Sibling Reflux: A Dual Center Retrospective Study

The Intrarenal Reflux Diagnosed by Contrast-Enhanced Voiding Urosonography (ceVUS): A Reason for the Reclassification of Vesicoureteral Reflux and New Therapeutic Approach?

Vesicoureteral reflux (VUR) is defined as the urine backflow from the urinary bladder to the pyelo-caliceal system. In contrast, intrarenal reflux (IRR) is the backflow of urine from the renal calyces into the tubulointerstitial space. VURs, particularly those associated with IRR can result in reflux nephropathy when accompanied by urinary tract infection (UTI). The prevalence of IRR in patients with diagnosed VUR is 1-11% when using voiding cystourethrography (VCUG), while 11.9-61% when applying the contrast-enhanced voiding urosonography (ceVUS). The presence of IRR diagnosed by VCUG often correlates with parenchymal scars, when diagnosed by a 99mTc dimercaptosuccinic acid scan (DMSA scan), mostly in kidneys with high-grade VURs, and when diagnosed by ceVUS, it correlates with the wide spectrum of parenchymal changes on DMSA scan. The study performed by both ceVUS and DMSA scans showed IRRs associated with non-dilated VURs in 21% of all detected VURs. A significant difference regarding the existence of parenchymal damage was disclosed between the IRR-associated and IRR-non-associated VURs. A higher portion of parenchymal changes existed in the IRR-associated VURs, regardless of the VUR grade. That means that kidneys with IRR-associated VURs represent the high-risk group of VURs, which must be considered in the future classification of VURs. When using ceVUS, 62% of places where IRR was found were still unaffected by parenchymal changes. That was the basis for our recommendation of preventive use of long-term antibiotic prophylaxis until the IRR disappearance, regardless of the VUR grade. We propose a new classification of VURs using the ceVUS method, in which each VUR grade is subdivided based on the presence of an IRR.

Evidence-based clinical practice guideline for management of urinary tract infection and primary vesicoureteric reflux

We present updated, evidence-based clinical practice guidelines from the Indian Society of Pediatric Nephrology (ISPN) for the management of urinary tract infection (UTI) and primary vesicoureteric reflux (VUR) in children. These guidelines conform to international standards; Institute of Medicine and AGREE checklists were used to ensure transparency, rigor, and thoroughness in the guideline development. In view of the robust methodology, these guidelines are applicable globally for the management of UTI and VUR. Seventeen recommendations and 18 clinical practice points have been formulated. Some of the key recommendations and practice points are as follows. Urine culture with > 104 colony forming units/mL is considered significant for the diagnosis of UTI in an infant if the clinical suspicion is strong. Urine leukocyte esterase and nitrite can be used as an alternative screening test to urine microscopy in a child with suspected UTI. Acute pyelonephritis can be treated with oral antibiotics in a non-toxic infant for 7-10 days. An acute-phase DMSA scan is not recommended in the evaluation of UTI. Micturating cystourethrography (MCU) is indicated in children with recurrent UTI, abnormal kidney ultrasound, and in patients below 2 years of age with non-E. coli UTI. Dimercaptosuccinic acid scan (DMSA scan) is indicated only in children with recurrent UTI and high-grade (3-5) VUR. Antibiotic prophylaxis is not indicated in children with a normal urinary tract after UTI. Prophylaxis is recommended to prevent UTI in children with bladder bowel dysfunction (BBD) and those with high-grade VUR. In children with VUR, prophylaxis should be stopped if the child is toilet trained, free of BBD, and has not had a UTI in the last 1 year. Surgical intervention in high-grade VUR can be considered for parental preference over antibiotic prophylaxis or in children developing recurrent breakthrough febrile UTIs on antibiotic prophylaxis.

A genome‑wide scan to locate regions associated with familial vesicoureteral reflux

Vesicoureteral reflux (VUR) is a congenital malformation carrying a high risk of recurrent urinary tract infections (UTI) and, at worst, chronic renal failure. Familial clustering implies a genetic etiology, but studies during the past few decades have demonstrated a causal gene variant in <10% of patients with VUR. The aim of the present study was to search for fully or partially shared ancestral haplotypes in 14 families from south-western Sweden with at least three affected members. High-density single nucleotide polymorphism microarray was used for genotyping prior to analysis with a compatibility matching method developed in-house, and the analysis of copy number variations (CNV). No single unique haplotype was revealed to be shared by the families, thereby excluding a common ancestry and founder mutations as a probable cause of VUR. After evaluation of haplotypes shared by subsets of families, a haplotype shared by nine families was found to be of particular interest. This haplotype, located at chromosomal region 4q21.21, harbours two tentative candidate genes (bone morphogenetic protein 3 and fibroblast growth factor 5), both expressed in metanephros and with known functions during nephrogenesis. As to CNV, only one family had a specific CNV shared by all affected members. This was a focal deletion at 5q31.1 including follistatin-like 4, a gene without a previous known connection to VUR. These data demonstrated the genetic heterogeneity of VUR and indicated that an interaction of environmental and genetic factors, including non-coding and epigenetic regulators, all contribute to the complexity of VUR.

