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The question of the best donor type between haploidentical (HAPLO) and matched-related donors (MRD) for patients with advanced HL receiving an allogeneic hematopoietic cell transplantation (allo-HCT) is still debated. Given the lack of data comparing these two types of donor in the setting of non-myeloablative (NMA) or reduced-intensity (RIC) allo-HCT, we performed a multicentre retrospective study using graft-vs.-host disease-free relapse-free survival (GRFS) as our primary endpoint. We analysed the data of 151 consecutive HL patients who underwent NMA or RIC allo-HCT from a HAPLO (N = 61) or MRD (N = 90) between January 2011 and January 2016. GRFS was defined as the probability of being alive without evidence of relapse, grade 3-4 acute GVHD or chronic GVHD. In multivariable analysis, MRD donors were independently associated with lower GRFS compared to HAPLO donors (HR = 2.95, P

Background Post-transplant non-Hodgkin lymphoma (NHL) is a well-recognized complication of solid-organ transplantation, and pharmacologic suppression of adaptive immunity plays a major role in its development. However, the role of natural killer (NK) cells in post-lung transplant de novo NHL is unknown. Methods Extensive phenotypic analyses of NK cells from patients diagnosed with NHL after liver or lung transplantation were conducted with multicolor flow cytometry. Polyfunctionality assays simultaneously assessed NK cell degranulation (CD107a) and intracellular cytokine production (interferon-γ and tumor necrosis factor-α) in the presence of NHL target cells. Results The development of de novo NHL is linked to NK-cell maturation defects, including overexpression of NKG2A and CD62L and down-modulation of inhibitory killer immunoglobulin-like receptors and CD57 receptors. More importantly, in patients who developed NHL after lung transplantation, we observed a specific down-modulation of the activating receptors (NKp30, NKp46, and NKG2D) and a sharp decrease in perforin expression and degranulation against NHL target cells. Conclusions Our results suggest that accumulation of abnormal NK cells could play a role in the outgrowth of NHL after lung transplantation, independently of the immunosuppressive regimen.

A prospective phase II multicenter trial was performed with the aim to obtain less than 25% nonrelapse mortality (NRM) after unrelated cord blood transplantation (UCBT) for adults with acute myeloid leukemia (AML) using a reduced-intensity conditioning regimen (RIC) consisting of total body irradiation (2 Gy), cyclophosphamide (50 mg/kg), and fludarabine (200 mg/m2). From 2007 to 2009, 79 UCBT recipients were enrolled. Patients who underwent transplantation in first complete remission (CR1) (n = 48) had a higher frequency of unfavorable cytogenetics and secondary AML and required more induction courses of chemotherapy to achieve CR1 compared with the others. The median infused total nucleated cells (TNC) was 3.4 × 107/kg, 60% received double UCBT, 77% were HLA mismatched (4/6), and 40% had major ABO incompatibility. Cumulative incidence of neutrophil recovery at day 60 was 87% and the cumulative incidence of 100-day acute graft-versus-host disease (II to IV) was 50%. At 2 years, the cumulative incidence of NRM and relapse was 20% and 46%, respectively. In multivariate analysis, major ABO incompatibility (P = .001) and TNC (

Despite great improvements in the outcome of patients with lymphoma, some may still relapse or present with primary refractory disease. In these situations, allogeneic hematopoietic cell transplantation is a potentially curative option, this is true particularly in the case of after autologous stem cell transplantation if remission can be achieved. Recently, novel agents such as anti-PD1 and BTK inhibitors have started to challenge the use of allogeneic hematopoietic cell transplantation for relapsed or refractory lymphoma. During the 2016 annual workshop of the Francophone Society of Bone Marrow Transplantation and Cellular Therapy (SFGM-TC), we performed a comprehensive review of the literature published in the last 10 years and established guidelines to clarify the indications and transplant modalities in this setting. This section specifically reports on our conclusions regarding diffuse large B cell lymphoma.

Unrelated cord blood transplantation (UCBT) after a reduced intensity conditioning regimen (RIC) has extended the use of UCB in elderly patients and those with co-morbidities without an HLA-identical donor, although post-transplant relapse remains a concern in high-risk acute myeloid leukemia (AML) patients. HLA incompatibilities between donor and recipient might enhance the alloreactivity of natural killer (NK) cells after allogeneic hematopoietic stem-cell transplantation (HSCT). We studied the reconstitution of NK cells and KIR-L mismatch in 54 patients who underwent a RIC-UCBT for AML in CR in a prospective phase II clinical trial. After RIC-UCBT, NK cells displayed phenotypic features of both activation and immaturity. Restoration of their polyfunctional capacities depended on the timing of their acquisition of phenotypic markers of maturity. The incidence of treatment-related mortality (TRM) was correlated with low CD16 expression (P=0.043) and high HLA-DR expression (P=0.0008), whereas overall survival was associated with increased frequency of NK-cell degranulation (P=0.001). These features reflect a general impairment of the NK licensing process in HLA-mismatched HSCT and may aid the development of future strategies for selecting optimal UCB units and enhancing immune recovery.

Background Fludarabine/busulfan-based conditioning regimens are widely used to perform allogeneic stem-cell transplantation (allo-SCT) in high-risk non-Hodgkin lymphoma (NHL) patients. The impact of the dose intensity of busulfan on outcomes has not been reported yet. Patients and methods This was a retrospective with the aim to compare the outcomes of NHL patients who received before allo-SCT a fludarabine/busulfan conditioning regimen, either of reduced intensity (FB2, 2 days of busulfan at 4 mg/kg/day oral or 3.2 mg/kg/day i.v.) (n = 277) or at a myeloablative reduced-toxicity dose (FB3/FB4, 3 or 4 days of busulfan at 4 mg/kg/day oral or 3.2 mg/kg/day i.v.) (n = 101). Results In univariate analysis, the 2-year overall survival (FB2 66.5% versus 60.3%, P = 0.33), lymphoma-free survival (FB2 57.9% versus 49.8%, P = 0.26), and non-relapse mortality (FB2 19% versus 21.1%, P = 0.91) were similar between both groups. Cumulative incidence of grade III–IV acute graft versus host disease (GVHD) (FB2 11.2% versus 18%, P = 0.08), extensive chronic GVHD (FB2: 17.3% versus 10.7%, P = 0.18) and 2-year GVHD free-relapse free survival (FB2: 44.4% versus 42.8%, P = 0.38) were also comparable. In multivariate analysis there was a trend for a worse outcome using FB3/FB4 regimens (overall survival: HR 1.47, 95% CI: 0.96–2.24, P = 0.08; lymphoma-free survival: HR: 1.43, 95% CI: 0.99–2.06, P = 0.05; relapse incidence: HR 1.54; 95% CI: 0.96–2.48, P = 0.07). These results were confirmed using a propensity score-matching strategy. Conclusion We conclude that reduced toxicity myeloablative conditioning with fludarabine/busulfan does not improve the outcomes compared with reduced-intensity conditioning in adults receiving allo-SCT for NHL.

