Study on the Hook Effect in the Detection of Beta2-Microglobulin with Different Reagents in Fully Automated Biochemical Analyzers

Objective: To investigate the hook effect in the detection of beta2-microglobulin (β2-MG) with different reagents as well as on two fully automated biochemical analyzers and their solutions. Methods: Using immunoturbidimetric assay for β2-MG as the research object, β2-MG levels were detected by different concentration gradients of β2-microglobulin samples in Liedemann, Mack, and Myriad reagents of three manufacturers on two automatic biochemical analyzers, and the difference of the hook effect was comparatively analyzed. Results: Leadman reagent showed the hook effect on the Beckman AU5800 automated biochemistry analyzer, while both Maccura and Mindray reagents did not show the hook effect. After the experiments, we found the limit value of the pre-zone check of Leadman reagent, and changed the parameters of the instrument, when the limit value of the pre-zone check was reached, the instrument automatically diluted the specimen five times and then detected it again. After changing the parameters of the instrument, the correlation between the three methods of detecting samples of different concentrations was r > 0.99. Conclusion: Before selecting the application of immunoturbidimetric reagents, we have to carry out the risk assessment of the hook effect and selectively set the parameters of the pre-zone check based on the highest concentration that may occur in the clinic; for the items that may have the hook effect, we have to selectively set the parameters of the pre-zone check when the ratio of average reaction rate and the immediate reaction rate is at the limit value, and the phenomenon of antigen excess may occur, the instrument will carry out automatic dilution before detection, so as to avoid the issuance of erroneous results of high-value samples due to the hook effect.