Pyelonephritis following pediatric renal transplant: increased incidence with vesicoureteral reflux

The association between pyelonephritis and vesicoureteral reflux (VUR) following pediatric renal transplantation is unclear. To understand the relationship of vesicoureteral reflux with urinary tract infection (UTI) and pyelonephritis, 67 patients were evaluated for reflux and pyelonephritis. Sixty-seven pediatric patients, aged 2 to 18 (39 males and 28 females) underwent renal transplantation. Beginning in 1982, all patients underwent voiding cystourethrography or radionuclide voiding studies 1 to 3 months postoperatively to assess the incidence of VUR. Techniques of ureteroneocystostomy (UNC) included the Leadbetter-Politano (L-p) in 39 cases, and two different modifications of the LICH (herein called LICH-1 and LICH-2) in 30 cases. Urinary cultures were performed routinely. Pyelonephritis was considered present in any patient with UTI and increased serum creatinine or fever greater than 38.5. VUR occurred in 36% of patients; highest in LICH-1 (79%), intermediate in L-P (22%), and lowest in LICH-2 (9%). VUR was not statistically significantly higher in females (43%) v males (31%). UTI occurred in 37% of patients. The difference in incidence between females (54%) and males (26%) was significant (P less than .05). The frequency of UTI in patients with VUR was 46% v 33% in patients without reflux (NS). However, pyelonephritis that occurred in 16% of cases overall was present in 82% of UTIs in patients with reflux v 14% of UTIs in patient without reflux (P less than .01). Pyelonephritis is significantly increased in pediatric renal transplant patients with UTI was have VUR. A nonrefluxing UNC is advocated in all patients. All renal transplant patients should have routine monitoring of urinary cultures and should be evaluated of VUR posttransplant.     

Vesicoureteral reflux after kidney transplantation in children.

BACKGROUND: The prevalence and significance of vesicoureteral reflux (VUR) after kidney transplantation in adults varies between authors and there have been few reports in children. METHODS: We conducted a retrospective study in a single-centre paediatric cohort. Fifty-five of the 84 children who underwent kidney transplantation over a 5-year period were checked with routine cystography after a median of 8 months post-transplantation. Graft function and urinary-tract infections were assessed during the first 6 years after transplantation. RESULTS: VUR into the graft was present in 58% of the patients. Graft function and incidence of urinary-tract infections were similar in the two groups, independent of VUR. After having excluded infections attributed to the presence of a catheter, actuarial survival rates without pyelonephritis and without pyelonephritis following a first lower urinary-tract infection were worse in patients with VUR (P:=0.017 and P:=0.0039 respectively). None of the eight patients with VUR treated with antibiotic prophylaxis after a first acute pyelonephritis (APN) episode presented subsequent APN after 4.4+/-3.3 years on therapy. CONCLUSIONS: VUR to the graft occurred in more than half paediatric renal transplant recipients. This condition was associated with an increased risk of APN. Long-term antibiotic prophylaxis seems to be able to prevent APN in transplanted children with VUR.     

Use of collagen injections for vesicoureteral reflux in transplanted kidneys

Reports in the literature suggest the incidence of vesicoureteral reflux (VUR) in transplanted kidneys to range from 2-79%. Collagen injections have been used with reported success rates of up to 65% to prevent VUR into native orifices in children, but have not been studied in transplant neo-orifices. We evaluated the use of collagen injections in seven patients with transplant kidney neo-orifices who displayed grades II-IV VUR and seemed to be related to symptomatic urinary tract infections (UTIs). Postoperative VCUGs obtained at 2 months showed improvement in the grade of reflux in four of seven (57.1%) patients; one (14.3%), no change; and two (28.6%), worse reflux. All patients also redeveloped symptomatic UTIs after collagen injection. We conclude that the use of collagen injections in kidney transplant neo-orifices did not prevent VUR. Although prevention of VUR may have been achieved short term, VCUG examinations 2 months after initial injection revealed persistent reflux. Etiologies for failure to prevent VUR may be the readily absorbable nature of collagen, technical aspects of the procedure, the degree of reflux, and anatomic differences between native orifices (which lie on a well-supported trigone) and transplant neo-orifices (which lie on the posterior wall with less support).     

