Transplantation for myelofibrosis patients in the ruxolitinib era: a registry study from the Société Francophone de Greffe de Moelle et de Thérapie Cellulaire

In this SFGM-TC registry study, we report the results after stem cell transplantation (HSCT) in 305 myelofibrosis patients, in order to determine potential risk factors associated with outcomes, especially regarding previous treatment with ruxolitinib. A total of 102 patients were transplanted from an HLA-matched-sibling donor (MSD), and 143 patients received ruxolitinib. In contrast with previous studies, our results showed significantly worse outcomes for ruxolitinib patients regarding overall survival (OS) and non-relapse mortality (NRM), especially in the context of unrelated donors (URD). When exploring reasons for potential confounders regarding the ruxolitinib effect, an interaction between the type of donor and the use of ATG was found, therefore subsequent analyses were performed separately for each type of donor. Multivariable analyses did not confirm a significant negative impact of ruxolitinib in transplantation outcomes. In the setting of URD, only age and Fludarabine-Melphalan (FM) conditioning were associated with increased NRM. For MSD, only Karnoksfy <70% was associated with reduced OS. However, a propensity score analysis showed that ruxolitinib had a negative impact on OS but only in non-responding patients, consistent with previous data. To conclude, with all the precautions due to confounders and bias, ruxolitinib itself does not appear to increase mortality after HSCT.

Matched related versus unrelated versus haploidentical donors for allogeneic transplantation in AML patients achieving first complete remission after two induction courses: a study from the ALWP/EBMT

We compared transplants (HSCT) from matched related siblings (MSD) with those from matched 10/10 and mismatched 9/10 unrelated (UD) and T-replete haploidentical (Haplo) donors in acute myeloid leukemia (AML) in first complete remission (CR1) achieved after two inductions, a known poor prognostic factor. One thousand two hundred and ninety-five patients were included: MSD (n = 428), UD 10/10 (n = 554), UD 9/10 (n = 135), and Haplo (n = 178). Acute GVHD II-IV was higher in all groups compared to MSD. Extensive chronic (c) GVHD was significantly higher in UD 9/10 (HR = 2.52; 95% CI 1.55-4.11, p = 0.0002) and UD 10/10 (HR = 1.48; 95% CI 1.03-2.13, p = 0.036) and cGVHD all grades were higher in UD 9/10 vs MSD (HR = 1.77; 95% CI 1.26-2.49, p = 0.0009). Non-relapse mortality was higher in all groups compared to MSD. Relapse incidence, leukemia-free, and overall survival did not differ significantly between donor types. Finally, GVHD-free relapse-free survival was lower in HSCT from UD 9/10 (HR = 1.56, 95% CI 1.20-2.03, p = 0.0009) but not in those from UD 10/10 (HR = 1.13, p = 0.22) and Haplo donors (HR = 1.12, p = 0.43) compared to MSD. In conclusion, in AML patients undergoing HSCT in CR1 achieved after two induction courses 10/10 UD and Haplo but not 9/10 UD donors are comparable alternatives to MSD.

Leukemia relapse via genetic immune escape after allogeneic hematopoietic cell transplantation

Graft-versus-leukemia (GvL) reactions are responsible for the effectiveness of allogeneic hematopoietic cell transplantation as a treatment modality for myeloid neoplasia, whereby donor T- effector cells recognize leukemia neoantigens. However, a substantial fraction of patients experiences relapses because of the failure of the immunological responses to control leukemic outgrowth. Here, through a broad immunogenetic study, we demonstrate that germline and somatic reduction of human leucocyte antigen (HLA) heterogeneity enhances the risk of leukemic recurrence. We show that preexistent germline-encoded low evolutionary divergence of class II HLA genotypes constitutes an independent factor associated with disease relapse and that acquisition of clonal somatic defects in HLA alleles may lead to escape from GvL control. Both class I and II HLA genes are targeted by somatic mutations as clonal selection factors potentially impairing cellular immune responses and response to immunomodulatory strategies. These findings define key molecular modes of post-transplant leukemia escape contributing to relapse.

Comorbidities in transplant recipients with acute myeloid leukemia receiving low-intensity conditioning regimens: an ALWP EBMT study

Older age and a high burden of comorbidities often drive the selection of low-intensity conditioning regimens in allogeneic hematopoietic stem cell transplantation recipients. However, the impact of comorbidities in the low-intensity conditioning setting is unclear. We sought to determine the contribution of individual comorbidities and their cumulative burden on the risk of nonrelapse mortality (NRM) among patients receiving low-intensity regimens. In a retrospective analysis of adults (≥18 years) who underwent transplantation for acute myeloid leukemia in the first complete remission between 2008 and 2018, we studied recipients of low-intensity regimens as defined by the transplantation conditioning intensity (TCI) scale. Multivariable Cox models were constructed to study associations of comorbidities with NRM. Comorbidities identified as putative risk factors in the low-TCI setting were included in combined multivariable regression models assessed for overall survival, NRM, and relapse. A total of 1663 patients with a median age of 61 years received low-TCI regimens. Cardiac comorbidity (including arrhythmia/valvular disease) and psychiatric disease were associated with increased NRM risk (hazard ratio [HR], 1.54; 95% confidence interval [CI], 1.13-2.09 and HR, 1.69; 95% CI, 1.02-2.82, respectively). Moderate pulmonary dysfunction, though prevalent, was not associated with increased NRM. In a combined model, cardiac, psychiatric, renal, and inflammatory bowel diseases were independently associated with adverse transplantation outcomes. These findings may inform patient and regimen selection and reinforce the need for further investigation of cardioprotective transplantation approaches.

Age-related immune cell dynamics influence outcomes after allogeneic haematopoietic cell transplantation

An efficient immunological reconstitution construes the pillar for the success of allogeneic haematopoietic cell transplantation (HCT) in haematological disorders. Factors influencing post-transplant immune recovery have been largely investigated across multiple cohorts issuing heterogeneous results. Differences in outcomes in adult and paediatric populations suggest an age-related contribution to post-transplant immune reconstitution; however, it is unclear how recipient and donor age may affect the dynamics of single immune cells. Here, we retrospectively collected and analysed immunological data of 174 patients (58 children and 116 adults) consecutively transplanted for haematological disorders in our centre. We show that trajectories of specific immune cells were strictly dependent on recipient age and pretransplant virus exposure, with the strongest effect seen on T CD4+ and B-cell counterparts, while donor age and transplant platforms had a minimal impact. This mirrored different kinetics of immune reconstitution in adult and paediatric patients, with major divergences in immune cell composition in late post-transplant phases, featuring better survival, relapse-free survival and cumulative incidence of pathogen-specific infections in younger patients. Altogether, these findings underpin the importance of recipient age on post-transplant immune cell recovery and define the basic dynamics of the immune reconstitution in paediatric and adult populations as a benchmark for future studies.

