Sirolimus conversion for patients with posttransplant Kaposi's sarcoma.

This retrospective study aimed to evaluate the benefit of switching from calcineurin inhibitors (CnI) to sirolimus in posttransplant Kaposi's sarcoma (KS). Fourteen patients monitored in five French departments who had developed posttransplant KS were switched from CnI to sirolimus either abruptly (n=9) or progressively (n=5) with trough levels 5-12 ng/mL. Two patients had a complete remission, eight a partial response, and five no significant improvement of KS. The mean time to response was 3.9 months. After a mean follow-up of 16 months, 3 partial responders, with previous severe and refractory KS, suffered again from KS progression despite the lack of concomitant infectious or neoplastic event. These relapses occurred 5-9 months after switching. The tolerance of sirolimus has been excellent except for in one patient who developed severe interstitial pneumonitis. Sirolimus is usually useful in the management of posttransplant KS. It may be, however, ineffective or transiently effective in some patients with severe KS. Prospective studies with pharmacodynamic evaluation are important in order to better assess the duration of responses and the mechanisms of primary and acquired drug resistance.

[Kaposi's sarcoma and organ transplantation: 22 cases]. / Maladie de Kaposi et transplantation d'organes: 22 cas.

BACKGROUND: The discovery of the Human Herpes virus 8 (HHV8) improved our knowledge of the pathogenesis of Kaposi's sarcoma. After organ transplantation, Kaposi's sarcoma exhibits distinctive features compared with other forms of the disease. PATIENTS AND METHODS: We report 22 cases of post-transplant Kaposi's sarcoma (12 kidneys, 2 kidney-pancreas, 6 livers and 2 hearts). The aim of this retrospective study was to analyze clinical and virological characteristics in these transplant patients and to specify the frequency of HHV8 seroconversions in this population. RESULTS: Twenty-one patients showed cutaneous lesions and 9 had visceral involvement. HHV8 serology was positive in 16/20 patients at transplantation and in 21/22 cases at the time of Kaposi's sarcoma diagnosis. Most cases corresponded to viral reactivations whereas seroconversions occurred in 2 cases and may have been linked to viral transmission by the graft. Treatment led to recovery in 68p. 100 of the cases. Two heart-transplant patients died from their disease. We included in our series two cases of re-transplanted patients without recurrence of Kaposi's sarcoma and one case of familial Kaposi's sarcoma. DISCUSSION: Seroconversions after transplantation emphasize the interest of systematic screening of HHV8 serology in transplant recipients and their donors.

Humanized anti-CD20 monoclonal antibody (Rituximab) in post transplant B-lymphoproliferative disorder: a retrospective analysis on 32 patients.

BACKGROUND: B-lymphoproliferative post-transplant disorder (BLPD) is a severe complication of organ and bone marrow transplantation. The reduction of immuno-suppressive therapy or surgery for localized disease may cure some BLPDs. Other therapeutic approaches such as chemotherapy and antiviral drugs are toxic and of limited efficacy. Adoptive immunotherapy with donor T-cell infusions has yielded promising results but is, at the present time, easily applicable only in bone marrow-transplanted patients. Anti-B-cell Murine monoclonal antibodies (MoAbs) have proven effective but are no longer available for human use. We report the activity of a humanized anti CD 20 Mo Ab (Rituximab-MABTHERA Roche) in 32 episodes of BLPD treated in 14 French centers. PATIENTS AND METHODS: Between November 1997 and September 1998, 32 patients were diagnosed with BLPD. Twenty-six patients had undergone solid organ transplants (liver 8, kidney 8, heart 4, lung 3, heart lung 1, kidney-pancreas 1, liver-kidney 1) and six patients had received bone marrow transplantations. The median age of the patients was 34 years (3-67 years) and the median delay between graft and tumor 5 months (1-156 months). In organ recipients, tumors were classified as polymorphic and monomorphic in 10 and 15 cases, respectively; 4 of 6 bone marrow transplant recipients were treated without pathology documentation because of a rise in EBV load, fever and lymph node enlargement. Tumors were associated with EBV in 22 of 26 tested cases. Rituximab was used as first-line therapy in 30 patients (after reduction of immunosuppressive treatment in 27 patients) and as salvage therapy in 2 patients (after failure of chemotherapy). The median time from diagnosis of BLPD to treatment with Rituximab was 14 days (1-110 days). Two patients received eight infusions, twenty-six patients four infusions, one patient three infusions and three patients two infusions of 375 mg/m2. RESULTS: The tolerance of rituximab was good. The overall response rate was 69%, with 20 complete responses and 2 partial responses. In solid organ transplant the response rate was 65% (15 CR and 2 PR) while it was 83% in bone marrow-transplanted patients (5 CR). With a median follow-up of 8 months (1-16 months) 24 patients are still alive. The one-year projected survival is 73%. Of the 22 patients who achieved response, 15 patients (11 solid organ transplant and 4 bone marrow transplant) are alive with no evidence of disease, 4 patients relapsed a median of 7 months (3-10 months) after treatment and 3 died while in CR of concurrent diseases. Of the 10 patients who did not respond to Rituximab 5 are alive with no evidence of disease after salvage therapy. CONCLUSIONS: The use of rituximab appears to be a safe and relatively efficient therapy in BLPDs. The results need to be confirmed in a prospective multicentric trial.

