Influence of human cytomegalovirus on immune reconstitution after bone marrow transplantation.

HCMV infection diagnosed by the highly sensitive polymerase chain reaction (PCR) technology in blood, urine and skin biopsies of patients after bone marrow transplantation (BMT) correlated with the reconstitution of peripheral blood lymphocytes and dermal immunohistological alterations to evaluate the interaction of viral infection with the recovery of the immune system, as well as with the induction or aggravation of graft-versus-host disease (GVHD). In a prospective study 73% of 63 patients showed viremia at a median time of 25 days after BMT. Only 44% of these cases that also presented with a higher frequency of acute GVHD symptoms developed HCMB disease later on. In the skin, similar immunohistological alternations, as well as frequent primary local HCMV infection before the development of cutaneous signs of GVHD, was found, suggesting the direct involvement of anti-HCMV immune responses in the induction of GVHD-associated organ lesions.