Metabolic evaluation of children with recurrent nephrolithiasis

ABSTRACT

This study was conducted to define the underlying metabolic causes of recurrent renal stones in children at Alexandria, Egypt Out of 52 children with renal stones referred to Alexandria University Hospitals during the one year period of the study; 20 were recurrent [38.5%]. Their age ranged between one and 14 years. Mean age of onset was 3.5 +/- 3 years. Recurrence rate was one to three episodes over a mean period of 2.5 +/- 2 years. Before enrolment in the study, cases were subjected to one or more settings of stone surgery and/or ESWL. Thorough clinical, imaging and metabolic evaluation was done to all cases. Chemical analysis and infrared spectroscopy of all available stones were done. The results of the study revealed that stone recurrence was due to metabolic errors in 80% of the cases while the remaining 20% were idiopathic with no evidence of underlying metabolic diseases. Hypercalciuria was detected in 40% of cases. It was associated with distal renal tubular acidosis [RTA-l] in 62.5% and due to idiopathic renal leak [IH] in 37.5%. Cystinuria was present in 20% of cases, hyperuricosuria due to GSD-I in 10% and primary hyperoxaluria in another 10%. Hypocitraturia was found in 55% of cases. Hydronephrosis and recurrent UTIs were detected in 40% and 55% of cases respectively. All children with recurrent renal stones should undergo thorough metabolic evaluation to detect underlying etiology. Different etiological factors may coexist in the same patient; but underlying metabolic defects are the commonest in children with recurrent nephrolithiasis; [80%] in the current work. Early diagnosis and treatment of such metabolic errors will prevent or decrease the morbidity caused by recurrence, and will save these children from hazards of repeated stone surgery or ESWL