Vesicoureteral Reflux in Children with Urinary Tract Infections in the Inpatient Setting in Taiwan

Androgen exposure impairs neutrophil maturation and function within the infected kidney

Urinary tract infections (UTIs) in men are uncommon yet carry an increased risk for severe pyelonephritis and other complications. In models of Escherichia coli UTI, C3H/HeN mice develop high-titer pyelonephritis (most with renal abscesses) in a testosterone-dependent manner, but the mechanisms underlying this phenotype are unknown. Here, using female mouse models, we show that androgen exposure impairs neutrophil maturation in the upper and lower urinary tract, compounded by a reduction of neutrophil function within the infected kidney, enabling persistent high-titer infection and promoting abscess formation. Following intravesical inoculation with uropathogenic E. coli (UPEC), kidneys of androgen-exposed C3H mice showed delayed local pro-inflammatory cytokine responses while robustly recruiting neutrophils. These were enriched for an end-organ-specific population of aged but immature neutrophils (CD49d+, CD101-). Compared to their mature counterparts, these aged immature kidney neutrophils exhibited reduced function in vitro, including impaired degranulation and diminished phagocytic activity, while splenic, bone marrow, and bladder neutrophils did not display these alterations. Furthermore, aged immature neutrophils manifested little phagocytic activity within intratubular UPEC communities in vivo. Experiments with B6 conditional androgen receptor (AR)-deficient mice indicated rescue of the maturation defect when AR was deleted in myeloid cells. We conclude that the recognized enhancement of UTI severity by androgens is attributable, at least in part, to local impairment of neutrophil maturation in the urinary tract (largely via cell-intrinsic AR signaling) and a kidney-specific reduction in neutrophil antimicrobial capacity.IMPORTANCEAlthough urinary tract infections (UTIs) predominantly occur in women, male UTIs carry an increased risk of morbidity and mortality. Pyelonephritis in androgen-exposed mice features robust neutrophil recruitment and abscess formation, while bacterial load remains consistently high. Here, we demonstrate that during UTI, neutrophils infiltrating the urinary tract of androgen-exposed mice exhibit reduced maturation, and those that have infiltrated the kidney have reduced phagocytic and degranulation functions, limiting their ability to effectively control infection. This work helps to elucidate mechanisms by which androgens enhance UTI susceptibility and severity, illuminating why male patients may be predisposed to severe outcomes of pyelonephritis.

Clinical Outcomes of Voiding Cystourethrogram and Antibiotic Prophylaxis

Background Urinary tract infections (UTIs) are a prevalent and potentially serious bacterial infection observed among children. Presently, the primary use of diagnostic imaging for UTI is to pinpoint young patients who are at a high risk of developing renal scarring. The most significant procedure for pediatric urology fluoroscopic evaluation is voiding cystourethrogram (VCUG). VCUG-acquired UTIs continue to be an important concern and the purpose of this study is to assess the clinical outcomes of antibiotic prophylaxis on VCUG-associated UTIs. Methods This retrospective study included all patients who underwent VCUG procedures performed from the year 2014 to 2021. All data were retrieved from the medical registries and databases. Radiological and laboratory investigations related to the VCUG procedures were thoroughly reviewed. Patients were considered to have post-procedure UTI if urological symptoms including fever and dysuria along with positive urine culture were exhibited within four weeks after the VCUG study. Patients with incomplete medical records were excluded from the analysis. Results This study consisted of 147 participants. Continuous antibiotic prophylaxis (CAP) was observed in 57 (38.8%) participants of them 35 (23.8%) participants suffered from UTI while urine culture and sensitivity testing were performed among 142 (96.6%) participants before VCUG which came negative and only five (3.4%) had a positive result. Overall, the results of the Chi-square test of association revealed a significant association between sex and vesicoureteral reflux (VUR), indicating that the prevalence of VUR differs between males and females. However, no significant associations were observed between VUR and UTI, urine culture and sensitivity results, hydronephrosis, type of catheter, or choice of antibiotic. Conclusion In conclusion, this study contributes valuable insights into the clinical outcomes of antibiotic prophylaxis on VCUG-associated UTIs. Despite the prophylaxis rate of 38.8%, UTIs were still observed in a significant proportion of children undergoing VCUG. This calls for further research to identify additional risk factors, optimize prophylaxis strategies, and enhance the overall safety and efficacy of VCUG procedures in children.

Vesicoureteral Reflux Diagnosis After Hospitalization for Acute Cystitis and Pyelonephritis

Children with recurrent fevers in a short period of time need to be worked up to identify the underlying cause. Fevers in children and infants can be from many different sources. Vesicoureteral reflux (VUR) is an anatomical and physiological anomaly in children that can lead to retrograde urine flow from the bladder back into the distal ureters. This retrograde flow can cause distention, scarring, and recurrent infections including urinary tract infections (UTIs) and pyelonephritis. Identification of multiple UTIs in a short period of time should raise suspicion for a more complex pathology such as VUR and requires a more thorough workup. This workup is needed for both diagnosis and treatment. The patient in this report was seen by physicians in the emergency department, pediatric intensive care unit, nephrology, and her pediatrician. If surgery is needed, a urologist would also be involved. This report will discuss the pathophysiology of VUR and associated pathologies, diagnostic approach, medical and surgical treatment modalities, as well as prognosis.