International audience; Allogeneic stem cell transplantation (allo-SCT) following a non-myeloablative (NMA) or reduced-intensity conditioning (RIC) is considered a valid approach to treat patients with refractory/relapsed Hodgkin lymphoma (HL). When an HLA-matched donor is lacking a graft from a familial haploidentical (HAPLO) donor, a mismatched unrelated donor (MMUD) or cord blood (CB) might be considered. In this retrospective study, we compared the outcome of patients with HL undergoing a RIC or NMA allo-SCT from HAPLO, MMUD or CB. Ninety-eight patients were included. Median follow-up was 31 months for the whole cohort. All patients in the HAPLO group (N=34) received a T-cell replete allo-SCT after a NMA (FLU-CY-TBI, N=31, 91%) or a RIC (N=3, 9%) followed by post-transplant cyclophosphamide. After adjustment for significant covariates, MMUD and CB were associated with significantly lower GvHD-free relapse-free survival (GRFS; hazard ratio (HR)=2.02, P=0.03 and HR=2.43, P=0.009, respectively) compared with HAPLO donors. In conclusion, higher GRFS was observed in Hodgkin lymphoma patients receiving a RIC or NMA allo-SCT with post-transplant cyclophosphamide from HAPLO donors. Our findings suggest they should be favoured over MMUD and CB in this setting.

Long-term outcome of patients with BOS post HSCT with home spirometry is encouraging despite suboptimal adherence

Despite great improvements in the outcome of patients with lymphoma, some may still relapse or present with primary refractory disease. In these situations, allogeneic haematopoietic cell transplantation (allo-HCT) is a potentially curative option, in particular in the case of relapse after autologous stem cell transplantation. Recently, novel agents such as anti-PD1 and BTK inhibitors have started to challenge the use of allo-HCT for relapsed or refractory lymphoma. During the 2016 annual workshop of the Francophone Society of Bone Marrow Transplantation and Cellular Therapy (SFGM-TC), we performed a comprehensive review of the literature published in the last 10 years and established guidelines to clarify the indications and transplant modalities in this setting. This manuscript reports on general considerations regarding allo-HCT for lymphoma and elaborates on the use of alternative donors in this setting.

Despite great improvements in the outcome of patients with lymphoma, some may still relapse or present with primary refractory disease. In these situations, allogeneic hematopoietic cell transplantation is a potentially curative option, this is true particularly the case of relapse after autologous stem cell transplantation. Recently, novel agents such as anti-PD1 and BTK inhibitors have started to challenge the use of allogeneic hematopoietic cell transplantation for relapsed or refractory lymphoma. During the 2016 annual workshop of the Francophone Society of Bone Marrow Transplantation and Cellular Therapy (SFGM-TC), we performed a comprehensive review of the literature published in the last 10 years and established guidelines to clarify the indications and transplant modalities in this setting. This paper specifically reports on our conclusions regarding indolent lymphomas, mainly follicular lymphoma and chronic lymphocytic leukemia.

Despite great improvements in the outcome of patients with lymphoma, some may still relapse or present with primary refractory disease. In these situations, allogeneic haematopoietic cell transplantation is a potentially curative option, in particular in the case of relapse after autologous stem cell transplantation. Recently, novel agents such as anti-PD1 and BTK inhibitors have started to challenge the use of allogeneic haematopoietic cell transplantation for relapsed or refractory lymphoma. During the 2016 annual workshop of the Francophone Society of Bone Marrow Transplantation and Cellular Therapy (SFGM-TC), we performed a comprehensive review of the literature published in the last 10 years and established guidelines to clarify the indications and transplant modalities in this setting. This manuscript specifically reports on our conclusions regarding Hodgkin's lymphoma as well as rarer entities, such as T cell lymphomas.

Haploidentical allogeneic stem cell transplantation (CST) has globally taken off in the past decade. It appears to be a valid alternative to other sources of stem cells; however, further research is necessary to validate the use of this approach in standard patient care. In the attempt to harmonize clinical practices between different French transplantation centers, the French Society of Bone Marrow Transplantation and Cell Therapies (SFGM-TC) set up its fourth annual series of workshops which brought together practitioners from all of its member centers. These workshops took place in September 2013 in Lille. This is part two of the recommendations regarding allogeneic stem cell transplantation from an HLA-haploidentical related donor.

Haploidentical allogeneic stem cell transplantation (CST) has globally taken off in the past decade. It appears to be a valid alternative to other sources of stem cells; however, further research is necessary to validate the use of this approach in standard patient care. In the attempt to harmonize clinical practices between different French transplantation centers, the French Society of Bone Marrow Transplantation and Cell Therapies (SFGM-TC) set up its fourth annual series of workshops which brought together practitioners from all of its member centers. These workshops took place in September 2013 in Lille. This is part one of the recommendations regarding allogeneic stem cell transplantation from an HLA-haploidentical related donor.

Summary Background According to the National Institutes of Health classification of chronic graft-versus-host disease (cGVHD), skin ulcers after allogeneic haematopoietic stem-cell transplantation (HSCT) are recorded as having the maximal severity score but published data are scarce. Objectives To describe skin ulcers related to cGVHD with an emphasis on clinical findings, associated morbidity, management and evolution. Patients and methods A multicentre retrospective analysis was carried out of patients with a diagnosis of cGVHD skin ulcers. Results All 25 patients included in the study had sclerotic skin cGVHD and 21 had lichenoid skin lesions associated with the sclerotic skin lesions. Thirteen patients had severe cGVHD without considering the skin, because of the involvement of an extracutaneous organ by cGVHD. The median time from HSCT to the onset of ulcers was 44 months. In addition to scleroderma, initial skin lesions at the site of ulcers were bullous erosive lichen in 21 patients and bullous erosive morphoea in four patients. Fifteen patients had an inaugural oedema. Ulcers were mostly bilateral with a predilection for the lower limbs. They were frequently colonized but few infections occurred. Four patients died during a median follow-up period of 55 months. Conclusions Chronic graft-versus-host disease skin ulcers occur in patients with sclerodermatous skin cGVHD, are associated with severe cGVHD, often start with bullous lichenoid lesions or bullous morphoea and seem to cause more morbidity than mortality, given the low rate of mortality observed in our series of patients.

Waldenström’s macroglobulinemia is a rare B-cell malignancy defined by medullar infiltration by clonal lymphoplasmocytic cells and monoclonal IgM secretion. Treatment is reserved for symptomatic patients. The main first-line treatment strategies combine immunotherapy (principally the anti-CD20 monoclonal antibody rituximab) with chemotherapeutic agents, including alkylating agents, purine analogs and/or bortezomib. The overall response rate to these conventional treatments is between 70 and 90%, but a cure cannot be expected. For patients with relapsed or refractory disease, drugs that were not used for first-line treatment and other agents such as immunomodulators can be tried, but the response rate is generally lower and the responses are shorter lived. Recently, advances in our understanding of the biology of Waldenström’s macroglobulinemia have led to the development of new drugs targeting hyperactive pathways. This review focuses on current treatment options and on new therapeutic developments.