A single-center cohort of Canadian children with VUR reveals renal phenotypes important for genetic studies

BACKGROUND

Many genes and loci have been reported in genetic studies of primary vesicoureteral reflux (VUR), but few have been reproduced in independent cohorts, perhaps because of phenotype heterogeneity. We phenotyped children with VUR who attended urology clinics so we could establish criteria to stratify patients based on the presence or absence of a renal malformation.

METHODS

History, chart review, and DNA were obtained for 200 children with VUR from 189 families to determine the grade of VUR, the mode of presentation, and the family history for each child. Kidney length measured on ultrasound (US) and technetium dimercaptosuccinic acid (DMSA) scans at the time of VUR diagnosis were used to establish the presence of a concurrent renal malformation and identify the presence of renal scarring.

RESULTS

There was an even distribution of girls and boys, and most patients were diagnosed following a urinary tract infection (UTI). Thirty-four percent of the children had severe VUR, and 25 % had undergone surgical correction. VUR is highly heritable, with 15 % of the families reporting multiple affected members. Most patients had normally formed kidneys as determined by US and DMSA imaging. Of the 93 patients who underwent DMSA imaging, 17 (18 %) showed scarring, 2 (2 %) showed scarring and diffuse reduction in uptake, and 13 (14 %) showed an isolated diffuse reduction in uptake.

CONCLUSION

Prospective long-term studies of patients with primary VUR combined with renal phenotyping using US and DMSA imaging are needed to establish the presence of a renal malformation. The majority of patients in our study had no renal malformation. This cohort is a new resource for genetic studies of children with primary VUR.

Genetics of vesicoureteral reflux

Primary vesicoureteral reflux (VUR) is the most common urological anomaly in children, affecting 1-2% of the pediatric population and 30-40% of children presenting with urinary tract infections (UTIs). Reflux-associated nephropathy is a major cause of childhood hypertension and chronic renal failure. The hereditary and familial nature of VUR is well recognized and several studies have reported that siblings of children with VUR have a higher incidence of reflux than the general pediatric population. Familial clustering of VUR implies that genetic factors have an important role in its pathogenesis, but no single major locus or gene for VUR has yet been identified and most researchers now acknowledge that VUR is genetically heterogeneous. Improvements in genome-scan techniques and continuously increasing knowledge of the genetic basis of VUR should help us to further understand its pathogenesis.

Sibling vesicoureteral reflux in twins

AIM OF STUDY

Few studies have evaluated the incidence of familial vesicoureteral reflux (VUR) among multiple gestation births. The purpose of this study was to determine the incidence and characteristics of VUR in twins in a large cohort of families with VUR.

METHODS

Between 1998 and 2010, data were collected on 251 families (538 children) with at least 2 siblings who had VUR. The incidence of affected twins among the families was analysed. Data were assessed for age at presentation, gender, grading of VUR, laterality of affectation and renal scarring. VUR was diagnosed by voiding cystourethrography (VCUG) and dimercaptosuccinic acid (DMSA) scans were used to assess renal scarring.

RESULTS

There were 12 families (4.8%) in which twins were affected with VUR. There were 12 index cases (7 males/5 females), and 12 siblings (1 male/11 females). All index cases presented with urinary tract infection (UTIs), whereas 2 siblings had UTIs and 10 were screened. All cases presented between 3 months and 2 years. Among the index cases, three had unilateral and nine had bilateral VUR. Among the siblings, four had unilateral and eight had bilateral VUR. Thirty-seven (90%) of the 41 affected renal refluxing units had high-grade VUR. Three index cases had renal scarring. No scarring was seen in the siblings.

CONCLUSIONS

The vast majority of twins with VUR are females who have high grade VUR and a low incidence of renal scarring. Twins with VUR may represent a genetically different subgroup with female preponderance and severe reflux.

Five cases of severe vesico-ureteric reflux in a family with an X-linked compatible trait

Vesico-ureteric reflux (VUR) is one the most common inherited disorder in humans. Even though this defect is common among siblings and parents of index patients (27-40%), the mode of inheritance is not well defined. Parents and siblings (three female and two male) of a 13-year-old girl with end-stage renal failure (ESRF) due to reflux nephropathy were screened for VUR although they had not presented episodes of urinary tract infection. VUR was identified in the father (44 years old) and in all the three sisters (aged 15 years, 16 years and 18 years) while the two brothers (aged 5 years and 8 years) had normal renal ultrasonograms and cystograms. A technetium-99m di-mercapto-succinic acid ((99m)Tc-DMSA) scan demonstrated renal scars in the father and in two of the sisters with VUR. No episodes of urinary infection had been documented for any relatives. Haplotype analysis on the X-chromosome confirmed paternity. This is the first description of VUR compatible with an X-dominant trait. This mode of inheritance must be added to what is already known on familial VUR, and future studies should also consider this possibility.

Voiding cystography practices and preferences of North American pediatric urologists

PURPOSE

Little consensus exists regarding the choice of a specific modality of voiding cystography in the evaluation and management of vesicoureteral reflux. We hypothesized that choices of pediatric urologists are based on technical factors of the studies themselves, as well as institutional factors unique to their hospital(s). Therefore, we surveyed pediatric urologists to determine their current practices and preferences of modalities of voiding cystography.

MATERIALS AND METHODS

We mailed an anonymous survey of 40 questions to all fellows of the American Academy of Pediatrics Section on Urology.

