REDUCED INCIDENCE OF EPSTEIN-BARR VIRUS-ASSOCIATED POSTTRANSPLANT LYMPHOPROLIFERATIVE DISORDER USING PREEMPTIVE ANTIVIRAL THERAPY

Background. Posttransplant lymphoproliferative disorder (PTLD) has bee n observed with increasing frequency consequent to the availability of more effective and potent immunosuppression. Prior work suggested tha t a peripheral blood monitoring strategy detecting peripheral B lympho proliferation was effective in the early diagnosis of PTLD among 7 of 179 (3.9%) consecutive transplant; recipients, Each of those seven pat ients received at least one course of antithymocyte globulin, Minnesot a antilymphocyte globulin, or OKT3 before developing PTLD. Methods. To determine whether antiviral prophylaxis might reduce the incidence of PTLD, a subsequent group of 198 consecutive recipients received eithe r ganciclovir or acyclovir daring antilymphocyte antibody administrati on, When the donor or recipient were cytomegalovirus-seropositive, gan ciclovir was given; acyclovir was used when both were cytomegalovirus- seronegative. Baseline and protocol posttransplant cell surface profil es were obtained using immunofluorescence and flow cytometry to detect T cells, lymphocyte activation markers, and the CD19 B cell antigen. Results. Demographic factors, including the incidence of recipients mo re than 50 years of age, non-Caucasians, previous transplantation, and diabetes mellitus, were similar in both groups, Additionally, the num ber of patients receiving antilymphocyte preparations was similar, How ever, only one patient (0.5%) from the latter group who received preem ptive antiviral therapy developed PTLD, Although elevations in CD19(+) B cells preceded clinical PTLD among each of the seven earlier patien ts, evidence of peripheral B cell proliferation was not demonstrated f or the sole patient from the latter group, which suggests a possible e ffect of antiviral therapy. Conclusions. Prophylactic antiviral therap y may reduce the sensitivity of peripheral monitoring for B lymphoprol iferation, but the dramatic reduction in PTLD incidence strongly suppo rts its use among transplant recipients at risk.