Introduction La maladie aigue du greffon contre l’hote post-transplantation hepatique (GVH-TH) est rare et grave. Nous en rapportons un cas simulant une toxidermie de type necrolyse epidermique toxique (NET). Observation Un homme de 66 ans, transplante a 2 reprises en 15 ans pour une cholangite sclerosante primitive, etait en deuxieme recidive avec evolution vers une insuffisance renale terminale chez un diabetique. Admis en reanimation pour une troisieme transplantation hepatique et une premiere transplantation renale (donneur unique) son traitement comprenait : mycophenolate mofetil (MMF), tacrolimus (cible 10 ng/mL) et prednisone (20 mg/j). Le patient developpait rapidement une peritonite biliaire necessitant plusieurs lignes d’antibiotherapie et une reprise chirurgicale avec jejunostomie d’elimination. A j28 post-TH, le patient revelait une pancytopenie avec moelle deserte au myelogramme. Une reduction des traitements immunosuppresseurs a j31 etait realisee en raison de l’infection non controlee ( Fig. 1 et 2 ). A j38, le patient developpait une eruption maculopapuleuse avec intervalles de peau saine, touchant le tronc et les membres sur 45 % de la surface cutanee, avec bulles et erosions (decollement de 5 %). Un signe de Nikolsky et une cheilite erosive sans atteinte des autres muqueuses etaient presents. Le patient ne presentait pas d’augmentation du volume des selles, ni modification notable du bilan hepatique. L’histologie cutanee montrait un decollement supra-basal avec des corps apoptotiques confluents des couches basales prenant l’aspect d’une NET ; l’immunofluorescence directe etait negative. L’hypothese d’une GVH-TH etait evoquee sur l’aspect cutanee et l’atteint hematologique, puis confirmee par la recherche d’un macrochimerisme sanguin qui etait positif a 7 % des cellules circulantes. L’enquete de pharmacovigilance montrait plusieurs medicaments faiblement imputables (scores Alden bas), renforcant cette hypothese. A j42, le patient recevait une corticotherapie a 2 mg/kg/j de prednisone. Avec un decollement progressant a 10 %, il decedait a j49 post-TH. Discussion La GVH-TH est rare (156 cas rapportes) et grave (mortalite de 73 %). Ses principales manifestations, observees entre la 3e et la 5e semaine post-TH, sont : une eruption cutanee (92 %), une pancytopenie (78 %) et une diarrhee (65 %). Le diagnostic doit etre confirme par un macrochimerisme superieur a 1 %. Une NET, principal diagnostic differentiel de cette presentation de GVH-TH, est ici peu probable du fait de l’absence de lesion muqueuse en dehors de la cheilite et des faibles scores Alden. Conclusion Ce cas illustre une GVH grave sur organe solide, pour laquelle l’atteinte cutanee est au premier plan a distinguer d’une NET par enquete de pharmacovigilance et recherche de macrochimerisme, afin d’adapter tres rapidement le traitement.

The two first authors contributed equally. Introduction There is currently little data on the outcome of AML in adolescents and young adults (AyAs) after allogeneic HSCT. In this retrospective study from the SFGM-TC registry, we analyzed the outcome of AML patients classified in 3 groups according to the age at transplantation: children ( Patients and Method This study included 2240 patients from 43 centers among France, Belgium, Switzerland, Lebanon and Algeria, of whom 481 children (21.5%), 545 AyAs (24.3%) and 1214 adults (54.2%). All patients received a first allogeneic HSCT for AML between 2005 and 2015. Five-years OS, NRM, GRFS and EFS and cumulative incidence of relapse were compared between the three groups of patients. Results The median follow-up of the study was 7 years (range, 4-9.6). According to the 2016 WHO classification, children had the highest rate (31.8%) of adverse risk disease, followed by AyAs (25.2%) and adults (21.3%) (p=0.0001). Extramedullary disease was observed in 42.8%, 24% and 21.4 % of children, AyAs and adults (p=0.0001). Among patients in complete remission (CR), younger age was associated more frequently with advanced disease (29.9% ≥ CR2 for children, 23% for AyAs and 18.2% for adults) (p=0.0001). Donors were matched siblings in 36.4% of children, 36.7% of AyAs and 40.3% of adults, and matched unrelated in 29.1%, 33.4% and 35.7% respectively. Children had more mismatched unrelated donors (31.6%), compared to AyAs (25.3%), and adults (19.5%) (p=0.0001). Stem cell source was different between the 3 groups (p=0.0001): bone marrow (BM) was the main source for children (60.9 % of grafts) followed by cord blood (CB) (28.9%), whereas peripheral blood stem cells (PBSC) was the main source for adults (60 %), followed by BM (29.7%) and CB (10.2%). AyAs were transplanted with BM in 44.4% of cases, PBSC in 40.4% or CB in 15.2%. The intensity of the conditioning was myeloablative (MAC) in 93% of children, 79% of AYAs and 77.7% of adults, while a reduced-intensity regimen was used in 4% of children, 12.3% of AyAs and 14.1 % of adults (p=0.0001). The 5y-overall survival (OS) was higher in children (64%), compared to AyAs (54%) and adults (52%) (p=0.001) (figure). One-year cumulative incidence (CI) of relapse was comparable in the 3 groups: 27 % for children, 33% for AYAs and 28% for adults (p=0.19) (figure). The 5y-CI of EFS and the 5y-CI of NRM were better for children (56%) compared to AyAs (49%) and adults (47%) (p=0.017) respectively and 11%, 18% and 27% for NRM in each group respectively (p=0.0001). Regarding causes of deaths, GvHD related mortality was significantly higher in AyAs and adults with 3.1%, 5.1% and 7.7% in each group respectively. There was no difference in the CI of grade II-IV acute GvHD at day +100 between the 3 groups: 37.7%, 35.8% and 35% respectively (p=0.58) while the one-year CI of chronic GvHD was higher in adults (37%) and AyAs (31%) compared to children (17%) (p=0.0001) (Figure). AyAs had a significantly lower 5y-OS and 5y-EFS than children and AyAs had a greater risk of NRM than children in this study. Moreover the GRFS is significantly better in children with 5y-survival 26% for children, 18% for AyAs and 17% for adults (p=0.011) (figure). In univariate and multivariate analysis, independent factors associated with OS were age, TBI, cytogenetics and status of disease, HLA matching and donor age. Conclusion AyAs patients seem to have greater risk of NRM and cGvHD after HSCT than children. This study suggests that AyAs should be treated more like children and that donor age and HLA compatibility should be considered in the treatment strategy. Figure. Figure. Disclosures Chalandon: Roche: Membership on an entity's Board of Directors or advisory committees, Other: Travel costs. Beguin:Kiadis Pharma: Consultancy. Peffault De Latour:Amgen Inc.: Research Funding; Novartis: Consultancy, Honoraria, Research Funding; Pfizer Inc.: Consultancy, Honoraria, Research Funding; Alexion Pharmaceuticals, Inc.: Consultancy, Honoraria, Research Funding.

