The impact of total body irradiation on the outcome of patients with follicular lymphoma treated with autologous stem-cell transplantation in the modern era: a retrospective study of the EBMT Lymphoma Working Party.

BACKGROUND: The aim of this study was to investigate the impact of the high-dose regimen on the outcome of patients with follicular lymphoma (FL) having had autologous stem-cell transplantation (ASCT) in a recent time period. PATIENTS: Between 1995 and 2007, 2233 patients with FL had their first ASCT with either a total body irradiation (TBI)-containing regimen or carmustin, etoposide, cytarabine and melphalan (BEAM), of which 47% were autografted in first remission. RESULTS: After a median observation time of 73 months (interquartile range 30-107), 5- and 10-year non-relapse mortality (NRM) was similar (6% and 10% in both groups). No significant NRM differences became evident after multivariate adjustment for confounders. Secondary malignancies were observed in 9.7% and 7.9% of the patients after TBI and BEAM (P = 0.19), which were treatment-related myelodysplastic syndromes/acute myelogenous leukaemia (t-MDS/AML) in 3.4% and 2.8% (P = 0.57). The median time to t-MDS/AML was around 50 months in both groups. Because of a lower relapse incidence, TBI was associated with better event-free survival reaching statistical significance in the patients transplanted in first remission but not in those transplanted beyond first remission. CONCLUSIONS: In patients with FL who received TBI-based ASCT after 1995 increased NRM and t-MDS/AML risks did not emerge compared with BEAM while disease control was at least equivalent.

Identification of prognostic factors predicting outcome in Hodgkin's lymphoma patients relapsing after autologous stem cell transplantation.

BACKGROUND: High-dose chemotherapy followed by autologous stem cell transplantation (ASCT) is the standard of care for patients with relapsed Hodgkin's lymphoma (HL). However, there is currently little information on the predictors of outcome for patients whose disease recurs after ASCT. METHODS: Five hundred and eleven adult patients with relapsed HL after ASCT from EBMT-GITMO databases were reviewed. RESULTS: Treatments administered following ASCT failure included conventional chemotherapy and/or radiotherapy in 294 (64%) patients, second ASCT in 35 (8%), and alloSCT in 133 (29%). After a median follow-up of 49 months, overall survival (OS) was 32% at 5 years. Independent risk factors for OS were early relapse (<6 months) after ASCT, stage IV, bulky disease, poor performance status (PS), and age ≥50 years at relapse. For patients with no risk factors OS at 5 years was 62% compared with 37% and 12% for those having 1 and ≥2 factors, respectively. This score was also predictive for outcome in each group of rescue treatment after ASCT failure. CONCLUSION(S): Early relapse, stage IV, bulky disease, poor PS, and age ≥50 years at ASCT failure are relevant factors for outcome that may help to understand the results of different therapeutic approaches.

Autologous stem-cell transplantation in patients with mantle cell lymphoma beyond 65 years of age: a study from the European Group for Blood and Marrow Transplantation (EBMT).

BACKGROUND: Limited experience is available on the feasibility and efficacy of autologous stem-cell transplantation (ASCT) in patients with mantle cell lymphoma (MCL) beyond 65 years. DESIGN AND METHODS: We analysed 712 patients with MCL treated with ASCT from 2000 to 2007 and reported to the European Group for Blood and Marrow Transplantation registry. Patients>65 years were compared with patients<65 years for the end points non-relapse mortality (NRM), relapse incidence, progression-free survival (PFS), and overall survival (OS). RESULTS: Seventy-nine patients were ≥65 years old. Median time from diagnosis to ASCT was longer in the elderly patients (11 versus 9 months, P=0.005); they had more commonly received at least two treatment lines (62.0% versus 47.9%, P=0.02) and were less commonly in first complete remission at ASCT (35.4% versus 51.2%, P=0.002). Median follow-up after ASCT was 19 and 25 months, respectively. NRM was comparable at 3 months (3.8% versus 2.5%) and at 5 years (5.6% versus 5.0%). There were no differences in relapse rate (66% versus 55% at 5 years), PFS (29% versus 40%) and OS (61% versus 67%) between both populations of patients. CONCLUSION: ASCT beyond 65 years of age is feasible in selected patients with MCL and results in similar disease control and survival as in younger patients.

PP2A-Bgamma subunit and KCNQ2 K+ channels in bipolar disorder.