RESULTS

Surveys were returned from 186 of 301 fellows (62%). Of the respondents 57% were in academic, 30% in private and 13% in mixed practices. Given a choice of fluoroscopic voiding cystourethrography, radionuclide cystography and voiding ultrasonography, fluoroscopic voiding cystourethrography was preferred by 98% and 96% of respondents for initial evaluation of urinary tract infection in males and females, respectively, 96% for assessment of prenatal hydronephrosis, 54% for followup of vesicoureteral reflux, 59% for screening siblings, and 63% and 66%, respectively, after open and endoscopic correction of vesicoureteral reflux. Voiding ultrasonography was preferred by less than 10% of respondents in all groups, and radionuclide cystography was preferred by the remainder. Voiding images of the urethra, child-friendliness of staff, sensitivity and accuracy were factors most important in choosing a test. Of the respondents 83% reported full-time access to pediatric radiologists at their primary hospital, although a minority had full-time access to pediatric radiologists at additional institutions. Sedation was used in some or most cases by 29%, rarely by 56% and never by 15% of respondents.

CONCLUSIONS

Pediatric urologists prefer fluoroscopic voiding cystography in all situations to evaluate vesicoureteral reflux but the proportion varies by indication. Diagnostic and patient issues are of greater concern than radiation dose. Variability in access to pediatric radiologists and ability to obtain the desired study may also alter ordering practices.

Reflux nephropathy

Vesicoureteral reflux may be associated with abnormalities of the renal parenchyma. The purpose of this review is to define what the parenchymal abnormalities are histologically, what their etiologies may be, how they are identified and what their long-term clinical impact may be. Two categories are recognized, renal dysplasia and post-infection, chronic pyelonephritis. The diagnostic gold standard is microscopic evaluation of biopsy specimens but renal scintigraphy can be used in the diagnosis of renal dysplasia versus chronic pyelonephritis. Potential long-term sequelae of reflux nephropathy include hypertension and renal insufficiency although these may occur infrequently. A review of the current literature is provided.

TGF-beta1 gene polymorphisms and primary vesicoureteral reflux in childhood

The aim of this study was to assess the association between the transforming growth factor-beta1 (TGF-beta1) gene polymorphisms rs1800469 (commonly known as T-509C) and rs1982073 (commonly known as Leu (10)-->Pro) and primary vesicoureteral reflux (VUR) and renal scarring. Using a case-control approach, we examined 121 children with primary VUR and 169 controls. Genotyping of the TGF-beta1 gene polymorphisms was performed by restriction fragment length polymorphism (RFLP) analysis. The (99m)Tc-DMSA- or (99m)Tc-unitiol-single photon emission computed tomography method was used to evaluate renal scars in 84 of 121 VUR children. Statistical analysis revealed differences in rs1800469 genotype frequencies between VUR patients and controls (p = 0.0021). Our data demonstrate that individuals homozygous for the TT genotype are at risk of primary VUR [odds ratio (95% confidence interval) = 2.7 (1.46-5.08)]. Distribution of the rs1982073 polymorphism was similar in VUR children and controls. In terms of renal scarring, patients were stratified into non-scar and scar subgroups, and no differences in the genotype frequencies of either polymorphism was found. Previous reports have shown that the TT genotype of the rs1800469 polymorphism is a risk factor for renal scarring in primary VUR, and the results of our study suggest that this same polymorphism is associated with susceptibility to this congenital uropathy.

Vesicoureteral reflux

Vesicoureteral reflux (VUR), the retrograde flow of urine from the bladder toward the kidney, is common in young children. About 30% of children with urinary tract infections will be diagnosed with VUR after a voiding cystourethrogram. For most, VUR will resolve spontaneously; 20% to 30% will have further infections, but few will experience long-term renal sequelae. Developmentally, VUR arises from disruption of complex signaling pathways and cellular differentiation. These mechanisms are probably genetically programmed but may be influenced by environmental exposures. Phenotypic expression of VUR is variable, ranging from asymptomatic forms to severe renal parenchymal disease and end-stage disease. VUR is often familial but is genetically heterogeneous with variability in mode of inheritance and in which gene, or the number of genes, that are involved. Numerous genetic studies that explore associations with VUR are available. The relative utility of these for understanding the genetics of VUR is often limited because of small sample size, poor methodology, and a diverse spectrum of patients. Much, if not all, of the renal parenchymal damage associated with end-stage disease is likely to be congenital, which limits the opportunity for intervention to familial cases where risk prediction may be available. Management of children with VUR remains controversial because there is no strong supportive evidence that prophylactic antibiotics or surgical intervention improve outcomes. Furthermore, well-designed genetic epidemiological studies focusing on the severe end of the VUR phenotype may help define the causal pathway and identify modifiable or disease predictive factors.

Therapy Insight: what nephrologists need to know about primary vesicoureteral reflux

Vesicoureteral reflux (VUR) is the abnormal, retrograde flow of urine from the bladder to the upper urinary tract. This disease affects about 1% of otherwise normal children, 30-50% of those who present with urinary tract infections, and approximately 10% with prenatally diagnosed hydronephrosis. Over the past 50 years, tremendous progress has been made in the diagnosis, treatment and management of VUR. The realization that VUR is probably a component of generalized dysfunction of the lower urinary tract (i.e. dysfunctional elimination syndrome) has further enhanced understanding of the disease. This Review covers basic pathogenesis, diagnosis, management, clinical presentation, and current controversies surrounding VUR.

