Kidney length and scarring in children with urinary tract infection: importance of ultrasound scans.

BACKGROUND: Many studies have demonstrated that dimercaptosuccinic acid (DMSA) scintigraphy is the most sensitive diagnostic method in the identification of irreversible renal lesions (scars) in children with previous episodes of acute pyelonephritis (APN). This study assessed the reliability of ultrasound in identifying reflux nephropathy in children with acute pyelonephritis with or without vesicoureteric reflux (VUR). METHODS: Eighty children (45 female and 35 male, age range 5 months to 10 years, average age 2 years 1 month) with a positive history for at least one episode of APN participated in this study. All children underwent voiding cystourethrography, DMSA scintigraphy 4 to 8 months after the most recent episode of APN, and an ultrasound test evaluation less than 2 months after DMSA scintigraphy. RESULTS: Voiding cystourethrograms showed VUR in 52 children (68%); 13 of these were bilateral, for a total of 65 refluxing kidney units of the 154 (42%) evaluated; DMSA scintigram was normal for 108 of 154 kidneys (70%). Of the 65 kidneys with VUR, DMSA scintigram displayed normal findings in 29 cases (45%) and pathologic findings in 36 (55%). In the 79 nonrefluxing kidneys, DMSA scintigram was normal in 69 cases (87%). The relative risk of scarring in VUR kidneys is 2.6. The ultrasound study recorded a maximum longitudinal diameter between the 5th and 95th percentiles in 80 of 89 (81%) kidneys without VUR and in 21 of 65 (32%) with VUR. A significant correlation was found between maximum longitudinal diameters and DMSA scintigraphic findings in kidneys with VUR and those without VUR, respectively. CONCLUSION: This study establishes that ultrasound scans, by means of a simple and reproducible measurement technique, maximum longitudinal diameter, have a predictive value with regard to the presence of scars, with few exceptions. This finding, in our opinion, could lead to a decrease in the number of invasive procedures, in particular DMSA scan, in patients with APN.

Major COL4A5 gene rearrangements in patients with juvenile type Alport syndrome.

Mutations in the COL4A5 gene, which encodes the a5 chain of type IV collagen, are found in a large fraction of patients with X-linked Alport syndrome. The recently discovered COL4A6, tightly linked and highly homologous to COL4A5, represents a second candidate gene for Alport syndrome. We analyzed 177 Italian Alport syndrome families by Southern blotting using cDNA probes from both COL4A5 and COL4A6. Nine unrelated families, accounting for 5% of the cases, were found to have a rearrangement in COL4A5. No rearrangements were found in COL4A6, with the exception of a deletion encompassing the 5' ends of both COL4A5 and COL4A6 genes in a patient with Alport syndrome and leiomyomatosis. COL4A5 rearrangements were all intragenic and included 1 duplication and 7 deletions. Polymerase chain reaction (PCR) analysis was carried out to characterize deletion and duplication boundaries and to predict the resulting protein abnormality. The two smallest deletions involved a single exon (exons 17 and 40, respectively), while the largest ones spanned exons 1 to 36. The clinical phenotype of patients in whom a rearrangement in COL4A5 was detected was severe, with progression to end-stage renal failure in juvenile age and hypoacusis occurring in most cases. These data have some important implications in the diagnosis of patients with Alport syndrome.

[Dyslipidemia and reduced fibrinolysis in a child with hemolytic-uremic syndrome]. / Dislipidemia e ridotta fibrinolisi in un bambino con sindrome emolitico-uremica.

Many pathogenetic factors may enhance coagulation process and induce thrombosis. The Authors report a case of hemolytic-uremic syndrome, with marked evidence of macroscopic kidney thrombotic involvement, in which an important dyslipidemia (hypertriglyceridemia and hypercholesterolemia) was detected during the phase of clinical improvement. These findings, and the contemporary marked reduction of fibrinolytic activity, seem to be relevant pathogenetic factors in this case. The treatment with polyunsaturated fatty acids Omega 3 may have been helpful in modifying these serum abnormalities and maybe could have brought to the clinical improvement.

