Dimercaptosuccinic Acid Renal Scan Research Articles

Dimercaptosuccinic acid (DMSA) renal scan in the evaluation of hypertension in children

Renal scarring is known to be associated with hypertension. The primary objective of this study was to investigate the prevalence of renal scarring in children referred to our clinic with hypertension. The secondary objective was to compare renal ultrasound (US) examination with dimercaptosuccinic acid (DMSA) renal scan in diagnosing renal scars in these patients. The study included 159 patients who underwent DMSA renal scan as well as renal US for the evaluation of hypertension of unknown etiology. Thirty-three (21%) patients were found to have renal scars; their demographic details, including mean age and gender distribution, were not significantly different from those without renal scars. In comparison with the DMSA renal scan, sensitivity and specificity of renal US in diagnosing renal scars were 36% and 94%, respectively. In our study, in which the prevalence of scarring was 21%, this gave positive predictive and negative predictive values of 63% and 85%, respectively. In conclusion, our study indicates that renal scarring is present in 21% of otherwise healthy children who are evaluated for newly diagnosed hypertension, and renal US is not a sensitive imaging modality to rule out renal scarring.

Evaluation of imaging studies for vesicoureteral reflux in infants with first urinary tract infection.

Routine imaging studies following first urinary tract infection(UTI) in infancy are clinically used to identify who has vesicoureteral reflux (VUR) and acute pyelonephritis or renal scars. The potential value of these images in avoiding children acquiring renal complication and whether the children benefited from these examinations were not well justified. Analysis was undertaken of 114 infants (228 renal units) at the time of first documented UTI. All underwent renal ultrasound, voiding cystourethrography (VCUG) and dimercaptosuccinic acid (DMSA) renal scan on admission and repeated follow-up VCUG, DMSA or both after 4-6 months if initial examinations showed abnormal at first time. The VUR on VCUG when UTI and its statistical correlations with both acute and follow-up DMSA renal scan revealing renal scar were calculated. Seventeen children (14.9%) had VUR detected by VCUG. Forty-six patients (40.4%) had abnormal findings on acute DMSA renal scans (acute pyelonephritis or renal scars). The sensitivity, specificity, positive prediction rate and negative prediction rates of DMSA for VUR were 63%, 82.6%, 32.7% and 94.3%, respectively. The initial identified VUR versus renal scarring on follow-up DMSA showed little correlation. There is limited effectiveness of routine investigation by VCUG in infants with first confirmed UTI. VCUG may be withheld in a child who presents with first UTI before the age of one year if there has been no demonstrable abnormal DMSA scan.

Does a Normal DMSA Obviate the Performance of Voiding Cystourethrography in Evaluation of Young Children after Their First Urinary Tract Infection?

To determine whether a normal technetium-99m-labeled dimercaptosuccinic acid (DMSA) renal scan obviates the need for voiding cystourethrography (VCUG) in evaluating young children after their first urinary tract infection (UTI). This was a 10-year retrospective review of 142 children (age < or = 2 years, 77 boys and 65 girls) who had their first UTI and were admitted to a tertiary care general hospital. The association between DMSA renal scan results and VCUG results performed 48 hours and 1 month after diagnosis was evaluated. DMSA renal scans and VCUG were performed in 142 patients. Of these, 99 patients (69.7%) had evidence of pyelonephritis, although only 2 (1.4%) had evidence of renal scarring; 42 (29.6%) had vesicoureteral reflux (VUR) on VCUG. The sensitivity, specificity, positive and negative predictive values, and likelihood ratio negative for abnormalities on DMSA renal scans for detecting the the presence of VUR on VCUG were 88% (95% confidence interval [CI] = 73% to 100%), 36% (95% CI = 26% to 46%), 37% (95% CI = 27% to 46%), 88 % (95% CI = 73% to 100%), and 0.33 (95% CI = 0 to 0.88), respectively. Children with a negative DMSA renal scan during their first UTI episode rarely have VUR and may never have high-grade VUR. Avoiding VCUGs in children with negative DMSA renal scans could significantly reduce the use of this potentially traumatic test.

