Comparative analysis of tabelecleucel and current treatment in patients with Epstein-Barr virus-positive post-transplant lymphoproliferative disease following hematopoietic cell transplant or solid organ transplant.

Aims: With recent European Union marketing authorization, tabelecleucel is the first off-the-shelf, allogeneic Epstein-Barr virus (EBV)-specific T-cell immunotherapy approved for the treatment of relapsed/refractory EBV-positive post-transplant lymphoproliferative disease (EBV+ PTLD). In the absence of a control arm, real-world evidence can provide a comparative benchmark for single-arm studies in ultra-rare populations. This study assessed the treatment effect of tabelecleucel in the single-arm phase 3 ALLELE study (NCT03394365) versus a treatment group from a multinational, multicenter retrospective chart review study (RS002) of patients with EBV+ PTLD.Methods: In ALLELE, patients had disease relapsed/refractory to rituximab ± chemotherapy and received tabelecleucel 2x106 cells/kg on days 1, 8, and 15 in 35-day cycles. Patients in RS002 had disease relapsed/refractory to rituximab ± chemotherapy and received next line of systemic therapy between January 2000 and December 2018. Propensity score-based standardized mortality/morbidity ratio weighting was used to achieve balance between treatment and comparator arms. Kaplan-Meier estimators and Cox regression models were used to compare overall survival (OS) in the re-weighted sample.Results: 30 patients (n = 14 hematopoietic cell transplant [HCT], n = 16 solid organ transplant [SOT]) from ALLELE (data cutoff: November 2021) and 84 patients (n = 36 HCT, n = 48 SOT) from RS002 (data lock: January 2021) were included. Median time from diagnosis to first tabelecleucel dose (ALLELE) or start date of next line of systemic therapy (RS002) was 3.6 months. Tabelecleucel was associated with a substantial OS benefit compared with current treatment, with an unadjusted HR of 0.47 (95% CI 0.25-0.88) and adjusted HR of 0.37 (95% CI 0.20-0.71) when using the start date of the next line of therapy as the index date. Sensitivity analyses yielded consistent results.Conclusions: In this study of real-world data, tabelecleucel was associated with an OS benefit among patients with R/R EBV+ PTLD for whom there is high unmet need.

Host microRNAs are decreased in pediatric solid-organ transplant recipients during EBV+ Post-transplant Lymphoproliferative Disorder.

Post-transplant lymphoproliferative disorder (PTLD) is a serious complication of solid organ transplantation. Predisposing factors include primary Epstein-Barr virus (EBV) infection, reactivation of EBV in recipient B cells, and decreased T cell immunity due to immunosuppression. In our previous studies EBV infection was demonstrated to markedly alter the expression of host B cell microRNA (miR). Specifically, miR-194 expression was uniquely suppressed in EBV+ B cell lines from PTLD patients and the 3'untranslated region of IL-10 was determined to be targeted by miR-194. Although EBV has been shown to regulate host miR expression in B cell lymphoma cell lines, the expression of miRs in the circulation of patients with EBV-associated PTLD has not been studied. The objective of this study was to determine if changes in miR expression are associated with EBV+ PTLD. In this study, we have shown that miR-194 is significantly decreased in EBV+PTLD tumors and that additional miRs, including miRs-17, 19 and 106a are also reduced in EBV+PTLD as compared to EBV-PTLD. We quantitated the levels of miRs-17, 19, 106a, 155, and 194 in the plasma and extracellular vesicles (EV; 50-70 nm as determined by nanoparticle tracking analysis) from pediatric recipients of solid organ transplants with EBV+ PTLD+ that were matched 1:2 with EBV+ PTLD- pediatric transplant recipients as part of the NIH-sponsored Clinical Trials in Organ Transplantation in Children, (CTOTC-06) study. Levels of miRs-17, 19, 106a, and 194 were reduced in the plasma and extracellular vesicles (EV) of EBV+ PTLD+ group compared to matched controls, with miRs-17 (p = 0.034; plasma), miRs-19 (p = 0.029; EV) and miR-106a (p = 0.007; plasma and EV) being significantly reduced. Similar levels of miR-155 were detected in the plasma and EV of all pediatric SOT recipients. Importantly, ~90% of the cell-free miR were contained within the EV supporting that EBV+ PTLD tumor miR are detected in the circulation and suggesting that EVs, containing miRs, may have the potential to target and regulate cells of the immune system. Further development of diagnostic, mechanistic and potential therapeutic uses of the miRs in PTLD is warranted.