Oligo-monoclonal immunoglobulins frequently develop during concurrent cytomegalovirus (CMV) and Epstein-Barr virus (EBV) infections in patients after renal transplantation.

In the present study we report that the appearance of oligo-monoclonal immunoglobulins (oligoM-Igs) in the sera of transplanted individuals is concurrent with the detection of coincident active CMV infection and EBV replication. Eighty-four renal allograft patients were monitored with respect to CMV isolation, to CMV conventional serology and humoral response against the EBV trans-activator ZEBRA (an immediate-early antigen also called BZLF1). Titration of anti-ZEBRA antibodies (IgG and IgM) and amount of EBV DNA in serum were evaluated. Using the combination of four techniques (agarose gel electrophoresis, analytical isoelectric focusing, high resolution immunoelectrophoresis, immunofixation electrophoresis), oligoM-Igs were found in 25% of patients after allografting and significantly associated with rejection episodes (P < 0.001). Twenty out of 23 (86%) concurrent CMV/EBV infections were associated with serum oligoM-Igs (P < 0.001). One can thus reasonably assume that a sustained EBV replication following iatrogenic immunosuppression can promote the immunoglobulin heavy chain expression in EBV-infected B lymphocytes. The proliferation of immunoglobulin-secreting clones might occur after active CMV infection, through a transient over-immunosuppression or via immune subversion.

Interleukin-10 in Epstein-Barr virus-associated post-transplant lymphomas.

We used enzyme-linked immunosorbent assays (ELISA) to investigate the presence of interleukin-10 (IL-10) in the serum of patients developing post-transplant lymphomas. Serum IL-10 was detected in 14 out of 19 cases with a lymphoma or Hodgkin's disease, with higher values being observed in patients who had developed a lymphoma within the first few months post-transplantation, and who had an aggressive form of the disease. Eleven out of the 14 patients in whom IL-10 was detected had Epstein Barr virus-positive tumors. And 11 out of 14 patients died of lymphomas. In most of the patients who had detectable IL-10 at the time of diagnosis of the lymphoma, the IL-10 had not been present previously, but it was found in the serum of 7 out of 9 dialysis patients, and in 8 out of 17 stable transplant patients. We conclude that IL-10 plays a role in the development of the more severe forms of post-transplant lymphomas, and may be secreted by tumor cells. However. data from patients with chronic renal failure or patients undergoing immunosuppressive therapy must be treated with caution.

Anti-B-cell monoclonal antibody treatment of severe posttransplant B-lymphoproliferative disorder: prognostic factors and long-term outcome.