Leukemia relapse via genetic immune escape after allogeneic hematopoietic cell transplantation

Graft-versus-leukemia (GvL) reactions are responsible for the effectiveness of allogeneic hematopoietic cell transplantation as a treatment modality for myeloid neoplasia, whereby donor T- effector cells recognize leukemia neoantigens. However, a substantial fraction of patients experience relapses because of the failure of the immunological responses to control leukemic outgrowth. Here, through a broad immunogenetic study, we demonstrate that germline and somatic reduction of human leucocyte antigen (HLA) heterogeneity enhances the risk of leukemic recurrence. We show that preexistent germline-encoded low evolutionary divergence of class II HLA genotypes constitutes an independent factor associated with disease relapse and that acquisition of clonal somatic defects in HLA alleles may lead to escape from GvL control. Both class I and II HLA genes are targeted by somatic mutations as clonal selection factors potentially impairing cellular immune reactions and response to immunomodulatory strategies. These findings define key molecular modes of post-transplant leukemia escape contributing to relapse.

Efficacy of haematopoietic stem cell boost as a rescue for poor graft function after haematopoietic stem cell transplantation: A multicentre retrospective study on behalf of the Francophone Society for Bone Marrow Transplantation and Cell Therapy (SFGM-TC)

Haematopoietic stem cell reinjection may be a curative option for poor graft function after haematopoietic stem cell transplantation; however, literature supporting its use remains limited. We conducted a multicentre retrospective study on behalf of the Francophone Society of Bone Marrow Transplantation and Cellular Therapy, including 55 patients. We demonstrated response rates of nearly 40% and two-year survival of more than 60% in the context of an otherwise deadly complication and we observed that the timing of injection and the degree of cytopenia are strongly associated with outcomes. This study shows the feasibility of the procedure informing on its epidemiology, outcomes and prognostic factors, setting the stage for future guidelines.

Late relapse after hematopoietic stem cell transplantation for acute leukemia: a retrospective study by SFGM-TC

Late relapse (LR) after allogeneic hematopoietic stem cell transplantation (AHSCT) for acute leukemia is a rare event (nearly 4.5%) and raises the questions of prognosis and outcome after salvage therapy. We performed a retrospective multicentric study between January 1, 2010, and December 31, 2016, using data from the French national retrospective register ProMISe provided by the SFGM-TC (French Society for Bone Marrow Transplantation and Cellular Therapy). We included patients presenting with LR, defined as a relapse occurring at least 2 years after AHSCT. We used the Cox model to identify prognosis factors associated with LR. During the study period, a total of 7582 AHSCTs were performed in 29 centers, and 33.8% of patients relapsed. Among them, 319 (12.4%) were considered to have LR, representing an incidence of 4.2% for the entire cohort. The full dataset was available for 290 patients, including 250 (86.2%) with acute myeloid leukemia and 40 (13.8%) with acute lymphoid leukemia. The median interval from AHSCT to LR was 38.2 months (interquartile range [IQR], 29.2 to 49.7 months), and 27.2% of the patients had extramedullary involvement at LR (17.2% exclusively and 10% associated with medullary involvement). One-third of the patients had persistent full donor chimerism at LR. Median overall survival (OS) after LR was 19.9 months (IQR, 5.6 to 46.4 months). The most common salvage therapy was induction regimen (55.5%), with complete remission (CR) obtained in 50.7% of cases. Ninety-four patients (38.5%) underwent a second AHSCT, with a median OS of 20.4 months (IQR, 7.1 to 49.1 months). Nonrelapse mortality after second AHSCT was 18.2%. The Cox model identified the following factors as associated with delay of LR: disease status not in first CR at first HSCT (odds ratio [OR], 1.31; 95% confidence interval [CI], 1.04 to 1.64; P = .02) and the use of post-transplantation cyclophosphamide (OR, 2.23; 95% CI, 1.21 to 4.14; P = .01). Chronic GVHD appeared to be a protective factor (OR, .64; 95% CI, .42 to .96; P = .04). The prognosis of LR is better than in early relapse, with a median OS after LR of 19.9 months. Salvage therapy associated with a second AHSCT improves outcome and is feasible, without creating excess toxicity.

Comparison of NK alloreactivity prediction models based on KIR-MHC interactions in haematopoeitic stem cell transplantation

The biological processes underlying NK cell alloreactivity in haematopoietic stem cell transplantation (HSCT) remain unclear. Many different models to predict NK alloreactivity through KIR and MHC genotyping exist, raising ambiguities in its utility and application for clinicians. We assessed 27 predictive models, broadly divided into six categories of alloreactivity prediction: ligand-ligand, receptor-ligand, educational, KIR haplotype-based, KIR matching and KIR allelic polymorphism. The models were applied to 78 NGS-typed donor/recipient pairs undergoing allogeneic HSCT in genoidentical (n=43) or haploidentical (n=35) matchings. Correlations between different predictive models differed widely, suggesting that the choice of the model in predicting NK alloreactivity matters. For example, two broadly used models, educational and receptor-ligand, led to opposing predictions especially in the genoidentical cohort. Correlations also depended on the matching fashion, suggesting that this parameter should also be taken into account in the choice of the scoring strategy. The number of centromeric B-motifs was the only model strongly correlated with the incidence of acute graft-versus-host disease in our set of patients in both the genoidentical and the haploidentical cohorts, suggesting that KIR-based alloreactivity, not MHC mismatches, are responsible for it. To our best knowledge, this paper is the first to experimentally compare NK alloreactivity prediction models within a cohort of genoidentical and haploidentical donor-recipient pairs. This study helps to resolve current discrepancies in KIR-based alloreactivity predictions and highlights the need for deeper consideration of the models used in clinical studies as well as in medical practice.