The last three authors contributed equally to this work. Introduction: Allogeneic hematopoietic stem cell transplantation (HSCT) may improve long-term survival of patients with acute lymphoblastic leukemia (ALL) at high risk of relapse. However, ovarian failure is observed in 70 to 90% of patients who received myeloablative HSCT. Autotransplantation of cryopreserved ovarian cortex harvested before gonadotoxic treatments has been shown to re-establish the menstrual cycles and lead to the birth of healthy children (Donnez J. N Engl J Med, 2018). In patients treated for acute leukemia, concern has been expressed about the risk of leukemia recurrence after the ovarian autotransplantation due to the potential presence of residual leukemic cells in the ovarian tissue (Dolmans MM. Blood, 2010). To date, there were only few studies evaluating the presence of leukemic cells in cryopreserved ovarian tissue, and in most cases ovarian tissues were harvested at diagnosis of ALL or early after onset of chemotherapy. The present study prospectively investigated, in the context of fertility preservation, the presence of leukemic cells in cryopreserved ovarian samples harvested before allogeneic HSCT in patients in complete remission (CR) of ALL. Patients and Methods: From October 2015 to May 2018, all female patients with ALL who had a leukemia specific marker and underwent ovarian cryopreservation before allogeneic HSCT as part of preservation fertility program in 3 centers were included in the study. Consents were obtained from the guardians and/or age appropriate patients. The specific local ethical committees approved the study. Ovariectomy was performed after patients achieved CR, mostly in the weeks preceding HSCT. Ovarian cortex was separated into several fragments and cryopreserved as previously described (Poirot C. Human Reprod, 2002). When more than 14 cortical fragments were obtained, one was dedicated to molecular analysis, as well as the ovarian medulla. MRD quantification was performed by quantitative PCR of clonal rearrangements of immunoglobulin/T-cell receptor genes (Ig/TCR) or oncogenic fusion genes, according to EuroMRD and European Against Cancer (EAC) guidelines. MRD in ovarian samples were compared to MRD in bone marrow (BM) sample obtained at the same time point. Results: Fourteen patients were included in the study: 12 with B-cell precursor ALL, 1 with T-cell ALL and 1 with mixed phenotype acute leukemia. MRD marker was Ig/TCR rearrangement in 12 cases, M-BCR-ABL transcript in 1 case and genomic MLL-AF4 in 1 case. Median age at transplant was 18.2 years (range 1.1 - 35.2 years). Criteria for HSCT were poor early response to treatment (N=8), Philadelphia positive ALL (N=1), or previous relapse (N=5). With a median follow-up after HSCT of 8.1 months (range 0.8 - 29.8 months), all patients are disease-free. At the time of ovariectomy, 7/14 (50%) patients had undetectable MRD in ovarian samples, 6 had low positivity below 10-4 and one had positive MRD higher than 10-4. Unexpectedly of the 7 patients with positive ovarian MRD, 4 were undetectable in BM. One of the 7 patients with undetectable MRD in ovarian samples was positive in bone marrow. Concordant results were observed between the cortex and medulla samples in 10 of the 11 cases where both could be tested. Conclusions: To our knowledge, this series is the largest cohort evaluating MRD in ovarian samples from patients with ALL in complete remission after full chemotherapy regimen. We detected low levels of residual leukemic cells in ovarian tissues in half of the patients, some of them having no detectable MRD in BM at the time of ovariectomy, suggesting that leukemic cells could preferentially persist in ovary. Our results warrant further analyses of an extended cohort and longer post-transplant follow-up to better assess the potential presence of leukemic cells in ovarian samples and evaluate the impact of ovarian MRD status on post HSCT relapse. Still, autotransplantation of cryopreserved ovarian cortex could be discussed after allogeneic HSCT in patients with undetectable ovarian MRD. Table 1. MRD evaluation in bone marrow and ovarian samples. BM, bone marrow; BCP-ALL, B-cell precursor ALL; Ph-positive ALL, ALL with Philadelphia chromosome; NA: not available. Undetectable MRD means negative result obtained with a sensitivity of 10-4 or 10-5. BCR-ABL1 MRD results are expressed as the BCR-ABL1/ABL1 transcripts ratio. Disclosures No relevant conflicts of interest to declare.

Prognosis of graft failure patients is dismal, and another transplant is the sole option for long-term survival. Currently, there is no consensus concerning the best option for treating patients undergoing primary graft failure and finding a new donor within an acceptable delay is challenging. In the last years, haploidentical transplants with post-transplant cyclophosphamide (PT-Cy) have shown acceptable results in the treatment of many hematological diseases, including some cases of graft failure. To address the interest of haploidentical transplants as a salvage option in this context, we retrospectively collected and analyzed data from 26 primary graft failure (PGF) patients transplanted between 2011 and 2017 in 15 centers belonging to the Francophone Society for Bone Marrow Transplantation and Cellular Therapy (SFGM-TC). Inclusion criteria were the occurrence of PGF defined as non-achievement of a minimum absolute neutrophil count of 500/μL without evidence of disease relapse at D+28 after transplantation and the use of a haploidentical transplantation with PT-Cy as graft-versus-host-disease (GvHD) prophylaxis. Continuous variables are presented as medians and inter-quartile range. They were compared between groups using the Wilcoxon rank sum. Categorical variables are presented with counts and percentages and were compared using the Fisher exact test. All tests were 2-sided, and a p-value below 0.05 was considered to be significant. Analyses were performed using the R statistical platform (version 3.4.1). This study was performed according to the Declaration of Helsinki and was approved by the SFGM-TC scientific council. Nineteen patients had a diagnosis of myeloid malignancy (8 acute myeloid leukemias, 4 myelodysplastic syndromes, 4 myeloproliferative neoplasms, 1 unclassified myeloid disorder), 3 had a lymphoid neoplasm, and 4 had a bone marrow failure syndrome (2 acquired and 2 congenital). Twenty-four patients had previously received an allogeneic transplantation, and 2 had already failed two previous allogeneic transplants. Male/female ratio was 2.25. Median age at haploidentical transplant was 42 years (2-58). Fifteen patients received peripheral blood as stem cell source, and 11 received bone marrow. Eleven transplants were female to male. Twelve patients received an ABO-matched graft, 6 had a major ABO-incompatibility, 7 a minor incompatibility and one missing data. The median number of infused CD34+ cells was 5.2 x106/kg (1.2 - 12.5). There was no ex-vivomanipulation of cells. CMV matching was available for 22 transplantations, of which 6 were high-risk (seropositive recipient with a seronegative donor). Fludarabine-based reduced intensity conditioning was used in all but one patient who received clofarabine + 4Gy TBI. Twenty patients received TBI 2Gy. Three patients received ATG. Fourteen patients received the Baltimore regimen (53%). The median delay between the previous and the salvage transplantation was 77 days (39-1161). All patients received PT-Cy associated with cyclosporine, and 24 patients also received MMF for GvHD prophylaxis. Median follow up was 487 (16-2010) days. The cumulative incidence (CI) of neutrophil recovery at day 30 was 81%, and the median time to neutrophil engraftment was 19 (13-34) days. Four patients (15%) presented primary graft failure and died within a median time of 5 (3-8) weeks after transplantation of infectious complications. Cumulative incidence of grade II-IV aGvHD at day-100 was 13%, and 1-year CI of cGvHD was 32%. One-year CI of relapse was 16%. Overall survival was 58% at 1 year (Figure 1; confidence interval: 39-85). Among the 22 patients who engrafted, 6 patients died. HSCT complications accounted for 80% of the causes of deaths (4 multiorgan failure, 1 GvHD, 1 interstitial pneumonitis, 1 bacterial infection, 1 post-transplant lymphoproliferative disorder). To the best of our knowledge, this is the first cohort describing the outcomes of haploidentical transplants with PT-Cy rescuing patients with primary graft failure. Our cohort presents promising outcomes in a particularly challenging situation, suggesting that haploidentical transplants with PT-Cy might appear as a valid salvage strategy for patients with PGF. Prospective well-designed trials are urgently needed before the inclusion of Haplo-PT-Cy in the treatment strategy of patients with PGF. Figure 1. Figure 1. Disclosures Mohty: MaaT Pharma: Consultancy, Honoraria. Peffault De Latour:Pfizer Inc.: Consultancy, Honoraria, Research Funding; Alexion Pharmaceuticals, Inc.: Consultancy, Honoraria, Research Funding; Amgen Inc.: Research Funding; Novartis: Consultancy, Honoraria, Research Funding.