Clinical outcome of fetal uropathy. I. Predictive value of prenatal echography positive for obstructive uropathy.

Clinical followup was performed in 73 neonates with a prenatal echographic suspicion of uropathy. Of 42 patients with a prenatal suspicion of unilateral hydronephrosis only 15 had pathological obstruction and 2 had multicystic dysplastic kidneys. Among 10 infants with a prenatal suspicion of bilateral hydronephrosis only 1 had true bilateral obstruction and 2 had unilateral obstruction. In 2 patients hydroureteronephrosis seen on prenatal echography was due to massive bilateral vesicoureteral reflux. In this group there was also a multicystic dysplastic kidney and 1 patient with bilateral cystic dysplasia. There was a prenatal suspicion of cystic disease in 8 infants. Postnatally, diagnosis was multicystic dysplastic kidney in 2 patients and a simple renal cyst in 4. The remaining 2 neonates had obstructive uropathy. Finally, of 13 neonates with a prenatal suspicion of anatomical-echo-structural abnormalities a definitive abnormality could be established in only 8. The predictive value of prenatal echography positive for obstructive uropathy was 34.6%.

Clinical outcome of fetal uropathy. II. Sensitivity of echography for prenatal detection of obstructive pathology.

Among 8,579 neonates born between February 1, 1981 and March 31, 1987, and cleared by prenatal sonography for significant urinary tract abnormality 158 subsequently were hospitalized because of signs or symptoms of urinary tract disease, predominantly urinary tract infection. Evaluation of these 158 patients revealed 24 with vesicoureteral reflux, 7 with duplicated systems (2 of which showed reflux), 1 with the syndrome of Fraley, 1 with pyelectasis and 5 with mild hydronephrosis (3 secondary to reflux and 2 with diethylenetriaminepentaacetic acid renal scans considered to be nonobstructed). There was no incidence of significant obstructive uropathy that had been missed by the previous prenatal sonography and that surfaced subsequently to cause morbidity in this series. The principal disorder of the urinary tract that may fail prenatal investigation is vesicoureteral reflux.

[Neonatal hypoxic-ischemic nephropathy and urinary diagnostic indices: the utility of measuring tubular enzymes (NAG and AAP)]. / Nefropatia ipossico-ischemica nel neonato ed indici diagnostici urinari: utilità del dosaggio di enzimi tubulari (NAG ed AAP).

Feto-neonatal hypoxia can cause a functional kidney impairment, which is often temporary and not clinically overt, but sometimes leading to acute renal failure. Hypoxic stress may result in a tubulo-interstitial damage, and kidney tubular enzymes determination has proved to be an easy, early, and non invasive method to define a tubular interstitial lesion. A major target of nephrotoxicity is the proximal tubular cell: alterations in brush-border membrane and cytoplasm result in increased turnover processes in the kidney cortex, following by a corresponding increased excretion of alanine-aminopeptidase (AAP) and N-acetyl-glucosaminidase (NAG) from the proximal tubular cells, long before glomerular or tubular functions are impaired. AAP and NAG excretion is directly correlated with the strength and the duration of toxic alteration of the proximal tubule. NAG and AAP have been already studied in the adults and the children; they have been chosen for this investigation with a double aim: 1) to define the amount of their urinary excretion in relation with gestational age at birth; 2) to evaluate if in the newborn, independently of the gestational age, their urinary concentration may be increased by ischaemic conditions caused by hypoxia. We studied 52 healthy newborns (7 preterm of 33-36 weeks and 45 full-term) and 16 newborns with feto-neonatal hypoxia (8 preterm of 26-36 weeks and full-term) at the forth day of life. Urinary NAG and AAP were assayed by colorimetric methods and the results expressed as mU/mg. creatininuria.(ABSTRACT TRUNCATED AT 250 WORDS)

[Neutropenia caused by low-dose trimethoprim-sulfamethoxazole in children with chronic pathology of the urinary tract]. / Neutropenia da trimetoprim-sulfametossazolo a basso dosaggio nei bambini con patologia cronica delle vie urinarie.