B-lymphoproliferative disorder (BLPD) is a rare but severe complication of organ and bone marrow transplantation (BMT). Profound cytotoxic T-cell deficiency is thought to allow the outgrowth of Epstein-Barr virus-transformed B cells. When possible, reduction of immunosuppressive treatment or surgery for localized disease may cure BLPD. Therapeutic approaches using chemotherapy or antiviral drugs have limited effects on survival. Adoptive immunotherapy with donor T-cell infusions has given promising results in BMT recipients. We previously reported that administration of two monoclonal anti-B-cell antibodies (anti-CD21 and anti-CD24) could contribute to the control of oligoclonal BLPD. Here we report the long-term results of treatment with these monoclonal anti-B-cell antibodies for cases of severe BLPD. In an open multicenter trial, 58 patients in whom aggressive B-cell lymphoproliferative disorder developed after BMT (n = 27) or organ (n = 31) transplantation received 0.2 mg/kg/d of specific anti-CD21 and anti-CD24 murine monoclonal antibodies (MoAbs) for 10 days. The treatment was well tolerated. Thirty-six of the 59 episodes of BLPD in the 58 patients presented complete remission (61%). The relapse rate was low (3 of 36, 8%). Multivariate analysis identified the following risk factors for partial or no response to anti-B-cell MoAb therapy: multivisceral disease (P

[Treatment of lymphocele after kidney transplantation]. / Traitement des lymphocèles après transplantation rénale.

Lymphocele is a possible postoperative complication of renal transplantation and its treatment is still controversial. Over a 3-year period (January 1992 to December 1993), 7 patients with a complicated lymphocele were treated by various modalities. Puncture-drainage was used in 7 cases, Povidone sclerotherapy was performed in 4 cases and internal drainage was performed by surgical marsupialization in one case and by laparoscopy in 4 cases. The results of external drainage and sclerotherapy were disappointing, with 1 good result out of 7 and 1 moderate result out of 4, respectively. On the other hand, internal drainage was effective in every case, whether it was performed by surgical or laparoscopic marsupialization. The latter technique avoids the disadvantages of open surgery in high-risk patients. Laparoscopy appears to be the treatment of choice for post-renal transplantation lymphoceles, as it is simple, rapid and effective.

Hodgkin's disease after transplantation.

Hodgkin's disease (HD) has seldom been reported after transplantation. Epstein-Barr virus (EBV) is present in about 50% of Reed-Sternberg cells in HD developing in immunocompetent individuals, but is more frequently found in HD of acquired immune deficiency syndrome patients. We report 7 cases of HD that occurred in transplant recipients. Clinical and pathological data and studies of EBV reveal specific features of HD after transplantation. Six patients received kidney transplants and 1 patient received combined kidney and pancreas transplantation. Immunosuppressive therapy consisted of cyclosporine, steroids, azathioprine, and antilymphocyte globulins. One patient received, in addition, anti-CD3 mAb therapy and an EBV+ B cell lymphoma developed. Retrospective EBV serological data from patients were collected. Tumors were classified according to pathology. EBV studies were conducted by immunohistochemical methods with monoclonal antibodies to EBV-latent membrane protein (LMP) or EBV-nuclear antigen 2 (EBNA2), and by in situ hybridization for latent nuclear EBV-early RNAs (EBERs). The mean lapse of time between transplantation and HD was 49 months. Six patients presented with enlarged lymph nodes and 1 patient presented with liver involvement. HD was classified as IA in 2 patients, IIA in 3 patients, IIIB in 1 patient, and IVB in 1 patient. Four patients had primary EBV infection after graft, before HD, and the others reactivated latent EBV infection. Histological subtypes were mixed cellularity in 6 cases and lymphocytic depletion in 1 case. Latent EBV infection was detected with EBERs in all tumors. Reed-Sternberg cells expressed LMP, and were negative for EBNA2 expression. Six patients were treated: 2 patients at stage I received radiotherapy, and relapsed within 1 year with a more advanced stage of HD; chemotherapy was indicated as primary therapy in 5 patients, and as salvage therapy in 2 patients; it was associated with radiotherapy in 4 patients. Immunosuppressive therapy was reduced in all patients. Four patients were alive and in complete remission 18, 25, 31, and 67 months after chemotherapy, with a functioning graft in 3 patients. Two patients died of infection. Mixed cellularity is the most frequent histological subtype observed in HD occurring in transplant patients. EBV is present in all Reed-Sternberg cells. Posttransplant HD shows similarities with human immunodeficiency virus-associated HD. These facts argue for a role of EBV infection and immunosuppression in the progression of HD after transplantation.