Modified risk-stratified sequential treatment (subcutaneous rituximab with or without chemotherapy) in B-cell Post-transplant lymphoproliferative disorder (PTLD) after Solid organ transplantation (SOT): the prospective multicentre phase II PTLD-2 trial.

The prospective multicentre Phase II PTLD-2 trial (NCT02042391) tested modified risk-stratification in adult SOT recipients with CD20-positive PTLD based on principles established in the PTLD-1 trials: sequential treatment and risk-stratification. After rituximab monotherapy induction, patients in complete remission as well as those in partial remission with IPI < 3 at diagnosis (low-risk) continued with rituximab monotherapy and thus chemotherapy free. Most others (high-risk) received R-CHOP-21. Thoracic SOT recipients who progressed (very-high-risk) received alternating R-CHOP-21 and modified R-DHAOx. The primary endpoint was event-free survival (EFS) in the low-risk group. The PTLD-1 trials provided historical controls. Rituximab was applied subcutaneously. Of 60 patients enrolled, 21 were low-risk, 28 high-risk and 9 very-high-risk. Overall response was 45/48 (94%, 95% CI 83-98). 2-year Kaplan-Meier estimates of time to progression and overall survival were 78% (95% CI 65-90) and 68% (95% CI 55-80) - similar to the PTLD-1 trials. Treatment-related mortality was 4/59 (7%, 95% CI 2-17). In the low-risk group, 2-year EFS was 66% (95% CI 45-86) versus 52% in the historical comparator that received CHOP (p = 0.432). 2-year OS in the low-risk group was 100%. Results with R-CHOP-21 in high-risk patients confirmed previous results. Immunochemotherapy intensification in very-high-risk patients was disappointing.

Reduction of immunosuppression combined with whole-brain radiotherapy and concurrent systemic rituximab is an effective yet toxic treatment of primary central nervous system post-transplant lymphoproliferative disorder (pCNS-PTLD): 14 cases from the prospective German PTLD registry.

Post-transplant lymphoproliferative disorders (PTLD) exclusively affecting the central nervous system-primary CNS-PTLD (pCNS-PTLD)-are rare. There is no standard therapy, and previous case series have included heterogeneous treatment approaches. We performed a retrospective, multi-centre analysis of 14 patients with pCNS-PTLD after solid organ transplantation (SOT) treated in the prospective German PTLD registry with reduction of immunosuppression (RI), whole-brain radiotherapy (WBRT), and concurrent systemic rituximab between 2001 and 2018. Twelve of fourteen patients were kidney transplant recipients and median age at diagnosis was 65 years. Thirteen of fourteen cases (93%) were monomorphic PTLD of the diffuse large B-cell lymphoma type, and 12/13 were EBV-associated. The median dose of WBRT administered was 40 Gy with a median fraction of 2 Gy. The median number of administered doses of rituximab (375 mg/m2) IV was four. All ten patients evaluated responded to treatment (100%). Median OS was 2.5 years with a 2-year Kaplan-Meier estimate of 63% (95% confidence interval 30-83%) without any recorded relapses after a median follow-up of 2.6 years. Seven of fourteen patients (50%) suffered grade III/IV infections under therapy (fatal in two cases, 14%). During follow-up, imaging demonstrated grey matter changes interpreted as radiation toxicity in 7/10 evaluated patients (70%). The combination of RI, WBRT, and rituximab was an effective yet toxic treatment of pCNS-PTLD in this series of 14 patients. Future treatment approaches in pCNS-PTLD should take into account the significant risk of infections as well as radiation-induced neurotoxicity.

