraciones de aminoácidos en orina, fundamentalmente con menores niveles de lisina y arginina (p<0,05). CONCLUSIONES: Diversos componentes de la dieta, además del tratamiento estándar, modulan las manifestaciones fenotípicas de la enfermedad (AU)

OBJECTIVES: The final phenotype of patients with cystinuria depends on the absence or molecular defect, more or less acute, of the transport of cystine and dibasic aminoacids, and, also on environmental factors. The objective of this work is to study the effect of the modulation of some environmental factors (urinary pH, intake of liquids, pharmacological treatment and, specially, diet) on the final phenotype of the patient with cystinuria. METHODS: We study 45 patients with cystinuria (25 men and 20 women), 42 relatives (15 men and 27 women) and 90 unrelated controls. Anthropometric, clinical (personal and familiar history of urinary infections, colics and calculi expulsion), biochemical (microscopy analysis of urine and urinary aminoacids cuantification) and life style (diet and medical treatment) variables were obtained. Statistical analysis was performed using tests to compare means and frequencies and, also, logistic regression and multivariate analysis. RESULTS: Of the 45 patients with cystinuria, only 20% showed cystine cristalls in urine, the rest of the phenotypical manifestations of cystinuria were found with the same prevalence as in relatives and in the control group. 50% of the patients did not undergo any therapeutic intervention; of these, only 50% were effective. In patients with cystinuria, the presence of cystine cristalls was associated with a diet rich in meats and poor in milk products (p < 0.05). Meat consumption also tend to associate with a higher risk of urinary infections, meanwhile the stone expulsion showed a negative tendance with a diet rich in phytate. The elevate consumption of oranges and mandarins was the variable of the diet which was more associated with urinary aminoacids concentrations, specially with lower levels of lysine and arginine (p < 0.05). CONCLUSIONS: Some components of the diet, in addition to standard treatment, modulate the phenotypical manifestations of cystinuria (AU)

[Beneficial effect of angiotensin converting enzyme inhibitor treatment in severe cystine urolithiasis]. / Korzystny efekt leczenia inhibitorem enzymu konwertujacego angiotensyne w ciezkiej cystynowej kamicy nerkowej.

Cystinuria is an autosomal recessive defect in transepithelial transport of dibasic amino acids (e.g. cystine) which involves the proximal canaliculi, small intestine and central nervous system. It is the least common cause of nephrolithiasis, accounting for 1 to 3% of renal calculi. The natural course of the disease, characterised by recurrent stone formation, can frequently lead to renal failure, if left untreated. Until recently, treatment of cystinuria has been limited to symptomatic management including intensive hydration and urine alkalinisation. Different drugs that react with cystine to form soluble complexes have been used but their efficacy remains questionable. We present the case of a 6-year-old boy with severe, recurrent cystine urolithiasis treated with captopril. The diagnosis of cystine urolithiasis was established after a 3-year course of clinically apparent nephrolithiasis, characterised by stone passage. At the age of 5 years he underwent lithotripsy and nephrolithotomy for removal of staghorn calculi. Since then treatment with citrate and magnesium supplementation combined with captopril was introduced. After a follow-up of 12 months the patient remained stone-free. Urinary cystine decreased from 230 to 136 mg per gram creatinine. We conclude that captopril can be useful in the treatment of cystine urolithiasis in children.

Treatment of cystine stones: combined approach using open pyelolithotomy, percutaneous pyelolithotripsy, extracorporeal shock wave lithotripsy and chemolysis.

Treatment of cystine stones in the urinary tract can be difficult because of a high frequency of recurrence, resistance to Extracorporeal Shock Wave Lithotripsy (ESWL), difficulty in localization and access to peripheral stones during Percutaneous Nephrolithotripsy (PCNL), and the insufficient effect of oral chemolysis. We present two cases of urinary cystine calculi treated with a combination of pyelolithotomy, PCNL, ESWL and percutaneous irrigation chemolysis, using N-acetylcysteine and Tromethamine-E.

[Preventive measures in stones due to infection, uric acid and cystine]. / Prophylaxe bei Infekt-, Harnsäure- und Zystinsteinen.

General prophylaxis of renal stone formation consists of 1. high fluid intake and 2. modest consumption of protein-rich foods. Specific prophylactic measures are based on pathophysiologic mechanisms of stone formation. In infection-induced renal stones, combined treatment with culture specific antibiotics and complete stone removal is of utmost importance. In all cases where stone fragments cannot be removed completely and/or partial obstruction remains, long-term antibiotics in combination with urine acidification by methionine (urine pH 5.6 to 6.2) are most appropriate. Prophylaxis of uric acid stones primarily consists of reducing purine intake and alkalizing the urine by potassium citrate. Only if this regimen failed or gout occurred, allopurinol should be administered. In patients with cystine stones, urine volume should be increased to greater than 3000 ml/die. Alkalizing the urine to a pH greater than 7.5 rises cystine solubility, whereas cystine excretion may be reduced by a diet low in sodium and/or low in methionine/cysteine. Thiols form mixed thiol-cysteine disulfides that are many times more soluble than cystine in urine; because of their high rate of adverse side-effects, however, these compounds are of lowest priority in the treatment of cystine stones. There is no convincing evidence for the efficacy of high dose ascorbic acid treatment in cystinuria.

Cystine calcium bladder calculus in a 2-year-old child.

We report on a 2-year-old child who presented with urinary tract infection and a large solitary bladder calculus. Dietary history indicated an intake of 2 gm. calcium with supplemental vitamin D daily. Urinary amino acid analysis revealed cystinuria. The high dietary intake of calcium and vitamin D may have precipitated early cystine calcium stone formation.