Introduction. Chronic lymphocytic leukemia (CLL) has typically an indolent course but can undergo transformation into a more aggressive lymphoma (mainly of diffuse large B-cell lymphoma histology) that is called Richter's syndrome. While the advent of novel therapies targeting the BCR signaling or the BCL-2 protein is transforming the management of patients with CLL, these drugs failed to prevent the risk of RS that is estimated to be 0.5-1% per year. RS is associated with a very poor outcome and is thus becoming the main obstacle to long term CLL cure. Allogeneic stem-cells transplantation (allo-SCT) has been recommended as the treatment of choice in eligible patients with clonally related RS (Rossi Blood 2018) but previous experience is still limited to less than 50 cases. We here aimed to investigate the safety and efficacy of allo-SCT for patients with RS. Methods. We report on a retrospective study of consecutive patients with RS who underwent allo-HSCT between 2005 and 2016 in 15 French and Belgian centers from the Société Francophone de Greffe de Moelle et de Transplantation Cellulaire (SFGM-TC). Inclusion criteria were: age >18, confirmed RS diagnosis, allo-HCST from either sibling or unrelated donor. Data quality was ensured using computerized discrepancy errors and on-site data verification. Results. A total of 24 patients (median age=59 years [19-69], M/F= 18/6) were included in the present study. Median time from CLL to RS diagnosis was 59 months [0-198]. The histology was DLBCL (86%) or HL (14%). The patients received a median of 1 [0-4] therapeutic line for CLL and 1 [0-3] for RS. Nine (38%) patients underwent auto-SCT prior to allo-HCT. At allo-HCT, 17 (71%) of patients were in complete and 7 (29%) in partial response. Most patients received reduced intensity conditioning (RIC) regimen (n= 18, 75%) and peripheral blood (76%) as source of stem-cells. Two (8%) patients received bone marrow stem cells and 4 (16%) cord blood stem cells. Donors were related (n=8) or unrelated (mismatched, n=8; matched, n=5; missing, n=3). A total of 15 patients (63%) received total body irradiation (TBI) within the conditioning. With a median follow-up of 27 months, 2-year OS was 44% (figure 1). The 100-day non-relapse mortality was 25%. Cause of death was relapse (n=3), treatment toxicity (n=10; GVHd, n=3; infectious complications, n=6; pulmonary toxicity, n=1), infection complications (n=1) and cerebral stroke (n=1). 2-year OS was significantly shorter for older patients (20% if >59 years old vs 64% if ≤59,P = 0.031). The 2-year OS was influenced by presence of cGVHD (73% vs 25%,P = 0.006). Neither donor type, prior auto-SCT, disease status prior to allo-HCT, use of antilymphocyte serum infusions nor the regimen conditioning significantly impact OS. Conclusion. Our study suggests that allo-HCT is a strategy achieving prolonged survival but should be performed in young patients to limit the risk of NRM. The favorable impact of GVHd suggests an anti-RS allogenic effect. Disclosures Guieze: abbvie: Honoraria; janssen: Honoraria; gilead: Honoraria.

Graft-versus-T-cell lymphoma effect: a sustained CR after tapering immunosuppressive drugs in a patient with angioimmunoblastic T-cell lymphoma in relapse after allogeneic transplantation

Waldenstrom's macroglobulinemia is a rare chronic lymphoproliferative disorder. Treatment is usually based on nucleoside analogues, alkylators, bortezomib and monoclonal antibodies, alone or in combination. Fludarabine is a fluorinated purine analogue effective in chronic lymphoproliferative disorders. In Waldenstrom's macroglobulinemia, fludarabine was first studied in patients with relapsed or refractory disease after alkylator therapy, yielding an overall response rate of 30%. In the late 1990 s, fludarabine started to be used as a first-line treatment monotherapy yielding response rates between 36 and 94%. A recent Phase III trial showed that fludarabine monotherapy was more effective than chlorambucil in terms of progression-free survival, duration of response and overall survival. Fludarabine has also been studied in combination with rituximab and/or alkylating agents, leading to better-quality and longer lasting responses. Hematological toxicity is a major concern; however, restricting first-line use of fludarabine in patients who do not qualify for autologous stem cell transplantation, require rapid disease control or have factors of poor prognosis.

Waldenström macroglobulinemia is a rare chronic lymphoproliferative disorder. Treatments are currently reserved for symptomatic patients and usually consist of nucleoside analogues (NAs), alkylating agents, bortezomib, and monoclonal antibodies, alone or in combination. Fludarabine and 2-chlorodeoxyadenosine (2-CdA) have been studied in first-line treatment of Waldenström macroglobulinemia (WM) since the end of the 1990s. In monotherapy, response rates vary between 36% and 94%. In a phase III trial, fludarabine in monotherapy was more efficient than chlorambucil for progression-free survival (PFS) (37.8 vs. 27.1 months), duration of response (DOR) (38.5 vs. 21.3 months) and overall survival (OS) (median not reached vs. 69.8 months), but the overall response rate (ORR) was similar (45.6% and 35.9%). NAs have been studied in combination with rituximab and/or alkylating agents for increasing the quality and duration of the response. Hematologic toxicities are a major concern, limiting the indication for NAs in first-line treatment to patients who are not candidates for autologous stem cell transplantation, those in need of rapid control of the disease, or those with poor prognostic factors.