Autologous stem cell transplantation for post-transplant lymphoproliferative disorders after solid organ transplantation: a retrospective analysis from the Lymphoma Working Party of the EBMT.

Published data describing the efficacy and safety of autologous stem-cell transplantation (autoSCT) in post-transplant lymphoproliferative disorders (PTLD) is limited to case reports. This is a retrospective analysis of 21 patients reported to the EBMT registry who received an autoSCT for PTLD post solid organ transplant (SOT). Median age at autoSCT was 47 (range: 22-71) years. The commonest SOTs were kidney (48%) and liver (24%). Commonest histologies included DLBCL-type PTLD (14/21) and plasmacytoma-like PTLD (3/21). Patients received a median of two lines of therapy (range: 1-4) pre-autoSCT. ECOG performance status pre-autoSCT was 0 in 14% and 1 in 86%. Remission status pre-autoSCT was CR 47% and PR 38%. BEAM conditioning was used in 57% and high-dose melphalan in 10%. The median follow-up post-autoSCT was 64 months for alive patients. 3-year PFS was 62% [95% confidence interval (CI) 44-87%] and 3-year OS was 61% [95% CI:43-86]. There were 12 deaths, including four related to autoSCT. 100-day non-relapse-mortality (NRM) was 14% and 1-year NRM was 24%. This study suggests that autoSCT, although feasible and with potential therapeutic activity, is associated with a high NRM, primarily driven by infectious toxicity. A multi-disciplinary approach, expert microbiological input and stringent patient selection are required to optimise outcomes.

Immunosuppression Is Associated With Clinical Features and Relapse Risk of B Cell Posttransplant Lymphoproliferative Disorder: A Retrospective Analysis Based on the Prospective, International, Multicenter PTLD-1 Trials.

BACKGROUND: Current guideline recommendations for immunosuppression reduction after diagnosis of posttransplant lymphoproliferative disorder (PTLD) include stopping antimetabolites, reducing calcineurin inhibitors, and maintaining corticosteroids. However, the effect of immunosuppression on PTLD relapse risk after up-to-date therapy is unclear. METHODS: This is a retrospective analysis of immunosuppression, patient baseline characteristics, and relapse risk measured as landmark time to progression (TTP) starting 1 year after start of therapy in 159 patients with B cell PTLD after solid organ transplantation treated in the prospective, international, multicenter PTLD-1 trials with either sequential treatment (rituximab followed by cyclophosphamide (CHOP-21 chemotherapy) 750 mg/m intravenously [IV] day (d) 1, doxorubicin 50 mg/m IV d1, vincristine 1.4 mg/m (maximum, 2 mg) IV d1, and prednisone 50 mg/m PO d1-5, every 21 days) or risk-stratified sequential treatment (rituximab followed by rituximab or rituximab (R-CHOP-21 immunochemotherapy) 375 mg/m IV day (d) 1, cyclophosphamide 750 mg/m IV d1, doxorubicin 50 mg/m IV d1, vincristine 1.4 mg/m (max. 2 mg) IV d1, and prednisone 50 mg/m PO d1-5, every 21 days). RESULTS: Patient baseline characteristics at diagnosis of PTLD differed significantly depending on immunosuppression before diagnosis. Compared with immunosuppression before diagnosis, significantly fewer patients received an antimetabolite or a calcineurin inhibitor (CNI) after diagnosis of PTLD. Relapse risk measured as landmark TTP was significantly higher for patients on corticosteroids compared to all others (P = 0.010) as well as for patients on ciclosporin compared with those on tacrolimus (P = 0.002), but similar for those on antimetabolites compared with all others (P = 0.912). In a Cox regression analysis of landmark TTP, corticosteroid-containing immunosuppression after diagnosis of PTLD (P = 0.002; hazard ratio, 11.195) and age (P = 0.001; hazard ratio, 1.076/year) were identified as independent, significant risk factors for PTLD relapse. CONCLUSIONS: In the prospective PTLD-1 trials, corticosteroid use after diagnosis of PTLD is associated with an increased risk of relapse, whereas the use of antimetabolites is not. These findings require prospective validation.

