Reflection and observation: cell-based screening failing to detect HBV in HUMSCs derived from HBV-infected mothers underscores the importance of more stringent donor eligibility to reduce risk of…

Wei Liu, Yuanyuan Xie, Tianyun Gao, Feifei Huang, Liudi Wang, Lijun Ding, Wenqing Wang, Shuo Liu, Jianwu Dai, Bin Wang

In cell-based therapy, the transmission of communicable diseases imposes a substantial threat to recipients. In this study, we investigated whether cell-based screening could detect hepatitis B virus (HBV) in human umbilical cord-derived mesenchymal stem cells (HUMSCs) isolated from HBV-infected donors to understand the susceptibility of HUMSCs to HBV infection. HBV assay was performed in HUMSCs derived from healthy and HBV-infected donors with enzyme-linked immunosorbent assay (ELISA), fluorescence quantitative PCR (FQ-PCR) assay, and droplet digital PCR (ddPCR) assay. Further, HBV DNA was assayed in HUMSCs derived from healthy donors after incubation with human sera containing a high titer of HBV using FQ-PCR. HBV antigen/antibody and DNA failed to be detected using ELISA, FQ-PCR, and ddPCR. After incubation with HBV infection sera, HBV DNA could be detected, but below the valid titer of the assay kit. The HBV DNA levels in HBV-incubated HUMSCs gradually decreased with medium change every 2 days and then significantly decreased, not even detected after passage. The current cell-based screening methods could not detect HBV in HUMSCs derived from HBV-infected donors, indicating the importance of more stringent donor eligibility to reduce the risk of transmission of communicable diseases in cell-based therapy. To solve the problem of an occult HBV window period in donor eligibility determination, we recommend that the donors undergo another HBV serological test 3 months after the first serological communicable disease screening.