Una nueva mutación de la enfermedad de Dent en un niño de 11 años con nefrolitiasis y nefrocalcinosis / A novel mutation of Dent's disease in an 11-year-old male with nephrolithiasis and nephrocalcinosis

La enfermedad de Dent es una tubulopatía recesiva ligada al cromosoma X caracterizada por proteinuria de bajo peso molecular (bpm), hipercalciuria, nefrocalcinosis o nefrolitiasis, disfunción tubular proximal e insuficiencia renal en la adultez. Las mujeres son portadoras y, en general, padecen una forma leve de la enfermedad. La progresión hacia la insuficiencia renal en estadio terminal se da entre los 30 y los 50 años de edad en el 30-80% de los varones afectados. A falta de un tratamiento dirigido al defecto molecular, en la actualidad, los pacientes con enfermedad de Dent reciben tratamientos complementarios orientados a prevenir la nefrolitiasis y la nefrocalcinosis. El caso que presentamos es el de un niño de 11 años con nefrocalcinosis y nefrolitiasis, en quien se detectó una nueva mutación en el gen CLCN5.

Dent's disease is a rare X-linked recessive tubulopathy characterized by low molecular weight (LMW) proteinuria, hypercalciuria, nephrolcalcinosis or nephrolithiasis, proximal tubular dysfunction and renal failure in adulthood. Females are carriers and usually mildly affected. Progression to endstage renal failure are at the 3rd-5th decades of life in 30-80% of affected males. In the absence of therapy targeting for the molecular defect, the current care of patients with Dent's disease is supportive, focusing on the prevention of nephrolithiasis and nephrocalcinosis. We present an 11-year-old child with nephrocalcinosis and nephrolithiasis caused by a new mutation at CLCN5 gene.

A novel mutation of Dent's disease in an 11-year-old male with nephrolithiasis and nephrocalcinosis. / Una nueva mutación de la enfermedad de Dent en un niño de 11 años con nefrolitiasis y nefrocalcinosis.

Dent's disease is a rare X-linked recessive tubulopathy characterized by low molecular weight (LMW) proteinuria, hypercalciuria, nephrolcalcinosis or nephrolithiasis, proximal tubular dysfunction and renal failure in adulthood. Females are carriers and usually mildly affected. Progression to endstage renal failure are at the 3rd-5th decades of life in 30-80% of affected males. In the absence of therapy targeting for the molecular defect, the current care of patients with Dent's disease is supportive, focusing on the prevention of nephrolithiasis and nephrocalcinosis. We present an 11-year-old child with nephrocalcinosis and nephrolithiasis caused by a new mutation at CLCN5 gene.

La enfermedad de Dent es una tubulopatía recesiva ligada al cromosoma X caracterizada por proteinuria de bajo peso molecular (bpm), hipercalciuria, nefrocalcinosis o nefrolitiasis, disfunción tubular proximal e insuficiencia renal en la adultez. Las mujeres son portadoras y, en general, padecen una forma leve de la enfermedad. La progresión hacia la insuficiencia renal en estadio terminal se da entre los 30 y los 50 años de edad en el 30-80% de los varones afectados. A falta de un tratamiento dirigido al defecto molecular, en la actualidad, los pacientes con enfermedad de Dent reciben tratamientos complementarios orientados a prevenir la nefrolitiasis y la nefrocalcinosis. El caso que presentamos es el de un niño de 11 años con nefrocalcinosis y nefrolitiasis, en quien se detectó una nueva mutación en el gen CLCN5.

Epicardial Adipose Tissue Thickness and Carotid Intima-Media Thickness in Hemodialysis Patients.

