The abnormal reaction data-detecting function of the automated biochemical analyzer was useful to prevent erroneous total-bilirubin measurement and to identify monoclonal proteins.

BACKGROUND

Recently, to detect abnormal reactions and failures of the device in biological analysis, a reaction data monitoring system has been provided for automated biochemical analyzers. We investigated the usefulness of this function for total-bilirubin (T-Bil) measurement in routine testing.

METHODS

Abnormal reactions of T-Bil were detected in the reaction data over time based on the following items: whether the absorbance variance after mixing of the first reagent and sample exceeds the cut-off value.

RESULTS

In the cases in which the abnormal reaction was observed, the absorbance rapidly rose because of turbidity after mixing the sample with Reagent-1. The measured value was higher than the actual T-Bil level, for which the analyzer showed a warning mark with the output data. When this particular serum sample was subjected to immunofixation electrophoresis, the presence of a monoclonal protein was confirmed. We encountered seven similar cases out of 30,731 samples.

CONCLUSIONS

The reaction data monitoring system of the automated biochemical analyzers was useful to prevent false reports (misdiagnosis) due to unpredictable problems during T-Bil measurement. It was also suggested that detection of false reaction with a reagent may be a clue to find a new pathology, such as monoclonal gammopathy.