A dual-label time-resolved fluorescence immunoassay for the simultaneous determination of ferritin and β2-microglobulin

BackgroundLymphocytic leukemia is a kind of primary malignant tumor of hematopoietic tissue. The aim was to establish a dual-label time-resolved fluorescence immunoassay (TRFIA) for the simultaneous determination of ferritin (FER) and beta(2)-microglobulin (beta(2)-MG) for the early screening and follow-up surveillance of lymphocytic leukemia. MethodsThe sandwich immunoassay was used to detect the concentration of FER, and the competitive immunoassay was used to detect the concentration of beta(2)-MG in serum. FER in serum was captured by anti- FER antibody immobilized on microtiter wells, and then banded together with another anti- FER labeled with europium(III) Eu3+ chelate, followed by fluorescence measurement using time-resolved fluorometry (TRF). Sm3+ labeled (2)-MG and (2)-MG samples were added to compete with a certain amount of anti-(2)-MG antibody, followed by fluorescence measurement using TRF. The performance of this dual-label TRFIA was evaluated using the clinical blood and compared with the commercial assays. ResultsThe linear correlation coefficient (R-2) of the FER and (2)-MG standard curves were 0.9914 and 0.9927, respectively. The sensitivity for FER detection was 8ng/mL (dynamic range 0-1000ng/mL), the average recovery was 100.51%; The sensitivity for (2)-MG detection was 1ng/mL (dynamic range 0-1000ng/mL), the average recovery was 101.02%. High correlation coefficients (R-2) were obtained between the commercial assays (R-2=.9966 for FER, and R-2=.9897 for (2)-MG). ConclusionThe present dual-label TRFIA has high sensitivity, specificity, and accuracy in clinical sample analysis. It is an effective detection method for the early screening and follow-up surveillance of the acute and chronic lymphocytic leukemia.