ABSTRACT
Background: Long term complications of glycogen storage disease (GSDs) include delayed puberty, hepatic adenomata, and renal disease. Objectives: In the present study we aimed at detecting renal involvement in children with glycogen storage disease, and determining the most accurate laboratory test to be the gold standard for early detection of this renal dysfunction. Methods: Twenty seven children known to have GSD were included in this study. Fifteen healthy age-and sex-matched children were also included as controls. Routine urine analysis, urinary β2 microglobulin and microalbumin were done for all patients and controls. Renal function tests, serum electrolytes, alkaline phosphatase, urinary calcium, blood and urine PH, urinary and plasma aminogram, in addition to calculation of glomerular filtration rate (GFR), bone X rays to detect rachitic manifestations and abdominal ultrasound to measure renal size were done for all patients. Results: Twenty one patients had one or more renal abnormality. The most common was increased urinary β2 microglobulin (15/21) followed by abnormal GFR whether low or high (8/21) and microalbuminuria (6/21). Sonographically  there was nephrocalcinosis in one case and renal stone in another one. The area under the receiver operating characteristic (AUROC) curve for β2 microglobulin was 0.86, (p=0.01) and 0.7 for urinary microalbumin/creatinine ratio (p=0.15). The best cut-off level to predict renal abnormality for urinary β2 microglobulin was 0.22 mg/I with 70% sensitivity and 100% specificity and the best cut-off value for urinary microalbumin/creatinine ratio was 4.5 with 86% sensitivity and 50% specificity. Conclusions: Renal abnormalities are common in patients with GSD. Urinary β2 microglobulin can be considered the gold standard for early detection of renal dysfunction in these patients.