Comprehensive Transcriptomic Analysis of VISTA in Acute Myeloid Leukemia: Insights into Its Prognostic Value

The V-domain Ig suppressor of T-cell activation (VISTA) has been recognized as a critical negative regulator of antitumor immune response and is gaining growing interest as a potential pharmacological target in immunotherapy. This molecule is highly expressed in hematopoietic stem cells and myeloid compartment, and it has been found upmodulated in acute myeloid leukemia (AML). However, VISTA-associated immune features are relatively unexplored in myeloid malignancies. Herein, we aimed to explore whether this immune checkpoint regulator could play a role in the generation of an immune escape environment in AML patients. We characterized VISTA mRNA expression levels in leukemia cell lines and in large publicly available cohorts of specimens from bone marrow of healthy individuals and AML patients at diagnosis by deploying bulk and single-cell RNA sequencing. We also defined the correlations with leukemia-associated burden using results of whole-exome sequencing of AML samples at disease onset. We showed that VISTA expression linearly increased across the myeloid differentiation tree in normal hematopoiesis. Accordingly, its transcript was highly enriched in AML cell lines as well as in AML patients at diagnosis presenting with myelomonocytic and monocytic differentiation. A strong correlation was seen with NPM1 mutations regardless of the presence of FLT3 lesions. Furthermore, VISTA expression levels at baseline correlated with disease recurrence in patients with normal karyotype and NPM1 mutations, a subgroup traditionally considered as favorable according to current diagnostic schemes. Indeed, when compared to patients with long-term remission (>5 years after standard chemotherapy regimens), cases relapsing within 2 years from diagnosis had increased VISTA expression in both leukemia and T cells. Our results suggest a rationale for developing VISTA-targeted therapeutic strategies to treat molecularly defined subgroups of AML patients to prevent disease recurrence and treatment resistance.

A real-world comparison of tisagenlecleucel and axicabtagene ciloleucel CAR T cells in relapsed or refractory diffuse large B cell lymphoma

Axicabtagene ciloleucel (axi-cel) and tisagenlecleucel (tisa-cel) have both demonstrated impressive clinical activity in relapsed/refractory (R/R) diffuse large B cell lymphoma (DLBCL). In this study, we analyzed the outcome of 809 patients with R/R DLBCL after two or more previous lines of treatment who had a commercial chimeric antigen receptor (CAR) T cells order for axi-cel or tisa-cel and were registered in the retrospective French DESCAR-T registry study ( NCT04328298 ). After 1:1 propensity score matching (n = 418), the best overall response rate/complete response rate (ORR/CRR) was 80%/60% versus 66%/42% for patients treated with axi-cel compared to tisa-cel, respectively (P < 0.001 for both ORR and CRR comparisons). After a median follow-up of 11.7 months, the 1-year progression-free survival was 46.6% for axi-cel and 33.2% for tisa-cel (hazard ratio (HR) = 0.61; 95% confidence interval (CI), 0.46-0.79; P = 0.0003). Overall survival (OS) was also significantly improved after axi-cel infusion compared to after tisa-cel infusion (1-year OS 63.5% versus 48.8%; HR = 0.63; 95% CI, 0.45-0.88; P = 0.0072). Similar findings were observed using the inverse probability of treatment weighting statistical approach. Grade 1-2 cytokine release syndrome was significantly more frequent with axi-cel than with tisa-cel, but no significant difference was observed for grade ≥3. Regarding immune effector cell-associated neurotoxicity syndrome (ICANS), both grade 1-2 and grade ≥3 ICANS were significantly more frequent with axi-cel than with tisa-cel. In conclusion, our matched comparison study supports a higher efficacy and also a higher toxicity of axi-cel compared to tisa-cel in the third or more treatment line for R/R DLBCL.

Individual HLA heterogeneity and its implications for cellular immune evasion in cancer and beyond

Structural and functional variability of human leukocyte antigen (HLA) is the foundation for competent adaptive immune responses against pathogen and tumor antigens as it assures the breadth of the presented immune-peptidome, theoretically sustaining an efficient and diverse T cell response. This variability is presumably the result of the continuous selection by pathogens, which over the course of evolution shaped the adaptive immune system favoring the assortment of a hyper-polymorphic HLA system able to elaborate efficient immune responses. Any genetic alteration affecting this diversity may lead to pathological processes, perturbing antigen presentation capabilities, T-cell reactivity and, to some extent, natural killer cell functionality. A highly variable germline HLA genotype can convey immunogenetic protection against infections, be associated with tumor surveillance or influence response to anti-neoplastic treatments. In contrast, somatic aberrations of HLA loci, rearranging the original germline configuration, theoretically decreasing its variability, can facilitate mechanisms of immune escape that promote tumor growth and immune resistance. The purpose of the present review is to provide a unified and up-to-date overview of the pathophysiological consequences related to the perturbations of the genomic heterogeneity of HLA complexes and their impact on human diseases, with a special focus on cancer.

KIR in Allogeneic Hematopoietic Stem Cell Transplantation: Need for a Unified Paradigm for Donor Selection

Allogeneic hematopoietic stem cell transplantation (aHSCT) is a lifesaving therapy for hematological malignancies. For years, a fully matched HLA donor was a requisite for the procedure. However, new immunosuppressive strategies have enabled the recruitment of viable alternative donors, particularly haploidentical donors. Over 95% of patients have at least two potential haploidentical donors available to them. To identify the best haploidentical donor, the assessment of new immunogenetic criteria could help. To this end, the clinical benefit of KIR genotyping in aHSCT has been widely studied but remains contentious. This review aims to evaluate the importance of KIR-driven NK cell alloreactivity in the context of aHSCT and explain potential reasons for the discrepancies in the literature. Here, through a non-systematic review, we highlight how the studies in this field and their respective predictive models or scoring strategies could be conceptually opposed, explaining why the role of NK cells remains unclear in aHCST outcomes. We evaluate the limitations of each published prediction model and describe how every scoring strategy to date only partly delivers the requirements for optimally effective NK cells in aHSCT. Finally, we propose approaches toward finding the optimal use of KIR genotyping in aHSCT for a unified criterion for donor selection.

