Post-transplant non-Hodgkin lymphoma is a feared complication of immunosuppressive treatment and is associated with high mortality. Most post-transplant lymphomas develop from the uncontrolled proliferation of Epstein-Barr-virus (EBV)-infected B lymphocytes. No reliable methods for the prevention of EBV infection and lymphoma are available. We aimed to elucidate the effect of prophylactic treatment for cytomegalovirus (CMV) infection on the incidence of post-transplant lymphomas.

In a multicentre retrospective study, we analysed the incidence of post-transplant non-Hodgkin lymphoma in 44828 recipients of deceased-donor kidney transplants who were reported to the scientific registry of the Collaborative Transplant Study. Patients had received antiviral drugs (aciclovir or ganciclovir) or anti-CMV immunoglobulin to prevent CMV infection according to the transplant centres’ protocols, or no CMV prophylaxis. Standardised incidence ratios (SIR) of lymphoma were calculated and compared by χ² analyses

During the first post-transplantation year, 30255 patients who did not receive CMV prophylaxis developed lymphomas at SIR 26·4. Lymphoma incidence in 12470 patients who received antiviral treatment was nearly identical (SIR 24·2, p=0·62) to that in patients who did not receive CMV prophylaxis. However, 2103 patients who received anti-CMV immunoglobulin showed a complete absence of lymphomas in the first after-transplantation year (SIR 0; p=0·012 vs no treatment, p=0·016 vs antivirals). In the subsequent 5 years of follow-up, new cases of lymphoma developed at similar rates in all three groups (p=0·97).

These findings suggest that prophylactic anti-CMV immunoglobulin prevents the development of early post-transplant non-Hodgkin lymphoma in kidney-graft recipients. Prophylactic treatment with antiviral drugs does not reduce the risk of post-transplant lymphoma.