[Lymphoma with bladder involvement and renal transplantation]. / Lymphome à forme vésicale et transplantation rénale.

Based on the case of a renal transplant recipient who developed a monoclonal B cell lymphoma with plasma cell differentiation, arising in the bladder, the authors discuss the responsibility of intensive immunosuppressant protocols in the development of post-transplantation lymphoproliferative syndromes. The Epstein-Barr virus favours the development of these lymphomas. The bladder is a rare site. Diagnosis was based on endoscopic resection with immunohistochemical analysis. The prognosis depends on the stage at the time of diagnosis. At an early stage, resection of the tumour combined with reduction of immunosuppressant therapy may be sufficient, but more aggressive treatment is required for more advanced stages. Anti-B lymphocyte monoclonal antibodies (CD21, CD24) give good results, especially in polyclonal forms and Epstein-Barr virus primo-infections. Anti-CD38 monoclonal antibodies are currently being investigated and appear to be very promising. Conventional radiotherapy and chemotherapy are disappointing.

Low expression of CD20 and CD23 in Epstein-Barr virus-induced B cell tumors in SCID/hu mice.

Intraperitoneal injection of immunodeficient C.B.-17/scid (SCID) mice with human peripheral blood leukocytes from Epstein-Barr virus (EBV)-seropositive donors or with peripheral blood leukocytes from EBV-seronegative donors followed by an injection of EBV results in the development of human B-cell tumors. EBV-induced oligoclonal SCID/hu tumors closely resemble the EBV-associated lymphoproliferative disorders that are complications in immunosuppressed transplant patients. Previous reports have indicated that SCID/hu tumor cells are phenotypically similar to in vitro-transformed lymphoblastoid cell lines (LCL), which express high levels of mature B-cell lineage/activation antigens (CD19, CD20, CD21, CD23, CD30, CD39). In this study, however, flow cytometric (FACS) analysis showed that expression of CD20 and CD23 by SCID/hu tumor cells was markedly reduced relative to CD20 and CD23 expression by donor-matched, in vitro-transformed LCL. Injection of LCL into SCID mice also produced tumors in which CD20 and CD23 expression was greatly reduced relative to levels expressed by the injected LCL. In addition, tumorigenesis following LCL injection was associated with the production of high levels of human Ig in the sera of SCID mice. Our data thus indicate that EBV-driven tumorigenesis in vivo is associated with significant changes in B-cell phenotype relative to EBV-infected B cells transformed in vitro.

Plasmacytoid differentiation of Epstein-Barr virus-transformed B cells in vivo is associated with reduced expression of viral latent genes.

The Epstein-Barr virus (EBV)-associated B-cell lymphoproliferative disorders that arise in immunosuppressed individuals are considered to resemble EBV-transformed in vitro lymphoblastoid cell lines (LCLs) with a mature activated B-cell phenotype. In this study of human lymphoproliferative disorders in the severe combined immunodeficiency mouse model, however, we demonstrate that EBV-infected tumor cells are not LCL-like but are predominantly plasmacytoid and that this phenotype correlates with reduced expression of EBV latent genes. B-cell tumors developed within 3-6 weeks after injection of LCLs into severe combined immunodeficiency mice. The tumors and the injected LCLs were analyzed by flow cytofluorometry for B-cell differentiation and activation markers and by ribonuclease protection assay for cellular and viral gene expression. No differences in the expression of CD19 and CD21 were observed. However, a decrease in CD23, CD11a (lymphocyte function-associated antigen LFA-1), and CD58 (LFA-3) expression and an increase in CD38 (a plasma-cell-associated antigen), CD54 (intracellular adhesion molecule ICAM-1), and HLA class I in the tumor cells relative to the LCLs was observed. Two-color flow cytofluorometric analysis showed that the predominant population (> 80%) in LCLs was CD23hi/CD38lo and that the major population in LCL-derived tumors was CD23lo/CD38hi. Cell cycle analysis showed that, in contrast to actively cycling LCLs, the majority of tumor cells had exited the cell cycle and were restricted to G0/G1 phase. Finally, and most important, a reduction in mRNA for the EBV latent genes EBV nuclear antigen 2 (EBNA2) and latent membrane protein (LMP1) was observed in the tumors.

