Extended routine polymerase chain reaction surveillance and pre-emptive antiviral therapy for cytomegalovirus after allogeneic transplantation

Pre-emptive treatment strategies based on sensitive screening for cytomegal ovirus (CMV) infection up to day +100 after allogeneic transplantation have been shown to reduce the incidence of CMV disease during the period of sur veillance. However, the use of ganciclovir has been associated with delays in immune reconstitution and an increased incidence of late CMV disease aft er day +100. In the present study, 81 patients undergoing allogeneic transp lantation received polymerase chain reaction (PCR)-guided pre-emptive thera py based on detection of CMV DNA by PCR on 2 consecutive weeks up to day +1 80. Thirty-three of the 52 high-risk patients (CMV-seropositive donor or re cipient) received a total of 45 treatment episodes up to day +100. Three of these patients (5.7%) developed CMV disease, with one fatality. Twelve of the surviving 44 high-risk patients (27%) required pre-emptive treatment be tween days +101 and +192, but none of these patients developed late CMV dis ease with a median follow-up of 402 d (range 117-952 d). Antiviral therapy was stopped after a single negative PCR result with no subsequent episodes of CMV disease while patients remained off antiviral treatment. As all init ial episodes of CMV DNA detection occurred within 60 d of transplantation, it may be possible to discontinue monitoring beyond day +100 in patients wh o have remained CMV PCR negative before this. Thus, we have confirmed that PCR-guided pre-emptive therapy results in a low incidence of CMV disease be fore day +100 and that discontinuing treatment on the basis of viral cleara nce as determined by CMV PCR appears to be safe practice. In addition, we h ave observed no episodes of late CMV disease with an extension of surveilla nce to 26 weeks.