Imaging strategies for vesicoureteral reflux diagnosis

The prevalence of vesicoureteral reflux (VUR), although reported to be low in the general population, is high in children with urinary tract infection (UTI), first degree relatives of patients with known VUR and children with antenatal hydronephrosis. In addition, it has been shown that VUR and UTIs are associated with renal scarring, predisposing to serious long-term complications, i.e., hypertension, chronic renal insufficiency and complications of pregnancy. Therefore, diagnostic imaging for the detection of VUR in the high-risk groups of children has been a standard practice. However, none of these associations has been validated with controlled studies, and recently the value of identifying VUR after a symptomatic UTI has been questioned. In addition, several studies have shown that renal damage may occur in the absence of VUR. On the other hand, some patients, mainly males, may have primary renal damage, associated with high-grade VUR, without UTI. Recently, increasing skepticism has been noted concerning how and for whom it is important to investigate for VUR. It has been suggested that the absence of renal lesions after the first UTI in children may rule out VUR of clinical significance and reinforces the redundancy of invasive diagnostic techniques. Therefore, the priority of imaging strategies should focus on early identification of renal lesions to prevent further deterioration.

Familial Vesicoureteral Reflux: Influence of Sex on Prevalence and Expression

PURPOSE

Familial clustering of vesicoureteral reflux implies that genetic factors have an important role in the pathogenesis of vesicoureteral reflux. We investigated the impact of sex on familial vesicoureteral reflux.

MATERIALS AND METHODS

Between 1998 and 2003 we identified 159 white families with at least 2 children (range 2 to 5) with vesicoureteral reflux confirmed by a voiding cystourethrogram. Families were divided into 3 groups, including group 1 with only boys affected (29 or 18%), group 2 with only girls affected (57 or 36%) and group 3 with boys and girls affected (73 or 46%). Clinical characteristics, reflux grade and associated renal anomalies in these 3 groups were compared using the Mann-Whitney U and chi-square tests for statistical analysis.

RESULTS

Sisters of index female patients were at significantly higher risk for vesicoureteral reflux than brothers (p <0.01). Boys in group 1 had a significantly higher grade of vesicoureteral reflux than boys in group 3, and girls in groups 3 and 2 (p = 0.018, <0.001 and <0.0001, respectively). Severe renal scarring was present in 7% of boys in group 1, 6.6% of boys in group 3, 1.3% of girls in group 3 and 1.9% of girls in group 2. Duplex kidneys were present in 15.3% of boys in group 1 but only in 2.3% of boys in group 3 (p <0.01), 5.7% of girls in group 3 and 5.8% of girls in group 2. Age at diagnosis was not significantly different among boys in groups 1 and 3, and girls in group 2 (median 0.9, 0.6 and 1.9 years, respectively).

CONCLUSIONS

The risk and severity of vesicoureteral reflux in siblings depends on the sex of the affected child. Brothers of index male patients have higher grade of reflux and higher rate of associated duplex systems. This has implications for genetic counseling and for modeling the inheritance of vesicoureteral reflux.

Renal Scarring in Familial Vesicoureteral Reflux: Is Prevention Possible?

PURPOSE

Detailed knowledge about risk factors for renal scarring in familial reflux is necessary to decide whether these factors could be influenced by early screening and treatment of siblings. We evaluated the prevalence of and risk factors influencing renal scarring in familial vesicoureteral reflux.

MATERIALS AND METHODS

We reviewed the medical records and dimercapto-succinic acid scans of 306 children with familial vesicoureteral reflux. Scarring was classified as mild, moderate and severe. The impact of urinary tract infections, patient sex, reflux grade and age at diagnosis on renal scarring was evaluated.

RESULTS

The prevalence of renal scarring was identical at 36% in 142 index patients and 74 siblings presenting with urinary tract infection but it was only 10% in 87 asymptomatic siblings (p <0.001) The difference between siblings with and without urinary tract infection was only statistically significant for mild scarring (23% vs 4.6%, p <0.001). It did not attain significance in those with moderate to severe scarring (13.5% vs 5.7%). Moderate to severe scarring was significantly more common in grade V than in grade IV refluxing units (43% vs 10%, p <0.0001) and in male than in female siblings (15.8% vs 3.4%, p = 0.012). Mild scarring was not significantly associated with reflux grade or patient sex. Children diagnosed before age 3 years showed significantly less scarring than patients diagnosed later (23% vs 41%, p <0.002).

CONCLUSIONS

The development of mild renal scarring seems to mainly depend on urinary tract infections, while moderate and severe scarring are also associated with high grade reflux and male sex. Early detection and treatment may prevent further urinary tract infections as well as reflux related kidney damage.

Vesicoureteral reflux – current treatment options

Vesicoureteral reflux has long been recognised as a major child and public health problem. Widespread recognition and screening of at-risk populations has the potential to significantly reduce long-term morbidity in both children and adults. Advances in pharmacotherapy, materials science and surgery, have caused many experts to reassess established dictums of treatment. Concern regarding the overuse of antibiotics and surgery has led to efforts to tailor therapy more narrowly for those who are at the highest risk from recurrent urinary tract infection and pyelonephritis. Children after a certain age, without underlying voiding dysfunction, might not require treatment at all. Newer surgical and anaesthetic techniques have the potential of transforming surgical correction from a painful experience to an ambulatory procedure, with a rapid return to daily activities. Both the promise and pitfalls of these newest advances will be discussed in this review.