End-of-Treatment Positron Emission Tomography After Uniform First-Line Therapy of B-Cell Posttransplant Lymphoproliferative Disorder Identifies Patients at Low Risk of Relapse in the Prospective German PTLD Registry.

BACKGROUND: Fluorine-18 fluorodeoxyglucose (18F-FDG)-positron emission tomography (PET) is a recommended standard in the staging and response assessment of 18F-FDG-avid lymphoma. Posttransplant lymphoproliferative disorder (PTLD) can be detected by 18F-FDG-PET at diagnosis with high sensitivity and specificity. However, the role of response assessment by end-of-treatment (EOT) PET has only been addressed in small case series. METHODS: We performed a retrospective, multicenter study of 37 patients with CD20-positive PTLD after solid organ transplantation treated with uniform, up-to-date, first-line protocols in the prospective German PTLD registry who had received EOT 18F-FDG-PET between 2006 and 2014. Median follow-up was 5.0 years. Any nonphysiological 18F-FDG uptake (Deauville score greater 2) was interpreted as PET-positive. RESULTS: By computed tomography (CT) final staging, 18 of 37 patients had a complete response, 18 had a partial response and 1 patient had stable disease. EOT PET was negative in 24 of 37 patients and positive in 13 of 37 patients. The positive predictive value of EOT PET for PTLD relapse was 38%, and the negative predictive value was 92%. Time to progression (TTP) and progression-free-survival were significantly longer in the PET negative group (P = 0.019 and P = 0.013). In the 18 patients in a partial response by CT staging, we noted highly significant differences in overall survival (P = 0.001), time to progression (P = 0.007), and progression-free survival (P < 0.001) by EOT PET. CONCLUSIONS: Even without baseline imaging, EOT PET in PTLD identifies patients at low risk of relapse and offers clinically relevant information, particularly in patients in a partial remission by CT staging.

Response to Rituximab Induction Is a Predictive Marker in B-Cell Post-Transplant Lymphoproliferative Disorder and Allows Successful Stratification Into Rituximab or R-CHOP Consolidation in an International, Prospective, Multicenter Phase II Trial.

Purpose The Sequential Treatment of CD20-Positive Posttransplant Lymphoproliferative Disorder (PTLD-1) trial ( ClinicalTrials.gov identifier, NCT01458548) established sequential treatment with four cycles of rituximab followed by four cycles of cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) chemotherapy as a standard in the management of post-transplant lymphoproliferative disorder (PTLD) and identified response to rituximab induction as a prognostic factor for overall survival. We hypothesized that rituximab consolidation might be sufficient treatment for patients with a complete response after rituximab induction. Patients and Methods In this prospective, international, multicenter phase II trial, 152 treatment-naive adult solid organ transplant recipients, with CD20+ PTLD unresponsive to immunosuppression reduction, were treated with four weekly doses of rituximab induction. After restaging, complete responders continued with four courses of rituximab consolidation every 21 days; all others received four courses of rituximab plus CHOP chemotherapy every 21 days. The primary end point was treatment efficacy measured as the response rate in patients who completed therapy and the response duration in those who completed therapy and responded. Secondary end points were frequency of infections, treatment-related mortality, and overall survival in the intention-to-treat population. Results One hundred eleven of 126 patients had a complete or partial response (88%; 95% CI, 81% to 93%), of whom 88 had a complete response (70%; 95% CI, 61% to 77%). Median response duration was not reached. The 3-year estimate was 82% (95% CI, 74% to 90%). Median overall survival was 6.6 years (95% CI, 5.5 to 7.6 years). The frequency of grade 3 or 4 infections and of treatment-related mortality was 34% (95% CI, 27% to 42%) and 8% (95% CI, 5% to 14%), respectively. Response to rituximab induction remained a prognostic factor for overall survival despite treatment stratification. Conclusion In B-cell PTLD, treatment stratification into rituximab or rituximab plus CHOP consolidation on the basis of response to rituximab induction is feasible, safe, and effective.