Impact of vesicoureteral reflux on the size of renal lesions after an episode of acute pyelonephritis

PURPOSE: We determined the impact of vesicoureteral reflux (VUR) on the size of renal lesions in children after an episode of acute pyelonephritis. MATERIALS AND METHODS: A total of 161 children (mean age 2.44 years) with acute pyelonephritis were studied. All had renal lesions on dimercapto-succinic acid scintigraphy done at admission to the hospital. A second dimercapto-succinic acid scan was performed at 3 months. Voiding cystourethrography was done at 6 weeks and VUR was graded I to V. For each renal unit layouts of renal lesions were drawn, and the damage surface was calculated and reported for the total surface of the kidney. RESULTS: Mean size of acute lesions and scars increased with severity of reflux (p <0.0001), with an important overlap of individual values. Mean size of renal scars in the group of renal units with acute lesions was 5.8% +/- 8.5% in patients without VUR, 9.9% +/- 7.3% in those with grade I reflux, 7.7% +/- 11.0% in those with grade II reflux, 17.7% +/- 14.7% in those with grade III reflux and 17.4% +/- 27.7% in those with grade IV reflux (p <0.001). The size of renal lesions decreased significantly with time. The rate of regression of lesions decreased with increasing reflux. When analyzed according to 3 age groups sizes of scars increased significantly with age. CONCLUSIONS: VUR has an impact on the size of renal lesions after an episode of pyelonephritis. Children with a grade III or IV reflux are more likely to have larger renal scars. On the other hand, acute lesions of important size may develop even in the absence of VUR.     

Clinical significance of posttransplantation vesicoureteral reflux during short-term period after kidney transplantation

BACKGROUND: Urinary tract infection (UTI) may occur in the form of asymptomatic bacteruria but severe cases may cause life-threatening pyelonephritis or sepsis in immunosuppressed kidney transplant recipients. Vesicoureteral reflux (VUR) is one risk factor in the transplanted kidney. But controversy exists regarding the effect of VUR in terms of graft outcomes. The objective of this study was to analyze the clinical outcomes among patients with posttransplantation VUR. PATIENTS AND METHODS: Between April 2005 and June 2006, we examined 75 patients with functioning grafts for more than 1 year by voiding cystourethrography at 1 year for the grade of posttransplantation VUR: group A, absent (n = 28) including grade I (n = 6) and II (n = 22); group B, including grade III (n = 17) and IV (n = 2). Patient characteristics included etiology of end-stage renal disease, duration of dialysis before transplantation, serum creatinine, creatinine clearance at 1 and 12 months after transplantation, and postoperative complications. The presence/absence of UTI, acute rejection, and graft loss were compared for significance. RESULT: Posttransplantation VUR present in 47/75 patients (61.3%) was over grade III in 19 patients. There was no difference in significant risk factors between the groups as well as between the reflux subgroups. VUR did not influence graft function with the only significant factor being acute cellular rejection. CONCLUSION: We failed to confirm a risk of developing posttransplantation VUR. Posttransplantation VUR did not negatively affect graft function; acute cellular rejection was the only factor that influenced it. Longer follow-up needs to be performed to clarify the long-term effects of posttransplantation VUR on graft function.     