BACKGROUND: It is well-known that cardiovascular risk and all-cause mortality is increased in hemodialysis patients. Epicardial fat thickness (EFT), which reflects visceral adiposity, has been suggested as a new cardiometabolic risk factor. The purpose of this study was to investigate EFT in hemodialysis patients. METHODS: A total of 144 consecutive patients (60 hemodialysis patients and 84 controls) were enrolled into the study, and patients with diabetes mellitus and cardiovascular diseases (CVD) were excluded. EFT was measured on the free wall of the right ventricle at end-diastole from the parasternal long-axis view by standard transthorasic 2D echocardiography. RESULTS: The groups were similar in terms of sex distribution, age, blood pressure, heart rate and frequencies of CAD risk factors including smoking status, family history of CAD and hypertension. There were no significant differences between the hemodialysis patients and controls in 2D echocardiographic parameters, including ejection fraction and biochemical parameters except low-density lipoprotein, high-density lipoprotein and c- reactive protein. Despite having lower body mass index, EFT levels were significantly higher in hemodialysis patients compared to the controls (8.0 ± 2.2 mm vs. 5.8 ± 1.9 mm; p < 0.01). In multivariate linear regression analysis we determined that hemodialysis patient status was found to be an independent predictor for both EFT (ß = 0. 700, p = 0.014) and carotid intima-media thickness (CIMT, ß = 0. 614, p = 0.047). CONCLUSIONS: Hemodialysis patients are independently associated with high EFT and CIMT.

Procalcitonin and minimal-change nephropathy: a pilot study.

INTRODUCTION: This study assessed the role of procalcitonin (PCT) in the differentiation of minimal-change nephropathy (MCN) relapses from infections co-existent with proteinuria flares in children. METHODS: Data on the PCT levels of patients with MCN who were on follow-up were retrospectively gathered at relapse (Group I), during proteinuria attacks co-existent with intercurrent infection (Group II) and at remission (Group III). The results of these three groups were then prospectively compared with nephrologically healthy patients who had infections that were similar to those in Group II (Group IV), and controls (Group V). RESULTS: Significant differences in PCT level were noted between patients of Groups I, II and IV and the other two groups. A 93% reduction in proteinuria was achieved for Group II patients following an antibiotic regimen. The difference in PCT level between Groups I and II was significant. PCT showed a higher diagnostic predictability than C-reactive protein (CRP) in Group I patients, and was as good as CRP for those with infection and infection-related proteinuria. Sensitivity × specificity in relapse and infection-related states for PCT were 0.472 and 0.628, respectively, and those for CRP were 0.183 and 0.762, respectively. CONCLUSION: A combined approach with CRP and PCT readings may be beneficial in discriminating proteinuria attacks co-existent with intercurrent infection from sole relapses of nephrotic syndrome. PCT may be a part of the wide spectrum of immune abnormalities seen in patients with MCN.

A different interaction between parathyroid hormone, calcitriol and serum aluminum in chronic kidney disease; a pilot study.

BACKGROUND/AIMS: Aluminum (Al) is an ingredient of a variety of foodstuffs and medications as well as of domestic water supplies. The patients with chronic kidney disease (CKD) are more susceptible to bone toxicity of Al. The aim of the study was to investigate the interactions between serum Al, parathyroid hormone (PTH) and active vitamin-D in CKD. METHODS: A total of 10 pediatric patients with CKD and 20 healthy controls were enrolled in study. The blood calcium, aluminum, PTH, alkaline phosphatase and phosphorus were evaluated at onset and following a regimen of oral 1,25 dihydroxycholecalciferol (1,25 DHC) for 4 weeks. RESULTS: Although median values of PTH, calcium, phosphorus and alkaline phosphatase did not differ (P > 0.05) after calcitriol administration, the aluminum levels (median: 27.2 ng/ml, range: 11.3-175) declined significantly (median: 3.8 ng/ml, range: 0.64-11.9) after a regimen of oral 1,25 DHC for 4 weeks in all participants (P < 0.05). The median levels of aluminum after 1,25 DHC did not show statistically significant difference with median aluminum levels of healthy controls (median: 2.5 ng/ml, range: 0.2-33.2) (P < 0.05). CONCLUSION: Calcitriol may lead to decline in serum Al levels in CKD patients.

