Urinary tract calculi have been reported to account for between 1 in 1,000 and 1 in 7,600 hospital admissions in children in the USA. The annual incidence of urolithiasis in patients older than 10 years is 109 per 100,000 of the population in men and 36 per 100,000 of the population in women in Minnesota. The use of various medications is considered to be one of the etiologic factors of nephrolithiasis. Ceftriaxone is a widely used third-generation cephalosporin that is generally considered very safe, but complications such as biliary pseudolithiasis, and rarely, nephrolithiasis have been reported in children. There is limited information about urolithiasis as a side effect of ceftriaxone. The aim of this study was evaluation of the incidence of nephrolithiasis following ceftriaxone therapy in children. This quasi-experimental before and after study was conducted in Mofid Children's Hospital between 2003 and 2005. All patients were treated with 75 mg/kg intravenous ceftriaxone. Diagnosis of pyelonephritis was based on standard criteria. The first renal ultrasonography was performed on the first or second day of admission and was repeated on the last day of treatment. We also evaluated complicated patients for the third time with renal ultrasonography 3 months after treatment. Stone-forming patients underwent metabolic kidney stone risk factor evaluation. We evaluated 284 patients with pyelonephritis, 185 girls and 99 boys. The first ultrasonography was normal in all of our patients. On the second ultrasonography renal stones were reported in 4 out of 284 cases (1.4% and CI=0.96-1.83%). Underlying metabolic risk factors could not be identified in stone-forming patients. Follow-up ultrasonography 3 months later was normal. The results of our study suggest that ceftriaxone-treated patients may be at an increased risk of kidney stone formation. Stones passed spontaneously in all affected patients so the use of this effective drug can be safely continued. Close monitoring of ceftriaxone-treated patients with regard to kidney stone formation is recommended.

Cytokines play a major role in renal scar formation following febrile urinary tract infection (UTI). We investigated the role of dexamethasone combined with antibiotics in diminishing urinary interleukin-6 (UIL-6) and UIL-8 concentrations during the acute phase of pyelonephritis compared with standard antibiotic therapy. UIL-6 and UIL-8 concentrations were determined by enzyme immunoassay in 34 children with pyelonephritis who were treated with ceftriaxone plus dexamethasone (case group) and in 20 patients with the same diagnosis treated with ceftriaxone alone (control group). Urine samples were obtained at the time of presentation prior to drug administration and at follow-up 72 h after initiation of medication. Creatinine concentrations were also determined, and cytokine/creatinine ratios were calculated to standardize samples. Differences between cytokine/creatinine ratios in initial and follow-up urine samples were significant in the case group (P < 0.001) but not for controls. In addition, combined antibiotic and dexamethasone significantly decreased UIL-6 and UIL-8 concentrations compared with antibiotic alone (P < 0.05). We conclude that dexamethasone combined with antibiotics significantly decreases UIL-6 and UIL-8 levels in patients with acute pyelonephritis. This suggests that the clinical use of corticosteroids may prevent scar formation following febrile UTI.

Hydronephrosis is a common finding in patients with urinary tract infection (UTI). Endothellin-1 (ET-1) is a potent vasoactive peptide that has vasoconstrictive effects. It has been shown that urinary ET-1 increases in urinary obstructions. In this study, we measured the urinary ET-1 level in patients with UTI and hydronephrosis of various causes. In this case-control study, we evaluated the urinary ET-1 level in 45 patients who had UTI and hydronephrosis, serving as a case group, and 45 patients who had UTI without hydronephrosis, serving as a control group. Urinary ET-1 was quantified using enzyme-linked immunosorbent assay and urinary creatinine (Cr) by Jaffe method. To rule out the effect of urinary flow rate, the urinary ET-1 to Cr correlation was considered for analysis of the results. The mean age of the patients in the case and control groups was 36.5 ± 27.2 and 26.2 ± 15.5 months, respectively (P >0.01). The mean urinary ET-1 was 89.6 ± 41.7 pg/dL in the case group and 29.3 ± 26 pg/dL in the control group, P <0.001. The mean urinary ET-1 was 121 ± 55.4 pg/dL in patients who had grade 4 hydronephrosis. We conclude that urinary ET-1 was significantly higher in the obstructed than in non-obstructed cases. Urinary ET-1 could be a useful marker that can be utilized in young children for diagnosis of hydronephrosis, especially obstructive cases.

The outcome of pediatric renal transplantation was previously reported by a single-center study at the year 2006. Therefore, we aimed to evaluate and report the characteristics and outcome of renal pediatric renal transplantation in a multi-center nationwide study. In this nationwide report, medical records of 907 children (≤18yr) with renal transplantation in eight major pediatric transplant centers of Iran were recorded. These 907 patients received a total of 922 transplants. All children who failed to follow-up were excluded. Rather than baseline characteristics, graft and patient outcomes were considered for survival analysis. For further analysis, they were divided into two groups: patients who had graft survival time more than 10yr (n=91) and the ones with graft survival time of equal or less than 10yr (n=831). Of 922 recipients, 515 (55.8%) were boys and 407 (44.2%) were girls with the mean age of 13.10 (s.d.=3.54) yr. DGF and AR were occurred in 10% and 39.5% of the transplanted children, respectively. Transplantation year, dialyzing status before transplantation, DGF, and AR were significant enough to predict graft survival in cox regression model (overall model: p<0.001). Nowadays, there is a successful live donor pediatric renal transplantation in Iran. Graft survival has improved in our recipients and now the graft survival rates are near to international standards.

BackgroundDistal Renal Tubular Acidosis is a disorder of acid-base regulation caused by functional failure of α-intercalated cells in the distal nephron. The recessive form of the disease (which is usually associated with sensorineural deafness) is attributable to mutations in ATP6V1B1 or ATP6V0A4, which encode the tissue-restricted B1 and a4 subunits of the renal apical H+-ATPase. ATP6V1B1 lies adjacent to the gene encoding the homeobox domain protein VAX2, at 2p13.3. To date, no human phenotype has been associated with VAX2 mutations.Case presentationThe male Caucasian proband, born of a first cousin marriage, presented at 2 months with failure to thrive, vomiting and poor urine output. No anatomical problems were identified, but investigation revealed hyperchloremic metabolic acidosis with inappropriately alkaline urine and bilateral nephrocalcinosis. Distal Renal Tubular Acidosis was diagnosed and audiometry confirmed hearing loss at 2 years. ATP6V0A4 was excluded from genetic causation by intragenic SNP linkage analysis, but ATP6V1B1 completely failed to PCR-amplify in the patient, suggesting a genomic deletion. Successful amplification of DNA flanking ATP6V1B1 facilitated systematic chromosome walking to ascertain that the proband harbored a homozygous deletion at 2p13.3 encompassing all of ATP6V1B1 and part of VAX2; gene dosage was halved in the parents. This results in the complete deletion of ATP6V1B1 and disruption of the VAX2 open reading frame. Later ocular examinations revealed bilateral rod / cone photoreceptor dystrophy and mild optic atrophy. Similar changes were not detected in an adult harbouring a disruptive mutation in ATP6V1B1.ConclusionsThe genomic deletion reported here is firstly, the only reported example of a whole gene deletion to underlie Distal Renal Tubular Acidosis, where the clinical phenotype is indistinguishable from that of other patients with ATP6V1B1 mutations; secondly, this is the first reported example of a human VAX2 mutation and associated ocular phenotype, supporting speculation in the literature that VAX2 is important for correct retinal functioning.