Renal parenchymal damage in sibling vesicoureteric reflux

AIM

To compare the incidence of renal damage in siblings of patients with vesicoureteric reflux (VUR) who presented with a documented history of urinary tract infection (UTI) with asymptomatic siblings who were diagnosed with reflux during a screening programme for hereditary VUR.

METHODS

Medical and radiological records of the VUR patients (1990-2000) were examined for age, gender, mode of presentation, reflux grade and renal damage.

RESULTS

VUR was noted in 226 siblings (352 ureters) in 107 families. Of the 119 siblings of index patients, 64 were investigated for a documented UTI and 55 with no history of UTI were detected during screening for sibling reflux. Dimercaptosuccinic acid scan revealed reflux nephropathy in 25 (26%) of the 97 renal refluxing units (RRU) of siblings who presented with a UTI and in 6 (7%) of the 89 RRU of asymptomatic siblings who underwent screening voiding cystourethrography (p=0.0006). Mild renal damage was present in 20 (21%) RRU of siblings with UTI and in 2 (2%) RRU of the screened siblings (p < 0.001). Moderate to severe renal damage was present in 5 (5%) RRU of siblings with UTI and in 4 (4%) RRU of the screened siblings (p > 0.05).

CONCLUSION

This study demonstrated that the incidence of mild renal scarring was much higher in siblings who presented with UTI than in asymptomatic siblings. However, the incidence of moderate and severe renal scarring among asymptomatic siblings was comparable to that in siblings with VUR and UTI.

Familial vesicoureteral reflux

PURPOSE

Vesicoureteral reflux is known to occur in families. We summarized worldwide data on the incidence and nature of vesicoureteral reflux in siblings of children with vesicoureteral reflux.

MATERIALS AND METHODS

We searched MEDLINE using the words siblings vesicoureteral reflux, familial vesicoureteral reflux, offspring vesicoureteral reflux and vesicoureteral reflux screening. All articles that we identified that were published from 1972 to 2002 were analyzed for the incidence of renal damage in siblings of patients with vesicoureteral reflux.

RESULTS

Siblings of patients with vesicoureteral reflux have a much higher incidence of reflux than the normal population. There is a direct relationship of patient age to the incidence and severity of reflux. Most investigators advocate screening asymptomatic siblings of patients with vesicoureteral reflux.

CONCLUSIONS

The incidence of sibling reflux is significant. When vesicoureteral reflux is discovered in symptomatic siblings, it is usually high grade and associated with a high incidence of reflux nephropathy. Randomized controlled studies are needed to compare renal damage in patients with reflux detected through screening to renal damage in those diagnosed after urinary tract infection to establish how much renal damage may be prevented by screening in asymptomatic siblings.

Screening siblings for vesicoureteral reflux

PURPOSE

Publications on screening the siblings of patients with reflux were reviewed to determine the overall incidence and severity of reflux and renal scarring in siblings, and identify factors that predict siblings more likely to have reflux.

MATERIALS AND METHODS

A MEDLINE search for 1985 to the present was performed. Of 34 articles on familial reflux only 11, including 1 abstract, on sibling screening were used in this analysis.

RESULTS

The mean incidence of reflux in siblings in all studies was 32% (570 of 1,768). Of the siblings with reflux approximately two-thirds had grades I to II disease. Only 22 of 1,051 siblings (2%) had reflux greater than grade III. Reflux was unilateral in 162 of 307 cases (53%). Certain factors predicted the chance of sibling reflux. Sibling age varied inversely with the incidence of reflux. A twin relationship and absent dysfunctional voiding symptoms in the index patient may predict a higher chance of reflux in a sibling. The mean incidence of renal abnormality in siblings with reflux was 11%. The incidence of reflux and renal abnormality in the sibling population undergoing screening was 3%. In more than half of the siblings with an abnormal renal evaluation there was no history of urinary tract infection.

CONCLUSIONS

The studies reveal an incidence of reflux in siblings greater than in the general population. These data do not prove that screening and treating asymptomatic siblings decreases infectious renal scarring. Studies in a control group that consider sibling age are still needed to determine the benefit of screening asymptomatic siblings.

Future expectations--what paediatric nephrologists and urologists await from paediatric uroradiology

Cooperation between paediatric nephrology/urology and paediatric radiology is essential for timely and correct diagnosis and therapy of kidney and urinary tract disorders. We need the direct contact between doctors before or after investigations, interdisciplinary discussions, and rapid access to the images. This should lead to optimal settings for investigations, a reduction of radiation burden and the number of investigations, and further improvement in the management of patients. Modern sonography including colour Doppler sonography, amplitude-coded Doppler sonography, and eventually 3D-ultrasound is and will be the method of choice as the basic, non-invasive investigation. These investigations should become the routine in all institutions. Refinement and standardisation of already established investigations are needed. Recently introduced investigations, like MRI, will have to show their impact on future diagnostic imaging. Future introduction of new non-invasive methods is welcome, e.g. to correctly diagnose vesicoureteral reflux without catheterisation/puncture of the bladder.