Fcγ-receptor IIIA polymorphism p.158F has no negative predictive impact on rituximab therapy with and without sequential chemotherapy in CD20-positive posttransplant lymphoproliferative disorder.

We retrospectively analyzed the p.V158F polymorphism of Fcγ-receptor IIIA (FCGR3A, CD16) in patients with PTLD treated with rituximab monotherapy. Previous reports had indicated that the lower affinity F allele affects rituximab-mediated antibody-dependent cellular cytotoxicity (ADCC) and is linked to inferior outcome of rituximab monotherapy in B cell malignancies. 25 patients with PTLD after solid organ transplantation were included in this analysis. They had received 4 weekly doses of rituximab as part of two clinical trials, which had a rituximab monotherapy induction regimen in common. 16/25 patients received further treatment with CHOP-21 after rituximab monotherapy (PTLD-1, NCT01458548). The FCGR3A status was correlated to the response after 4 cycles of rituximab monotherapy. Response to rituximab monotherapy was not affected by F carrier status. This is in contrast to previous findings in B cell malignancies where investigators found a predictive impact of FCGR3A status on outcome to rituximab monotherapy. One explanation for this finding could be that ADCC is impaired in transplant recipients receiving immunosuppression. These results suggest that carrying a FCRG3A F allele does not negatively affect rituximab therapy in immunosuppressed patients.

EBV and posttransplantation lymphoproliferative disease: what to do?

This review summarizes the available evidence and outlines our approach to the prophylaxis and management of posttransplantation lymphoproliferative disorder (PTLD) in adult solid organ transplantation recipients. We attempt to reduce immunosuppression as tolerated in every patient with suspected PTLD in close cooperation with their transplantation physician. There is no evidence to guide the decision when to initiate further treatment; we usually wait no longer than 4 weeks and always initiate further therapy unless there is a complete or at least good partial remission. If clinical and histological findings indicate rapidly progressive disease, we initiate additional therapy significantly earlier. CD20-positive PTLD accounts for approximately 75% of PTLD cases. Outside of clinical trials, we currently regard sequential therapy with rituximab and CHOP (cyclophosphamide, hydroxydaunorubicin, vincristine, prednisone/prednisolone) chemotherapy as standard evidence-based treatment for CD20-positive PTLD unresponsive to immunosuppression. We also discuss our approach to the rare instance of adults with PTLD associated with primary EBV infection, localized (stage I) disease, rare PTLD subtypes, and refractory/relapsed disease based on the available retrospective data and our own experience. In addition to immunotherapy and chemotherapy, this includes local therapy approaches such as surgery and radiotherapy in stage I disease, plasmacytoma-like PTLD, and primary CNS PTLD. We also provide our view on the current indications for the use of allogeneic cytotoxic T cells, even though this treatment modality is so far unavailable in our clinical practice.

Burkitt post-transplantation lymphoma in adult solid organ transplant recipients: sequential immunochemotherapy with rituximab (R) followed by cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) or R-CHOP is safe and effective in an analysis of 8 patients.

