Beta 2 microglubulin as a marker for vesicouretral reflux in children

ABSTRACT

Reflux nephropathy is one of the main causes of advanced renal failure in children the world over. Vesicoureteral reflux [VUR] is seen in 1.8% of the children; however; its prevalence is 34% in children suffering from urinary tract infections [UTI] and 40% in their siblings. The current study was carried out to evaluate the potential of replacing cystography [which requires exposure to radiation] by measuring urinary levels of beta[2]-microglubolin in screening reflux. The urine samples of 83 children undergoing cystography were assessed for beta[2]-microglubolin/creatinine [beta[2MG/Cr] ratio]. There were 47 children suffering from VUR and 36 healthy children [55 girls and 28 boys]. The urine samples were obtained during voiding cysto-urethrography [VCUG] and were evaluated for beta[2]-microglubolin and creatinine. VUR was classified based on WHO classification and beta[2]-micro-glubolin was reported in microgram to milligram of creatinine. Measurement of beta[2]-microglubolin was performed using 96-test beta[2]MG radioimmunoassay kit and creatinine by spectrophotometry using autoanalyzer. The mean beta[2MG/Cr] ratio was significantly higher in children with VUR [7.9 7 +/- 3.45] than the children without VUR [0.24 +/- 0.23] [P=0.01]. The mean beta[2MG/Cr] ratio in children with reflux grades 4 and 5 [12.01 +/- 8.93] was significantly higher than children with VUR of lower grades [3.04 +/- 0.81] [P=0.02]. The maximum beta[2MG/Cr] ratio [23.3] was seen in a patient with VUR of grade 4 while the minimum of it [0] was observed in patients without reflux. The difference between/32MG/Cr ratio in the patients without reflux and the patients with lower grades of VUR [1-3] was not significant. The maximum/32MG/Cr ratio was 0.85 in patients without reflux. The maximum beta[2MG/Cr] ratio was 0.85 in patients without reflux. This ratio can be assumed as the cutoff point for reflux screening. This study revealed that patients with grades 4 and 5 reflux have significantly higher beta[2MG/Cr] ratios than patients without reflux or with lower degrees of reflux. Renal failure was very soon observed in 2 children with the highest amounts of beta[2MG/Cr] suggesting that a simple urine test may demonstrate the prognosis. It is recommended to study the relationship between beta[2MG/Cr] and renal scars