Primary vesicoureteric reflux as a predictor of renal damage in children hospitalized with urinary tract infection: a systematic review and meta-analysis.

Renal parenchymal disease after urinary tract infection (UTI) has been associated with the development of hypertension and renal functional impairment. A systematic literature review and meta-analysis was performed to determine how effectively the finding of primary vesicoureteric reflux (VUR) on micturating cystography (MCU) in children hospitalized with UTI predicted renal parenchymal disease on (99m)Technetium-dimercaptosuccinic acid ((99m)Tc-DMSA) scintigraphy. Medline, Embase, and PubMed were use to find reports with original data for children hospitalized with bacteriologically-proven UTI who had undergone both MCU and (99m)Tc-DMSA scintigraphy, and which also reported both positive and negative results of these tests. A meta-analysis of likelihood ratios positive and negative for MCU was then performed, including tests for heterogeneity. Twelve valid studies were found, seven with data for 537 children, with a positive (99m)Tc-DMSA scan prevalence of 59% overall, and seven studies with data for 1062 kidneys, with a positive (99m)Tc-DMSA scan prevalence of 36%. The likelihood ratio positive for MCU was 1.96 (95% CI, 1.51 to 2.54) for children, and 2.34 (1.53 to 3.57) for kidneys. The likelihood ratio negative was 0.71 (0.58 to 0.85) for children and 0.72 (0.61 to 0.86) for kidneys. There was evidence of heterogeneity. The meta-analysis showed that a positive MCU increases the risk of renal damage in hospitalized UTI patients by about 20%, whereas a negative MCU increases the chance of no renal involvement by just 8%. VUR is hence a weak predictor of renal damage in pediatric patients hospitalized with UTI. Physicians should be aware of the limitations of using MCU-detected primary VUR as an effective screening test for renal damage in this population. Furthermore, the pathogenesis of renal damage in such patients is probably complex because it is often detected without demonstrable VUR.