Many bipolar affective disorder (BD) susceptibility loci have been identified but the molecular mechanisms responsible for the disease remain to be elucidated. In the locus 4p16, several candidate genes were identified but none of them was definitively shown to be associated with BD. In this region, the PPP2R2C gene encodes the Bgamma-regulatory subunit of the protein phosphatase 2A (PP2A-Bgamma). First, we identified, in two different populations, single nucleotide polymorphisms and risk haplotypes for this gene that are associated to BD. Then, we used the Bgamma subunit as bait to screen a human brain cDNA library with the yeast two-hybrid technique. This led us to two new splice variants of KCNQ2 channels and to the KCNQ2 channel itself. This unusual K+ channel has particularly interesting functional properties and belongs to a channel family that is already known to be implicated in several other monogenic diseases. In one of the BD populations, we also found a genetic association between the KCNQ2 gene and BD. We show that KCNQ2 splice variants differ from native channels by their shortened C-terminal sequences and are unique as they are active and exert a dominant-negative effect on KCNQ2 wild-type (wt) channel activity. We also show that the PP2A-Bgamma subunit significantly increases the current generated by KCNQ2wt, a channel normally inhibited by phosphorylation. The kinase glycogen synthase kinase 3 beta (GSK3beta) is considered as an interesting target of lithium, the classical drug used in BD. GSK3beta phosphorylates the KCNQ2 channel and this phosphorylation is decreased by Li+.

Resistance of T-cells to apoptosis in autoimmune diabetic (NOD) mice is increased early in life and is associated with dysregulated expression of Bcl-x.

Activated lymphocytes of autoimmune non-obese diabetic (NOD) mice exhibit an increased resistance to programmed cell death (PCD) following withdrawal of interleukin-2 (IL-2). In the present study, we found that resistance of NOD T lymphocytes to PCD was increased as early as 1 week of age, hence several weeks before the invasion of the pancreas by inflammatory cells, which is compatible with a role of the NOD apoptotic phenotype in the autoimmune susceptibility of this strain. In the thymus, mature single positive but not double positive or double negative thymocytes were more resistant to PCD in NOD compared to B6 mice. Moreover, in both NOD and B6 mice, CD4+ T cells were more resistant to PCD induced by IL-2 deprivation than CD8+ cells. As a result, NOD CD4+ T cells were remarkably resistant to cell death induced in this manner. In relation with this increased resistance to apoptosis, expression of the anti-apoptotic Bcl-x protein was upregulated in activated T cells of NOD mice, most notably after 24 h of IL-2 deprivation. These results should help us to understand the relationship of the NOD apoptotic phenotype to the emergence of the NOD mouse autoimmune disease.

Defective Fc gamma RII gene expression in macrophages of NOD mice: genetic linkage with up-regulation of IgG1 and IgG2b in serum.

A quantitative trait locus for increased IgG serum levels in the NOD mouse strain was mapped to distal chromosome 1, close to the fcgr2 locus encoding the low-affinity type II receptor for the Fc portion of IgG (Fc gamma RII). Expression of membrane-inserted (b2) and soluble (b3) isoforms of Fc gamma RII was strongly decreased in macrophages of NOD compared with C57BL/6 (B6) mice. In contrast, B cell-specific (Fc gamma RIIb1) isoform was only slightly decreased and Fc gamma RIII was not altered. This Fc gamma RII regulatory defect was cis-encoded by fcgr2 or by a closely linked locus, occurred at the mRNA level, and was associated with multiple mutations in the fcgr2 gene promoter. In relation with this defect, binding of IgG1- and IgG2b- but not IgG2a-opsonized RBC by macrophages of NOD and congenic B6.NOD-fcgr2 mice was severely impaired, but was normal in macrophages of NOD.B6-fcgr2 congenic mice, indicating that Fc gamma RII plays a nondispensable role in binding of IgG1 and IgG2b isotypes. Likewise, serum levels of IgG1 and IgG2b but not IgG2a were up-regulated in NOD compared with NOD.B6-fcgr2 congenic mice. These findings indicate that macrophage Fc gamma RII may regulate serum IgG1 and IgG2b through their catabolism, and validate the NOD strain as a model to investigate the functions of Fc gamma RII isoforms.

Genetic analysis of immune dysfunction in non-obese diabetic (NOD) mice: mapping of a susceptibility locus close to the Bcl-2 gene correlates with increased resistance of NOD T cells to apoptosis induction.