[Lymphoproliferative syndromes associated with Epstein-Barr virus in transplantation]. / Syndromes lymphoprolifératifs associés au virus d'Epstein-Barr en transplantation.

We report 23 cases of lymphoproliferative diseases which occurred among 2,100 patients with kidney or combined kidney+pancreas transplant. Eleven patients developed a severe diffuse disease within the first 3 months post-transplantation; immunoblastic B cells of recipient origin infiltrated the bone-marrow, transplanted organs, liver, spleen, lymph nodes, lungs, and brain; immunoglobulin abnormalities with fever, leuko-thrombocytopenia and liver dysfunction constituted the symptoms; all patients received anti-lymphocyte globulins; 9 patients were also treated with cyclosporin. Three out of 6 tumors analysed were monoclonal. Epstein-Barr virus was present in 3 lesions analysed. Treatment consisted of cessation of immunosuppressive therapy. Nine patients died with lactic acidosis. Five patients had a less severe form. Seven patients had solid tumors involving the tonsils, lungs (2), lymph nodes (2), and bladder, 8 months after transplantation. All patients received cyclosporin; 4 also received anti-lymphocyte globulins and 3 OKT3. Tumor cells were immunoblasts expressing B cells markers at a late stage of B cell differentiation; 4 tumors were monoclonal. C myc was negative. Treatment consisted of cessation of immunosuppressive therapy, antiviral agents, and monoclonal antibodies (mAb): anti-CD21 and anti-CD24 mAb therapy was followed by cure of the lymphoma in 1 patient, by transient remission in a second one and by failure in the third patient. Two patients had a recurrence of the lymphoma and received chemotherapy; 2 patients died of the lymphoma, 1 died of unrelated cause; 4 are alive, 3 of them having a good graft function.

EBV-induced human B cell lymphomas in hu-PBL-SCID mice.

Epstein-Barr virus (EBV) infection is associated with Burkitt's lymphoma (BL) in normal individuals and immunoblastic B cell lymphomas in immunosuppressed or HIV-infected individuals. SCID mice reconstituted with human peripheral blood leukocytes (hu-PBL-SCID) from EBV-seropositive donors also may develop spontaneous B cell lymphomas which histologically and phenotypically resemble post-transplant tumors, and are distinct from BL. These tumors always contain EBV DNA. We have noted three different reproducible outcomes depending upon the EBV-seropositive donor used for generation of hu-PBL-SCID mice: (i) no tumors appear; (ii) tumors appear in a fraction of hu-PBL-SCID mice with a 10-20 wk. latent period; or (iii) tumors appear in all hu-PBL-SCID mice within 6-10 wk. Southern blot analysis of late versus early tumors using a probe specific for the EBV terminal repeat sequences (BamNJ), which allows distinction between circular latent and linear replicating genomes, shows that late tumors do not involve active EBV replication but that early tumors do show replicating genomes. In addition, EBV genomes were monoclonal in late tumors but polyclonal in early tumors. These data suggest two mechanisms for EBV lymphomagenesis, slow outgrowth of rare latently-infected B cells, and more rapid transformation of uninfected bystander B cells by replicating virus. The latter process may be highly amenable to therapy in patients at risk for EBV-related lymphomas. In addition, prospective screening of EBV-seropositive transplant recipients in the hu-PBL-SCID model may predict the risk of post-transplant lymphoma development.