Comparative analysis of tacrolimus blood concentrations by two determination methods based on renal function

Li Xiang; Yan Ming; Shi Guo-bing; Xia Dong-ya; Ren Tian-shu

doi:10.3969/j.issn.2095-4344.2014.05.014

Abstract：BACKGROUND:Whether determination of tacrolimus blood concentration by different immunoassay methods can influence predictive ability to immunosuppressive effects and toxicity, and whether it can be more sensitive to reflect blood concentration in patients with renal dysfunction are worthy of studying. <br> OBJECTIVE:To analyze the correlation of tacrolimus (FK506) concentrations determined by enzyme-multiplied immunoassay technique (EMIT) and enzyme linked immunosorbent assay (ELISA) in combination with renal function parameters. <br> METHODS:133 clinical blood samples were col ected. EMIT and ELISA techniques were used to determine the FK506 concentration. The correlation of two determination methods were analyzed, combined with renal function. RESULTS AND CONCLUSION:In patients with renal dysfunction, the mean results and standard deviation mensurated by ELISA were higher than those by EMIT. For blood concentration in 5-20μg/L by ELISA, the incidence of renal dysfunction occurred less than by EMIT. The overal mean results of blood concentration for two methods appeared no significant difference (r=0.904 5, P>0.05). When the concentration was less than 2.0μg/L, the concentration results by EMIT were higher than those by ELISA (P<0.01). When the concentration was more than 2.0μg/L, there was no significant difference between two determination methods (P>0.05). These findings indicate that EMIT and ELISA has good correlation, which are both suitable for clinical routine determination of plasma concentration. It is not recommended for applying EMIT method to determine low blood concentrations (<2.0μg/L). The reference range of concentration should be compartmentalized depending on combination of determination methods and renal function.