Post-pyelonephritic renal scars are not associated with vesicoureteral reflux in children

PURPOSE: Children with pyelonephritis are at risk for renal damage. We assess the value of clinical signs and urological abnormalities in predicting renal scars in children following pyelonephritis. MATERIALS AND METHODS: A total of 64 hospitalized children (29 females and 35 males, median age 2.9 years) underwent ultrasonography and technetium labeled dimercapto-succinic acid (DMSA) scintigraphy imaging within 1 week following the diagnosis of the first pyelonephritis. Voiding cystourethrography was performed 8 weeks after the diagnosis. Followup DMSA scintigraphy was performed in 58 patients after 2 years of followup. RESULTS: Urological abnormalities observed were vesicoureteral reflux (VUR, grade 2 or higher) in 11 patients (19%), nonrefluxing and nonobstructed megaureter in 2 (4%) and pyeloureteral obstruction in 1 (2%). The first DMSA scintigraphy showed parenchymal defects in 48% of patients. VUR did not increase the risk of renal defects. At 2 years after the infection 12 of the 58 patients (21%) had renal scars. Nine of these patients did not have VUR. However, 2 patients with high grade VUR and repeat infections demonstrated deterioration of kidney function during followup. The patients with renal scars were older than those without scars (3.1 vs 0.8 years, p = 0.0291) at the time of infection. CONCLUSIONS: Renal scars after first pyelonephritis are in most cases not associated with abnormalities of the urinary tract, but are caused by the infection itself. However, structural abnormalities may predispose to recurrent infections. Following pyelonephritis new renal scars may develop in all age groups in both sexes.     

Vesicoureteral reflux and renal scarring. Report of cooperative study of "Progressive renal disease" of Ministry of Health and Welfare

196 cases with vesicoureteral reflux (VUR) from multiple centers were analysed to examine the relationship between VUR and reflux nephropathy. The high correlation (p less than 0.01) was observed between reflux and renal scarring. Even in cases in whom VUR was not demonstrated at the time of testing, renal scarring of various degrees was recognized, suggesting either co-existed hypoplastic kidney or pre-existed infection. The renal scarring, but not VUR, had a significant correlation with proteinuria and hypertension. Retrospective analysis shows that the surgical treatment was closely related to the degree of renal scarring but not to the degree of reflux. Renal scarring progressed even when reflux did not become worse, which is probably accounted for by the presence of pyelonephritis. Although frequency of pyelonephritis decreased significantly (p less than 0.01) from 0.60 +/- 0.89 to 0.084 +/- 0.305 times/patient. year after anti-reflux surgery, renal scarring progressed in 13 kidneys (5.8%). Seven of the 13 kidneys became worse due to the surgical failure. The scar progression was recognized in the remaining six kidneys (three patients) including adult cases despite the successful surgical correction of reflux. Our study points to the urged need for a prospective clinical trial designed for the study of the pathological and clinical background of progressive renal failure in VUR.     

Reflux nephropathy secondary to intrauterine vesicoureteric reflux

In 107 infants with 182 antenatally diagnosed urinary tract anomalies, 24 had either unilateral (12) or bilateral (12) vesicoureteric reflux (VUR). The VUR was more common in boys (male to female ratio, 16:8) and usually severe (grades IV [16], III [10], II [4], and I [6]). Intravenous pyelography showed the changes of atrophic pyelonephritis in 10 refluxing units, and in another two with an associated pelviureteric junctional hydronephrosis. Lateral ectopia of the ureteric orifices was noted in six of these 10 refluxing renal units. Isotopic renography showed a reduction in function in nine of the 14 patients examined, ranging between 9% and 41%. (45% and above was considered within the normal range). Only two patients developed a urinary infection before intravenous pyelography or isotopic renography was performed, suggesting that renal changes noted were primary rather than secondary. Findings support the hypothesis that foetal VUR may be a contributing factor in the causation of atrophic pyelonephritis (foetal reflux nephropathy) observed in these patients.     

