Use of deproteinizer to eliminate interference of high bilirubin on measurement of serum creatinine by the kinetic jaffe reaction

Abstract

Introduction: Serum creatinine is a useful diagnostic parameter of kidney function. Its concentration reflects glomerular filtration rate. Because of negative interference of bilirubin over creatinine level, may mislead the clinician. The most common and serious problems in the determination of serum creatinine concentration by the kinetic Jaffe method is the negative interference by bilirubin. Materials and Methods: This cross sectional study was done on 160 patients which have high bilirubin level, taken from B. J. Medical College, Civil hospital, Ahmedabad from August 2013 to December 2013. These samples were studied for interference of total bilirubin on measurement of Serum creatinine level before and after treating with deproteinizer (trichloroacetic acid 0.55 mmol/ltr). Serum bilirubin and serum creatinine level were measured by modified Jendrassik & Groff's method and kinetic Jaffe's reaction respectively by using Erba XL-640 fully auto analyzer. Results: In this study significant difference was found in Serum Creatinine level with the samples of high bilirubin content before and after treating with deproteinizer (trichloroacetic acid) (p<0.01). This result shows negative interference of Serum Bilirubin on serum creatinine estimation. Preprecipitation of albumin along with bilirubin by trichloroacetic acid beforehand is suggested as an approach to correct the bilirubin interference. Conclusion: From this study it is concluded that bilirubin have negative interference on serum creatinine level. And this is corrected by using deproteinizer trichloroacetic acid.