Development of models and detection methods for different forms of cytomegalovirus for the evaluation of viral inactivation agents

BACKGROUND:  Cytomegalovirus (CMV) is transmitted by transfusion of infected blood products and can cause serious diseases in specific risk groups. CMV can be present in infected blood as cell-free virus (CFV), cell-associated actively replicating virus (CAV), and cell-associated latent virus (LV). STUDY DESIGN AND METHODS:  In vitro models for all three infectious forms of CMV and virus detection assays based on both tissue culture and polymerase chain reaction (PCR) were developed. The utility of the CMV model systems and assays were tested by validation studies of a novel pathogen inactivation agent, PEN110, for red blood cells. RESULTS:  Reproducible high titers of CFV and CAV were obtained by optimized tissue culture techniques for CMV-infected MRC-5 cells. An LV model was obtained with CMV-infected THP-1 cells and reactivation of virus replication by phorbol ester treatment. The model systems showed that PEN110 treatment is effective against all three forms of CMV as measured by tissue culture–based infectivity assays and a long-range PCR method specific for detection of damage to CMV viral DNA. CONCLUSION:  This study describes model systems to the relevant forms of CMV in blood and detection assays that can be used to evaluate the efficacy of viral inactivation agents.