Value of Routine Voiding Cystourethrography After Renal Transplantation

The impact of vesicoureteral reflux (VUR) on renal allograft outcomes is debatable, with small cohort studies reporting controversial results. The objective of this retrospective study was to evaluate long‐term clinical effects of early VUR in a large cohort of kidney transplant patients. Posttransplantation voiding cystourethrography was used to evaluate 646 consecutive kidney transplant recipients before discharge. The study endpoints included VUR grade, death‐censored graft or patient survival, renal function, proteinuria and occurrence of urinary tract infections (UTIs). Of the 646 recipients, 263 (40.7%) were diagnosed with VUR. VUR grade II was most common (19.8%), followed by grades III (10.2%), I (7.9%) and IV (2.8%). VUR was less common in transplantations performed by experienced compared to inexperienced surgeons (36% vs. 48%; p = 0.004). VUR did not affect death‐censored graft or patient survival and was not associated with proteinuria or occurrence of UTIs. Patients with VUR had a lower eGFR at 1 year after transplantation than did patients without VUR (60 vs. 52 mL/min/1.73 m²; p = 0.02), although this difference was not observed at 3 and 5 years after transplantation. We conclude that early VUR, a common finding among renal transplant patients, may not have a meaningful impact on long‐term transplant outcomes.     

Surgical management of vesicoureteral reflux in children

Vesicoureteral reflux (VUR) is the most common uropathy affecting children. Compared to children without VUR, those with VUR have a higher rate of pyelonephritis and renal scarring following urinary tract infection (UTI). Options for treatment include observation with or without antibiotic prophylaxis and surgical repair. Surgical intervention may be necessary in patients with persistent reflux, renal scarring, and recurrent or breakthrough febrile UTI. Both open and endoscopic approaches to reflux correction are successful and reduce the occurrence of febrile UTI. Estimated success rates of open and endoscopic reflux correction are 98.1% (95% CI 95.1, 99.1) and 83.0% (95% CI 69.1, 91.4), respectively. Factors that affect the success of endoscopic injection include pre-operative reflux grade and presence of functional or anatomic bladder abnormalities including voiding dysfunction and duplicated collecting systems. Few studies have evaluated the long-term outcomes of endoscopic injection, and with variable results. In patients treated endoscopically, recurrent febrile UTI occurred in 0–21%, new renal damage in 9–12%, and recurrent reflux in 17–47.6% of treated ureters with at least 1 year follow-up. These studies highlight the need for standardized outcome reporting and longer follow-up after endoscopic treatment.     

Screening for vesicoureteral reflux and renal scars in siblings of children with known reflux

The incidence of vesicoureteral reflux (VUR) in the general population is less than 1%, but it is high in families with reflux. The reported prevalence of VUR among siblings of index patients with reflux has ranged from 4.7% to 51%. Reflux carries an increased risk of pyelonephritis and long-term renal impairment. The purpose of this study was to identify the age-related incidence and severity of reflux, and the frequency of associated renal parenchymal damage in siblings of children with reflux in order to assess the use of screening at different ages. Between October 1994 and February 2003, 40 siblings of 34 index patients were screened with direct voiding cystography. 99( m ) technetium (Tc)-dimercaptosuccinic acid (DMSA) nuclear renal scans were performed in siblings with VUR to detect renal scarring. The cystograms were interpreted as showing the presence or absence of VUR and the DMSA scan as symmetrical or asymmetrical differential function, with or without renal scarring. Of 40 siblings, 17 had VUR, representing an incidence of 42.5%. The mean age at study entry of the 15 boys and 25 girls was 63 months (range 6 months to 12 years). The majority of siblings with abnormal DMSA scans were asymptomatic. Reflux was unilateral in 12 siblings and bilateral in 5. Of the 17 refluxing siblings (22 refluxing ureters), 7 (41.17%) had a history of symptomatic urinary tract infection (UTI). The frequency of VUR was nearly equal in siblings over 6 years and those younger than 6 years. Of the 17 siblings with VUR, 16 had DMSA scintigraphy. Of these, 5 were normal and 11 (68.75%) showed abnormalities (7 asymmetrical differential function and 4 parenchymal defect), which was bilateral in 7 and unilateral in 4. In conclusion, this study confirms a significant overall incidence of VUR and renal parenchymal damage in the siblings of patients with known reflux. The prevalence of reflux in older siblings is similar to that in younger siblings. Our review suggests that all siblings over 6 years should undergo a screening cystogram, even in the absence of urinary tract infection. DMSA scintigraphy of asymptomatic siblings appears to be beneficial in preventing renal injury.     

