A carboxylated magnetic bead-based CLIA method for detecting anti-pp62 antibody of African swine fever virus

Abstract:

[Background] African swine fever (ASF), as a highly pathogenic infectious disease, has caused serious economic losses in China’s pig farming industry, so it is crucial to establish a fast and sensitive diagnostic method. [Objective] To develop a chemiluminescence immunoassay (CLIA) for the detection of the anti-pp62 antibody of African swine fever virus (ASFV). [Methods] The recombinant pp62 protein was used as the coating antigen, carboxylated magnetic beads as the solid-phase carrier, and alkaline phosphatase (AP)-conjugated rabbit anti-swine IgG as the secondary antibody. The reaction conditions were optimized, and the standard curve was established with the national reference product of ASFV as the traceable serum. Finally, a CLIA method for detecting the anti-pp62 antibody of ASFV was established. [Results] The established CLIA method was used to test 277 clinical samples, and the negative and positive thresholds were determined by the receiver operating characteristic (ROC) curve. The concentrations >140.02 U and <140.02 U were determined as antibody positive and negative, respectively. Furthermore, the established method was used to detect the serum antibodies to six different pathogens, which showed no cross-reactivity, the intra- and inter-batch coefficients of variation below 10%, and a compliance rate of 96.7% with the results obtained by commercial ASFV antibody detection kits. [Conclusion] The CLIA method established for the detection of ASFV has good specificity, sensitivity, and reproducibility, which can provide a reference for the early monitoring of ASF and the research and development of the relevant kits.