Susceptibility to vesicoureteral reflux in Japanese is linked to HLA-DR antigen

OBJECTIVES

To determine whether vesicoureteral reflux is associated with the human leukocyte antigen (HLA) genes.

METHODS

We evaluated 40 Japanese patients (27 males and 13 females) with reflux. HLA-DR low-resolution genotyping and high-resolution typing of HLA-DRB1 alleles were performed. The frequencies of the HLAs and alleles were calculated and compared with those previously reported in 493 healthy Japanese.

RESULTS

Low-resolution typing showed that the frequency of the HLA-DR11 antigen was significantly higher in the patients with reflux than in the control group. High-resolution typing revealed that the frequencies of HLA-DRB1*1101 and 1502 alleles were significantly higher in the patients with reflux than in the control group. In the patients with and without renal scarring, the frequencies of the HLA-DR11 antigens and HLA-DRB1*1101 alleles were significantly lower in those with renal scarring. In the patients with and without the chief complaint of urinary tract infection symptoms, the frequencies of HLA-DR13 antigens and HLA-DRB1*1302 alleles were significantly lower in those with that chief complaint.

CONCLUSIONS

The susceptibility to reflux is, in part, controlled by HLA genes themselves or an unknown gene or genes, the locus for which is located close to the DRB1 gene. The lack of a HLA-DRB1*1101 allele and DRB1*1302 allele in patients with reflux might be connected with renal scarring and urinary tract infection, respectively.

Reflux nephropathy in infancy: a comparison of infants presenting with and without urinary tract infection

PURPOSE

We compared the incidence of renal scarring in infants with high grade vesicoureteral reflux in those presenting with and without urinary tract infection.

METHODS AND METHODS

We reviewed the medical records of 81 male and 46 female infants (194 renal refluxing units) with a mean age of 4 months who had grade IV or V primary vesicoureteral reflux and underwent an anti-reflux procedure between 1984 and 1997. Dimercapto-succinic acid (DMSA) scans and voiding cystourethrography were performed in all cases. Patients were followed for 2 to 16 years, including 90% for greater than 3 years. Renal ultrasound and DMSA scan were done at followup.

RESULTS

A total of 97 patients (76%) (148 refluxing renal units) presented clinically with urinary tract infection. The initial DMSA scan demonstrated renal scarring in 40 of the 106 grade IV (38%) and 28 of the 42 grade V (67%) refluxing renal units. There was no scarring on followup in previously normal refluxing renal units. Of the patients 30 (24%) (46 refluxing renal units) were diagnosed before a urinary tract infection developed, 16 underwent screening due to vesicoureteral reflux in a sibling and in 10 reflux was initially suspected due to hydronephrosis on prenatal ultrasound. In the remaining 4 patients vesicoureteral reflux was suspected during abdominal ultrasound to investigate abdominal pain, jaundice, associated hypospadias and fetal alcohol syndrome, respectively. DMSA scan showed evidence of scarring in 6 of 21 grade IV (29%) and 9 of 25 grade V (36%) refluxing renal units in this group. Followup revealed scarring in only 1 previously normal refluxing renal unit.

CONCLUSIONS

The incidence of reflux nephropathy in primary grade V vesicoureteral reflux is lower in cases detected by screening and with treatment it remained lower than in cases of urinary tract infection that presented clinically. Early treatment of grade V vesicoureteral reflux made possible by screening may prevent renal damage.

Management of vesicoureteral reflux in children

Although much has been learned about the diagnosis and management of vesicoureteral reflux, several important areas of investigation remain. Because not all children with reflux are equally susceptible to renal scarring and the development of reflux nephropathy, controversy surrounds the need to evaluate all children with urinary tract infection or to continue prophylaxis in known refluxing children after a certain age. In addition to age, other factors such as sex, grade of reflux, and the presence of voiding dysfunction can all play a role. The grade of reflux as seen on the contrast voiding cystourethrogram is the best predictor of reflux resolution in large numbers of patients, but grade alone cannot predict spontaneous cessation in any one individual. Attempts at refining more quantitative imaging modalities have so far proved unsuccessful. Open ureteral reimplantation remains the standard for surgical care if surgery is necessary. Both cystoscopic and laparoscopic techniques, however, may ultimately prove to be reliable, minimally invasive approaches to definitive correction. Finally, there are data to support continued diagnosis and treatment of reflux in at-risk populations. The incidence of reflux-related morbidity in children has significantly diminished over the last three decades. A major challenge is to better identify at-risk subpopulations of children with reflux, so that not every child will require intensive, long-term medical treatment or surgery.

Scintigraphic screening for renal damage in siblings of children with symptomatic primary vesico-ureteric reflux

OBJECTIVE

To define prospectively the incidence of renal parenchymal lesions in the siblings of patients treated at one institution for primary vesico-ureteric reflux (VUR).

PATIENTS AND METHODS

From January 1997 to October 1998, a prospective study including renal scintigraphy (using dimercaptosuccinic acid, DMSA) and a radionuclide cystogram was proposed systematically to the asymptomatic siblings of children treated for primary VUR. The radionuclide cystograms were interpreted as showing the presence or absence of VUR and the DMSA scan as symmetrical or asymmetrical differential function, with or with no renal defect.

