Abstract: SA-PO485

Peptide Vaccination against Cytomegalovirus (CMV) Induces Cellular Immune Responses in CMV Seronegative ESRD Patients

Session Information

Category: Dialysis

  • 610 Dialysis: Infection

Authors

  • Sommerer, Claudia, University Hospital Heidelberg, Heidelberg, Germany
  • Schmitt, Anita, University Hospital Heidelberg, Heidelberg, Germany
  • Schnitzler, Paul, University Hospital Heidelberg, Heidelberg, Germany
  • Zeier, Martin G., University Hospital Heidelberg, Heidelberg, Germany
  • Schmitt, Michael, University Hospital Heidelberg, Heidelberg, Germany
Background

Cytomegalovirus (CMV) reactivation occurs particularly in patients after solid organ transplantation (SOT) from seropositive donors. CMV reactivation is associated with a high risk of disease and mortality. The nonamer peptide NLVPMVATV derived from CMV phosphoprotein 65(CMVpp65) is highly immunogenic. Here we report on a clinical phase I peptide vaccination trial with this peptide in a water-in-oil emulsion (Montanide™) plus administration of or imiquimod (Aldara™) as adjuvant.

Methods

Four vaccines were administered subcutaneously at a biweekly interval to ten CMV seronegative endstage renal disease patients waiting for kidney transplantation. The clinical course, CMVpp65 antigenemia and CMV replication were monitored. CMV-specific CD8+ T cells were characterized by multi-color flow cytometry and Enzyme Linked Immuno Spot Assay (ELISPOT) and correlated it to clinical parameters.

Results

Peptide vaccination was well tolerated and no drug-related serious adverse events were detected except from local skin reactions. In four patients, specific CD8+ T cell responses against CMV could be elicited by prophylactic vaccinations. In responders an increase of CMV-tetramer positive CD8+ T cells and interferon gamma secretion was detected. Interestingly a shift from CCR7+CD45+ naïve T cells towards CCR7-CD45RA+ effector T cells could be observed suggesting an effective immune response against the virus.

Conclusion

In ten CMV seronegative endstage renal disease patients on the waiting-list for kidney transplantation we demonstrated that administration of CMVpp65 peptide vaccination was safe, well tolerated and clinically encouraging. Imiquimod can serve as an adjuvant with a similar efficacy.