[Mechanisms of resistance and escape to CAR-T cells]

CAR-T cells represent a new approach to anti-tumor cellular immunotherapy allowing to combine the recognition of tumor antigens on target cells and the activation, proliferation and cytotoxic capacity of T lymphocytes. Impressive clinical results have been obtained with CAR-T cells targeting the CD19 antigen in relapsing or refractory B cell malignant lymphomas or acute lymphoblastic leukemias, with complete response rates of 40 to 90%. However, 30 to 50% of responding patients in B malignancies will escape treatment secondarily, and the effectiveness of these approaches in solid tumors remains limited. Different mechanisms of primary resistance and/or escape to CAR-T cells have been described. This review aims to describe these mechanisms and explore potential ways for optimization. We will see that the initial response and its long-term persistence depends on several parameters: the functional characteristics of the CAR-T cells in vivo, the expression of targeted antigens on tumor cells, the development of a immunosuppressive microenvironment. Or of an immune response directed against the CAR molecule. In solid tumors in particular, the specificity of the antigen target and the "homing" of CAR-T cells in the tumor site are additional elements to consider. A better knowledge of mechanisms of resistance will help to improve the clinical outcomes by either modulating the construction and the production of CAR-T cells and/or to combine them with other immunotherapeutic approaches to better control the tumor microenvironment.

Impact of donor-derived CD34 + infused cell dose on outcomes of patients undergoing allo-HCT following reduced intensity regimen for myelofibrosis: a study from the Chronic Malignancies Working Party of the EBMT

The optimal CD34 + cell dose in the setting of RIC allo-HCT for myelofibrosis (MF) remains unknown. We retrospectively analyzed 657 patients with primary or secondary MF transplanted with use of peripheral blood (PB) stem cells after fludarabine/melphalan or fludarabine/busulfan RIC regimen. Median patient age was 58 (range, 22-76) years. Donors were HLA-identical sibling (MSD) or unrelated (UD). Median follow-up was 46 (2-194) months. Patients transplanted with higher doses of CD34 + cells (>7.0 × 10⁶/kg), had an increased chance of achievement of both neutrophil (hazard ratio (HR), 1.46; P < 0.001) and platelet engraftment (HR, 1.43; P < 0.001). In a model with interaction, for patients transplanted from a MSD, higher CD34 + dose was associated with improved overall survival (HR, 0.63; P = 0.04) and relapse-free survival (HR, 0.61; P = 0.02), lower risk of non-relapse mortality (HR, 0.57; P = 0.04) and higher rate of platelet engraftment. The combined effect of higher cell dose and UD was apparent only for higher neutrophil and platelet recovery rate. We did not document any detrimental effect of high CD34 + dose on transplant outcomes. More bulky splenomegaly was an adverse factor for survival, engraftment and NRM. Our analysis suggests a potential benefit for MF patients undergoing RIC PB-allo-HCT receiving more than 7.0 × 10⁶/kg CD34 + cells.

Impact of prior JAK-inhibitor therapy with ruxolitinib on outcome after allogeneic hematopoietic stem cell transplantation for myelofibrosis: a study of the CMWP of EBMT

JAK1/2 inhibitor ruxolitinib (RUX) is approved in patients with myelofibrosis but the impact of pretreatment with RUX on outcome after allogeneic hematopoietic stem cell transplantation (HSCT) remains to be determined. We evaluated the impact of RUX on outcome in 551 myelofibrosis patients who received HSCT without (n = 274) or with (n = 277) RUX pretreatment. The overall leukocyte engraftment on day 45 was 92% and significantly higher in RUX responsive patients than those who had no or lost response to RUX (94% vs. 85%, p = 0.05). The 1-year non-relapse mortality was 22% without significant difference between the arms. In a multivariate analysis (MVA) RUX pretreated patients with ongoing spleen response at transplant had a significantly lower risk of relapse (8.1% vs. 19.1%; p = 0.04)] and better 2-year event-free survival (68.9% vs. 53.7%; p = 0.02) in comparison to patients without RUX pretreatment. For overall survival the only significant factors were age > 58 years (p = 0.03) and HLA mismatch donor (p = 0.001). RUX prior to HSCT did not negatively impact outcome after transplantation and patients with ongoing spleen response at time of transplantation had best outcome.

[Immunomonitoring of patients treated with CAR-T cells for hematological malignancy: Guidelines from the CARTi group and the Francophone Society of Bone Marrow Transplantation and Cellular Therapy (SFGM-TC)]

CAR-T cells represent a new anti-tumor immunotherapy which has shown its clinical efficacy in B-cell malignancies. The results of clinical trials carried out in this context have shown that certain immunological characteristics of patients before (at the time of apheresis) and after the administration of the treatment, or of the CAR-T cells themselves, are correlated with the response to the treatment or to its toxicity. However, to date, there are no recommendations on the immunological monitoring of patients treated in real life. The objectives of this workshop were to determine, based on data from the literature and the experience of the centers, the immunological analyses to be carried out in patients treated with CAR-T cells. The recommendations relate to the characterization of the patient's immune cells at the time of apheresis, the characterization of the injected CAR-T cells, as well as the monitoring of the CAR-T cells and other parameters of immune reconstitution in the patient after administration of the treatment. Harmonization of practices will allow clinical-biological correlation studies to be carried out in patients treated in real life with the aim of identifying factors predictive of response and toxicity. Such data could have a major medico-economic impact by making it possible to identify the patients who will optimally benefit from these expensive treatments.

Role and Modulation of NK Cells in Multiple Myeloma

Myeloma tumor cells are particularly dependent on their microenvironment and sensitive to cellular antitumor immune response, including natural killer (NK) cells. These later are essential innate lymphocytes implicated in the control of viral infections and cancers. Their cytotoxic activity is regulated by a balance between activating and inhibitory signals resulting from the complex interaction of surface receptors and their respective ligands. Myeloma disease evolution is associated with a progressive alteration of NK cell number, phenotype and cytotoxic functions. We review here the different therapeutic approaches that could restore or enhance NK cell functions in multiple myeloma. First, conventional treatments (immunomodulatory drugs-IMids and proteasome inhibitors) can enhance NK killing of tumor cells by modulating the expression of NK receptors and their corresponding ligands on NK and myeloma cells, respectively. Because of their ability to kill by antibody-dependent cell cytotoxicity, NK cells are important effectors involved in the efficacy of anti-myeloma monoclonal antibodies targeting the tumor antigens CD38, CS1 or BCMA. These complementary mechanisms support the more recent therapeutic combination of IMids or proteasome inhibitors to monoclonal antibodies. We finally discuss the ongoing development of new NK cell-based immunotherapies, such as ex vivo expanded killer cell immunoglobulin-like receptors (KIR)-mismatched NK cells, chimeric antigen receptors (CAR)-NK cells, check point and KIR inhibitors.