Therapy for vesicoureteral reflux: Antibiotic prophylaxis,urotherapy, open surgery,endoscopic injection,or observation?

Vesicoureteral reflux (VUR) refers to the retrograde flow of urine from the bladder into the ureter and renal pelvis. It generally results from congenital maldevelopment of the ureterovesical junction, although VUR may develop in individuals with abnormally high detrusor pressure. VUR increases a child’s susceptibility to pyelonephritis and renal scarring. Treatment goals include the prevention of pyelonephritis, reflux nephropathy, and other complications of reflux. Treatment alternatives include antibiotic prophylaxis, urotherapy (correction of voiding dysfunction), and surgical correction (open, injection therapy, or laparoscopic). Recent studies have challenged the presumed benefit of prophylaxis in children with VUR, while long-term retrospective studies have documented a high rate of hypertension in adults with reflux nephropathy. In addition, the risk of persistent VUR in adulthood is unresolved. These reports have stimulated a reevaluation of the role of various treatment options in children with VUR.     

Recurrent pyelonephritis without vesicoureteral reflux: is there a role for an antireflux procedure?

PURPOSE: To evaluate the results of an endoscopic antireflux procedure in women with recurrent acute pyelonephritis and no evidence of vesicoureteral reflux (VUR) on voiding cystograms. PATIENTS AND METHODS: From 1989 to 1999, 603 female patients were hospitalized for acute pyelonephritis with unilateral loin pain, chills, fever, and a positive urine culture. Of these patients, 48 (8%) had recurrent episodes of acute pyelonephritis and underwent a thorough diagnostic work-up including intravenous urography or renal CT scan, cystoscopy, and voiding cystourethrography (VCUG). Vesicoureteral reflux was demonstrated in 21 patients, who were then offered an antireflux procedure, either surgical or endoscopic. Another 27 patients had no reflux on VCUG; in 15 cases, the upper urinary tract was normal, and the ureteral orifices did not show any abnormality on cystoscopy. The other 12 patients in this group with a normal VCUG had one or more abnormal findings normally associated with VUR: renal scarring in five and ureteral duplication in two. Golf-hole ureteral orifices were noted in two patients. The intravesical ureter was short (< 5 mm) in five patients. In spite of the normal VCU, we offered these patients endoscopic treatment of VUR by submeatal injection of Teflon or microparticulate silicone (Macroplastic). The median follow-up before treatment was 4 years (range 1-15.3 years); 0.3 episodes of acute pyelonephritis per patient-month of follow-up were noted. The frequence of preoperative and postoperative episodes of acute pyelonephritis was compared with Wilcoxon's paired analysis. The median postoperative follow-up was 3.9 years (range 1.1 months-10.2 years). RESULTS: There were no significant postoperative complications. One patient had two episodes of acute pyelonephritis during pregnancy. On the whole, 11 patients (91%) were free of recurrent pyelonephritis after treatment. Overall, 0.003 episodes of acute pyelonephritis per patient-month of postoperative follow-up were observed. The result was statistically significant (P < 0.01). CONCLUSION: Recurrent acute pyelonephritis is frequently related to VUR. Intermittent reflux can be difficult to demonstrate on voiding conventional or nuclear cystograms but can be suspected in the presence of ureteral duplication, renal scarring, or abnormal ureteral orifices. Adult patients with recurrent episodes of upper urinary tract infection and normal cystograms should be considered for an endoscopic antireflux procedure in the presence of anatomic abnormalities commonly associated with reflux.     

Presence of Vesicoureteral Reflux in the Graft Kidney Does Not Adversely Affect Long-Term Graft Outcome in Kidney Transplant Recipients

Introduction

We studied the incidence of vesicoureteral reflux (VUR) in the graft kidney and its effect on the occurrence of urinary tract infection (UTI) and long-term graft function.

