High frequency of metabolite abnormalities in pediatric isolated hematuria

Background:Hematuria, either macroscopic or microscopic, could be originated from anywhere of the kidney and urinary tract and could be a finding of an important underlying disease. Hematuria is always an accidentally finding and the detection of underlying causes are difficult or impossible inmost patients. In this study, weevaluated the underlying causes of hematuria in problematic cases.Methods: Weincluded522 referred children with hematuria who had not renal stone, urinary tract infection or glomerular diseases, based on clinical and laboratory findings. Then weevaluated the records and clinical symptoms and laboratory findings for other structural and hematological disorders andtheir urinary metabolites in 24-hour urine collection.Results: In this study, from 659 referred children with culture negative hematuria, 100 patients had renal stone in theirultrasonography and 59 patient had findings of glomerular disorders.In other522 enrolled patient,microscopicand gross hematuriawere found in 88.7% and11.3% respectively, the mean age was 5.9 years and the female to male ratio was 2 to 1. The most common symptoms were occasional abdominal pain and dysuria.Also in the 24-hour urine evaluation, we found metabolic disorders in 94% of cases and the most common findings werehypocitraturia (60.7%) followed by hypomagnesuria(58.2%), hyperuricosuria (35.8%), hypercalciuria (33.7%), hyperoxaluria (24.9%) and cystinuria (in only 4 cases).Conclusion:Disorders in urine metabolites include a large proportion of the underlying factors for hematuria in children and adolescents specially in previously considered cases as idiopathic hematuria.Therefore 24-hour urine collectionfor urinary metabolites, could be a recommended evaluation in cases with isolated hematuria.

Keywords:

Isolated hematuria , children , urine metabolites