Increased incidence of cytomegalovirus (CMV) infection and CMV-associated disease after allogeneic bone marrow transplantation from unrelated donors

Cytomegalovirus (CMV) infection and CMV-associated disease were monitored using the CMV antigenemia assay in 72 patients who received allogenic bone marrow transplantation (BMT), and their incidences were compared between related and unrelated donor transplant patients. The incidence of CMV infection after BMT was significantly higher in patients who received transplants from HLA-matched unrelated donors than from HLA-matched sibling donors (87% vs 53%, P < 0.05). CMV-associated disease developed in 73% of unrelated and 14% of sibling donor transplant patients (P < 0.01). The peak levels of CMV antigenemia were significantly higher in unrelated donors than in sibling donor transplant patients (16 vs 1 CMV antigen-positive cells per 50 000 WBCs, P < 0.01). The median number of CMV antigen-positive cells on first detection was also significantly higher in unrelated donor transplant patients (15 vs 1, P < 0.01). The detection of CMV antigen-positive cells preceded the development of CMV-associated disease in 18% of unrelated donor transplant patients, suggesting a lower predictive value of CMV antigenemia for subsequent CMV-associated disease in unrelated donor BMT. Careful monitoring and further studies are needed for the early diagnosis and prevention of CMV-associated disease in unrelated donor BMT.