RESULTS

Fifty-five families gave informed consent, of whom 46 completed the study (eight refused secondarily and one was omitted by exclusion criteria), representing 46 symptomatic patients and 65 siblings. There were 17 siblings with VUR (26%) including two of 13 infants and 15 of 52 children aged > 18 months. One radionuclide cystogram failed. Of the 17 refluxing siblings, four had a history of symptomatic urinary tract infection; 62 of the 65 siblings had a DMSA scan, of which 56 were normal and six (10%) showed abnormalities (five asymmetrical differential function and one parenchymal defect). Only one of these six patients had VUR at the time of the evaluation and only one had a small kidney detected by ultrasonography on one side (and no VUR). There were no adverse effects associated with screening.

CONCLUSION

This study confirms a significant overall incidence of VUR (26%) in the asymptomatic siblings of patients treated for primary VUR. From the results of the DMSA scan (only one sibling had a parenchymal defect), the systematic screening of asymptomatic siblings does not appear to be beneficial.

Sibling vesicoureteral reflux in multiple gestation births

BACKGROUND

Vesicoureteral reflux (VUR) is the most commonly inherited disease of the genitourinary tract. Although the majority of evidence supports a genetic cause, the tendency for this condition to spontaneously improve over time has made it difficult to determine the actual mode of transmission. We report the incidence of VUR in siblings of multiple gestation births and for the first time compare the relative incidence of reflux between identical and fraternal twins.

METHODS

A database consisting of all radionuclide cystograms and voiding cystourethrograms performed between the years 1986 and 1996 was searched for multiple gestation births. The medical records of each patient were evaluated for age at presentation, zygosity, reflux grade, and time to resolution. Children with secondary causes of VUR (eg, posterior urethral valves) were excluded. Triplets were treated as 2 pairs of twins for statistical analysis.

RESULTS

Forty-six pairs met the inclusion criteria (31 dizygotic and 15 monozygotic). Overall, 23 (50%) of 46 siblings of index cases had demonstrable VUR. Comparison of VUR prevalence between identical and nonidentical twins was revealing with 80% (12/15) of identical twins and 35% (11/31) of fraternal twins having VUR. When only the youngest individuals in each group were considered, 100% (7/7) of the monozygotics and 50% (5/10) of the dizygotics demonstrated this trait.

CONCLUSIONS

High concordance for VUR in identical twin siblings supports a genetic basis for the transmission of this disease. Results obtained from fraternal twin siblings provides convincing evidence that this trait is transmitted in an autosomal dominant fashion.

Vesico-ureteric reflux: occurrence and long-term risks

The prevalence of vesico-ureteric reflux in the general population is unknown, but it is increased in risk groups, such as children with symptomatic urinary tract infection, schoolgirls with asymptomatic bacteriuria, first-degree relatives of patients with reflux and children with prenatal dilatation of their upper urinary tract. Children and adults with pyelonephritic renal scarring are at risk of serious long-term complications, e.g. hypertension and renal failure. Modern paediatric care, with early detection and treatment of urinary tract infections and reflux during childhood and adolescence, may improve long-term prognosis. In the adult patient with established pyelonephritic renal scarring, careful control of hypertension may retard the rate of progression, and angiotensin converting enzyme inhibitors may have renal protective properties.

Associated urological anomalies in children with unilateral renal agenesis

PURPOSE

Unilateral renal agenesis has been noted in 1:1,000 autopsies. Recently an increased incidence of vesicoureteral reflux was reported in patients with a solitary kidney. We determined the incidence of associated renal abnormalities in children with unilateral renal agenesis.

MATERIALS AND METHODS

We retrospectively reviewed 46 consecutive cases of unilateral renal agenesis diagnosed at our hospital between January 1985 and February 1998. Patient age at diagnosis ranged from newborn to 12.5 years (mean 2.8 years). There were 24 boys and 22 girls. The left kidney was absent in 27 patients and the right kidney was absent in the remaining 19. A total of 24 patients were evaluated for urinary tract infection and in the other 22 a solitary kidney was found during examination for congenital malformations, enuresis or abdominal pain. The diagnosis was made in all patients by abdominal ultrasound and confirmed by excretory urography, or diethylenetriaminepentaacetic acid or dimercapto-succinic acid scan. A voiding cystourethrogram was performed in 40 patients (87%).

RESULTS

Associated urological anomalies were present in 22 of the 46 patients (48%) with unilateral renal agenesis, including primary vesicoureteral reflux in 13 (28%), ureterovesical junction obstruction in 5 (11%), ureteropelvic junction obstruction in 3 (7%), and ureterovesical and ureteropelvic junction obstruction in 1 (2%). Of the 22 patients 14 (64%) underwent surgical intervention.

CONCLUSIONS

Nearly half of the patients with unilateral renal agenesis had associated urological anomalies. Vesicoureteral reflux was the most common associated anomaly and it was usually of high grade. Early recognition and treatment of urological anomalies in a patient with a solitary kidney are imperative to decrease the long-term risk of renal damage.

Associated urological anomalies in children with unilateral renal agenesis

PURPOSE

Unilateral renal agenesis has been noted in 1:1,000 autopsies. Recently an increased incidence of vesicoureteral reflux was reported in patients with a solitary kidney. We determined the incidence of associated renal abnormalities in children with unilateral renal agenesis.

