Tehran University Medical Journal

---

Background: Impairment in the function of the lower urinary tract can be the cause of recurrent urinary tract infections (UTI) and vesico-ureteral reflux (VUR) in children. The purpose of our research was to evaluate the frequency of occurrence of bladder instability in children with UTI.

Methods: The research involved 133 children (11 boys, 122 girls), ranging in age from seven months to 14 years. Group A consisted of 78 children with a history of recurrent UTI, while Group B included 55 children with recurrent UTI and VUR. Urodynamic tests (cystometry) were performed on all the children.

Results: Abnormal functioning of the lower urinary tract was found in 98 children (73.1%) from Group A and 41 children (78.8%) from Group B. The most common dysfunction was detrusor-sphincter dyssynergia (DSD), which was found in 54% of all subjects, 46.2% of patients in Group A and 60% of patients in Group B (p<0.05). Unstable bladder was found in 42 (33%) children with no significant difference between the two groups. In 17 children (12.6%) DSD was accompanied by bladder instability. In both groups about 20% of the children did not present with symptoms indicative of urination dysfunction, where as 80% reported various symptoms, of which the most common were constipation and urinary urgency. In half of the children from Group A and one-fourth of the children from Group B there were several co-occurring symptoms: frequency, urgency, intermittent voiding, incontinence, dribbling and retention, and constipation.

Conclusions: The most common disturbance of lower urinary tract function in these children with recurrent UTI was DSD, which occurred more often in children with VUR.

---

Background: Urinary Tract Infection (UTI) is one of the major etiological factors of permanent kidney impairment, resulting in renal scarring and severe and pernicious side effects, such as arterial hypertension and renal failure. The purpose of this study was to clarify the impression of renal parenchyma involvement by first UTI (on the basis of acute DMSA scan) and vesicoureteral reflux (VUR-on the basis of VCUG/ RNC) on the renal scar formation (on the basis of late DMSA scan).

Methods: Children diagnosed with their first UTI at the Children's Hospital Medical Center, Tehran, Iran, were evaluated. For each patient, we recorded age, sex, results of VCUG/RNCs and acute DMSA scan, as well as those of a late DMSA scan performed 4-6 months later. The results of acute and late DMSA scans were compared along with the results of VCUG/RNCs.

Results: This study included a total of 103 children, of whom 16 (15.5%) were boys and 87 (84.5%) were girls. The mean age was 27.2±27.7 months. The frequency of renal scars in kidneys with mild (28.6%, 8.7%) and moderate (33.3%, 18.2%) pyelonephritis with or without VUR was not significantly different, while the frequency of renal scars in kidneys with severe pyelonephritis (84.6%, 23.1%) in the presence of VUR was significantly higher than non-refluxing kidneys with severe pyelonephritis (p=0.005). Furthermore, the frequency of renal scars in refluxing kidneys increased significantly with the severity of pyelonephritis (normal 8.3%, mild 28.6%, moderate 33.3%, and severe 84.6% p=0.001). This pattern was not significant in non-refluxing kidneys (0%, 10.3%, 18.2%, and 23.1%, respectively p=0.062).

Conclusion: The present study indicates that the incidence of renal scarring increases with pyelonephritis severity in patients with VUR. Furthermore, we can estimate the risk of renal scar formation from the results of acute DMSA scan and VCUG/RNC.

---

Background: Vesicoureteral reflux (VUR) is the retrograde flow of urine from the bladder into the ureter and toward the kidney. Vesicoureteral reflux is the most com-mon inherited disease in urogenital system. Primary VUR is the most common urologi-cal anomaly in children and it has been reported in 30-50% of those who present with urinary tract infection (UTI). The association of vesicoureteral reflux, urinary tract in-fection and renal damage is well known. ‍Current methods for vesicoureteral reflux di-agnosis are unpleasant. Therefore, human leukocyte antigen system not only might help to detect causative gene but also would assists to establish better prognoses tests of this disease. In this study, the relationship between vesicoureteral reflux and HLA-DRB1 and HLA-DQB1 genes were investigated. Methods: This study applied on forty vesicoureteral reflux confirmed children from Kerman province, Iran. These children have been admitted to the Afzalipour Hospital for UTI and primary VUR for them was proved by voiding cystourethrogram (VCUG). Also, forty children without any VUR sign as control group. DNA was extracted from the whole blood sample and was amplified using sequence-specific priming polymerase chain reaction (PCR-SSP) method. Finally PCR products were evaluated by electropho-resis in 1.5% agarose gel and frequency of alleles and haplotypes were compared by Chi-square test. Significance level was assumed at P< 0.05. Results: Low-resolution HLA typing showed the frequency of the HLA-DR17 antigen was significantly increased in vesicoureteral reflux children compared to control group (P= 0.039). On the other hand HLA-DR16 was significantly decreased in vesicoureteral reflux group. Also, frequency of HLA-DQ2 was significantly higher in patients com-pared to control group (P= 0.002). DRB1 (11, 17) and DQ (2, 7) haplotypes were also higher in vesicoureteral reflux patients (P= 0.027, P= 0.01). Conclusion: The HLA cluster might affect on susceptibility to vesicoureteral reflux es-pecially by locus which located close to HLA-DRB1 and HLA-DQB1 genes. This study demonstrates for the first time in Iran. However, further extensive researches with a large number of samples from different populations and ethnicities are required to val-idate the results obtained in this study.