Persistence of antibody to human parvovirus B19 after allogeneic bone marrow transplantation: role of prior recipient immunity.

Human parvovirus B19 (B19) IgG was studied retrospectively in 66 allogeneic bone marrow transplantation (BMT) patients using an enzyme-linked immunosorbent assay. Recipient and donor sera had been stored pre-BMT together with sequential sera thereafter. Approximately half of donors and recipients had anti-B19 IgG pre-BMT and thus the relative contributions of donor and recipient immunity to antibody production after transplantation could be assessed. For each patient, a serum taken 2 to 3 years after BMT was also tested and the results show that persistence of B19 antibody depends on prior recipient (P = .0003) but not on donor immunity (P = .8). The findings were similar in both sibling and (VUD) BMT volunteer unrelated donor patients. Analysis of sequential post-BMT sera from 41 of the patients, for whom appropriately timed samples were available, showed primary B19 infection in 3 seronegative individuals, whereas 5 others who were seropositive before BMT underwent recurrent infection. Sequential results from the remaining 33 patients without recent B19 infection showed no evidence for donor antibody transfer and confirmed that antibody persistence depends on prior recipient immunity. B19 IgG levels decreased variably with time and some patients eventually became seronegative. It is concluded that this long-term persistence of B19 antibody post-BMT is most probably due to the existence of long-lived recipient plasma cells.