Successful Percutaneous Renal Intervention in a Patient With Acute Traumatic Renal Artery Thrombosis

A 20-year-old male who had fallen from the third floor of a building after excessive alcohol intake presented to our emergency room. He complained of flank pain, and subsequent simple x-ray and pelvis computed tomography revealed a right acetabular fracture, which we decided to treat conservatively. There were no other major injuries. An abdominal computed tomography scan (Figure 1A and 1B) revealed bilateral multifocal renal infarction. An urgent technetium-labeled dimercaptosuccinic acid renal scan (Figure 1C and 1D) showed significantly reduced perfusion in both lower lobes of the kidney. An emergent renal angiogram showed normal right main renal artery (Figure 2A). The anomalous right inferior polar artery showed complete thrombotic occlusion (Figure 2B). We prudently pursued the percutaneous renal intervention because there were no …

Endoscopic Management of Vesicoureteral Reflux in Women Presenting With Pyelonephritis

Vesicoureteral reflux is not usually considered a major cofactor in acute pyelonephritis in women. However, there is a subset of individuals in whom reflux must be considered in the evaluation of acute pyelonephritis. We sought to evaluate the effectiveness of endoscopic treatment for vesicoureteral reflux in this subset of patients. We retrospectively reviewed the records of 13 female patients presenting with clinical pyelonephritis between 2001 and 2005. All of these patients had either a history of vesicoureteral reflux in childhood or a family history of reflux, or had previously undergone surgery for reflux. All patients underwent voiding cystourethrogram and dimercapto-succinic acid renal scan as part of the evaluation. Of the 13 individuals evaluated 9 had vesicoureteral reflux. Of these patients 5 had been operated on previously for vesicoureteral reflux, 2 had a strong family history of reflux and 2 had reflux as a child with documented resolution. Six of the 9 patients with reflux exhibited renal scarring on dimercapto-succinic acid renal scintigraphy. Endoscopic correction of reflux was done in all 9 patients and was successful in 8, as shown on voiding cystourethrogram at 3 months postoperatively. One patient required a second procedure, which was successful. Only 1 patient has had a subsequent episode of clinical pyelonephritis, and voiding cystourethrogram following treatment again revealed resolution of reflux. There is a subset of women presenting with acute pyelonephritis in whom vesicoureteral reflux is a risk factor. When documented, vesicoureteral reflux can be managed effectively with endoscopic treatment.

Clinical Significance of Primary Vesicoureteral Reflux and Urinary Antibiotic Prophylaxis After Acute Pyelonephritis: A Multicenter, Randomized, Controlled Study

To evaluate the role of primary vesicoureteral reflux (VUR) in increasing the frequency and severity of urinary tract infections (UTIs) and renal parenchymal damage among patients with acute pyelonephritis and to determine whether urinary antibiotic prophylaxis reduces the frequency and/or severity of UTIs and/or prevents renal parenchymal damage among patients with mild/moderate VUR. Patients 3 months to 18 years of age with acute pyelonephritis, with or without VUR, were assigned randomly to receive urinary antibiotic prophylaxis or not. Patients were monitored every 3 months for 1 year. Dimercaptosuccinic acid renal scans were repeated at 6 months or if there was a recurrence of febrile UTI. Urinalysis and urine culture were performed at each clinic visit. Renal ultrasound scans and voiding cystourethrograms were repeated at the end of 1 year of follow-up monitoring. Of the 236 patients enrolled in the study, 218 completed the 1-year follow-up monitoring. Groups were similar with respect to age, gender, and reflux grade distribution for those with VUR. No statistically significant differences were found among the groups with respect to rate of recurrent UTI, type of recurrence, rate of subsequent pyelonephritis, and development of renal parenchymal scars. After 1 year of follow-up monitoring, mild/moderate VUR does not increase the incidence of UTI, pyelonephritis, or renal scarring after acute pyelonephritis. Moreover, a role for urinary antibiotic prophylaxis in preventing the recurrence of infection and the development of renal scars is not supported by this study.