Impact of spleen size and splenectomy on outcomes of allogeneic hematopoietic cell transplantation for myelofibrosis: A retrospective analysis by the chronic malignancies working party on behalf of European society for blood and marrow transplantation (EBMT)

The role of spleen size and splenectomy for the prediction of post-allogeneic hematopoietic stem cell transplant (allo-HCT) outcome in myelofibrosis remains under debate. In EBMT registry, we identified a cohort of 1195 myelofibrosis patients transplanted between 2000-2017 after either fludarabine-busulfan or fludarabine-melphalan regimens. Overall, splenectomy was performed in 202 (16.9%) patients and its use decreased over time (28.3% in 2000-2009 vs 14.1% in 2010-2017 period). By multivariate analysis, splenectomy was associated with less NRM (HR 0.64, 95% CI 0.44-0.93, P = .018) but increased risk of relapse (HR 1.43, 95% CI 1.01-2.02, P = .042), with no significant impact on OS (HR 0.86, 95% CI 0.67-1.12, P = .274). However, in subset analysis comparing the impact of splenectomy vs specific spleen sizes, for patients with progressive disease, an improved survival was seen in splenectomised subjects compared to those patients with a palpable spleen length ≥ 15 cm (HR 0.44, 95% CI 0.28-0.69, P < .001), caused by a significant reduction in NRM (HR 0.26, 95% CI 0.14-0.49, P < .001), without significantly increased relapse risk (HR 1.47, 95% CI 0.87-2.49, P = .147). Overall, despite the possible biases typical of retrospective cohorts, this study highlights the potential detrimental effect of massive splenomegaly in transplant outcome and supports the role of splenectomy for myelofibrosis patients with progressive disease and large splenomegaly.

Plasmacytoid dendritic cells proliferation associated with acute myeloid leukemia: phenotype profile and mutation landscape

Neoplasms involving plasmacytoid Dendritic Cells (pDCs) include Blastic pDC Neoplasms (BPDCN) and other pDC proliferations, where pDCs are associated with myeloid malignancies: most frequently Chronic MyeloMonocytic Leukemia (CMML) but also Acute Myeloid Leukemia (AML), hereafter named pDC-AML. We aimed to determine the reactive or neoplastic origin of pDCs in pDC-AML, and their link with the CD34+ blasts, monocytes or conventional DCs (cDCs) associated in the same sample, by phenotypic and molecular analyses (targeted NGS, 70 genes). We compared 15 pDC-AML at diagnosis with 21 BPDCN and 11 normal pDCs from healthy donors. CD45low CD34+ blasts were found in all cases (10-80% of medullar cells), associated with pDCs (4-36%), monocytes in 14 cases (1-10%) and cDCs (2 cases, 4.8-19%). pDCs in pDC-AML harbor a clearly different phenotype from BPDCN: CD4+ CD56- in 100% of cases, most frequently CD303+, CD304+ and CD34+; lower expression of cTCL1 and CD123 with isolated lymphoid markers (CD22/CD7/CD5) in some cases, suggesting a pre-pDC stage. In all cases, pDCs, monocytes and cDC are neoplastic since they harbor the same mutations as CD34+ blasts. RUNX1 is the most commonly mutated gene: detected in all AML with minimal differentiation (M0-AML) but not in the other cases. Despite low number of cases, the systematic association between M0-AML, RUNX1 mutations and an excess of pDC is puzzling. Further evaluation in a larger cohort is required to confirm RUNX1 mutations in pDC-AML with minimal differentiation and to investigate whether it represents a proliferation of blasts with macrophage and DC progenitor potential.

Allogeneic Stem Cell Transplantation in Therapy-Related Myelodysplasia after Autologous Transplantation for Lymphoma: A Retrospective Study of the Francophone Society of Bone Marrow Transplantation and Cellular Therapy

Therapy-related myelodysplastic syndrome (t-MDS) after autologous stem cell transplantation (ASCT) is a rare complication with no curative option. Allogeneic hematopoietic stem cell transplantation (allo-HSCT) may be considered for eligible patients and has been understudied in t-MDS. We report 47 consecutive patients with t-MDS after an ASCT who underwent allo-HSCT with a median age of 58 years (range, 30 to 71 years) at transplantation and a median follow-up of 22 months (range, 0.7 to 107). The median overall survival (OS) was 6.9 months (95% confidence interval [CI], 0 to 19 months). OS rates were 45% (29% to 60%) and 30% (15% to 45%) at 1 and 3 years after transplantation, respectively. On univariate analysis, prior therapy for t-MDS before allo-HSCT (P = .02) and mismatched donors (P = .004) were associated with poor OS. Three-year nonrelapse mortality (NRM) and relapse rates were 44% (25% to 63%) and 41% (22% to 61%), respectively. Mismatched donors (P < .001) were associated with higher NRM and a high-risk MDS (P = .008) with a higher relapse risk. On multivariate analysis, HLA mismatch was associated with higher NRM (hazard ratio, 6.21; 95% CI, 1.63 to 23.62; P = .007). In conclusion, our results suggest that one third of the patients who develop t-MDS after an ASCT for lymphoma are cured after an allo-HSCT. The use of mismatched donors with standard graft-versus-host disease prophylaxis should be avoided in such an indication for allo-HSCT. It will be worthwhile to see if the implementation of cyclophosphamide post-transplantation will improve the outcome with mismatched donors.

