Management of paediatric monomorphic post-transplant lymphoproliferative disorders with low-intensity treatment: A multicentre international experience.

BACKGROUND: Monomorphic post-transplant lymphoproliferative disorder (mPTLD) is a major cause of morbidity/mortality following solid organ transplant (SOT), with infection, mPTLD progression and organ rejection presenting equal risks. Balancing these risks is challenging, and the intensity of therapy required by individual patients is not defined. Although an increasing body of evidence supports the use of a stepwise escalation of therapy through reduction in immunosuppression (RIS) to rituximab monotherapy and low-dose chemo-immunotherapy, many centres still use B-cell non-Hodgkin lymphoma (B-NHL) protocols, especially when managing Burkitt/Burkitt-like (BL) PTLD. This study sought to define outcomes for children managed in the UK or Spanish centres using low-intensity first-line treatments. PROCEDURE: Retrospective data were anonymously collected on patients younger than 18 years of age, with post-SOT mPTLD diagnosed between 2000 and 2020. Only patients given low-intensity treatment at initial diagnosis were included. RESULTS: Fifty-six patients were identified. Age range was 0.9-18 years (median 10.7). Most (62.5%) had early-onset PTLD. Haematopathological analysis showed 75% were diffuse large B-cell like, 14.3% were BL and nine of 33 (27%) harboured a MYC-rearrangement. Stage III-IV disease was present in 78.6%. All but one had RIS, 26 received rituximab monotherapy and 24 low-dose chemo-immunotherapy, mostly R-COP. Intensified B-NHL chemotherapy was required in 10/56 (17.9%). There were a total of 13 deaths in this cohort, three related to PTLD progression. The 1-year overall survival (OS), event-free survival (EFS) and progression-free survival (PFS) were 92.8%, 78.6% and 80.2%, respectively. CONCLUSIONS: R-COP provides an effective low-dose chemotherapy option. Escalation to more intensive therapies in the minority of inadequately controlled patients is an effective strategy.

Multicenter study of pediatric Epstein-Barr virus-negative monomorphic post solid organ transplant lymphoproliferative disorders.

BACKGROUND: Pediatric Epstein-Barr virus-negative monomorphic post solid organ transplant lymphoproliferative disorder [EBV(-)M-PTLD] comprises approximately 10% of M-PTLD. No large multi-institutional pediatric-specific reports on treatment and outcome are available. METHODS: A multi-institutional retrospective review of solid organ recipients diagnosed with EBV(-)M-PTLD aged ≤21 years between 2001 and 2020 in 12 centers in the United States and United Kingdom was performed, including demographics, staging, treatment, and outcomes data. RESULTS: Thirty-six patients were identified with EBV(-)M-PTLD. Twenty-three (63.9%) were male. Median age (range) at transplantation, diagnosis of EBV(-)M-PTLD, and interval from transplant to PTLD were 2.2 years (0.1-17), 14 years (3.0-20), and 8.5 years (0.6-18.3), respectively. Kidney (n = 17 [47.2%]) and heart (n = 13 [36.1%]) were the most commonly transplanted organs. Most were Murphy stage III (n = 25 [69.4%]). Lactate dehydrogenase was elevated in 22/34 (64.7%) and ≥2 times upper limit of normal in 11/34 (32.4%). Pathological diagnoses included diffuse large B-cell lymphoma (n = 31 [86.1%]) and B-non-Hodgkin lymphoma (B-NHL) not otherwise specified (NOS) (n = 5 [13.9%]). Of nine different regimens used, the most common were: pediatric mature B-NHL-specific regimen (n = 13 [36.1%]) and low-dose cyclophosphamide, prednisone, and rituximab (n = 9 [25%]). Median follow-up from diagnosis was 3.0 years (0.3-11.0 years). Three-year event-free survival (EFS) and overall survival (OS) were 64.8% and 79.9%, respectively. Of the seven deaths, six were from progressive disease. CONCLUSIONS: EFS and OS were comparable to pediatric EBV(+) PTLD, but inferior to mature B-NHL in immunocompetent pediatric patients. The wide range of therapeutic regimens used directs our work toward developing an active multi-institutional registry to design prospective studies. PLAIN LANGUAGE SUMMARY: Pediatric Epstein-Barr virus-negative monomorphic post solid organ transplant lymphoproliferative disorders (EBV(-)M-PTLD) have comparable outcomes to EBV(+) PTLD, but are inferior to diffuse large B-cell lymphoma in immunocompetent pediatric patients. The variety of treatment regimens used highlights the need to develop a pediatric PTLD registry to prospectively evaluate outcomes. The impact of treatment regimen on relapse risk could not be assessed because of small numbers. In the intensive pediatric B-non-Hodgkin lymphoma chemoimmunotherapy group, 11 of 13 patients remain alive in complete remission after 0.6 to 11 years.

Primary post-transplant lymphoproliferative disorder of the central nervous system: characteristics, management and outcome in 25 paediatric patients.