The Efficacy of Imaging Studies after a First Febrile Urinary Tract Infection in Young Children with Normal Prenatal Ultrasonographic Findings

Purpose: The primary purpose for imaging the urinary tract of children with urinary tract infection is to detect congenital anomalies that may predispose the children to persistent or recurrent infection and also to prevent progressive renal deterioration. We evaluated the efficacy of imaging studies after a first febrile urinary tract infection in young children with normal prenatal ultrasonographic findings. Materials and Methods: We retrospectively reviewed 52 young children who were treated due to their first febrile urinary tract infection between 2001 and 2003. In all cases, urine specimens were collected via suprapubic aspiration. An the ultrasonogram and dimercaptosuccinic acid(DMSA) renal scans were obtained within 48 and 72 hours after hospitalization. Contrast voiding cystourethrograms were obtained within 1 to 4 week later after controlling the urinary tract infection. Results: On the ultrasonographic studies, 43 children(90%) were normal and 9 children(10%) were abnormal, and all of these abnormalities were upper tract dilatation that was not due to obstructive uropathy. DMSA renal scans revealed acute pyelonephritis in 34 children(65%) and normal findings in 18(35%). Voiding cystourethrogram revealed reflux in 15 children(31%). 4 children had Grade II reflux, 1 child had III reflux and 9 children had grade IV reflux. Conclusions: After the first febrile urinary tract infection in young children with normal prenatal ultrasonographic findings, an ultrasonogram performed at the time of acute illness is of limited value for the clinical decision about further treatment. A DMSA renal scan is useful for identifying pyelonephritis and renal scar, but its effect on the outcomes is unclear. Voiding cystourethrogram is most useful imaging study for identifying the reflux that needs antimicrobial prophylaxis for reducing reinfections and to prevent renal scarring.

ASSOCIATION OF TRANSFORMING GROWTH FACTOR-β1 GENE POLYMORPHISM WITH REFLUX NEPHROPATHY

Reflux nephropathy (RN) is recognized as a major cause of end stage renal failure in children and young adults. Transforming growth factor-beta1 (TGF-beta1) is a potent proinflammatory and fibrogenetic cytokine known to have a key role in the regulation of renal tissue fibrosis. We investigate genotype frequencies for polymorphisms of the TGF-beta1 gene at position -509, codon 10 and 25, and examine circulating levels of TGF-beta1 in patients with reflux nephropathy. Renal scaring was evaluated with 99technetium dimercapto-succinic acid renal scan. Genotyping was performed in 123 patients with severe to moderate reflux nephropathy and 58 controls for the position -509, the coding region at position 10 and 25 of the TGF-beta1 gene polymorphisms by polymerase chain reaction, gel analysis and appropriate restriction digest. TGF-beta1 serum levels were measured with standard ELISA technique. The genotype distribution of -509-CT was significantly increased in the RN group compared to controls, (82% vs 37%). Similarly, there was a significant increase in the CC Lue(10)-->Pro (codon 10) genotype (77% vs 27.5%, p <0.05), while TC Lue(10)-->Pro was significantly lower (7.3% vs 43%, p <0.05) in patients compared to controls. There was no significant difference in the Arg(25)-->Pro (codon 25) TGF-beta1 genotypes distribution between patients and controls. There were no statistically significant differences in the serum levels of TGF-beta1 in children with RN (4.2 +/- 0.3 mIU/ml) compared to controls (3.9 +/- 0.4 mIU/ml) (p >0.05). Patients with TGF-beta1 -509 and Lue(10)-->Pro gene polymorphisms may be at higher risk for reflux nephropathy.

Childhood urinary tract infection: a clinical analysis of 597 cases.

To gain new insights into the epidemiology, genitourinary (GU) tract anomalies, etiologies, susceptibility of urinary pathogens to antibiotics in children with urinary tract infection (UTI) during the past decade in Taiwan. By reviewing medical charts for patients admitted to Kaohsiung Veterans General Hospital between January 1995 and December 2003, we identified and enrolled patients 14 years of age or less admitted due to UTI that was confirmed by positive urine culture. A total of 597 patients made up our sample. Sixty-eight percent of patients were 1 year old or younger. Boys predominated infant cohort (68.1%). Twenty-seven point one percent of the patients were found in urinalysis to have 5 white blood cells or fewer per high power field and 17.6% had positive nitrite reaction. The pathogens were Escherichia coli, the most common (74.7%), followed by Proteus spp. (6.7%), and Klebsiella spp. (6.4%). E. coli was resistant to ampicillin in 82.0% of the cases, followed by sulfamethoxazole/trimethoprim (55.2%), gentamicin (24.9%), and cefazolin (24%). Resistance to ampicillin and sulfamethoxazole/trimethoprim tended to increase year by year. Forty point seven percent (164/408) of patients had GU tract anomalies, the most common being vesicoureteral reflux (VUR) (87/164, 53.0%). Thirty-three point two percent of the patients with acute pyelonephritis, confirmed by 99mTc dimercaptosuccinic acid (DMSA) renal scan, had VUR. Our cohort was predominated by boys, especially in those less than a year old. E. coli, the most common pathogen, had a higher rate of resistance to ampicillin and sulfamethoxazole/ trimethoprim. The pathogens that cause UTI were found to be becoming increasingly resistant to the common antimicrobial agents used in this study. The most common GU tract anomaly was VUR, yet the incidence was lower than that of other reports. A positive DMSA renal scan finding was a good indicator for prediction the possibility of VUR in UTI patients.