Outcomes of Advanced Hodgkin Lymphoma after Umbilical Cord Blood Transplantation: A Eurocord and EBMT Lymphoma and Cellular Therapy & Immunobiology Working Party Study

Allogeneic stem cell transplantation is an alternative for patients with relapsed or refractory Hodgkin lymphoma (HL), but only limited data on unrelated umbilical cord blood transplantation (UCBT) are available. We analyzed 131 adults with HL who underwent UCBT in European Society for Blood and Marrow Transplantation centers from 2003 to 2015. Disease status at UCBT was complete remission (CR) in 59 patients (47%), and almost all patients had received a previous autologous stem cell transplantation. The 4-year progression-free survival (PFS) and overall survival (OS) were 26% (95% confidence interval [CI], 19% to 34%) and 46% (95% CI, 37% to 55%), respectively. Relapse incidence was 44% (95% CI, 36% to 54%), and nonrelapse mortality (NRM) was 31% (95% CI, 23% to 40%) at 4 years. In multivariate analysis refractory/relapsed disease status at UCBT was associated with increased relapse incidence (hazard ratio [HR], 3.14 [95% CI, 1.41 to 7.00], P = .005) and NRM (HR, 3.61 [95% CI, 1.58 to 8.27], P = .002) and lower PFS (HR, 3.45 [95% CI, 1.95 to 6.10], P < .001) and OS (HR, 3.10 [95% CI, 1.60 to 5.99], P = .001). Conditioning regimen with cyclophosphamide + fludarabine + 2 Gy total body irradiation (Cy+Flu+2GyTBI) was associated with decreased risk of NRM (HR, .26 [95% CI, .10 to .64], P = .004). Moreover, Cy+Flu+2GyTBI conditioning regimen was associated with a better OS (HR, .25 [95% CI, .12 to .50], P < .001) and PFS (HR, .51 [95% CI, .27 to .96], P = .04). UCBT is feasible in heavily pretreated patients with HL. The reduced-intensity conditioning regimen with Cy+Flu+2GyTBI is associated with a better OS and NRM. However, outcomes are poor in patients not in CR at UCBT.

Impact of in vivo T cell depletion in HLA-identical allogeneic stem cell transplantation for acute myeloid leukemia in first complete remission conditioned with a fludarabine iv-busulfan myeloablative regimen: a report from the EBMT Acute Leukemia Working Party

Background

The impact of the use of anti-thymocyte globulin (ATG) in allogeneic stem cell transplantation performed with HLA-identical sibling donors following fludarabine and 4 days intravenous busulfan myeloablative conditioning regimen has been poorly explored.

Methods

We retrospectively analyzed 566 patients who underwent a first HLA-identical allogeneic stem cell transplantation with this conditioning regimen for acute myeloid leukemia in first complete remission between 2006 and 2013 and compared the outcomes of 145 (25.6%) patients who received ATG (ATG group) to 421 (74.4%) who did not (no-ATG group). The Kaplan-Meier estimator, the cumulative incidence function, and Cox proportional hazards regression models were used where appropriate.

Results

Patients in the ATG group were older, received more frequently peripheral blood stem cell grafts from older donors, and were transplanted more recently. With a median follow-up of 19 months, patients in the ATG group had reduced 2-year cumulative incidence of chronic graft-versus-host disease (GVHD) (31 vs. 52%, p = 0.0002) and of its extensive form (8 vs. 26%, p < 0.0001) but similar relapse incidence (22 vs. 27%, p = 0.23) leading to improved GVHD and relapse-free survival (GRFS) (60 vs. 40%, p = 0.0001). In multivariate analyses, the addition of ATG was independently associated with lower chronic GVHD (HR = 0.46, p = 0.0001), improved leukemia-free survival (HR = 0.67, p = 0.027), overall survival (HR = 0.65, p = 0.027), and GRFS (HR = 0.51, p = 4 × 10⁻⁵). Recipient age above 50 years was the only other factor associated with worse survivals.

Conclusions

These results suggest that the use of ATG with fludarabine and 4 days intravenous busulfan followed by HLA-identical sibling donor allogeneic stem cell transplantation for acute myeloid leukemia improves overall transplant outcomes due to reduced incidence of chronic GVHD without increased relapse risk.

Electronic supplementary material

The online version of this article (doi:10.1186/s13045-016-0389-4) contains supplementary material, which is available to authorized users.

The impact of allogeneic-hematopoietic stem cell transplantation on patients' and close relatives' quality of life and relationships

PURPOSE

Although evidence suggests considerable disruption to families, the impact of allo-Hematopoietic Stem Cell Transplantation (HSCT) on patients' partners and close relatives has not been sufficiently explored. The present mixed-methods study aimed to enlighten allo-HSCT effects on patients' and close relatives' quality of life (QOL) and their relationships.

METHODS

Patients who received allo-HSCT between 2007 and 2010 (N = 58) and their close relatives (parents, partners and/or adult children) were asked to respond to an anonymous questionnaire including socio-demographic data, Likert-scale of the impact of HSCT on sexual, couple, family, professional and social life, as well as on perceived support. QOL of patients and close relatives was evaluated (by the FACT-BMT and by WHO-QOL-bref) as were the adjustments of the couples (patients/partners by the DAS). In-depth interviews were performed with patients and partners who consented to this proposition.

RESULTS

Patients (N = 28) and close relatives (N = 48) reported fatigue, sleep and sexual problems, emotional distress and relationship difficulties. Patients were mainly concerned with « being a burden » to their close relatives. Close relatives' main concerns were changes in marital and family dynamics, disruptions in daily routine tasks and the responsibility for being the main provider of physical and emotional care. These difficulties increased after HSCT - notably when patients have to face the long-term consequences of the procedure.

CONCLUSION

HSCT has a negative impact on patients' partners and other close relatives' QOL. Data on this topic is still scarce and this study might pave the way for future research in this field and notably guide psychosocial interventions.

The impact of graft-versus-host disease prophylaxis in reduced-intensity conditioning allogeneic stem cell transplant in acute myeloid leukemia: a study from the Acute Leukemia Working Party of the European Group for Blood and Marrow Transplantation

The impact of the intensity of graft-versus-host-disease immunoprophylaxis on transplantation outcomes in patients undergoing transplantation following reduced-intensity conditioning is unclear. This study addresses this issue in 228 adult patients above 50 years of age with acute myeloid leukemia in first complete remission given peripheral blood stem cells from HLA-identical siblings after fludarabine and 2 days of intravenous busulfan reduced-intensity conditioning. A total of 152 patients received anti-thymocyte globulin, either in combination with cyclosporine A in 86 patients (group 1), or with cyclosporine A and mycophenolate mofetil or short course methotrexate in 66 patients (group 2). The remaining 76 patients did not receive anti-thymocyte globulin but were given cyclosporine A and methotrexate or mycophenolate mofetil (group 3). Incidences of grade II-IV acute graft-versus-host-disease were comparable in the three groups (16.5%, 29.5% and 19.5% in groups 1, 2 and 3, respectively, P=0.15). In multivariate analysis, the absence of anti-thymocyte globulin was the only factor associated with a higher risk of chronic graft-versus-host-disease (P=0.005), while the use of triple immunosuppression (group 3) was associated with an increased risk of relapse (P=0.003). In comparison to anti-thymocyte globulin and cyclosporine A alone, the other two strategies of graft-versus-host-disease prophylaxis were associated with reduced leukemia-free survival and overall survival (P=0.001 for each parameter), independently of the dose of anti-thymocyte globulin. These data suggest that fine tuning of the intensity of this prophylaxis can affect the outcome of transplantation and that anti-thymocyte globulin and cyclosporine A alone should be the preferred combination with the fludarabine-busulfan reduced-intensity conditioning regimen and sibling donors.