Methods

We performed a retrospective analysis of 64 adult kidney transplant recipients based upon voiding cystourethrography at 12 months post-transplantation. Patients underwent analysis of survival, incidence of UTIs beyond 1 year, and graft function.

Results

Thirty-seven male and 27 female patients in the study populations showed a mean age 42 years. VUR in the transplanted kidney at 12 months post-transplant occurred among 78.1% (50/64) of subjects: grade I (n = 6), grade II (n = 30), or grade III (n = 14) reflux. Patients followed for a median 61 months (range 44–74s) showed 11 cases of UTIs in 9 subjects. There were no significant differences in clinical characteristics or incidence of, UTIs according to the presence or severity of VUR (P = .81) or the Serum creatinine and estimated glomerular filtration rate values at 12, 36, 48, or 60 months post-transplantation.

Conclusions

VUR present in 78.1% of patients after kidney transplantation affected neither graft functions or graft survival. The incidence of UTI did not differ according to the presence of VUR.     

Transurethral injection therapy with carbon‐coated beads (Durasphere®) for treatment of recurrent pyelonephritis in kidney transplant patients with vesico‐ureteral reflux to the allograft

Antonopoulos IM, Piovesan AC, Falci R Jr, Kanashiro H, Saito FJA, Nahas WC. Transurethral injection therapy with carbon‐coated beads (Durasphere^®) for treatment of recurrent pyelonephritis in kidney transplant patients with vesico‐ureteral reflux to the allograft.
Clin Transplant 2011: 25: 329–333. © 2010 John Wiley & Sons A/S. Abstract: Introduction and objectives: Recurrent transplant pyelonephritis (RTP) secondary to vesico‐ureteral reflux (VUR) to the transplant kidney (KTx) remains a significant cause of infectious complications with impact on patient and graft outcomes. Our objective was to verify the safety and efficacy of transurethral injection of Durasphere^® to relieve RTP secondary to VUR after renal transplantation. Patients and methods: Between June 2004 and July 2008, eight patients with RTP (defined as two or more episodes of pyelonephritis after transplantation) and VUR to the KTx were treated with subureteral injections of Durasphere^®. The mean age at surgery was 38.8 ± 13.8 yr (23–65). The patients were followed regularly every six months. The mean interval between the KTx and the treatment was 76 ± 74.1 (10–238 months). The mean follow‐up was 22.3 ± 16.1 months (8–57 months). Results: Six patients (75%) were free of pyelonephritis during a mean period of follow‐up of 23.2 ± 17.1 months (8–57 months). Two of them had no VUR and four cases presented with G II VUR (pre‐operative G IV three cases and one case G III). In one case, symptomatic recurrent cystitis made a second treatment necessary. This patient remained free of infections for three yr after the first treatment and for 18 months after the second treatment. Of the remaining two patients, one had six episodes of RTP before treatment in a period of three yr and only two episodes after treatment in two yr of follow‐up. The last case had a new episode of pyelonephritis five months after treatment. Conclusions: Transurethral injection therapy with Durasphere^® is a safe and effective minimally invasive treatment option for KTx patients with recurrent RTP. A second treatment seems to be necessary in some cases.     

Does pre-transplantation antireflux surgery eliminate post-renal transplantation pyelonephritis in children?

