Among these detection methods, ELISA is suitable for large-scale detection of infections that have already produced an immune response (Liu et al., 2015), but sometimes the sensitivity of reagent anti-HEV IgM detection is low, and some studies have reported that existing diagnostic reagents lack the reactivity of serum anti-HEV against some infected genotypes of patients (Wang and Zhuang, 2004). Here, CD40LG is linked to infection.