Lenalidomide as salvage treatment for multiple myeloma relapsing after allogeneic hematopoietic stem cell transplantation: a report from the French Society of Bone Marrow and Cellular Therapy

Optimal salvage treatment for multiple myeloma relapsing after allogeneic stem cell transplantation remains to be determined. Usually, such patients have been heavily pre-treated and present at relapse with a relatively refractory disease. Immunomodulatory properties of lenalidomide may be beneficial by facilitating a graft-versus-myeloma effect after allogeneic stem cell transplantation. However, the safety of such treatment is still under debate. We conducted a multicenter retrospective study and included 52 myeloma patients receiving lenalidomide alone or in combination with dexamethasone as salvage therapy after allogeneic stem cell transplantation. The first aim was to assess the efficacy and tolerance of this drug. The second aim was to evaluate its potential immunomodulatory effects evaluated on the occurrence of acute graft-versus-host disease under treatment. In this cohort, we show that lenalidomide can induce a high response rate of 83% (including 29% complete response). On lenalidomide therapy, 16 patients (31%) developed or exacerbated an acute graft-versus-host disease, which was the only factor significantly associated with an improved anti-myeloma response. Side effects were mostly reversible, whereas 2 deaths (4%) could be attributed to treatment toxicity and to graft-versus-host disease, respectively. With a median follow up of 16.3 months, the median overall and progression free survival were 30.5 and 18 months, respectively, independently of the occurrence of acute graft-versus-host disease under lenalidomide. Lenalidomide can induce high response rates in myeloma relapsing after allogeneic stem cell transplantation at least in part by triggering an allogeneic anti-myeloma response. Induced graft-versus-host disease has to be balanced against the potential benefit in terms of disease control. Further immunological studies would help us understand lenalidomide immunomodulatory activity in vivo.

Extraosseous plasmacytoma of the lacrimal duct

OBJECTIVE

Extraosseous plasmacytoma (EOP) is a rare plasma cell proliferative disorder that commonly affects the head and neck region. We report the first case of a plasmacytoma of the lacrimal duct.

METHODS

A 66-year-old man presented with an isolated plasmacytoma of the right lacrimal duct and was treated surgically.

RESULTS

The tumour grew slowly for a few months. CT scan and MRI showed a right lateral nasal mass extending from the right lacrimal duct toward the floor of the right maxillary sinus. The lesion was removed completely by endoscopic nasal surgery.

DISCUSSION

EOP accounts for up to 3% of all plasma cell tumours. Management of this rare lesion involves surgery and radiotherapy with or without adjuvant chemotherapy. Guided by a literature review, we discuss the diagnostic and therapeutic management of EOP.

[Loa Loa and Mansonella perstans coinfection in a patient from Guinea]

We present a case of mixed infection by two filariae (Loa loa and Mansonella perstans). It seems that the infection was suspected due to a pronounced eosinophilia in a routine analysis. Sheathed and unsheathed microfilariae were observed in the spread of peripheral blood, which enabled a diagnosis to be established of mixed infection by filariae. The definitive diagnosis of the species was carried out at the National Centre of Microbiolgy of Majadahonda. A treatment was initiated with dietilcarbamazina and mebendazole which resulted in the patient's being cured and in the elimination of the microfilariae in the patient's blood. Filariasis is still endemic in many countries. Due to the increase of travellers to such zones and the migratory movements from such areas it is not unusual for us to come across such a diagnosis. The implantation of massive treatments against filariae in endemic zones by the World Health Organisation is reducing their transmission and is managing to eliminate the disease in some areas.

Evolución en las características epidemiológicas de la tuberculosis en Navarra (1994-2003)

AIM

To describe the changes in the incidence and the epidemiological profile of tuberculosis in Navarra.

METHODS

The cases of tuberculosis in the 1994-2003 period were analysed. Cases reported to the system of obligatory notifiable diseases, completed with the microbiological diagnoses and the cases collected in other health registers.

RESULTS

The incidence of tuberculosis fell from 21 per 100,000 inhabitants in the five-year period 1994-1998 to 16 per 100,000 in 1999-2003. In both periods the number of cases in men doubled that in women, and the maximum incidence occurred in the age groups from 25 to 44 and over 65 years of age. The diagnoses of tuberculosis in persons with HIV infection fell from 15.1% to 6.6% and those in immigrants rose from 2.2% to 21.3%. Somewhat over 3% of the cases had received prior anti-tuberculosis treatment and about 6% showed resistance to some medicine, without significant differences between periods. The proportion of potentially transmissible tuberculosis (73%) underwent no significant changes, nor did that of those with positive sputum bacilloscopy. The number of outbreaks (groupings of two or more cases) rose from 18 to 26 and the percentage of cases secondary to another recent case rose from 3.6% to 10.1% (p<0,001). In the 1999-2003 period, pulmonary localisation occurred in isolated form in 67.7% of the patients, and in combination with other localisations in another 5.1%. The isolated pleural form appeared in 9.9% and the meningeal form in 1.5%.

CONCLUSION

There has been an advance in the control of tuberculosis although its incidence is still high with respect to other European countries. Control of imported cases is one of the challenges to be faced in coming years, without neglecting control measures in the autochthonous population.

The immunosuppressive effect of vincristine on allostimulatory potential of human dendritic cells interferes with their function and survival

Mature dendritic cells (mDC) are professional and potent antigen presenting cells required for initiation of primary immune responses. In the present study, we have investigated the effect of vincristine on the T cell allostimulatory potential of human monocyte-derived mDC in allogeneic mixed lymphocyte reaction. Using T lymphocytes as responding cells and mDC as stimulating cells, our data indicate that incubation of DC with vincristine decreased the accessory potency dose dependently and resulted in a subsequent inhibition of T cell proliferative responses. Treatment of mDC with vincristine also led to the alteration of their capacity to produce IL-12 but enhanced their production of IL-10. Using flow cytometry, we demonstrated that vincristine had no effect on mDC phenotype (CD83, CD40, CD86, CD58, CD54) but promoted apoptotic cell death of these cells as revealed by PI and annexin-V. These findings suggest that DC may be potential targets of cytotoxic drugs and point out the possible impairment of the immunocompetence of these cells following chemotherapy.