Haploidentical hematopoietic stem cell transplantation (HSCT) is being increasingly used due to improvement of the transplantation procedures allowing a reduction of graft-versus-host-disease (GVHD) and of transplant-related mortality (TRM). Such improvements have been particularly observed after administration of T-replete HSCT graft associated to an in vivo T cell depletion by the administration of high-doses of cyclophosphamide (HD-Cy) after transplantation. Here, we have analyzed the results of haplo-identical T replete HSC transplants, in particular, when performed with post-transplant HD-Cy in order to provide recommendations for the clinical practice. Criteria of choice for a haploidentical donor by priority order are absence of donor-specific antibodies (DSA) and to prioritize: CMV seronegative recipient/donor couples, ABO matching in case of deserythrocytation, male donor for a male recipient, the youngest donor. There is no clear argument in favor of the use of bone marrow versus peripheral blood stem cells (PBSC) after non myeloablative conditioning regimen, while after ablative conditioning PBSC seem to be associated with higher risks of GVHD without obvious impact on survival. Results of haploidentical HSCT, confirmed by several groups, are interesting in lymphomas (in particular Hodgkin disease) and for acute leukemia. Outcomes of patients rely on age, disease status at transplant and conditioning intensity. At equivalent disease risk, results of haploidentical HSCT seem comparable to those of HLA matched HSCT, raising the question of the classification of such transplants as alternatives. In all cases, we recommend to include patients in prospective clinical trials.

International audience; BACKGROUND: The impact of antithymocyte globulin (ATG) in the setting of a myeloablative conditioning transplantation remains controversial, especially when using bone marrow (BM) as the stem cell source. METHODS: We therefore conducted a retrospective analysis to investigate the impact of ATG in patients with acute myeloid leukemia or myelodysplastic syndrome receiving myeloablative conditioning followed by a matched 10 of 10 unrelated donor transplant from BM or peripheral blood stem cells (PBSCs). Our study included 356 patients conditioned with cyclophosphamide associated with fractionated total body irradiation or busulfan. RESULTS: Median follow-up was 17.6 months (range, 0-156). The ATG and PBSCs were the only variables that independently decreased the cumulative incidence (CI) of chronic graft-versus-host disease (GvHD) (hazards ratio [HR], 0.4; 95% CI, 0.21-0.73; P \textless 0.01; and HR, 0.53; 95% CI, 0.30-0.90; P = 0.02, respectively). The ATG had no impact on overall survival, disease-free survival, relapse, and nonrelapse mortality. In the PBSC group (n = 139), ATG was associated with a lower CI of both grades III to IV acute GvHD (HR, 0.17; 95% CI, 0.03-0.91; P = 0.04), chronic GvHD (HR, 0.31; 95% CI, 0.11-0.87; P = 0.03), and GvHD-free/relapse-free survival (HR, 0.48; 95% CI, 0.29-0.80; P \textless 0.01), whereas these correlations were not significant in the group of patients (n = 217) receiving BM (HR, 0.36; 95% CI, 0.11-1.93; P = 0.06 for grade III-IV acute GvHD; HR, 0.49; 95% CI, 0.22-1.06; P = 0.08 for chronic GvHD; and HR, 0.69; 95% CI, 0.46-1.01; P = 0.06 for GvHD-free/relapse-free survival). CONCLUSIONS: Although our results confirm the recommendation for ATG to be added after PBSC transplantation, no obvious benefit was identified using this approach in the setting of BM transplantation. Only prospective studies may yield definitive answers to this question

Background Neutrophils are key effectors against the widely distributed mold Aspergillus fumigatus , which is a major threat for immunocompromised patients, including allogeneic hematopoietic stem cell transplant (HSCT) recipients. Yet little is known about neutrophil activity over time after cell transplantation, especially regarding A fumigatus . Objective We aimed at assessing the activity of neutrophils on A fumigatus in allogeneic HSCT recipients at different posttransplantation time points. Methods We performed a longitudinal study involving 37 patients undergoing HSCT, drawing blood samples at engraftment and at 2, 6, and 10 months after the HSCT. Posttransplantation neutrophil activity in the recipients was compared with that of the respective donors. Neutrophil/ A fumigatus coculture, flow cytometry, and video microscopy were used to assess neutrophil inhibition of fungal growth, cell/fungus interactions, reactive oxygen species production, major surface molecule expression, and neutrophil extracellular trap (NET) formation. Results The ability of neutrophils to interfere with Aspergillus species hyphal growth was impaired after HSCT. The administration of calcineurin inhibitors appeared to play an important role in this impairment. We also observed that post-HSCT neutrophils produced less NETs, which was correlated with increased fungal growth. Tapering immunosuppression led to the recuperation of inhibition capacity 10 months after HSCT. Conclusion In HSCT recipients neutrophil-driven innate immunity to fungi is altered in the early posttransplantation period (between recovery from neutropenia and up to 6 months). This alteration is at least partly related to administration of calcineurin inhibitors and diminution of NETs production.

Human NK cells comprise two main subsets, CD56(bright) and CD56(dim) cells, which differ in function, phenotype, and tissue localization. To further dissect the differentiation from CD56(bright) to CD56(dim) cells, we performed ex vivo and in vitro experiments demonstrating that the CD56(bright)CD16(+) cells are an intermediate stage of NK cell maturation. We observed that the maximal frequency of the CD56(bright)CD16(+) subset among NK cells, following unrelated cord blood transplantation, occurs later than this of the CD56(bright)CD16(-) subset. We next performed an extensive phenotypic and functional analysis of CD56(bright)CD16(+) cells in healthy donors, which displayed a phenotypic intermediary profile between CD56(bright)CD16(-) and CD56(dim)CD16(+) NK cells. We also demonstrated that CD56(bright)CD16(+) NK cells were fully able to kill target cells, both by Ab-dependent cell cytotoxicity (ADCC) and direct lysis, as compared with CD56(bright)CD16(-) cells. Importantly, in vitro differentiation experiments revealed that autologous T cells specifically encourage the differentiation from CD56(bright)CD16(-) to CD56(bright)CD16(+) cells. Finally, further investigations performed in elderly patients clearly showed that both CD56(bright)CD16(+) and CD56(dim)CD16(+) mature subsets were substantially increased in older individuals, whereas the CD56(bright)CD16(-) precursor subset was decreased. Altogether, these data provide evidence that the CD56(bright)CD16(+) NK cell subset is a functional intermediate between the CD56(bright) and CD56(dim) cells and is generated in the presence of autologous T CD3(+) cells.