Urinary Excretion of Vascular Endothelial Growth Factor Is Increased in Children with Reflux Nephropathy

Background: We determined the urinary levels of vascular endothelial growth factor (VEGF) in patients with reflux nephropathy to elucidate its clinical significance as a predictor of the development of renal damage. Patients and Methods: Seventy-two patients (47 boys and 25 girls) aged 10–18 years with reflux nephropathy were studied. Vesicoureteral reflux was resolved surgically in all cases at least 2 years before enrollment. Urinary VEGF, α₁-microglobulin and albumin levels were determined using morning spot urine samples. Plasma VEGF, serum creatinine and β₂-microglobulin levels were measured simultaneously. The severity of renal scarring and right and left kidney function were assessed by ^99mTc dimercaptosuccinic acid renal scan. Results: No significant correlation was found between the plasma and urinary VEGF levels. Urinary VEGF increased significantly with the increase in severity of renal scarring (p < 0.0001). Urinary VEGF levels correlated significantly with serum β₂-microglobulin (p < 0.002) and urinary α₁-microglobulin (p < 0.03). No significant correlation of urinary VEGF levels with serum creatinine and urinary albumin levels was found. Nearly 60% of the patients with elevated urinary VEGF had normal levels of serum β₂-microglobulin and/or urinary α₁-miocroglobulin. Conclusions: Urinary VEGF level appears to reflect its production in the kidney. Since urinary VEGF shows a propensity to elevate before the increase in serum β₂-microglobulin and/or urinary α₁-microglobulin, urinary VEGF may serve as an early indicator of the development of reflux nephropathy.

TUMOR NECROSIS FACTOR-α GENE POLYMORPHISM IN REFLUX NEPHROPATHY

Interstitial scarring contributes to the progression of renal failure in reflux nephropathy. The proinflammatory cytokine tumor necrosis factor-alpha (TNF-alpha) has been implicated in the disease susceptibility and pathogenesis of several inflammatory diseases promoting interstitial infiltration of inflammatory cells. We evaluate the frequency of TNF-alpha gene polymorphism in patients with reflux nephropathy. Renal scarring was evaluated with technetium dimercapto-succinic acid renal scan. Genotyping was performed on 104 patients with reflux nephropathy and 30 controls for the TNF-alpha gene polymorphisms using polymerase chain reaction and restriction digest. This polymorphism involved a guanidine to adenosine transition at position -308 and was designated as TNF1 (-308G) and TNF2 (-308A). The allele frequencies of TNF1 and TNF2 were 18.8% and 81.2% in patients with reflux nephropathy and 76.7% and 23.3% in controls, respectively. The genotype distribution of TNF-alpha-AA was significantly higher (66.4% vs 10%, p <0.05), while the TNF-alpha-GG was lower (13.4% vs 60%, p <0.05) in patients with reflux nephropathy compared to controls. This study demonstrates for the first time the association of the cytokine TNF-alpha gene polymorphism in patients with reflux nephropathy. Our data suggest that patients with vesicoureteral reflux and TNF-alpha AA genotype may have increased susceptibility to reflux nephropathy.