MATERIALS AND METHODS

We retrospectively reviewed 46 consecutive cases of unilateral renal agenesis diagnosed at our hospital between January 1985 and February 1998. Patient age at diagnosis ranged from newborn to 12.5 years (mean 2.8 years). There were 24 boys and 22 girls. The left kidney was absent in 27 patients and the right kidney was absent in the remaining 19. A total of 24 patients were evaluated for urinary tract infection and in the other 22 a solitary kidney was found during examination for congenital malformations, enuresis or abdominal pain. The diagnosis was made in all patients by abdominal ultrasound and confirmed by excretory urography, or diethylenetriaminepentaacetic acid or dimercapto-succinic acid scan. A voiding cystourethrogram was performed in 40 patients (87%).

RESULTS

Associated urological anomalies were present in 22 of the 46 patients (48%) with unilateral renal agenesis, including primary vesicoureteral reflux in 13 (28%), ureterovesical junction obstruction in 5 (11%), ureteropelvic junction obstruction in 3 (7%), and ureterovesical and ureteropelvic junction obstruction in 1 (2%). Of the 22 patients 14 (64%) underwent surgical intervention.

CONCLUSIONS

Nearly half of the patients with unilateral renal agenesis had associated urological anomalies. Vesicoureteral reflux was the most common associated anomaly and it was usually of high grade. Early recognition and treatment of urological anomalies in a patient with a solitary kidney are imperative to decrease the long-term risk of renal damage.

Contemporary incidence of morbidity related to vesicoureteral reflux

OBJECTIVES

The association among vesicoureteral reflux (VUR), renal scarring, and reflux nephropathy is well established. Screening programs for children who present with urinary tract infection (UTI) and their siblings, along with medical and surgical management, have been promoted by pediatric medical and urologic specialists in Buffalo and the surrounding community for more than two decades. Has this comprehensive and costly effort resulted in a decrease in VUR-related morbidity and should it be continued?

METHODS

The records of all active patients who presented from 1982 through 1997 to this region's single pediatric nephrology referral center were reviewed. One hundred twenty-two children and adolescents (73 boys, 49 girls) were identified with hypertension (HTN), renal insufficiency (RI), and end-stage renal disease (ESRD) requiring dialysis or transplantation.

RESULTS

There were 70 patients (57%) with HTN, 19 (16%) with RI, and 33 (27%) with ESRD. Reflux nephropathy was the underlying cause in 6 patients (5%)-3 with HTN and 3 with ESRD. The etiologies of morbidity in the remaining patients were medical renal disease, 61 (50%); idiopathic, 17 (14%); obstructive uropathy, 14 (11%); primary congenital renal hypoplasia, 12 (10%); and vascular, 12 (10%). Of the 6 patients with VUR-related morbidity, 4 were boys (3 with ESRD, 1 with HTN) and 2 were girls (with HTN). Five children presented in the 1980s and 1 in the 1990s. Only 1 patient had a history of UTI, and she presented early in the series in 1982 at 5 years of age. Ages of presentation were infancy (2 boys), early childhood (1 boy, 1 girl), and adolescence (1 boy, 1 girl). Reasons for presentation were failure to thrive (n = 2), voiding dysfunction without UTI (n = 1), muscle cramps (n = 1), UTI (n = 1), and HTN (n = 1). Reflux grade ranged from I to V, but 4 patients had grade III or less.

CONCLUSIONS

Awareness of VUR-related morbidity has led to more widespread diagnosis and treatment, which appears to have resulted in a dramatic decrease in the numbers of affected patients in this community. The diagnosis and treatment of VUR has altered the epidemiology of HTN and renal failure in children and young adults.

Urinary tract infection and renal damage in sibling vesicoureteral reflux

PURPOSE

Siblings of index patients with vesicoureteral reflux are known to have an increased incidence of reflux. Previously reported studies have evaluated vesicoureteral reflux in asymptomatic siblings of children who were previously proved to have reflux. We determine the incidence and nature of vesicoureteral reflux in symptomatic siblings of children with documented vesicoureteral reflux.

MATERIALS AND METHODS

Between January 1990 and December 1996, 624 patients were diagnosed with vesicoureteral reflux during the investigation of documented urinary tract infections. All patients were evaluated for reflux by contrast voiding cystourethrography and reflux was graded according to the international reflux study. 99mTechnetium dimercapto-succinic acid nuclear renal scans were performed to detect renal scarring. The medical records and voiding cystourethrograms of the 624 consecutive patients with vesicoureteral reflux were retrospectively reviewed to identify siblings with vesicoureteral reflux.

RESULTS

Vesicoureteral reflux was noted in 85 siblings (134 refluxing ureters) of the 624 index patients (13.6%), including 1 and 2 siblings of 38 and 3 patients, respectively. Mean age at presentation of the 37 boys and 48 girls was 2.5 years. Reflux was unilateral in 36 siblings and bilateral in 49. Reflux was grades I to V in 8, 9, 51, 55 and 11 ureters, respectively. Nuclear scan revealed reflux nephropathy in 22 of the 77 tested siblings (28.5%).

CONCLUSIONS

When vesicoureteral reflux is discovered in symptomatic siblings, it is usually high grade and associated with a higher incidence of reflux nephropathy. Of further interest are the findings that refluxing symptomatic siblings of index patients are usually younger and boys are as commonly affected as girls. Screening for vesicoureteral reflux in asymptomatic siblings is recommended to decrease the incidence of reflux nephropathy.