BACKGROUND: Allogeneic donor natural killer (NK)-cell infusion (NK-DLI) is a promising immunotherapy for patients with hematologic disorders. CASE REPORT: This report describes the case of a patient who received a single haploidentical NK-DLI for a relapse of acute myeloid leukemia (AML) after haploidentical hematopoietic stem cell transplantation. He underwent a cytoreductive, immunosuppressive regimen before NK-DLI and received high-dose interleukin-2 in vivo for 8 weeks afterward. RESULTS: No major adverse effect was observed. Prospective phenotypic and functional studies of the NK cells showed major expansion of infused NK cells and, more importantly, of the alloreactive KIR2DL1+KIR2DL2/DL3–NKG2A– subset, which reached 117 × 106 cells/L on Day +14 after NK-DLI, the greatest expansion of infused alloreactive NK cells reported so far. Infused NK cells conserved their lytic capacities against K562 target cells and primary AML-mismatched blasts. CONCLUSION: We review the literature to clarify these data and to detail the indications for allogeneic NK-DLI, the criteria for determining the most suitable donor, the types of conditioning regimens, and the procedures for selecting and activating NK cells.

Invariant natural killer T (iNKT) cells have a pivotal role in immune regulation, tumor surveillance, and the induction of allograft tolerance. In this report, we analyze the recovery of iNKT cells after unrelated cord blood transplantation (UCBT) of adult patients with high-risk acute myeloid leukemia. We found that iNKT cells were reconstituted within 1 month after UCBT, at the same time as NK cells and before conventional T cells. These iNKT cells displayed a unique primed/central memory CD4(+)CD45RO(+)CCR7(+)CD62L(+) phenotype soon after the transplant. Interestingly, the functional competence of these cells was poor, except for their high GM-CSF production capacity. However, this post-graft functionally immature state was transient and all of the patients tested had fully functional iNKT cells 3 to 6 months post-UCBT and high cytolytic capacity for destroying primary CD1d(+) myeloid blast cells. Our results raise the possibility that iNKT cells might play a key role in graft-versus-leukemia activity after UCBT.

Ruxolitinib may induce pulmonary alveolar proteinosis and favour respiratory non-tuberculous mycobacterial infections http://ow.ly/bTXn30jogC8

Promising results of umbilical cord blood transplantation (UCBT) from unrelated donors have been reported in patients with hematologic disorders. These transplants, having potential to trigger beneficial donor-versus-recipient natural killer (NK) cell-mediated alloreaction, we have conducted the first extensive analysis of the phenotypic and functional properties of NK cells after UCBT. NK cells from 25 patients with high-risk hematologic malignancies were compared with cells derived from both healthy adult and CB cells. We found that following UCBT, NK cells display not only some phenotypic features associated with maturity but also unique characteristics that make them fully functional against leukemic blasts. We propose that this full functionality of alloreactive donor-derived NK may drive graft-versus-leukemia reactions after UCBT.

Natural killer (NK) cells generated after haploidentical hematopoietic SCT in patients with AML are characterized by specific phenotypic features and impaired functioning that may affect transplantation outcome. We show that IFN-gamma produced by immature CD56(bright) NK cells upregulates cell surface expression of HLA-E on AML blasts and that this upregulation protects leukemic cells from NK-mediated cell lysis through the mediation of CD94/NKG2A, an inhibitory receptor overexpressed on NK cells after haploidentical SCT. Two years after transplantation, however, maturing NK cells were functionally active, as evidenced by high cytotoxicity and poor IFN-gamma production. This implies that maturation of NK cells is the key to improved immune responses and transplantation outcome.

Recovery of human cytomegalovirus (HCMV)-specific T immunity is critical for protection against HCMV disease in the early phase after allogeneic stem cell transplantation (SCT). Using an enzyme-linked immunospot assay with overlapping 15-mer peptides spanning pp65 and immediate-early 1 HCMV proteins, we investigated which HCMV-specific CD8 + gamma interferon-positive (IFN-γ + ) T-cell responses against pp65 and IE-1 were associated with control of HCMV replication in 48 recipients of unmanipulated HLA-matched allografts at 3 months (M3) and 6 months (M6) after SCT and in 23 donors. At M3 after SCT, the magnitude of the pp65-specific IFN-γ-producing CD8 + T-cell response was greater in recipients than in donors, regardless of HCMV status. In contrast, expansion of IE-1-specific CD8 + T cells at M3 was associated with protection against HCMV, and no patient with this expansion had HCMV replication at M3. At M6, the number of HCMV-specific CD8 + T cells against both pp65 and IE-1 had expanded in all recipients, regardless of their previous levels of HCMV replication. The recipients' HCMV-specific CD8 + T cells already detectable in related donors were predominantly targeting pp65. In contrast, in 40% of the cases, the HCMV-specific CD8 + T cells in recipients involved new CD8 + T-cell specificities undetectable in their related donors and preferentially targeting IE-1. Taken together, these results showed that the delay in reconstituting IE-1-specific CD8 + T cells is correlated with the lack of protection against HCMV in the first 3 months after SCT. They also show that IE-1 is a major antigenic determinant of the early restoration of protective immunity to HCMV after SCT.

We previously demonstrated that natural killer (NK) cells generated after haploidentical stem-cell transplantation (SCT) are blocked at an immature state characterized by phenotypic features and impaired functioning and that this may affect transplantation outcome. We hypothesize that the absence of mature donor T cells in the graft may affect NK cell differentiation. NK cells from 21 transplant recipients who underwent either partial (pTCD; n=11) or extensive (eTCD; n=10) T-cell depletion were compared with NK cells from their healthy donors. We report that despite the strong graft-versus-host disease (GvHD) reaction, pTCD patients, with T cells present during SCT, had a better clinical outcome than patients with eTCD transplants. In addition, the frequency of CD3- CD56(bright) and NKG2A+ NK cells was much lower in pTCD than in eTCD patients after transplantation, and the level of cytotoxicity against primary haplo-mismatched blasts was significantly more pronounced after pTCD than eTCD transplants. These finding strongly suggest that mature donor T cells in the graft may play a key role in NK cell differentiation in vivo, after haploidentical SCT.

Allogeneic stem cell transplantation (allo-SCT) for de novo Ph+ AML: a study from the French Society of Bone Marrow Transplantation and Cell Therapy

Background The prognosis of myelodysplastic syndromes (MDS) after allogeneic stem cell transplantation is critically determined by cytogenetic abnormalities, as previously defined by International Prognostic Scoring System (IPSS) cytogenetics. It has been shown that a new cytogenetic classification, included in the IPSS-R (cytogenetic-IPSS-R [C-IPSS-R]), can better predict the outcome of untreated MDS patients. Methods In this study, we assessed the impact of the IPSS-R cytogenetic score (C-IPSS-R) on the outcome of 367 MDS patients transplanted from HLA-identical siblings or HLA allele-matched unrelated donors. Results According to the C-IPSS-R, 178 patients (48%) fell in the good risk, 102 (28%) in the intermediate risk, 77 (21%) in the poor risk, and 10 (3%) in the very poor risk group. In multivariate analysis, after a median follow-up of 4 years, the poor and very poor-risk categories correlated with shorter overall survival (OS) (4-year OS, 32%; hazard ratio [HR], 1.59; P = 0.009 and OS, 10%; HR, 3.18; P = 0.002, respectively) and higher cumulative incidence of relapse (CIR) (CIR, 52%; HR, 1.82; P = 0.004 and CIR, 60%; HR, 2.44; P = 0.060, respectively). Conclusions Overall, the C-IPSS-R changed the IPSS cytogenetic risk only in 8% of cases but identified a new risk group, the very poor C-IPSS-R category, with dismal outcome after allogeneic stem cell transplantation (10% 4-year OS, 60% 4-year CIR). Posttransplantation maintenance therapy should be investigated in prospective trials for patients with high-risk C-IPSS-R karyotypes.

