ABSTRACT
Background: Early detection of pediatric urolithiasis is important to avoid the associated morbidities that can affect renal function. Hypercalciuria is a common contributing factor to urinary stone formation in children.
Aim of the work: To assess the diagnostic performance of urinary calcium/creatinine (UCa/UCr) ratio as a screening test for cases of hypercalciuria with urolithiasis.
Subjects and Methods: One hundred children with urolithiasis who attended the Nephrology and Urology Outpatient Clinics in Fayoum University Hospitals, Fayoum Insurance Hospital, and Fayoum General Hospital, during the period from June 2019 to June 2020 selected by simple random method an subjected to history taking, clinical examination, and investigations including blood chemistry, urine analysis, spot urine sample analysis for UCa/UCr ratio, calcium, and creatinine. Thirty age- and sex-matched, healthy children were included as control.
Results: The UCa/UCr ratio was significantly higher among the cases (Median: 0.08 vs. 0.04, p-value = 0.019). Twenty-two percent of cases had a high UCa/UCr ratio above 0.2. The UCa/UCr ratio had the highest area under the curve (AUC = 0.641, p = 0.018) compared to urinary calcium (AUC = 0.575, p = 0.216) and creatinine (AUC = 0.625, p = 0.038). The optimal cut-off point for UCa/UCr ratio was 0.06, with 59% sensitivity and 62.3% specificity. Conclusions: UCa/UCr ratio is a potentially early, useful, practical, and non-invasive screening tool for the early detection of urolithiasis in children. We recommend urine microscopy and strict metabolic work-up for all patients who present with symptoms suggestive of urolithiasis