Guidance of ganciclovir therapy with pp65 antigenemia in cytomegalovirus-free recipients of livers from seropositive donors.

Cytomegalovirus (CMV*), the first reported transplantassociated opportunistic virus (1), has remained the most frequent single cause or co-cause ofinfections throughout the ensuing three decades (2). Because prophylactic drug and hyperimmune globulin therapy has not been effective in these CMV-infected patients (2-4), Rubin (5) suggested withholding treatment until the phase of rapid viral replication (preemptive therapy). Early diagnosis of CMV infection, upon which this strategy depends, can be accomplished in the presymptomatic phase (6, 7) with a rapid quantitative direct demonstration of CMV antigen pp65 in cytospin preparations of peripheral blood leukocytes (PBL) (8, 9). This method has aided in the management of 20 CMV seronegative recipients of livers from seropositive donors, a circumstance that carries an 85-90% risk of virus transmission of CMV disease, presumably from migratory monocytes from the graft (10) that are known to harbor the latent virus in healthy seropositive individuals (1]). The 20 recipients under tacrolimus/prednisone immunosuppression were followed for 308± 100.5 days (range, 63-520 days) after transplantation; a death at 63 days unrelated to CMV accounted for the only follow-up of <3 months. Heparinized blood samples were obtained by schedule during the first 3 months or when clinically indicated during this period and later. The pp65 antigen was detected in duplicate leukocyte spots (2X 105 cells in 200 J.l.lIglass slide) with the tech· nique of Van der Bij et a1. (8), using immunofluorescence (2) instead of immunoperoxidase staining (9). The anti·pp65 mouse monoclonal antibody was clone 1C3 (Hiosoft, Argene, France). Fluorescein·isothiocyanate-Iabeled goat anti·mouse Fab2 fragment (Cappel, Durham, NC) was applied as the conjugate. Slides were counterstained with Evans blue dye and observed under 400 x magnification for the typical green nuclear fluorescence. /\. conventional shell vial culture assay was done on the same blood specimens. Anti·CMV antibodies (lgG and IgM)