Francesco Frassoni

Risk assessment for patients with chronic myeloid leukaemia before allogeneic blood or marrow transplantation

Summary Background Transplantation of blood or bone-marrow stem cells is the treatment of choice for selected patients with chronic myeloid leukaemia (CML). Transplantation is used with increasing frequency and success, but remains associated with substantial risks of morbidity and mortality. Other treatments with satisfactory short-term outcome are available. For appropriate counselling of patients, a rapid and simple way to assess risk is needed. Methods Data from 3142 patients (1873 [60%] male, 1269 [40%] female; mean age 34 years, range Findings At the time of analysis, 1922 (61%) of the 3142 patients were alive—1567 (65%) of those with HLA-identical sibling donors and 417 (57%) of those with unrelated donors. 1682 (54%) were alive without relapse. 1220 (39%) patients had died, 1013 (83%) of transplant-related causes, 207 (17%) of relapse. 447 (14%) patients had relapsed. The final scoring system was highly predictive for leukaemia-free survival, survival and transplant-related mortality. Survival at 5 years was 72%, 70%, 62%, 48%, 40%, 18%, and 22% for patients with scores 0, 1, 2, 3, 4, 5, and 6, respectively. Risk of transplant-related mortality was 20%, 23%, 31%, 46%, 51%, 71%, and 73%. Data showed the same trends for HLA—identical sibling transplants and unrelated transplants for transplants done in 1989–93 and 1994–96. Interpretation Pretransplant risk factors are cumulative for individual patients with CML having blood or marrow transplantation. A simple system based on five main factors gives adequate risk assessment for counselling of patients and taking decisions.

Mesenchymal stem cells effectively modulate pathogenic immune response in experimental autoimmune encephalomyelitis

To evaluate the ability of mesenchymal stem cells (MSCs), a subset of adult stem cells from bone marrow, to cure experimental autoimmune encephalomyelitis.

Allogeneic and autologous transplantation for haematological diseases, solid tumours and immune disorders: definitions and current practice in Europe

The Accreditation Subcommittee of the EBMT regularly publishes special reports on current practice of haemopoietic stem cell transplantation for haematological diseases, solid tumours and immune disorders in Europe. Major changes have occurred since the first report was published in 1996. Haemopoietic stem cell transplantation today includes grafting with allogeneic and autologous stem cells derived from bone marrow, peripheral blood and cord blood. With reduced intensity conditioning regimens in allogeneic transplantation, the age limit has increased, permitting the inclusion of older patients. New indications have emerged such as autoimmune disorders and AL amyloidosis for autologous, and solid tumours for allogeneic transplants. The introduction of alternative therapies has challenged well-established indications such as imatinib for chronic myeloid leukaemia. An updated report with revised tables and operating definitions is presented here.

A survey of fully haploidentical hematopoietic stem cell transplantation in adults with high-risk acute leukemia : a risk factor analysis of outcomes for patients in remission at transplantation

Haploidentical hematopoietic stem cell transplantation (haplo-HSCT) is an alternative treatment to patients with high-risk acute leukemia lacking a human leukocyte antigen-matched donor. We analyzed 173 adults with acute myeloid leukemia (AML) and 93 with acute lymphoblastic leukemia (ALL) who received a haplo-HSCT in Europe. All grafts were T cell-depleted peripheral blood progenitor cells from a direct family or other related donor. At transplantation, there were 25 patients with AML in CR1 (complete remission 1), 61 in more than or equal to CR2, and 87 in nonremission, and 24 with ALL in CR1, 37 in more than or equal to CR2, and 32 in nonremission. Median follow-up was 47 months in AML and 29 months in the ALL groups. Engraftment was observed in 91% of the patients. Leukemia-free survival at 2 years was 48% plus or minus 10%, 21% plus or minus 5%, and 1% for patients with AML undergoing transplantation in CR1, more than or equal to CR2, and nonremission, and 13% plus or minus 7%, 30% plus or minus 8%, and 7% plus or minus 5% in ALL patients, respectively. In conclusion, haplo-HSCT can be an alternative option for the treatment of high-risk acute leukemia patients in remission, lacking a human leukocyte antigen-matched donor.

