Exogenous interferences with Jaffe creatinine assays: addition of sodium dodecyl sulfate to reagent eliminates bilirubin and total protein interference with Jaffe methods

Abstract

Endogenous interferences continue to plague creatinine accuracy measurement in both Jaffe and enzymatic methods, and consequentially the estimated glomerular filtration rate. The addition of SDS to the alkaline-pirate reagent was shown to be effective in reducing bilirubin and protein interferences.

Point-of-Care Measurement of Serum Creatinine in the Intensive Care Unit

“…22,23 Amperometric enzymatic methods, on the other hand, have been reported not to be affected by chromogens and to yield lower values for serum Cr. 24,25 Others, however, found some interaction with chromogens, in particular bilirubin, 15 with these methods as well. To overcome its limitations, several different adjustments have been proposed to the Jaffé method.…”

“…11,12 Several chromogens are known to interfere with this method. They include ketones, 13 bilirubin, [14][15][16][17] glucose, [18][19][20] hemoglobin, 12,17 and cephalosporin antibiotics. 21 Although modifications to the Jaffé method have been made over the years, its specificity for Cr has only moderately improved.…”

“…The National Kidney Disease Education Program acknowledges that although many automated routine methods for measuring Cr meet or exceed the required precision, standardization of calibration does not correct for analytical interferences. 27 These observations in their aggregate suggest that central laboratory measurement of serum Cr in critical illness, where ketones, 13 bilirubin, [14][15][16][17] glucose, [18][19][20] and cephalosporin antibiotics 21 are commonly high, may be particularly likely to overestimate serum Cr values. They also suggest that enzymatic methods are less likely to lead to such overestimation.…”

“…All these chromogens are known to cause interference with the Jaffé method. [12][13][14]18,21 For example, two studies 15,16 found a lower Cr value with increasing bilirubin concentration that was more evident with the Jaffé method than with an enzymatic assay. A higher Cr value was found with increasing protein concentration with both techniques, while glucose values >30 mmol/L had a positive bias only for the Jaffé method.…”

“…Glucose has been extensively reported 15,19,20 to increase Cr readings while negligible effects are reported with amperometric enzymatic techniques. We did not find any interference of glucose on δCr in our study.…”