Neutropenia is the most common hematologic abnormality detected as consequence of Trimethoprim Sulfamethoxazole (TMP-SMX) therapy. Its incidence is evaluated in 27 children affected by urinary tract anomalies and treated with low doses of TMP SMX (2 + 10 mg/kg/die) for more than one month. A slight neutropenia was detected in 8 children (6 of these were in their first two years of life). In all the 27 cases a supplementation of folinic acid was started: a significant increase of PMN count was noted in all cases. Neutropenia can also appear after low (prophylactic) dosage of TMP-SMX, and can be prevented by concomitant administration of folinic acid.

Fosfomycin trometamol versus netilmicin in children's lower urinary tract infections.

Fosfomycin trometamol (FT), an antibiotic active against the common urinary pathogens, may be demonstrated in adequate urine concentrations up to 36-48 h after a single oral dose of 1-2 g. This pharmacokinetic peculiarity seems to indicate that this antibiotic may be used in single doses in the therapy of lower urinary tract infections (UTIs) in infants and children. The efficacy and safety of FT in single oral doses was compared with those of netilmicin (NM), an aminoglycoside antibiotic with a demonstrated efficacy in bolus doses against UTIs, shown in a multicentric study. One hundred and thirty-five children with lower UTI, diagnosed on the basis of fever (less than 38 degrees C), erythrocyte sedimentation rate (less than 25 mm/l h) and C-reactive protein (less than 20 micrograms/ml), were included in the study: 71 received 2 g of FT, 64 5 mg/kg of NM. Cure, defined as persistence of sterile urine up to 30 days after therapy, was reached in 80.2% of children in the FT group and in 81.2% of children in the NM group. Persistence of infection was demonstrated in 7 and in 3 children, respectively. Recurrence of infection was noticed in 7 patients in the FT group and in 9 in the NM group. No differences between FT- and NM-treated children are demonstrable even if the patient population is analyzed according to the higher risk of UTI because of the presence of an anatomical and/or functional abnormality of the urinary tract or due to a previous tendency to recurrent UTIs. FT is as effective as NM in the treatment of lower UTIs in infants and children.

Epidemiology of urinary tract infections and vesico-ureteral reflux in children.

The purpose of this study was to assess the incidence of symptomatic urinary tract infection (U.T.I.) and malformations, such as vesico-ureteral reflux (V.U.R.), in the Trieste area. Data were collected in the framework of a survey based on the application of a protocol on urinary infections between 1979 and 1983. The U.T.I. incidence was found to be 1.38% of the 0-14-year-old residents, with a higher frequency in females (2.36%) than in males (0.46%). As regards V.U.R., the incidence in the population studied turned out to be 0.25%, with a females/males ratio of 4:1. Striking differences in incidence data were observed according to the age of U.T.I. and V.U.R. diagnosis and to the infection level (cystitis or pyelonephritis). The incidence of renal scarring resulted to be extremely low, which can be ascribed to the early diagnosis in our cases.

Evaluation of kidney growth in vesico-ureteral reflux.

The parenchymal growth of 80 kidneys with vesicoureteral reflux (VUR), 50 of them surgically corrected, has been evaluated by calculating the ratio between bipolar thickness (BT) and the kidney length (KL), as measured radiographically. We consider this ratio provides a more precise evaluation of the morphologic and functional state of the refluxing kidney as it corresponded closely with the planimetric measurement of the area of renal parenchyma (ARP) in the 12 kidneys where this has also been calculated. Eighteen out of 30 medically treated refluxing kidneys showed a BT/KL ratio inferior to the 2 SD value for age at the time of diagnosis. A worsening BT/KL ratio has been observed in 6 out of 30 kidneys in which reflux ceased spontaneously and in 11 out of 50 which have been corrected surgically. The unfavourable outcome, as far as this parameter is concerned, in the medically treated cases seems to be due to the recurrence of urinary tract infection (UTI); while there is non so clear explanation for it in cases which have been surgically corrected.