Primary central nervous system (CNS) post-transplant lymphoproliferative disorder (PTLD) in childhood is rare. Twenty-five patients were retrieved from nine European Intergroup for Childhood Non-Hodgkin's Lymphoma and/or international Berlin-Frankfurt-Münster Study Group members. Types of allografts included kidney (n = 11), liver (n = 4), heart (n = 5), bowel (n = 1) and haematopoietic stem cells (n = 4). Eighteen were male, 16 ≥ 10 years old, 21 had monomorphic disease and 24 solid intracranial tumour masses. Four-year event-free and overall survival rates were 50% ± 10% and 74% ± 9% respectively. This report represents the largest paediatric series of CNS PTLD reported to date, showing favourable survival odds following systemic and intrathecal chemotherapy and rituximab administration.

Preliminary experience on the use of PET/CT in the management of pediatric post-transplant lymphoproliferative disorder.

INTRODUCTION: Post-transplant lymphoproliferative disorder (PTLD) is a well-known complication following prolonged immunosuppression. Contrary to other lymphomas, there is no standardized imaging approach to assess PTLD either at staging or for response to therapy. Positron emission tomography/computed tomography (PET/CT) is an imaging modality that has proven to be useful in lymphoma. However, there is still limited data concerning its use in pediatric PTLD. Our study evaluates the use of PET/CT in pediatric PTLD at our institution. METHODS: To assess the role of PET/CT in pediatric PTLD, we reviewed the pediatric patients with PTLD who had undergone PET/CT at our institution between 2000 and 2016. RESULTS: Nine patients were identified. Six had PET/CT at diagnosis. All lesions seen on CT were identified with PET/CT. Fourteen PET/CTs were done during treatment. Eight PET/CTs were negative, including three where CT showed areas of uncertain significance. In these cases, PET/CT helped us to stop treatment and the patients remain in remission after a long follow-up (mean 74.3 months; range 12.4-180.9 months). PET/CT revealed additional disease in two cases, therefore treatment was intensified. Six biopsies and close follow-up was done to confirm PET/CT results. In one case, PET/CT did not identify central nervous system involvement demonstrated on magnetic resonance imaging. CONCLUSION: PET/CT may have an important role in the staging and follow-up of pediatric PTLD. In our cohort, PET/CT was helpful in staging and assessing treatment response and in clarifying equivocal findings on other imaging modalities.

Efficacy and tolerability of high-dose methotrexate in central nervous system positive or relapsed lymphoproliferative disease following liver transplant in children.

Childhood post-transplant lymphoproliferative disease (PTLD) is a heterogeneous condition in which treatment varies, from the reduction of immunosuppression to moderately intensive chemotherapy. While low-dose chemotherapy/rituximab has been found to be effective, moderately intensive chemotherapy is required for patients who relapse, have classic non-Hodgkin lymphoma or have fulminant PTLD. Methotrexate (Mtx) is highly effective in lymphomas and crosses the blood-brain barrier. However, there are no data in the literature regarding its safety in post-liver transplant patients. We describe four cases of high-grade lymphomas (three diffuse large B cell and one T-cell lymphoblastic), post-liver transplant, for which chemotherapy including high-dose Mtx (HDMTX) was the treatment of choice. In total, 20 doses of HDMTX (1-5 g/m(2)) were given. The treatment was well tolerated and all four patients had a good response. One case of central nervous system (CNS) diffuse large B-cell lymphoma was treated with HDMTX alone. We conclude that, in the absence of significant organ damage, HDMTX can safely be given to liver transplant patients, but should only be administered in specialist oncology units. Proof of effectiveness as a single agent in CNS lymphoma needs further studies.

Single agent efficacy of rituximab in childhood immunosuppression related lymphoproliferative disease: a United Kingdom Children's Cancer Study Group (UKCCSG) retrospective review.

Survival in childhood lymphoproliferative disease (LPD) remains poor, particularly in non-transplant patients. The anti-CD20 antibody rituximab shows promise but data in children is scant. A retrospective study of 22 (aged 11 months to 18 years) children treated with rituximab is presented. Two had primary immunodeficiency, two had prolonged immunosuppression and 18 had post-transplant LPD (eight bone marrow, five liver, four heart, one kidney). Nine patients had multi-organ involvement and 13 single site disease. Seventeen out of 22 had rituximab alone. In 16, a dose of 375 mg/m2 i.v. weekly was used (less in one patient due to renal dysfunction). Twelve patients received four courses and ten patients received one to three courses. Fever was the main side-effect in four. Eight (47%) had single agent response; four complete and four partial. All had other treatment prior to rituximab. Median follow-up was 35 months (range 22 - 47 months). In childhood LPD unresponsive to standard treatment, rituximab showed single agent response and requires further evaluation.

Comparison of Presentation and Outcome in 100 Pediatric Hodgkin Lymphoma Patients Treated at Children Hospital, Lahore, Pakistan and Royal Marsden Hospital, UK.