PERCUTANEOUS NEPHROLITHOTOMY IN CHILDREN: EARLY AND LATE ANATOMICAL AND FUNCTIONAL RESULTS

We report our experience with percutaneous nephrolithotomy (PCNL) in children, and evaluate its early and late anatomical and functional results. A total of 65 children with renal calculi were treated with PCNL. Patient age at operation ranged from 9 months to 16 years (mean +/- SD of 5.9 +/- 0.9 years), and 27 (41.5%) were younger than 5 years. Seven patients had bilateral renal stones and, therefore, the number of kidneys treated by PCNL was 72. The patients were followed regularly every 3 months during year 1 and every 6 months thereafter. Renal scans using technetium dimercapto-succinic acid for detection of renal scarring and technetium diethylenetetramine-pentaacetic acid for determination of selective glomerular filtration rate (GFR) were performed in all patients at least once during followup, which ranged from 6 to 72 months (mean +/- SD 40 +/- 10). Early complications included significant intraoperative bleeding in 1 case, renal pelvis perforation in 1 and transient fever in 2. Mean hospital stay +/- SD was 3 +/- 1.2 days (range 2 to 21). Of the renal units 62 (86%) were stone-free after a single PCNL, and the remaining 10 with residual stones were treated with a second look PCNL (4) and shock wave lithotripsy (6). Stone-free rates at hospital discharge and at 3 months were 93% and 100%, respectively. During followup 6 patients (9%) had recurrence of small renal stones and were successfully treated with shock wave lithotripsy. None of the kidneys had scarring on dimercapto-succinic acid renal scan. All of the kidneys except 1 showed improvement or stabilization of the corresponding GFR determined by diethylenetetraminepentaacetic acid renal scan. Comparison of the mean preoperative GFR of the corresponding kidney (28.8 +/- 11.2 ml per minute) with mean value at followup (36.1 +/- 9.9) showed an increase of statistical significance (p <0.01). PCNL is a safe and effective procedure for the treatment of children with renal calculi. At long-term followup the procedure improves renal function without renal scarring.

Obstructive ureterocele-an ongoing challenge.

Ureterocele is a cystic dilatation of the intravesical ureter that is most commonly observed in females and children, and usually affects the upper moiety of a complete pyeloureteral duplication. According to their position, ureteroceles are divided into intravesical, when the ureterocele is completely contained inside the bladder, and extravesical when part of the cyst extends to the urethra or bladder neck. Most ureteroceles are diagnosed in utero or immediately after birth during an echographic screening of renal malformations. Severe, febrile urinary tract infection is the most common postnatal presentation of ureteroceles, but they may, rarely, prolapse and acutely obstruct the bladder outlet. Once an ureterocele is identified sonographically, a voiding cystourethrogram to detect vesicoureteral reflux (VUR) and a 99m-technetium dimercapto-succinic acid renal scan to evaluate the function of the different portions of the kidney are mandatory. VUR in the lower pole is observed in 50% of cases and in the contralateral kidney in 25%. Simple endoscopic puncture of the ureterocele has recently been advocated as an emergency therapy for infected or obstructing ureteroceles and as an elective therapy for intravesical ureteroceles. The rate of additional surgery after elective endoscopic puncture of an orthotopic ureterocele ranges from 7 to 23%. Treatment of ectopic ureteroceles is more challenging and both endoscopic puncture and upper pole partial nephrectomy frequently require additional surgery at the bladder level. The reoperation rate after endoscopic treatment varies from 48 to 100%. It is 15 to 20% after upper pole partial nephrectomy if VUR was absent before the operation, but is as high as 50-100% when VUR was present. Thus, endoscopic incision is appropriate as an emergency treatment or when dealing with a completely intravesical ureterocele. Upper pole partial nephrectomy is the elective treatment for an ectopic ureterocele without preoperative VUR. In an ectopic ureterocele with VUR, no matter which type of primary therapy has been chosen, a secondary procedure at the bladder level, involving ureterocele removal and reimplantation of the ureter(s), should be anticipated.