Direct intrabone transplant of unrelated cord-blood cells in acute leukaemia: a phase I/II study

BACKGROUND Cord-blood transplants are associated with delayed or failed engraftment in about 20% of adult patients. The aim of this phase I/II study was to establish the safety and efficacy of a new administration route (intrabone) for cord-blood cells, measured by the donor-derived neutrophil and platelet engraftment. METHODS Adult patients with acute leukaemia, for whom an unrelated stem-cell transplantation was indicated and no suitable unrelated human leucocyte antigen (HLA)-matched donor had been identified, were included in the study and underwent a cord-blood transplant in San Martino Hospital, Genoa, Italy. Eight patients were in first complete remission, ten in second complete remission, and 14 had advanced-stage, refractory disease. HLA matching was 5/6, 4/6, and 3/6 for 9, 22, and one patient, respectively. Cord-blood cells were concentrated in four 5-mL syringes, and were infused in the superior-posterior iliac crest under rapid general anaesthesia. Median transplanted cell dose was 2.6 x 10(7)/kg (range 1.4-4.2). The primary endpoint was the probability of neutrophil and platelet recovery after intrabone cord-blood transplantantion. Secondary endpoints included the incidence of acute graft-versus-host disease, relapse, and overall survival. This trial is registered on the ClinicalTrials.gov website, number NCT 00696046. FINDINGS Between March 31, 2006, and Jan 25, 2008, 32 consecutive patients with acute myeloid leukaemia (n=20) or acute lymphoblastic leukaemia (n=12) underwent a cord-blood transplant (median age 36 years [range 18-66]). No complications occurred during or after the intrabone infusion of cells. Four patients with advanced-stage disease died within 12 days of the procedure. Median time to recovery of neutrophils in 28 patients (>/=0.5 x 10(9)/L) was 23 days (range 14-44) and median time to recovery of platelets in 27 patients (>/=20 x 10(9)/L) was 36 days (range 16-64). All patients were fully chimeric from 30 days after transplantation to the last follow-up visit, suggesting an early complete donor engraftment. No patient developed grade III-IV acute graft-versus-host disease. Causes of death were transplant related (n=5), infection (n=7), and relapse (n=4). 16 patients were alive and in haematological remission at a median follow-up of 13 months (range 3-23). INTERPRETATION Our preliminary data suggest that direct intrabone cord-blood transplantation overcomes the problem of graft failure even when low numbers of HLA-mismatched cord-blood cells are transplanted, thus leading to the possibility of use of this technique in a large number of adult patients.

Human Mesenchymal Stem Cells Promote Survival of T Cells in a Quiescent State

Mesenchymal stem cells (MSC) are part of the bone marrow that provides signals supporting survival and growth of bystander hematopoietic stem cells (HSC). MSC modulate also the immune response, as they inhibit proliferation of lymphocytes. In order to investigate whether MSC can support survival of T cells, we investigated MSC capacity of rescuing T lymphocytes from cell death induced by different mechanisms. We observed that MSC prolong survival of unstimulated T cells and apoptosis‐prone thymocytes cultured under starving conditions. MSC rescued T cells from activation induced cell death (AICD) by downregulation of Fas receptor and Fas ligand on T cell surface and inhibition of endogenous proteases involved in cell death. MSC dampened also Fas receptor mediated apoptosis of CD95 expressing Jurkat leukemic T cells. In contrast, rescue from AICD was not associated with a significant change of Bcl‐2, an inhibitor of apoptosis induced by cell stress. Accordingly, MSC exhibited a minimal capacity of rescuing Jurkat cells from chemically induced apoptosis, a process disrupting the mitochondrial membrane potential regulated by Bcl‐2. These results suggest that MSC interfere with the Fas receptor regulated process of programmed cell death. Overall, MSC can inhibit proliferation of activated T cells while supporting their survival in a quiescent state, providing a model of their activity inside the HSC niche.

Cause of death after allogeneic haematopoietic stem cell transplantation (HSCT) in early leukaemias: an EBMT analysis of lethal infectious complications and changes over calendar time

Summary:We analysed a large homogeneous group of 14 403 patients transplanted for early leukaemia from an HLA-identical sibling and reported to the EBMT in four time cohorts: 1980–1989 (24%), 1990–1994 (26%), 1995–1998 (30%) and 1999–2001 (20%). We focused on death from infection. End points were survival, death from relapse and transplant-related mortality (TRM), which was subdivided into death from graft-versus-host disease (GvHD) (1315 patients; 25% of deaths), infection (597 patients; 11% of deaths) or ‘other’ causes (1875 patients; 34% of deaths). Survival increased from 52% at 5 years in the first to 62% in the third cohort (P<0.05) and TRM decreased from 36 to 26% (P<0.05) due to a reduction in death from infection (P<0.001). GvHD, ‘other’ causes and relapse did not improve. The relative proportions of bacteria (217 patients; 36%), viruses (183 patients; 31%), fungi (166 patients; 28%) or parasites (32 patients; 5%) as cause of infectious death (cumulative incidence of death at 5 years 1.8, 1.6, 1.4 and ⩾0.3%, respectively) and median time to death from infections (3 months (range 0–158 months)) did not change. Death from infections has been reduced significantly, but it still represents an ongoing risk after HSCT and draws attention to the time beyond the initial period of neutropenia.