BACKGROUND: Burkitt lymphoma post-transplantation lymphoproliferative disorder (Burkitt-PTLD) is a rare form of monomorphic B-cell PTLD for which no standard treatment has been established. Currently, the treatment of Burkitt lymphoma outside the post-transplantation setting involves high doses of alkylating agents, frequent dosing, and intrathecal and/or systemic central nervous system prophylaxis. In PTLD, however, such protocols are associated with considerable toxicity and mortality. METHODS: The authors present a retrospective series of 8 adult patients with Burkitt-PTLD. Six patients were reported to the prospective German PTLD registry or were enrolled in the PTLD-1 trial, and 2 patients had received treatment before 2000, thus allowing for comparison with the pre-rituximab era. RESULTS: Seven of the 8 patients were men. The median age at presentation was 38 years, and the median time since transplantation was 5.7 years. Five of 8 patients had histologically established, Epstein-Barr virus-associated disease, and 7 of 7 patients were positive for a MYC translocation. Five of 8 patients received sequential immunochemotherapy (4 courses of rituximab [R] followed by 4 cycles of cyclophosphamide, doxorubicin, vincristine, and prednisolone [CHOP] or R plus CHOP [R-CHOP]). In this group, 5 of 5 patients reached complete remission (CR), and their overall survival (OS) was significantly longer (P = .008) compared with the OS for 2 of 8 patients who received first-line CHOP and did not respond. One of 8 patients (who had stage IV disease with meningiosis) received combination therapy (cyclophosphamide pretreatment, rituximab, intrathecal chemotherapy, whole-brain irradiation, and radioimmunotherapy) and reached CR. Overall, 6 of 8 patients reached CR; and, after a median follow-up of 4.7 years (range, 1.7-4.8 years), the median OS was 36.7 months. There was no treatment-related mortality under first-line therapy. CONCLUSIONS: In the largest adult case series in Burkitt-PTLD to date, sequential immunochemotherapy with rituximab followed by standard CHOP or R-CHOP was a both safe and effective treatment.

Plasmablastic posttransplant lymphoma: cytogenetic aberrations and lack of Epstein-Barr virus association linked with poor outcome in the prospective German Posttransplant Lymphoproliferative Disorder Registry.

BACKGROUND: Plasmablastic posttransplant lymphoma is a rare subtype of monomorphic B-cell posttransplant lymphoproliferative disorder (PTLD). There is little published clinical data to guide treatment. METHODS: The German prospective PTLD registry D2006-2012 records baseline features, treatment, and outcome of rare PTLD subtypes in adults after solid organ transplantation. Treatment is at the discretion of the local physician. Clinical data on the patients in the registry is collected before, during, and at least 4 weeks, 6 months, 12 and 24 months after treatment. RESULTS: Eight cases of plasmablastic posttransplant lymphoma were reported to the registry until 2011. The majority occurred as late PTLD in male heart transplant recipients. Extranodal manifestations were common in stage I and in stage IV disease. Histological Epstein-Barr virus (EBV) association was confirmed in five of eight cases. MYC/IGH rearrangement was present in two of six patients examined. Although five of eight patients died from early disease progression, we observed that long-term survival can be achieved in localized (2/3) and in disseminated disease (1/5) by immunosuppression reduction (IR) followed by immediate systemic chemotherapy. However, all patients with cytogenetic aberrations and patients with non-EBV-associated PTLD were refractory to IR and to chemotherapy. Chemotherapy parallel to IR was associated with a high rate of infectious complications. CONCLUSIONS: In this series, IR and local therapy were not sufficient to treat plasmablastic posttransplant lymphoma even in localized disease whereas IR and systemic chemotherapy (CHOP-21) could achieve lasting complete remissions. Cytogenetic aberrations and lack of EBV association were linked with poor outcome.

Sequential treatment with rituximab followed by CHOP chemotherapy in adult B-cell post-transplant lymphoproliferative disorder (PTLD): the prospective international multicentre phase 2 PTLD-1 trial.