Using Tc-99m DMSA renal cortex scan to detect renal damage in women with type 2 diabetes

Women with diabetes mellitus (DM) have urinary tract infection (UTI) more often than women without DM. It is unknown, however, what the prevalence and type of renal damage due to UTI is in these women. Therefore, in this study, we compared type 2 DM women with or without UTI history for the prevalence and type of renal damage by technetium-99m dimercapto-succinic acid (Tc-99m DMSA) renal scan. A total of 128 type 2 DM women with or without UTI history received Tc-99m DMSA renal scan were included in this study. The patients were separated into three groups: (1) 43 patients without UTI history, (2) 42 patients with only lower UTI (cystitis) history and (3) 43 patients with upper UTI (pyelonephritis) history. The renal scan findings were separated into three types: (A) normal, (B) inflammation and (C) scar. The 31.9% (50/128) of type 2 DM patients had renal damages. Group 1 patients had a significantly lower prevalence of renal damages including inflammation and scar as compared to Groups 2 and 3 patients. In addition, the prevalence of renal damage was significantly higher in Group 3 than in Group 2 patients. Renal scars only were visualized in Group 3 patients. However, other clinical data were not statistically different among the three group patients. Type 2 DM women with UTI history, especially if they had upper UTI have a significantly higher prevalence of renal damage than in those without UTI.

Urinary tract infections in children.

To gain new insights into the epidemiology, imaging and conservative management of urinary tract infections based on the peer-reviewed literature of the last year. It has been estimated that 3% of prepubertal girls and 1% of prepubertal boys are diagnosed with urinary tract infections. Breastfeeding has been shown to offer significant protection against urinary tract infection in infants. Any young child with an acute pyelonephritis should be evaluated by dimercaptosuccinic acid renal scan to confirm or rule out renal scarring. The voiding cystourethrogram can be performed within the first 7 days of diagnosis. Amoxicillin, trimethoprim-sulfamethoxazole and cephalosporin are the first-line antibiotics to treat children with uncomplicated urinary tract infection. The incidence of urinary tract infections during infancy and childhood is high and influenced by the age and sex of the patient. Voiding cystourethrogram and dimercaptosuccinic acid renal scan are required for imaging. Short-course treatment is sufficient for children with acute uncomplicated lower urinary tract infections.

Objective evidence of a high prevalence of renal damage in women with type 2 diabetes by technetium-99m DMSA renal cortex scan findings

Objectives To compare control women with men and women with type 2 diabetes mellitus (DM) for the prevalence and type of renal damage due to urinary tract infections (UTIs) using technetium-99m dimercapto-succinic acid ( 99mTc DMSA) renal scanning. Women with DM have UTIs more often than do women without DM. It is unknown, however, what the prevalence and type of renal damage due to UTI are in these women. Methods Three groups of patients: 28 control women without type 2 DM and a history of UTIs, 25 male patients with type 2 DM but without a history of UTIs, and 103 female patients with type 2 DM underwent 99mTc DMSA renal scan. The 103 women with type 2 DM were separated into three groups: 36 women without a history of UTIs, 34 patients with a history of cystitis only, and 33 with a history of pyelonephritis. Results All the control women and male patients with type 2 DM without a history of UTIs had normal 99mTc DMSA renal scan findings. However, 39.8% of women with type 2 DM had abnormal 99mTc DMSA renal scan findings. Women with type 2 DM without a history of UTI had a significantly lower prevalence of abnormal renal scan findings than did those with a history of cystitis only or pyelonephritis. In addition, the prevalence of abnormal renal scan findings was significantly higher in women with type 2 DM with pyelonephritis than in those with a history of cystitis only. Renal scars on 99mTc DMSA renal scans were found in women with type 2 DM and a history of pyelonephritis. Conclusions Compared with control women and men with type 2 DM, women with type 2 DM, especially if they had a history of UTIs, had a significantly higher prevalence of abnormal 99mTc DMSA renal scan findings.

Evolution of differential renal function after acute pyelonephritis.

(99m)Tc dimercaptosuccinic acid (DMSA) renal scans can provide accurate diagnosis of acute pyelonephritis, its sequelae (renal scars) and differential renal function (DRF). The purposes of this retrospective study were (1) to assess the relationship between DRF obtained during acute pyelonephritis and at follow-up, and (2) to elucidate the value of initial DRF in predicting subsequent renal scars. A total of 47 children were enrolled. All had both unilateral acute pyelonephritis diagnosed by initial DMSA renal scans, and follow-up DMSA renal scans. We found the correlation between initial and follow-up DRF poor (adjusted R2 = 0.396). Whether or not renal scars developed determined the follow-up DRF. Vesicoureteral reflux was significantly more common in children who developed renal scars. In addition, the higher the grade of vesicoureteral reflux, the lower the follow-up DRF and the improvement in DRF. When using a DRF of 46% as the cut-off value to predict subsequent renal scars, the sensitivity and specificity were 47.8% and 83.3%, respectively. Owing to the low sensitivity, initial DRF is not suitable for predicting the occurrence of renal scars.