The non-obese diabetic (NOD) mouse strain provides a remarkable model for investigating the mechanisms of autoimmunity. Independent genetic analyses of this model have previously shown that chromosome 1-linked loci were involved in the control of periinsulitis and sialitis on the one hand and of insulitis and diabetes on the other hand. In the present work, analysis of a [NOD x (NOD x C57BL/6)F1] backcross progeny allowed us to clearly dissociate two genetic regions: one was associated with periinsulitis and mapped to the middle region of chromosome 1, in the vicinity of the Bcl-2 gene; the other was associated with insulitis and mapped to the proximal part of the chromosome. Three intermediate markers D1Mit18, D1Mit5 and D1Mit19 covering at least 25 centiMorgans between these two regions, were associated with neither periinsulitis nor insulitis. The role of the Bcl-2-linked region in the immune anomalies of NOD mice was further investigated in a (NOD x C57BL/6)F2 cross where the Bcl-2nod haplotype was linked to elevated serum levels of IgG (p < 0.0005). The middle region of chromosome 1 is, therefore, involved in the control of three phenotypes, including periinsulitis, sialitis and hyperIgG, pointing to Bcl-2 as a good candidate for a cause of the NOD mouse disease. Consistent with the anti-apoptotic function of the Bcl-2 gene product, activated T lymphocytes from NOD mice showed a markedly increased resistance to induction of apoptosis following deprivation of interleukin-2 when compared to those from non-autoimmune strains. After the recent observation of the Fas gene alterations in the lpr and lprcg mutations, these findings indicate that deregulation of lymphoid cell apoptosis may be a general pathogenetic mechanism in autoimmune diseases.

Lymph node T-cells do not optimally transfer diabetes in NOD mice.

The nonobese diabetic mouse in a model of spontaneous development of autoimmune type I diabetes. The disease can be induced in young, irradiated recipients by injecting splenic T-cells from diabetic donors. The adoptive transfer of diabetes requires the presence of both CD4+ and CD8+ splenic T-cell subsets. To test whether diabetogenic cells distribute in other lymphoid organs of diabetic mice, we first analyzed lymph node cells. Lymph node cells were much less efficient in transferring diabetes than splenocytes. This inefficacious transfer was not attributable to the absence of hematopoietic precursors or a lack of macrophages. Lymph node cells did not protect from the transfer of diabetes by splenocytes, indicating the absence of suppressor cells. Although CD8+ lymph node T-cells seemed functionally comparable to CD8+ splenocytes, CD4+ lymph node T-cells failed to cooperate with CD8+ splenocytes to transfer diabetes. Our study suggests that diabetogenic cells are not evenly distributed in the different lymphoid organs. This may reflect a differential migration pattern of pathogenic T-cells in this animal model.

Characterization of the extracellular matrix-containing giant perivascular spaces in the NOD mouse thymus.

It is well established that the NOD mouse develops T-cell-dependent autoimmune type I diabetes that is abolished by neonatal Tx and enhanced by Tx at weaning. In a previous study, we demonstrated that the NOD thymus displays various abnormalities in the microenvironmental compartment, including abnormal distribution of epithelial cell subsets, precocious decline in thymic hormone production and formation of giant PVS. These latter structures present an internal ECM-containing network filled with T-cells and to a lesser extent B-cells. Herein we have investigated further the giant PVS and particularly the origin of the T-cells that colonize these structures. The thymic origin of intra-PVS T-cells was ascertained by distinct protocols. First, sublethal X-ray irradiation or HC treatment leading to cortical thymocyte depletion showed that intra-PVS lymphocytes were resistant, similar to medullary thymocytes. Second, adoptive transfer experiments that used newborn or adult irradiated Thy-1 congenic recipients demonstrated that intra-PVS accumulation of T-cells did not result from the reentry of peripheral mature T-cells into the thymus. Third, kinetic studies that used BrdUrd pulse chase revealed that labeled intra-PVS cells appear late, simultaneously with medullary thymocytes, and remain only transiently within the PVS. Thus, the kinetics of T-cell reconstitution of PVS was compatible with the progressive differentiation of T-cell precursors originating from the thymic cortex. In this respect, the giant PVS of the NOD mouse thymus may represent a useful model to study the relationships between trafficking thymocytes and ECM proteins.