beta2-Microglobulin is a Sensitive Marker for Predicting Renal injury in Childhood Urinary Tract Infection

Lee, Won Uk; An, Buyng Moon; Kim, Il Soo; Kim, Eun Ryoung

Abstract

PURPOSE: Urinary tract infection(UTI) in children may be cause of end stage renal failure and hypertension. So, early detection of renal scar, vesicoureteral reflux(VUR) and anomaly, and proper management are important. We carried this study to observe the significance of 24 hours urine beta2-microglobulin(beta2-MG) for predicting renal injury and correlation of beta2-MG with the grade of VUR.
METHODS
We evaluated 52 patients with UTI who were admitted to the department of Pediatrics, Sung-Ae General Hospital from April 1994 to December 1994. All patients were evaluated with 99mTc-2,3-dimercaptosuccinic acid (DMSA) renal scan, voiding cystourethrogram(VCUG) and 24 hours urine beta2-MG. We divided them into 3 groups, group A; renal scarring in DMSA scan and no reflux in VCUG(14 patients), group B; renal scarring and reflux (10 patients), and group C; no renal scarring and reflux (24 patients).
RESULTS
1) Among 52 patients, 31 patients(59.6%) were less than 1 year of age and 21 patients(40.4%) were older than 1 year. The sex ratio of male to female was 1.6:1. 2) Among 24 patients with renal scarring, 15 patients(63%) were less than 1 year of age, and vesicoureteral reflux was observed in 10 patients (41.6%). 3) Vesicoureteral reflux was seen in 14 patients (26.9%): one with grade I, four with grade II, six with grade III, one with grade IV, and two with grade V. 4) The values of 24 hours urine beta2-MG in group A and B were 3.94+/-6.13mg /g Cr and 3.72+/-5.38mg/g Cr respectively, while 0.85+/-0.63mg/g Cr in group C, showing significant difference between group A and group C(p<0.05). However, there was no significant difference between group A and B(p>0.05). The grade of vesicoureteral reflux was also significantly correlated with the level of 24 hours urine beta2-MG. 5) 24 hours urine beta2-MG was significantly decreased with improvement of renal scarring after successful treatment of urinary tract infection.
CONCLUSIONS
Measurement of 24 hours urine beta2-MG can be used as a sensitive marker of the severity of UTI and also useful for the evaluation of successful treatment and prognosis of patients with urinary tract infection.