A comparative study on the estimation of serum Creatinine levels by Jaffe’s and Enzymatic methods at different levels of serum Bilirubin

In the present study, based upon their total serum bilirubin values ranging from 0.3-30.8 mg/dl, 47 patients visiting OPD and IPD of HIMS were divided into five groups. Their serum creatinine levels were estimated by the Jaffe's and the Enzymatic methods. Total serum bilirubin concentration was estimated by the timed endpoint Diazo method. Results obtained during the studies revealed that in all the five groups, estimation of serum creatinine by the Jaffe's method always gave significantly higher values (p< 0.01) as compared to their estimated values by the Enzymatic method at the identical serum bilirubin concentrations. The differences in the mean values of serum creatinine obtained between the two methods were found to significantly increase with the increase in the serum total bilirubin concentrations. At serum total bilirubin concentration of < 2.0 and >20.0 mg/dl, the mean differences between the Jaffe's and Enzymatic methods were found to be 0.2206 ± 0.0508 and 0.6786 ± 0.0530 mg/dl respectively, resulting in an approximately three-fold increase in the difference in the estimated serum creatinine concentration by the two methods. The highly significant enhancement in the differences in the estimated values of serum creatinine, between the Jaffe's and the Enzymatic method, with an increase in serum bilirubin concentrations, are attributed to the negative and positive interference in creatinine estimation caused by lower and higher concentrations of total serum bilirubin respectively.