Potential of Anti-CMV Immunoglobulin Cytotect CP In Vitro and Ex Vivo in a First-Trimester Placenta Model

Background: Congenital CMV infection is the leading cause of neonatal neurological deficit. We herein studied in vitro and ex vivo the potential of the hyperimmune globulin Cytotect CP (Biotest, Germany) for congenital infection prevention and treatment.

Methods: In vitro neutralization assays were conducted in fibroblasts and retinal epithelial cells on the CMV strains TB40/E and VHL/E to determine the 50% and 90% neutralizing doses (ND50 and ND90). The toxicity was assessed by measuring LDH release. Ex vivo assays were conducted in first-trimester villi explants with the TB40/E strain, namely, neutralization assays, the prevention of villi infection, and the inhibition of viral replication in infected villi. Viability was assessed by β-HCG quantification in supernatants.

Results: The in vitro neutralization tests showed that Cytotect CP inhibits the development of infection foci (DN50: 0.011-0.014 U/mL for VHL/E and 0.032-0.033 U/mL for TB40E) without any toxicity. In the ex vivo neutralization assays, the DN50 were 0.011 U/mL on day 7 and 0.093 U/mL on day 14. For the prevention of villi infection, the EC50 was 0.024 U/mL on day 7. Cytotect-CP did not inhibit viral growth in infected villi. No impact on villi viability was observed.

Conclusions: These results sustained that Cytotect CP has the potential to prevent CMV congenital infection.