BACKGROUND: Post-transplantation lymphoproliferative disorder (PTLD) develops in 1-10% of transplant recipients and can be Epstein-Barr virus (EBV) associated. To improve long-term efficacy after rituximab monotherapy and to avoid the toxic effects of CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisolone) chemotherapy seen in first-line treatment, we initiated a phase 2 trial to test whether the subsequent use of rituximab and CHOP would improve the outcome of patients with PTLD. METHODS: In this international multicentre open-label phase 2 trial, treatment-naive adult solid-organ transplant recipients diagnosed with CD20-positive PTLD who had failed to respond to upfront immunosuppression reduction received four courses of rituximab (375 mg/m(2) intravenously) once a week followed by 4 weeks without treatment and four cycles of CHOP every 3 weeks. In case of disease progression during rituximab monotherapy, CHOP was started immediately. Supportive therapy with granulocyte-colony stimulating factor after chemotherapy was mandatory and antibiotic prophylaxis was recommended. The primary endpoint was treatment efficacy measured as response rates in all patients who completed treatment with rituximab and CHOP, per protocol, and response duration, in all patients who completed all planned therapy and responded. Secondary endpoints were frequency of infections, treatment-related mortality, and overall survival. This study is registered at ClinicalTrials.gov, number NCT01458548. FINDINGS: 74 patients were enrolled between Dec 12, 2002 and May 5, 2008, of whom 70 patients were eligible to receive treatment. PTLD was of late type in 53 (76%) of 70 patients, monomorphic in 67 (96%) of 70, and histologically EBV associated in 29 (44%) of 66 cases. Four of 70 patients did not receive CHOP. 53 of 59 patients had a complete or partial response (90%, 95% CI 79-96), of which 40 (68%, 55-78) were complete responses. At data cutoff (June 1, 2011) median response duration in the 53 patients who had responded to treatment had not yet been reached (>79·1 months). The main adverse events were grade 3-4 leucopenia in 42 of 62 patients (68%, 55-78) and infections of grade 3-4 in 26 of 64 patients (41%, 29-53). Seven of 66 patients (11%, 5-21) had CHOP-associated treatment-related mortality. Median overall survival was 6·6 years (95% CI 2·8-10·4; n=70). INTERPRETATION: Our results support the use of sequential immunochemotherapy with rituximab and CHOP in PTLD. FUNDING: F Hoffmann-La Roche, Amgen Germany, Chugaï France.

Plasmacytoma-like post-transplant lymphoproliferative disorder, a rare subtype of monomorphic B-cell post-transplant lymphoproliferation, is associated with a favorable outcome in localized as well as in advanced disease: a prospective analysis of 8 cases.

Post-transplantation lymphoproliferative disorder (PTLD) with plasmacellular differentiation has been reported as a rare subtype of monomorphic B-cell post-transplant lympho-proliferation with histological and immunophenotypical features of plasmacytoma in the non-transplant population. Here we present clinical, laboratory and histopathological features, treatment and outcome of 8 patients from the German prospective PTLD registry. Clinically, extranodal manifestations were common while osteolytic lesions were rare and none of the patients had bone marrow involvement. Immunohistochemistry showed light chain restriction and expression of CD138 without CD20 expression in all samples. An association with Epstein-Barr virus was found in 3 out of 8 cases. We suggest that the Ann Arbor classification is most useful for this disease entity and report a generally good response to treatment including reduction of immuno-suppression, surgery and irradiation in localized disease and systemic chemotherapy analogous to plasmacell myeloma in advanced disease.

IL-6 and IL-10 in post-transplant lymphoproliferative disorders development and maintenance: a longitudinal study of cytokine plasma levels and T-cell subsets in 38 patients undergoing treatment.

