Approach to the Child with Hematuria and/or Proteinuria

Abstract

Hematuria and proteinuria are among the common reason why children are referred to a pediatric nephrologist. The initial step in a child with hematuria is to establish the diagnosis by performing a urine microscopy to look for the presence of >5 RBC/microliter in a fresh uncentrifuged urine specimen. The prevalence of isolated hematuria is reported to be 0.4-0.5% in large epidemiological studies. There is increasing evidence that persistent hematuria, particularly if associated with proteinuria, is a risk factor fo chronic kidney disease in the longer term. Therefore, careful history and clinical examination is important so that appropriate investigations are undertaken to identify the etiology. Glomerular causes of hematuria (glomerulonephritis and familial hematuria) are more common in children than lower tract causes of hematuria (cystitis and hypercalciuria). There is increasing role for genetic testing in children with hematuria, particularly where there is family history of hematuria, deafness, or chronic kidney disease. Imaging (ultrasound and CT scan) is important if urolithiasis or a structural abnormality is suspected. Proteinuria can be nonpathological (febrile, exercise, or orthostatic) or pathological. Children with persistent proteinuria can be asymptomatic or they can present with nephrotic syndrome. Spot first morning urine sample for urine protein: creatinine ratio (PCR), or albumin: creatinine ratio (ACR) is the ideal test to confirm the presence of proteinuria. Children with urine PCR >50 mg/mmol (>1 g/1.73m2/day) merit further evaluation in order to exclude significant pathology like primary or secondary glomerulonephritis. Renal biopsy should be considered in children with persistent proteinuria, especially if it is associated with hematuria, reduced GFR, or hypertension.