Still trouble with serum creatinine measurements

Excerpt

Utilizing serum creatinine to calculate the estimated glomerular filtration rate (eGFR) is a vital tool in classifying chronic kidney disease (CKD) stages and demands correct measurement. The study in this issue of Pediatric Nephrology, titled “Large Inter-assay Difference of Serum Creatinine in the Pediatric Population: a Threat to Accurate Staging of Chronic Kidney Disease,” addresses an important concern regarding limitations of precise creatinine measurement in a pediatric sample from Beaumont Health, Royal Oak, MI, USA. In pediatric populations, there are multiple factors which contribute to lower serum creatinine levels, including lower muscle mass overall and increased levels of non-creatinine chromogens, such as bilirubin [1]. Calibration procedures, which are traceable to isotope dilution mass spectroscopy (IDMS), allow standardization of serum creatinine levels [2]. The creation of reference materials is valuable and efforts to create standardized tools should be applauded. Unfortunately, there remains a paucity of reference materials that incorporate the much lower creatinine concentrations commonly seen in children. …