Idiopathic light-chain proteinuria: case report and review of the literature

Isolated Bence Jones proteinuria (BJP) is a distinct form of monoclonal gammopathy of undetermined significance (MGUS) rarely described. The prognosis of the disease is apparently good. We report here a case of idiopathic BJP and review the literature.

Adult T-biphenotypic acute leukaemia: clinical and biological features and outcome

Biphenotypic acute leukaemia with T-lymphoid and myeloid markers is rare and poorly documented. In the Leucemie Aigue Lymphoblastique de l'Adulte (LALA) prospective trial (LALA 94) of treatment for adult acute lymphoblastic leukaemia (ALL), seven patients (0.86%) had T-biphenotypic forms. The clinical and biological characteristics and outcome of these seven patients are reported here. The patients' median age was 35 years. At diagnosis, all had a tumoural syndrome and five had a mediastinal mass. In all the cases, leukaemic cells expressed myeloid and lymphoid markers. Two patients (28%) entered complete remission (CR) after induction chemotherapy. Four of the five remaining and assessable patients entered CR after designed salvage chemotherapy with mitoxantrone and high-dose cytosine arabinoside. Three patients are currently in CR. Three patients died, from treatment toxicity in two cases and progressive disease in one case. One patient relapsed 6 months after allogeneic bone marrow transplantation and is still alive. Thus, biphenotypic T-acute leukaemia is clinically frequently associated with mediastinal involvement and the response to conventional chemotherapy used in ALL is poor. However, sustained CR can be achieved by salvage chemotherapy combining an intercalating agent with high-dose cytosine arabinoside, as used in acute myeloid leukaemia.

Hypereosinophilia as a presenting sign of acute graft-versus-host disease after allogeneic bone marrow transplantation

The authors report two cases of hypereosinophilia as the major presenting sign of acute graft-versus-host disease (GVHD) after allogeneic bone marrow transplantation (BMT). Tissue biopsies of the skin, salivary gland, gut, and liver showed evidence of acute GVHD (aGVHD). In one case, further investigations have been performed. Elevated levels of interleukin (IL)-5 and soluble IL-2 receptor were found in the blood, and skin biopsy specimens demonstrated high levels of IL-5 messenger ribonucleic acid (mRNA). In contrast, skin biopsy specimens from other patients with aGVHD but without eosinophilia were negative for IL-5 mRNA. The authors also demonstrated the presence of IL-4 and interferon(IFN)-gamma mRNA within the same skin biopsy specimen, suggesting that this case of aGVHD was mediated by both Th1 and Th2 cell type. These two patients were treated by glucocorticoids with resolution of the hypereosinophilia and the symptoms of GVHD. The authors briefly discuss the possible mechanisms of this hypereosinophilia with respect to aGVHD.

Remission of transformed myelodysplastic syndrome with fibrosis after danazol therapy

Danazol has been used with success in some hematological diseases, but there is no report of this treatment in acute leukemia. We report here a case of remission of myelodysplastic syndrome with myelofibrosis in transformation after danazol therapy in a 72-yr-old man. The role of danazol in remission induction is briefly discussed.

[Hodgkin's disease: biology can help the physician towards new prognostic factors and new therapeutic approaches]

Hodgkin's disease is a lymphoma pathology characterized, histology wise, by the presence of rare tumoral cells, known as Reed-Sternberg cells, in a polymorph, inflammatory and reactive cell environment. Recent studies in molecular biology have shown that the Reed-Sternberg cell is mainly derived from a post germinal B lymphoid cell. Reed-Sternberg cell is also known to express characteristic molecules of an antigen presenting cell. Paradoxically, Hodgkin's disease shows an intensive inflammatory reaction but activated immune cells are not efficient in this disease. The abnormal survival and proliferation rates of Reed-Sternberg cells are in relation with immune system escape, acquired mechanisms of apoptosis resistance and amplification of activation of NFkappaB in tumoral cells. If these observations allow a better understanding of the presentation and the evolution of this disease, they might lead to the determination of new prognostic factors and of specific therapeutic approaches.

Risk model for severe anemia requiring red blood cell transfusion after cytotoxic conventional chemotherapy regimens. The Elypse 1 Study Group

PURPOSE

Cancer patients frequently experience anemia as a consequence of myelosuppressive therapy or bone marrow invasion.

PATIENTS AND METHODS

A risk model for chemotherapy-induced severe anemia requiring RBC transfusions (SARRT) within 31 days after the administration of chemotherapy was delineated in the cohort of cancer patients treated with chemotherapy in the Department of Medicine of Centre Léon Bérard in 1996 (CLB-1996). The risk model was tested on a series of 797 patients treated in 1997 (CLB-1997) and on 295 patients included in a multicenter prospective series (ELYPSE 1).

RESULTS

One hundred seven of the 1,051 patients of the CLB-1996 cohort (10%) experienced SARRT. In univariate analysis, only female sex, performance status greater than 1, hemoglobin level less than 12 g/dL before chemotherapy on day 1 (d1), and d1 lymphocyte count < or = 700/microL significantly correlated with the risk of SARRT. Using logistic regression, d1 hemoglobin level less than 12 g/dL (odds ratio [OR] = 14.0; 95% confidence interval [CI], 7 to 30), performance status greater than 1 (OR = 2.2; 95% CI, 1.4 to 3.5), and d1 lymphocyte count < or = 700/microL (OR = 1.7; 95% CI, 1. 1 to 2.6) were identified as independent risk factors for SARRT. These three factors were given arbitrary risk coefficients of 3, 1, and 1 respectively, and a risk score for each individual patient was obtained by adding the coefficients. The calculated probability of RBC transfusions was 30% for patients with a score > or = 4, and 11%, 4%, and 1% in patients with a score of 2 or 3, 1, and 0 respectively. This model was then tested and validated in the CLB-1997 and ELYPSE 1 series.

CONCLUSION

This risk index could be useful to identify patients at high risk for chemotherapy-induced SARRT who might be appropriate candidates for prophylactic erythropoietin treatment.