Nephrogenic diabetes insipidus due to a novel AVPR2 mutation.

Congenital nephrogenic diabetes insipidus (CNDI) is a rare inherited disease characterized by renal tubular unresponsiveness to the antidiuretic effect of arginine-vasopressin due to the mutations of two molecules, the vasopressin V2 receptor (AVPR2) and the aquasporin-2 water channel. We report a novel AVPR2 mutation in a Turkish 18 month-old boy with skeletal anomalies.

Nutcracker syndrome in a child with familial Mediterranean fever (FMF) disease: renal ultrastructural features.

Renal nutcracker syndrome is an uncommon clinical condition caused by compression of the left renal vein. It is usually accompanied by hematuria and/or orthostatic proteinuria. To date, the pathogenic mechanism of proteinuria and its ultrastructural features have not been clearly identified. Here, we present the glomerular ultrastructural features of nutcracker syndrome and our attempt to analyze the relationship between proteinuria and ultrastructural features. Two months prior to admission, a 11-year-old girl with familial Mediterranean fever who was treated with colchicine was found to have proteinuria. Accompanying hematuria was not identified, and laboratory findings were otherwise normal. Doppler ultrasonography and computerized tomography angiography revealed an entrapment of the left renal vein. A kidney biopsy was performed due to the persistent proteinuria. Light microscopy revealed segmental, minimal increases in the mesangial cells and matrix. No amyloid deposition was present. Neither immunofluorescence nor electron microscopy showed immunoglobulin deposition. Increased thickness of the glomerular basement membrane due to the unequivocal radiolucent widening of the lamina rara interna was the most striking ultrastructural finding. At high magnification, there were no amyloidal fibrils. It has been proposed that hemodynamic alterations and structural changes in glomerular basement membrane glycosaminoglycans may play a role in the pathogenesis of proteinuria. Radiolucent expansion of the lamina rara interna of the glomerular basement membrane in the presenting case would seem to support these data.

Pupillometric assessment of autonomic nervous system in children with functional enuresis.

Functional enuresis is defined as repeated voiding of urine into bed or clothes in children after 5 years of age following the exclusion of major somatic diseases. Autonomic nervous system dysregulation has been proposed as a pathophysiologic mechanism in the etiopathogenesis. The objective of this study was to evaluate autonomic nervous system functions with pupil diameter measurement in enuretic children. The study group consisted of 17 children with functional enuresis (ten boys, seven girls), and the control group consisted of 34 healthy children (20 boys, 14 girls). Pupil diameter measurements were performed under photopic and mesopic lighting conditions by using a pupillometer. Mean photopic pupil diameter was found to be larger in the enuretic children than in the healthy controls (4.47 +/- 0.52 mm vs. 4.03 +/- 0.75 mm; P = 0.03). Autonomic nervous system imbalance of the ocular system is considered to be part of the autonomic nervous system dysregulation in functional enuretic children.

Electronic microarray screening of podocin mutations: a single-center study.

BACKGROUND: Because of resistance to immunosuppressants in nephrotic syndrome and reduction of proteinuria relapses following renal transplantation, it seems that new horizons have arisen from mutational screening of the podocin gene. The aim of this study was to assess electronic microarray screening of the podocin mutation. METHODS: Twelve previously identified podocin mutations were screened by the electronic microarray method in known DNA samples and in patients (aged 5 months-18 years, n = 38) with steroid-resistant primary nephrotic syndrome, isolated proteinuria, end-stage renal disease secondary to idiopathic nephrotic syndrome, and proteinuria relapses following renal transplantation. RESULTS: DNA samples previously supplied to define the mutation profile for analysis and which were used as controls were completely and correctly detected by this method. None of the 12 mutations was detected in our patients. The duration of analysis for one mutation, including hybridization, was only 30 min for 38 cases. CONCLUSION: Electronic microarray screening for NPHS2 mutations is not only rapid but also accurate. Previous identification of the mutation profile most often encountered in the investigated population is needed, however.