SummaryPost-transplant lymphomas or other lymphoproliferative lesions, which were usually associated with Epstein-Barr virus infections, developed in 8, 4, 3, and 2 recipients, respectively, of cadaveric kidney, liver, heart, and heart-lung homografts. Reduction or discontinuance of immunosuppression caused regression of the lesions, often without subsequent rejection of the grafts. Chemotherapy and irradiation were not valuable. The findings may influence policies about treating other kinds of posttransplantation neoplasms.

Small, DNA-containing particles were separated from preparations of a simian adenovirus. These particles differed antigenically from the adenovirus. Replication of the particles in cell cultures was obtained only when theywere inoculated simultaneously with adenoviruses. This suggests that these adenovirus-associated particles behave as defective viruses.

Twenty cases of Epstein-Barr virus (EBV)-associated lymphoproliferative syndrome (LPS), defined by the presence of EBV nuclear antigen and/or EBV DNA in tissues, were diagnosed in 1467 transplant recipients in Pittsburgh from 1981-1985. The frequency of occurrence in pediatric transplant recipients was 4% (10/253), while in adults it was 0.8% (10/1214) (P less than .0005). The frequency of LPS in adults declined after 1983 coincidental with the introduction of cyclosporine monitoring. However there was no apparent decline of LPS in children. We describe these ten pediatric cases and one additional case of LPS in a child who received her transplant before 1981. The frequency of EBV infection in 92 pediatric liver recipients was 63%. Of these subjects, 49% were seronegative and 77% of those acquired primary infection. Of 11 cases of pediatric EBV-associated LPS, 10 were in children who had primary infection shortly before or after transplantation. These results reinforce the importance of primary EBV infection in producing LPS, which was previously shown in adults. Children are at greater risk because they are more likely to be seronegative for EBV and to acquire primary infection. Three clinical types of LPS were recognized in children. The first (5 cases) was a self-limited mononucleosislike syndrome. The second syndrome (4 cases) began similarly, but then progressed over the next two months to widespread lymphoproliferation in internal organs and death. The third type (2 cases) was an extranodal intestinal monoclonal B cell lymphoma, occurring late after primary infection.

Fourteen patients who developed B cell lymphomas or lymphoproliferative lesions after kidney, liver, heart, or heart-lung transplantation in Pittsburgh during [1981][1982][1983] had active infection with Epstein-Barr virus (EBV) of the primary (six patients), reactivated (seven patients), or chronic (one patient) type. In transplant patients without tumors, the incidence of EBV infection was 30% (39 of 128). Only three of these patients had primary infections. Thus the frequency of active infection was significantly higher in patients with tumors, and patients with primary infections were at greater risk of developing tumors. Five of 13 tumors tested contained EBV nuclear antigen (EBNA) and nine of 11 contained EBV genomes detected by DNA-DNA hybridization with BamHI K, BamHI W, or EcoRI B cloned probes. All EBNA-positive tumors, except one, were also positive by hybridization. Only one tumor was negative for both EBNA and EBV DNA. These data suggest that EBV plays an etiologic role in the development of these lesions.Epstein-Barr virus (EBV) is a human herpesvirus associated with an array of conditions that range from inapparent infection and infectious mononucleosis to lethal lymphoproliferative syndromes, nasopharyngeal carcinoma, Burkitt's lymphoma, and B cell lymphomas in immunocompromised patients [1]. The precise role of the virus in carcinogenesis is unclear, although in Burkitt's lymphoma the importance of viral transformation of infected B lymphocytes and chromosomal translocations has been emphasized [2]. It is even less clear in lymphomas and lymphoproliferative lesions arising in immuno-compromised patients, where the immunopathology may not be uniform and where chromosomal studies are largely lacking.Recently, we reported on the reversibility of lymphomas and lymphoproliferative lesions in a series of 17 transplant patients after reduction of cyclosporine and steroid immunosuppression [3]. In that preliminary report we noted that seven of these patients had evidence of primary EBV infections and eight had evidence of reactivated infection. Six tumors had evidence of EBV nuclear antigen (EBNA) and seven had evidence of EBV DNA by nucleic acid hybridization. [6] reported the results of studies on 19 renal transplant patients who developed lymphoproliferative disorders and lymphomas after transplantation. All the patients except one were receiving azathioprine, prednisone, and antithymocyte globulin. Two of their patients developed primary EBV infection, in six the infection reactivated, and 12 had evidence of EBV DNA in their tumors by hybridization studies. Bieber et al. [7] reported that five of 39 heart transplant recipients receiving cyclosporine, prednisone, and antithymocyte globulin developed lymphomas. Four tumors were positive for EBV DNA by cRNA-DNA filter hybridization, and three patients had serological evidence of EBV infection.We report here evidence for active EBV infection in all of our patients with tumors and a significantly higher frequency of primary infection than found i...