Relationship between Vesicoureteral Reflux and Glomerular Filtration Rate in Children

Functional assessment of renal damage in children with primary vesicoureteral reflux

Objectives

To evaluate the renal function damage in children with primary vesicoureteral reflux (VUR).

Methods

A total of 226 children with VUR (65 cases with left, 39 with right, and 122 cases with bilateral VUR) were screened. Eighty-five urinary tract infection (UTI) cases, without urinary malformations, during the same period were collected as controls. Age at diagnosis, body weight, renal ultrasound, VUR grade, serum creatinine level, dimercaptosuccinic acid (DMSA) level, and effective renal plasma flow (ERPF) values were retrospectively analyzed.

Results

There were no significant differences in age at diagnosis between study groups. Total ERPF was significantly lower in the bilateral VUR group than in the control group. The ERPF in unilateral VUR was significantly lower than that in the contralateral or ipsilateral side in the control group (P < 0.001). The mean split renal function, as assessed by DMSA of VUR, was 28.00% and 29.12% on the left and right sides, respectively, both of which were lower than the control group's 40.27%. Renal damage was also correlated with a VUR grade (P = 0.008), a transverse diameter (P = 0.002), and pyelectasis (P = 0.037).

Conclusion

Split renal function was impaired in the reflux kidney. The total ERPF in the bilateral VUR group was lower than that in the unilateral VUR group. Renal damage was correlated with a VUR grade, a transverse diameter, and pyelectasis.

Higher incidence of hematuria was observed in female children with microtia

The goals of this study were to investigate the incidence and characteristics of hematuria in patients with microtia, and to clarify that more attention should be paid to renal dysfunction in patients with microtia. We conducted a retrospective cohort study of a total 9447 children diagnosed with microtia (selected as study group, 7037 children) or pigmented nevus (selected as control group, 2410 children) at the Plastic Surgery Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College from January 2009 to June 2021. All of the routine urinalysis report of these children were reviewed to assess the incidence and characteristics of hematuria in each group. No statistically significant differences were observed when analyzing the overall incidence of hematuria between the study and control groups (P > 0.05). However, after grouping by sex, the incidence of hematuria in female children with microtia was significantly higher than that in femalecontrol group and no similar results were observed in the male patients. In addition, after further grouping by age in case group, the incidence of hematuria in girls of all ages with microtia was significantly higher than that in males with microtia (age 0-10:males: Girls = 1.89%:4.14%; age 0-5: males: Girls = 1.22%:3.73%; age 6-10: males:Girls = 1.97%:4.14%,P < 0.05), while no similar results were obtained in the control group.(age 0-10:males: Girls = 1.39%:2.22%; age 0-5: males: Girls = 1.07%:1.95%; age 6-10: males: Girls = 3.38%:3.17%, P > 0.05). Higher incidence of hematuria was observed in female children with microtia.

Renal function damage in children with duplex kidneys

PURPOSE

To evaluate renal function damage in children with duplex kidneys.

METHODS

A total of 355 duplex kidneys, 110 urinary tract infection (UTI) kidneys without abnormalities, and 104 kidneys with primary unilateral vesicoureteral reflux (VUR) were reviewed. Clinical data including age at diagnosis, body weight, history of UTI, ureteroceles, ectopic ureteral opening, VUR grade, serum creatinine level, cystatin C level, renal scarring, split renal function in dimercaptosuccinic acid scans, and effective renal plasma flow (ERPF) were analyzed.

RESULTS

Duplex kidneys had a higher grade of VUR and renal scarring. Split renal function in unilateral duplex kidneys (45.58 ± 12.85%) was much lower than that in contralateral duplex kidneys (56.33 ± 11.90%) and controls (50.00 ± 11.38%) (P < 0.001 and P = 0.014, respectively). Both left and right split renal functions in bilateral duplex kidneys were similar to those ipsilateral to the controls (P = 0.906 and P = 0.932, respectively). However, the total ERPFs in the left, right, and bilateral duplex kidneys were significantly lower than that in the control group (P = 0.003, P = 0.001, and P = 0.003, respectively). The total ERPFs in the left and right unilateral duplex kidneys were similar. ERPF in unilateral duplex kidneys (106.70 ± 48.05 mL/min/m²) was significantly lower than that in contralateral duplex kidneys (150.18 ± 49.01 mL/min/m²) or those ipsilateral to controls (145.98 ± 41.16 mL/min/m²) (P < 0.001 and P < 0.001, respectively).

CONCLUSION

Duplex kidneys are usually accompanied by a higher grade of VUR, more severe renal scarring, and renal function impairment. Split renal function in duplex kidneys often declines significantly. Notably, the evaluation of split renal function in bilateral duplex kidneys should be performed cautiously.