PURPOSE: Antireflux surgery for VUR before renal transplantation decreases the risk of post-kidney transplant UTI in pediatric patients with primary vesicoureteral reflux. We studied the risk of post-kidney transplant UTI in patients with or without surgical correction of VUR before transplantation compared to patients without VUR. MATERIALS AND METHODS: We compared 12 patients who had VUR corrected before transplantation (group 1) to 17 patients with VUR who did not undergo antireflux surgery before transplantation (group 2) and 36 patients undergoing renal transplantation without VUR (group 3). A total of 10 patients in group 1 (83.3%) and 10 in group 2 (58.8%) had high grade VUR. RESULTS: Eight patients in group 1 (66.7%), 6 in group 2 (35.3%) and 33 in group 3 (91.7%) remained free of febrile UTI during followup (p = 0.00). Among patients with high grade VUR 6 in group 1 and 1 in group 2 remained UTI-free (p = 0.02). A total of 33 patients in the control group (91.7%) remained free of febrile UTI, an incidence that was significantly lower compared to group 1 (p = 0.03) and group 2 (p = 0.00). Of the patients with high grade VUR 3 in group 1 (30%) and 4 in group 2 (40%) experienced recurrent febrile UTIs (p = 0.64). CONCLUSIONS: Even after surgical correction of VUR before transplantation the frequency of febrile UTI remained higher than that in kidney transplant recipients without VUR. In cases of high grade VUR reimplantation before renal transplantation decreased the rate of febrile UTI but it was still higher than the level of risk in the control group.     

Vesicoureteral reflux increases the risk of renal scars: a study of unilateral reflux

The aim of this study was to assess the impact of vesicoureteral reflux (VUR) on renal scar following acute pyelonephritis by comparing the refluxing renal units with nonrefluxing renal units in children with unilateral primary VUR. Forty-eight children with unilateral primary VUR diagnosed after the first pyelonephritis were enrolled. Mean age of patients was 1.0±1.6 years (29 boys and 19 girls). All patients underwent renal ultrasonography and renal 99 m-technetium dimercaptosuccinic acid (DMSA) scan within three days following the diagnosis of pyelonephritis, and voiding cystourethrography (VCU) was performed soon after fever subsided and the infection was controlled. The DMSA scan was rechecked six months after the initial study when the first scan showed a renal defect. The first DMSA showed renal defects in 34 (70.8%) out of 48 of the refluxing renal units and in 13 (27.1%) out of 48 of the nonrefluxing renal units (P<0.01, OR: 6.54). At six months after the infection, 23 (47.9%) out of 48 refluxing renal units and seven (14.6%) out of 48 nonrefluxing renal units had renal scars on DMSA scan (P<0.01, OR: 5.39). The prevalence of renal scars did not vary significantly according to the grade of VUR. The CRP level on admission was significantly higher in patients with acute renal defect and scar. In conclusion, VUR increases the risk of post-pyelonephritic renal scars in children.     

Clinical studies of bacteriuria in renal transplantation recipients. Correlation with pyuria and symptomatic genitourinary tract infection

The clinical state of bacteriuria and its correlation with pyuria and symptomatic genitourinary tract infection (GUTI) were studied in 42 renal transplantation recipients who were followed up in the Kidney Center of Tokyo Women's Medical College over 6 months and who showed bacteriuria more than 3 times between January and December in 1987. The results were as follows. 1) Of the 42 recipients, bacteriuria was found less than 5 times in 19 patients, 6 to 10 times in 18 patients and more than 11 times in 5 patients. There was a tendency for the same bacteria to be isolated several times from the same patient. The most commonly isolated bacterias were Enterobacter, Enterococcus, Serratia and E. coli. 2) Bacteriuria was accompanied by pyuria in 33 patients (79%) and by symptomatic GUTI in 12 patients (29%). Bacteriuria without pyuria was shown in 9 patients (21%) without symptomatic GUTI and it was suggested that bacteriuria did not result in graft hypofunction after two years. 3) Of 16 patients with bacteriuria accompanied by pyuria, symptomatic GUTI occurred in 9 patients (56%). Of these, one patient was found to have VUR of the transplanted kidney, another was found to have VUR of the native kidney, and a third patient died due to interstitial pneumonitis presumably as a result of overimmunosuppression. Transplantation recipients with bacteriuria accompanied by pyuria develop symptomatic GUTIs frequently and should be treated with proper antibacterial agents. When bacteriuria continues, further examination should be performed for an organic disease of the urinary tract or an overimmunosuppressed state. When a patient shows bacteriuria without pyuria, chemotherapy is not needed and it is sufficient to observe the course carefully.     