IL-6 and IL-10 have previously been implicated in the pathogenesis of post-transplant lymphoproliferative disorders (PTLD) and, like peripheral lymphocyte populations, are markers of immune status that are amenable to study in vivo. Thus, we analyzed cytokine plasma levels as well as lymphocyte subsets in a longitudinal analysis of 38 adult transplant recipients undergoing treatment for PTLD. Pretherapeutically, we found significantly elevated IL-6 (13.8 pg/ml) and IL-10 plasma levels (54.7 pg/ml) - in the case of IL-10, even higher in treatment nonresponders than in responders (116 vs. 14 pg/ml). Over time, however, IL-10 levels did not correlate with the course of disease, whereas those of IL-6 did, falling in responders and rising in nonresponders. These findings were independent of histological EBV-status, treatment type, and total peripheral T-cell counts, which were significantly reduced in patients with PTLD. Our observations support the idea that although IL-10 is important for creating a permissive environment for post-transplant lymphoma development, IL-6 is associated with PTLD proliferation. The analysis of lymphocyte subsets further identified HLA-DR+ CD8+ lymphocyte numbers as significantly different in non-PTLD controls (33%), treatment responders (44%) and nonresponders (70%). Although the specificity of these cells is unclear, their increase might correlate with the impaired tumor-specific cytotoxic-T-lymphocyte (CTL)-response in PTLD.

Therapeutic options in post-transplant lymphoproliferative disorders.

Post-transplantation lymphoproliferative disorders (PTLD) are the second most frequent malignancies after solid organ transplantation and cover a wide spectrum ranging from polyclonal early lesions to monomorphic lymphoma. Available treatment modalities include immunosuppression reduction, immunotherapy with anti-B-cell monoclonal antibodies, chemotherapy, antiviral therapy, cytotoxic T-cell therapy as well as surgery and irradiation. Owing to the small number of cases and the heterogeneity of PTLD, current treatment strategies are mostly based on case reports and small, often retrospective studies. Moreover, many studies on the treatment of PTLD have involved a combination of different treatment options, complicating the evaluation of individual treatment components. However, there has been significant progress over the last few years. Three prospective phase II trials on the efficacy of rituximab monotherapy have shown significant complete remission rates without any relevant toxicity. A prospective, multicenter, international phase II trial evaluating sequential treatment with rituximab and CHOP-based chemotherapy (cyclophosphamide, doxorubicin, vincristine, prednisone) is ongoing and preliminary results have been promising. Cytotoxic T-cell therapy targeting Epstein-Barr virus (EBV)-infected B cells has shown low toxicity and high efficacy in a phase II trial and will be a future therapeutic option at specialized centers. Here, we review the currently available data on the different treatment modalities with a focus on PTLD following solid organ transplantation in adult patients.

Effect of dexamethasone on pulmonary and renal angiotensin-converting enzyme concentration in fetal sheep during late gestation.

OBJECTIVES: The effect of dexamethasone on tissue angiotensin-converting enzyme (ACE) was investigated in fetal sheep. STUDY DESIGN: Pulmonary and renal ACE concentrations were measured in 16 sheep fetuses at between 127 and 131 days of gestation (term 145+/-2 days): 6 were untreated, whereas 10 were chronically catheterized and infused intravenously with either saline solution (0.9%, n=4) or dexamethasone (45-60 microg. kg(-1). d(-1), n=6) for the previous 2 days. The dexamethasone dose increased plasma dexamethasone to around one fifth of that measured in newborn human infants delivered after maternal dexamethasone treatment. RESULTS: Over the period of infusion, arterial blood pressure increased significantly in the dexamethasone (+6.8+/-1.5 mm Hg, P<.05) but not saline-treated fetuses (+1.6+/-0.6 mm Hg). At delivery, pulmonary ACE in the dexamethasone-infused fetuses (1.24+/-0.26 nmoles hippurate. min(-1). mg protein(-1)) was significantly greater than in the control fetuses (0.50+/-0.07 nmoles. min(-1). mg protein(-1), P<.005); renal ACE was unchanged by dexamethasone treatment. Overall, pulmonary ACE and blood pressure were correlated on the last day of infusion (r=0.70, P<.05). CONCLUSION: The rise in pulmonary ACE seen in dexamethasone-treated sheep fetuses may contribute, in part, to the glucocorticoid-induced increase in blood pressure.