False high level in total bilirubin estimation in nonicteric serum

Abstract

In day to day clinical biochemistry laboratory practices, occasionally abnormal  levels of individual parameters are noted. These reports cannot be explained immediately with certainty always. Inquisitiveness with in-depth analysis might  reveal the possible cause sometimes. To find out the possible cause of false elevation in total bilirubin estimation in nonicteric serum from one patient was the objective. Routine estimation of total bilirubin in serum/plasma by the decade old practice of using very reliable and stable reagent kit from Roche in the biochemistry laboratory of a general hospital revealed a falsely very high value of total bilirubin in a patient’s blood sample for the first time. Subsequently, the same sample was  subjected to estimation of total bilirubin by DiaSys and Randox reagents along with simultaneous re-estimation by Roche reagents in next three days. Repeated  estimations by Roche reagents showed falsely very high level of total bilirubin. However, estimation by DiaSys and Randox reagents showed acceptable normal levels as per visual estimation. There was interference, most probably due to paraprotein in the estimation of total bilirubin by Roche reagents but not by DiaSys and Randox reagents in that particular sample.

Keywords: False, high, positive, total bilirubin, nonicteric, serum.