The role of indirect radionuclide cystography during the acute phase of pyelonephritis in young women

OBJECTIVE: To review our experience using dynamic 99mTc-diethylenetriamine penta-acetic acid renal scintigraphy combined with indirect radionuclide cystography (IRC) in the acute phase of pyelonephritis, as a possible alternative to the conventional imaging, as investigating acute pyelonephritis usually includes imaging the upper urinary tract during the acute phase, to exclude obstruction, and delayed voiding cysto-urethrography (VCUG) when underlying vesico-ureteric reflux (VUR) is suspected. PATIENTS AND METHODS: Between 1997 and 1999, 47 young women (median age 22 years, range 18-37) were hospitalized for acute pyelonephritis. The combined study was used during the acute phase of the disease, usually within 24 h of hospitalization. The principle of IRC is based on the reappearance of radioactivity in the ureters or kidneys after previously detecting renal clearance of an intravenously injected radioisotope. The increase in radioactivity over the ureters or kidneys indicates VUR. The subsequent follow-up included VCUG, after recovery and at least 6 weeks after discharge. RESULTS: Overall, 47 patients had early IRC studies; obstruction of the urinary tract during the acute phase of the disease was excluded in all. In 13 (28%) of the patients early IRC studies showed VUR involving 21 upper tract units. The renal parenchymal scan was impaired in 17 (36%) patients, and six of these 17 also had detectable concomitant reflux on IRC. Overall, 24 IRC studies (51%) were considered positive, showing VUR, renal parenchymal pathology or both; 23 (49%) were normal. Follow-up VCUG was used in 32 patients (68%); only three (9%) detected VUR. All of the patients with VUR on follow-up VCUG had also had an abnormal early IRC study, showing either reflux (two) or findings suggestive of pathological renal parenchyma (one). CONCLUSIONS: In addition to the well-established role of renal scintigraphy in excluding obstruction of the collecting system, early IRC is characterized by high sensitivity and accurate negative predictive value for detecting VUR. It can therefore be used to screen adults presenting with acute pyelonephritis for the presence of VUR. Patients with an abnormal IRC require follow-up VCUG after complete recovery, while those with a negative study may be managed expectantly, with no further radiological evaluation. This proposed strategy may avoid up to half of the delayed VCUG studies, preclude the related inconvenience, and substantially reduce the costs.     

The etiology of renal scars in infants with pyelonephritis and vesicoureteral reflux

We aimed to investigate, by means of dimercaptosuccinic acid (DMSA) scan, the relations between vesicoureteral reflux (VUR) and its degree, pyelonephritis during infancy, and renal parenchymal findings. Seventy-four infants with pyelonephritis, 44 girls and 30 boys (mean age at their first pyelonephritic episode 4.12 months, median 3 months), were enrolled in the study. Voiding cystourethrography (VCU) and ultrasonography (US) were performed within 6 weeks following the infection. DMSA was performed at least 4 months after the urinary tract infection (UTI). The renal parenchymal pathology was defined as focal or multifocal defects or as a split renal uptake of less than 45%. DMSA scintigraphy revealed that 19% (14/74) of the children had renal damage. Renal parenchymal findings were observed only when VUR was present, and its grade was above 3/5. No abnormality was found in 51 renal units without reflux, 9 with VUR grade 1/5, and 54 with grade 2/5. Renal pathology was observed in 9/24 renal units with VUR grade 3, 3/8 with grade 4, and 2/2 with grade 5. No correlation was found between renal parenchymal defects and clinical presentation of the pyelonephritis, type of the microorganism, presence of bacteremia, or the number of recurrent infections. In adequately treated infants, renal damage is probably due to a reflux-associated, preexisting, congenital renal parenchymal pathology and not to the inflammatory process. We suggest that DMSA scintigraphy should not be performed routinely in every infant with UTI and should be reserved primarily for children with VUR grade 3 and above. Received: 17 February 1999 / Revised: 30 June 1999 / Accepted: 7 July 1999