Kenji Hosoda

Cytomegalovirus (CMV) antigenaemia for rapid diagnosis and monitoring of CMV‐associated disease after bone marrow transplantation

A technique for the rapid detection of cytomegalovirus (CMV) antigen‐positive blood leucocytes (CMV antigenaemia) was evaluated in 15 marrow transplant patients as a means of diagnosis and for monitoring CMV‐associated disease. CMV antigenaemia was determined by direct immunoperoxidase staining of leucocytes with a peroxidase‐labelled monoclonal antibody, HRP‐C7, which binds an immediate‐early antigen of human CMV.

Rapid Diagnosis of Cytomegalovirus Infections by Direct Immunoperoxidase Staining with Human Monoclonal Antibody against an Immediate-Early Antigen

Direct immunoperoxidase technique using a horseradish peroxidase (HRP)‐conjugated Fab fragment of human monoclonal antibody (humab C7), designated HRP‐C7, was evaluated as a rapid diagnosis of cytomegalovirus (CMV) infection. A total of 138 clinical specimens consisting of 124 urine samples and 14 oral swabs were examined for CMV by the direct HRP‐C7 staining in comparison with conventional virus isolation. The number of CMV‐positive samples by each method was 40 (29.0%) for the former and 37 (26.8%) for the latter, respectively. By HRP‐C7 staining, CMV was identifiable within 24 hr after inoculation. By conventional isolation method, an average of 10.3 days had passed before cytopathic effect characteristic of CMV appeared in the cell culture. Some false‐positive and false‐negative cases were discussed in relation to toxicity of urine samples, storage of the samples, and amount of CMV in the sample. The sensitivity and specificity of HRP‐C7 method against conventional isolation method were 89.2% and 93.1%, respectively. Thus, HRP‐C7 staining is useful for a rapid diagnosis of CMV infections.