OBJECTIVE: To compare differences in demographics and outcomes in childhood Hodgkin lymphoma (HL) presenting at the Children's Hospital Lahore (CHL), and Royal Marsden Hospital (RMH), UK. STUDY DESIGN: An observational comparative study. PLACE AND DURATION OF STUDY: From January 2011 to February 2012 at CH, Lahore and from October 2008 to February 2012 at RMH, UK. METHODOLOGY: Consecutive HL patients (50 from each hospital) were inducted. Data regarding age, gender, staging, histopathology and outcome were analysed. Clinical and pathological staging done according to Ann-Arbor and World Health Organization classification. Treatment duration was 6-8 months. They were followed for 6 months post-treatment. Frequencies of variables were noted and compared. Chi-square test was used for determining significance. RESULTS: Patients from Children's Hospital, Lahore were younger (mean 7.9 years) with male predominance (n=42, 84%). Histopathology showed Mixed Cellularity (MC) in 32 (64%), Nodular Sclerosis (NS) in 5 (10%), Lymphocyte Rich in 4 (8%) and lymphocyte depleted in 1 (2%), nodular lymphocyte predominant (NLP) in 1 (2%) each. Majority presented in stage IV (n=25,50%), or stage III (n=20,40%). Constitutional B symptoms were present in 37 (74%). Bone marrow involvement observed in 23 (46%). Remission was achieved in 42 (84%) patients; 2 (4%) relapsed, 4 (8%) expired and 2 (4%) left against medical advice. In contrast, RMH patients were older (mean 11.8 years.) and 30 (60%) were males. NS (n=40,80%) and NLP (n=6,12%) types were predominant. Two (4%) patients were in stage I, 27 (54%) in stage II, 12 (24%) in stage III and 9 (18%) presented in stage IV. Fourteen (28%) had B-symptoms. None had bone marrow disease. Event free survival was 46 (92%). Four (8%) patients relapsed. Three responded to second line therapy and one relapsed postautologous transplant. CONCLUSION: Significant differences were observed in age at presentation, stage, histopathology and extent of bone marrow involvement between the groups. Of interest is the bone marrow involvement in stage IV patients in Pakistan. Delayed diagnosis account for advanced stage but difference in pathological subtype needs further study.

Long-term outcome for immune suppression and immune related lymphoproliferative disorder: prospective data from the United Kingdom Children's Leukaemia and Cancer Group registry 1994-2004.

Prospective national registry data on 98 patients were studied to determine the long-term outcome of immune related lymphoproliferative disease (LPD) and define prognostic factors. Seventy-three developed LPD following organ transplant (26 liver, 21 heart, 15 kidney, nine bone marrow [BM], two bowel). Twenty-five had non-transplant related immunosuppression. Age was 1.1-17 years (median 8.6). Fifty-eight patients had lymphomatous, 21 systemic and 17 lymphadenopathic disease. Sixty (73%) were disseminated and 22 (27%) localized. Thirty-three (54%) were monoclonal. Seventy-three (83%) were Epstein-Barr virus (EBV) positive. Median follow-up was 7.6 years. LPD developed earlier after liver and BM as compared to heart or kidney transplant. Five-year overall survival (OS) was 58%. Prognosis was best after liver and kidney transplant (OS >77%). Mortality was higher following heart (2.5 times) and BM transplant (5 times). Adverse prognostic factors were disseminated or lymphomatous disease and lack of reduction of immunosuppression. With appropriate reduction of immunosuppression, rituximab and low-dose chemotherapy, long-term survival is high.

Outcome of childhood relapsed or refractory mature B-cell non-Hodgkin lymphoma and acute lymphoblastic leukemia.

Patients with childhood relapsed and refractory mature B-cell non-Hodgkin lymphoma (B-NHL) and acute lymphoblastic leukemia (B-ALL) are rare and have a dismal prognosis. The previous UK national analysis of 26 children over a 7-year period prior to 1996 had highlighted the poor outcome, with only three survivors. This 10-year multicenter study evaluated recent data, since 2000. Of 33 children, nine survived (27.3%), with a median follow-up of 4.3 years. On exclusion of six children treated with palliative intent, the survival was one-third (nine of 27; 33.3%). All patients with primary refractory disease (n = 7) and all except one with early relapse (n = 11) died. Administration of four doses of 375 mg/m(2) of rituximab was associated with a longer survival (p = 0.006). Response to reinduction (p < 0.001) and autologous hematopoietic stem cell transplant (auto-HSCT) (p = 0.003) were significant on multivariate analysis. Patients with a time to relapse of at least 6 months are potentially curable and must be offered intensive treatment with salvage chemotherapy, rituximab and auto-HSCT.

Symptomatic severe hypertriglyceridaemia with asparaginase therapy in acute lymphoblastic leukaemia (ALL) and lymphoblastic lymphoma: is rechallenging safe?

Severe hyperlipidaemia with asparaginase therapy is rare. We report six cases, four of which developed significant problems with severe hyperlipidaemia during induction therapy for ALL and lymphoblastic lymphoma. The median triglyceride level was 22.3 mmol/L and the median cholesterol level was 12.3 mmol/L. None of the patients showed signs or symptoms of pancreatitis. Three children were re-exposed with Peg asparaginase, and one with Erwinia asparaginase, without recurrence of hyperlipidaemia or other symptoms. These cases highlight the dilemma in managing such rare cases of symptomatic hypertriglyceridaemia secondary to asparaginase and steroid therapy.