Mesenchymal stem cells impair in vivo T-cell priming by dendritic cells

Dendritic cells (DC) are highly specialized antigen-presenting cells characterized by the ability to prime T-cell responses. Mesenchymal stem cells (MSC) are adult stromal progenitor cells displaying immunomodulatory activities including inhibition of DC maturation in vitro. However, the specific impact of MSC on DC functions, upon in vivo administration, has never been elucidated. Here we show that murine MSC impair Toll-like receptor-4 induced activation of DC resulting in the inhibition of cytokines secretion, down-regulation of molecules involved in the migration to the lymph nodes, antigen presentation to CD4+ T cells, and cross-presentation to CD8+ T cells. These effects are associated with the inhibition of phosphorylation of intracellular mitogen-activated protein kinases. Intravenous administration of MSC decreased the number of CCR7 and CD49dβ1 expressing CFSE-labeled DC in the draining lymph nodes and hindered local antigen priming of DO11.10 ovalbumin-specific CD4+ T cells. Upon labeling of DC with technetium-99m hexamethylpropylene amine oxime to follow their in vivo biodistribution, we demonstrated that intravenous injection of MSC blocks, almost instantaneously, the migration of subcutaneously administered ovalbumin-pulsed DC to the draining lymph nodes. These findings indicate that MSC significantly affect DC ability to prime T cells in vivo because of their inability to home to the draining lymph nodes and further confirm MSC potentiality as therapy for immune-mediated diseases.

Treatment with granulocyte colony-stimulating factor after allogeneic bone Marrow transplantation for acute leukemia increases the risk of graft-versus-host disease and death: A study from the acute leukemia working party of the European Group for Blood and Marrow Transplantation

PURPOSE Granulocyte colony-stimulating factor (G-CSF) is given after bone marrow transplantation (BMT) to shorten the neutropenic phase. Its effects have not been evaluated in a large patient population. PATIENTS AND METHODS We studied 1,789 patients with acute leukemia receiving BMT and 434 patients receiving peripheral-blood stem cells (PBSCs) from HLA-identical siblings from 1992 to 2002 and reported the findings to the European Group for Blood and Marrow Transplantation. Among the BMT and PBSC patients, 501 (28%) and 175 (40%), respectively, were treated with G-CSF during the first 14 days after the transplantation. The outcome variables were entered into a Cox proportional hazards model. RESULTS BMT and PBSC patients treated with G-CSF had a faster engraftment of absolute neutrophils greater than 0.5 x 10(9)/L (P <.01), but platelet engraftment ( > 50 x 10(9)/L) was slower (P <.001). In the BMT patients, acute graft-versus-host disease (GVHD) grades II to IV was 50% +/- 5% (+/- 95% CI) in the G-CSF group versus 39% +/- 3% in the controls (relative risk [RR], 1.33; P =.007, in the multivariate analysis). The incidence of chronic GVHD was also increased (RR, 1.29; P =.03). G-CSF was associated with an increase in transplantation-related mortality (TRM; RR, 1.73; P =.00016) and had no effect on relapse but reduced survival (RR, 0.59; P <.0001) and leukemia-free survival rates (LFS; RR, 0.64; P =.0003). No such effects of G-CSF were seen in patients receiving PBSC. CONCLUSION After BMT, platelet engraftment was delayed, and GVHD and TRM were increased. Survival and LFS were reduced. This suggests that G-CSF should not be given shortly after BMT.

Phenotypic and functional heterogeneity of human NK cells developing after umbilical cord blood transplantation: a role for human cytomegalovirus?

Natural killer (NK) cells play a crucial role in early immunity after hematopoietic stem cell transplantation because they are the first lymphocyte subset recovering after the allograft. In this study, we analyzed the development of NK cells after intrabone umbilical cord blood (CB) transplantation in 18 adult patients with hematologic malignancies. Our data indicate that, also in this transplantation setting, NK cells are the first lymphoid population detectable in peripheral blood. However, different patterns of NK-cell development could be identified. Indeed, in a group of patients, a relevant fraction of NK cells expressed a mature phenotype characterized by the KIR(+)NKG2A(-) signature 3-6 months after transplantation. In other patients, most NK cells maintained an immature phenotype even after 12 months. A possible role for cytomegalovirus in the promotion of NK-cell development was suggested by the observation that a more rapid NK-cell maturation together with expansion of NKG2C(+) NK cells was confined to patients experiencing cytomegalovirus reactivation. In a fraction of these patients, an aberrant and hyporesponsive CD56(-)CD16(+)p75/AIRM1(-) NK-cell subset (mostly KIR(+)NKG2A(-)) reminiscent of that described in patients with viremic HIV was detected. Our data support the concept that cytomegalovirus infection may drive NK-cell development after umbilical CB transplantation.