Risk factors for cytomegalovirus infection in BMT recipients transfused exclusively with seronegative blood products.

Risk factors for developing cytomegalovirus (CMV) infection and pneumonitis were analysed in 100 unselected consecutive patients undergoing allogenic BMT. This series is homogeneous because of the same diagnostic procedures, BMT technique and supportive care (exclusive seronegative blood products, no CMV immunoglobulin, no prophylactic antiviral). The incidence of CMV infection and CMV interstitial pneumonitis (CMV-IP) were 44% and 13% respectively, of whom five patients died. Variables such as age, sex, underlying disease, conditioning regimen and occurrence of GVHD were not found as significant risk factors. We confirm that the only major factor was recipient's serology as CMV infection and IP occurred in 4% and 0% respectively among negative recipients (R-) compared with 79% and 25% among positive R. In contrast to some studies among R+, neither donor's immunity nor recipient's CMV humoral response improved the clinical outcome. This study validates the good predictive value of viremia and urinary virus excretion for the occurrence of CMV-IP (respectively positive in 11 and 13 patients out of 13 with IP), always preceding IP by a median of 37 and 27 days. The highest risk patients for lethal CMV-IP were older recipients (> 30 years). Thus, prospective prophylactic trials with antiviral agents are suggested in such viremic or viruric patients. Furthermore, the use of seronegative blood products is highly effective and sufficient to prevent CMV infection in R-patients.