Results from the Belgian mantle cell lymphoma registry.

INTRODUCTION: Mantle cell lymphoma is a B-cell non-Hodgkin's lymphoma characterized by a t(11;14), resulting in overexpression of cyclin D1. Conventional chemotherapy obtains frequent (but short) remissions, leading to a poor median overall survival (OS) of 3-5 years. To obtain more information about the prevalence and current treatment of Mantle cell lymphoma (MCL) in Belgium, we collected data in a Belgian registry of MCL. MATERIALS AND METHODS: All Belgian MCL patients, t(11;14) and/or cyclin D1 positive, seen in hematology departments over a one-year period (April 2013-March 2014) were included. Data about patient characteristics, histology, treatment lines, and response were compiled and retrospectively analyzed. RESULTS: Four hundred and four patients were included with a median age at diagnosis of 64 years (range 23-96 years) and a male predominance (72%). For 2013, we calculated a prevalence of at least 36.2 per million and an incidence of at least 7.0 per million in the Belgian population. Characteristics at diagnosis involved lymphadenopathy (82%), splenomegaly (44%), B-symptoms (39%), and hepatomegaly (10%). Bone marrow invasion was present at diagnosis in 77%. Stage at diagnosis was advanced in the majority of cases. The median number of treatment lines was 1. Type of first line treatment included a combination of anthracyclin and cytarabine-based regimen (34%), anthracyclin (39%), and other. Rituximab was used in 88% of first line treatments. In 44% first line treatment was followed by autologous stem cell transplantation. CONCLUSION: The analysis of this Belgian MCL registry provides insight in the epidemiology, demographics, and current treatment of our Belgian MCL population.

Donor stem cell infusion after non-myeloablative conditioning for tolerance induction to HLA mismatched adult living-donor liver graft.

BACKGROUND AND AIM OF THE STUDY: The induction of transplantation tolerance, defined as the survival of a functioning allograft in the absence of continuing immunosuppressive therapy, would be a major advance. Clinical and experimental data have shown that transplantation tolerance could be induced by pre-transplant myeloconditioning and infusion of donor hematopoietic cells. We investigated the feasibility and safety of a protocol to induce tolerance to HLA mismatched living-donor liver graft by pre-transplant non-myeloablative conditioning followed by donor stem cells (SC) infusion, in patients with advanced liver cancers. PATIENTS AND METHODS: Two patients with intrahepatic cancers who did not fulfill criteria for cadaver liver transplantation were included in the study. Preparative regimen consisted in cyclophosphamide and anti-thymocyte globulin, followed by infusion of purified donor CD34(+) stem cells. Living-donor liver transplantation (LDLT) using the liver right lobe was performed after hematological reconstitution, respectively 40 and 55 days after donor stem cell infusion. Immunosuppressive therapies were discontinued when liver graft function returned to normal. RESULTS: The procedure could be completed in the two patients. No severe toxicity of the preparative regimen was observed. Neither patient presented graft versus host reaction after donor stem cell infusion. A transient macrochimerism was observed in the first case, while no chimerism could be detected in the second. Immunosuppression was discontinued, respectively 90 and 28 days, after liver transplantation, without subsequent rejection episode. In the two cases, liver function remained normal for the study period. In both patients, the period of immune reconstitution was prolonged, as illustrated by persisting low CD4(+) cell counts. Mixed lymphocyte cultures, performed after immunosuppression withdrawal, demonstrated donor specific hyporesponsiveness in the first case, but in a context of global hyporeactivity in the two patients. The first patient died from tumor recurrence 370 days after liver transplantation. The second patient is alive, 270 days after liver transplantation, but with a suspicion of tumor relapse as indicated by the reappearance of tumor marker in blood. CONCLUSION: In the two cases, acceptance of HLA mismatched living-donor liver graft was obtained after non-myeloablative conditioning and donor stem cell infusion. Improving the rate of immune reconstitution appears as a priority to reduce the risk of tumor recurrence in such patients.