Urinary Concentrations of Alpha-1-Microglobulin and Albumin in Patients with Reflux Nephropathy before and after Puberty

We determined urinary concentrations of α₁-microglobulin and albumin in 155 patients with reflux nephropathy including 72 prepubertal (48 males and 24 females) and 83 postpubertal patients (43 males and 40 females) to elucidate the effect of age and gender in the progression of renal damage. Vesicoureteral reflux was resolved in all patients at least two years before enrollment into this study. Renal scarring was diagnosed with ^99mtechnetium dimercaptosuccinic acid renal scan. More severe renal scarring was found predominantly in male compared to female patients. Urinary α₁-microglobulin levels were significantly lower in postpubertal female patients (mean ± SD: 1.59 ± 1.02 mg/g creatinine) than in prepubertal males and females (3.32 ± 3.53 and 4.06 ± 4, respectively; p < 0.007 and p < 0.002, respectively), and in postpubertal males (3.69 ± 2.6; p < 0.002) regardless of severity of renal scarring. In the patients with severe unilateral renal scarring, urinary albumin levels were significantly higher in postpubertal males (81.9 ± 239.5) than in prepubertal males and postpubertal females (25.8 ± 63.1 and 13.8 ± 7.7, respectively; p < 0.05 and p < 0.05, respectively). Our results suggest that glomerular injury may develop during adolescence predominantly in male patients with severe renal scarring. In contrast, renal damage indicated by urinary α₁-microglobulon level appears to be ameliorated in female postpubertal patients. This gender difference may be attributed to sex hormones.

Ultrasound Grade of Hydronephrosis and Severity of Renal Cortical Damage on 99mTechnetium Dimercaptosuccinic Acid Renal Scan in Infants With Unilateral Hydronephrosis During Followup and After Pyeloplasty

We performed ultrasonography and (99m)technetium dimercaptosuccinic acid (DMSA) renal scan in infants with unilateral hydronephrosis during followup and after pyeloplasty to examine the correlation of ultrasound hydronephrosis grade with the severity of renal cortical damage and assess the recovery of renal function in the obstructed kidneys after surgery. We studied 80 boys and 19 girls with unilateral hydronephrosis detected in the first year of life, including 75 (76%) in whom it was detected prenatally. Ultrasound images were graded according to the Society for Fetal Urology grading system. The severity of renal cortical damage was assessed by DMSA renal scan. Absolute function of the right and left kidneys was estimated by DMSA uptake and relative DMSA uptake was calculated by the formula, relative uptake = uptake in obstructed kidney/total uptake in right and left kidneys x 100%. On ultrasonography grades 1 to 4 hydronephrosis were diagnosed in 9, 21, 19 and 50 kidneys, respectively. On DMSA renal scan cortical damage was detected in 10 kidneys (53%) with grade 3 and 49 (98%) with grade 4 hydronephrosis but not in kidneys with grade 1 or 2 disease. Dysfunction in the obstructed kidney, defined as relative DMSA uptake less than 40%, was noted in 13 patients with grade 4 hydronephrosis. Relative DMSA uptake significantly increased after successful pyeloplasty compared with preoperative uptake (44% +/- 2% versus 40.1% +/- 2%, p <0.01). Ultrasound grading of hydronephrosis correlates with the severity of cortical damage or the decrease in renal function on DMSA renal scan. Differential renal function on DMSA renal scan may be a useful and less invasive tool for determining surgical indications and examining changes in renal function after surgery.

Ultrasound Grade of Hydronephrosis and Severity of Renal Cortical Damage on 99mTechnetium Dimercaptosuccinic Acid Renal Scan in Infants With Unilateral Hydronephrosis During Followup and After Pyeloplasty

Ultrasound Grade of Hydronephrosis and Severity of Renal Cortical Damage on 99mTechnetium Dimercaptosuccinic Acid Renal Scan in Infants With Unilateral Hydronephrosis During Followup and After Pyeloplasty