Rapid Immunodiagnosis of Active Cytomegalovirus Infection by pp65 Antigenemia Assay

Detection of early antigen pp65 in blood leucocytes is a new method of diagnosing active cytomegalovirus (CMV) infection. Using a mixture of two monoclonal antibodies, CMV pp65 antigen was detected in blood leucocytes by a quantitative indirect immunofluorescence test within 3-5 hours after sampling. The pp65 antigen was detected in 20 (29.8 %) of the 67 immunocompromised patients included in this study. The level of CMV antigenemia appears to be related to the severity of CMV infection. Thus, this method may provide a rapid and sensitive approach to early diagnosis of active CMV infection in immunocompromised patients and a promising marker for initiating therapy and monitoring disease activity and its response to therapy.