Thrombotic microangiopathy (TMA) occurring after allogeneic hematopoietic stem cell transplantation (HSCT) has a devastating prognosis. Response rates to current therapies (mainly plasma exchange) are unsatisfactory. Thrombotic microangiopathy after allogeneic HSCT shares similarities with atypical hemolytic uremic syndrome (aHUS) in the underlying pathomechanisms. Eculizumab has been associated with impressive results in aHUS.We retrospectively analyzed 12 patients who received Eculizumab in France between 2010 and 2013 for severe post-HSCT TMA.All 12 patients had severe TMA with neurological and/or renal involvement. Fifty-eight percent were refractory to first-line plasma exchange. At the time of TMA diagnosis, infections were present in 50% of the patients and acute graft-versus-host disease in 33%. Patients were treated with Eculizumab according to the aHUS therapeutic scheme. With a median follow-up of 14 months, hematological response and overall survival were 50% and 33%, respectively. Active acute graft-versus-host disease at TMA diagnosis was the only factor associated with worse overall survival (P = 0.009).Response rate and overall survival after Eculizumab in our cohort compare favorably with previously published data in TMA after allogeneic HSCT. Prospective trials are warranted to confirm these results. Early initiation of Eculizumab may have a favorable effect on long-term renal function and further contribute to the prolongation of survival.

Natural killer (NK) cell alloreactivity is reported to mediate strong GvL (graft versus leukemia) effect in patients after haploidentical stem-cell transplantation (SCT) for acute myeloid leukemia (AML). Because subsequent immune reconstitution remains a major concern, we studied NK-cell recovery in 10 patients with AML who received haplomismatched SC transplants, among whom no GvL effect was observed, despite the mismatched immunoglobulin-like receptor (KIR) ligand in the GvH direction for 8 of 10 patients. NK cells generated after SCT exhibited an immature phenotype: the cytotoxic CD3-CD56dim subset was small, expression of KIRs and NKp30 was reduced, while CD94/NKG2A expression was increased. This phenotype was associated to in vitro lower levels of cytotoxicity against a K562 cell line and against primary mismatched AML blasts than donor samples. This impaired lysis was correlated with CD94/NKG2A expression in NK cells. Blockading CD94/NKG2A restored lysis against the AML blasts, which all expressed HLA-E, the ligand for CD94/NKG2A. Our present study allows a better understanding of the NK-cell differentiation after SCT. These results revealed that the NK cells generated after haplomismatched SCT are blocked at an immature state characterized by specific phenotypic features and impaired functioning, having potential impact for immune responsiveness and transplantation outcome.

While the t(8;21) translocation is one of the most recurrent chromosomal abnormalities in acute myeloid leukemia, prognostic studies have been hampered by the relatively few number of patients reported. We thus performed a large retrospective study in 161 adults and children with t(8;21) acute myeloid leukemia, all prospectively enrolled in 6 different trials conducted in France between 1987 and 1998 (median follow-up 4.9 years). Prognostic studies were performed in the 154 patients who achieved a complete remission. Individual data were registered, including sex, age, blood and marrow counts, extramedullary disease, and cytogenetics. The value of allogeneic stem cell transplantation versus chemotherapy as postremission therapy was evaluated according to the intent-to-treat principle. Estimated 5-year disease-free survival (DFS) and overall survival were 52% and 59%, respectively. Outcome was not significantly better in patients from the stem cell transplantation group (estimated 5-year DFS and survival, 56% vs 52% and 67% vs 57%; P =.55 and.64, respectively). White blood cell count (WBC) was the only identified prognostic factor. To further take into account the spontaneous differentiation potential of the leukemic clone, a WBC index was derived as the product of WBC by the ratio of marrow blast. This WBC index was a more powerful factor than the original WBC, allowing us to distinguish 3 subgroups of patients with different outcomes (low index, < 2.5; intermediate index, 2.5-20; high index, 20 or more). In multivariate analysis, the WBC index was the only prognostic factor for DFS (P =.003), complete remission duration (P =.002), and overall survival (P =.04).

T-prolymphocytic leukemia (T-PLL), a rare aggressive mature T-cell disorder, remains frequently resistant to conventional chemotherapy. Studies have suggested that allogeneic hematopoietic stem cell transplantation (HSCT) might possibly serve to consolidate the response to initial chemotherapy. The current report summarizes the outcome of 27 T-PLL cases identified in the registry in French Society for stem cell transplantation (SFGM-TC). Prior to HSCT, 14 patients were in complete remission (CR), 10 in partial response, three refractory, or in progression. Following HSCT, 21 patients achieved CR as best response. With a median follow-up for surviving patients of 33 (range, 6-103) months, 10 patients are still alive in continuous CR. Overall survival and progression-free survival estimates at 3 yr were 36% (95% CI: 17-54%) and 26% (95% CI: 14-45%), respectively. The relapse incidence after HSCT was 47% occurring at a median of 11.7 (range, 2-24) months. Overall cumulative incidence of transplant-related mortality was 31% at 3 yr. These results suggest that HSCT may allow long-term survival in patients with T-PLL following induction treatment; however, it is associated with a significant rate of toxicity.

Detection of increasing mixed chimerism (IMC) using standard PCR correlates with relapse after allo-SCT for acute leukemias (ALs). Quantitative real-time PCR of insertion/deletion polymorphism (indel qrtPCR) is a much more sensitive method, which can be performed on peripheral blood. We studied the significance of low increases of recipient cells (0.1%) detected by indel qrtPCR in a cohort of 89 transplants. We did not observe relapse among the 32 patients with no IMC. Fifty-seven patients presented a first IMC, which was followed by four different scenarios: a decreasing MC (26 cases, no relapse), a stable MC (1 case, 1 relapse), a second IMC (24 cases, 15 relapse) or no control of chimerism (6 cases, 5 relapses). In multivariate analysis, detection of two successive IMCs was strongly associated with relapse (hazard ratio (HR): 9.4, 95% confidence interval (CI): 3.8-23; P0.0001). Among the 57 patients who presented at least one IMC, 27 underwent immunomodulation (tapering of immunosuppression or donor lymphocyte injection), leading to a 1-year relapse rate of 15.7% vs 57.6% in the 30 other patients (P=0.0007). Altogether, these results indicate that chimerism analysis using indel qrtPCR in peripheral blood is a useful tool for detection of relapse in patients transplanted for AL.