Impact of HLA-G polymorphism on the outcome of allogeneic hematopoietic stem cell transplantation for metastatic renal cell carcinoma.

Renal cell carcinoma (RCC) is particularly sensitive to immune intervention. HLA-G, a non-classical HLA class I molecule with immunomodulatory properties, has been studied with regard to outcome after hematopoietic stem cell transplantation (HSCT), in particular the 14 bp insertion/deletion polymorphism in the 3' untranslated region. Here we analyzed n=56 patients affected by metastatic RCC who received an allogeneic HSCT between 1998 and 2006 in Milano, Marseille, Clermont-Ferrand and Stockholm. The 14 bp polymorphism was analyzed in correlation with overall survival (OS), PFS, acute and chronic GvHD. With a median follow-up of 13 years, a trend towards better outcome was observed when homozygosity for the 14bp-del allele was present: multivariate hazard ratio was 0.50 (95% confidence interval (CI): 0.23-1.13; P=0.10) and 0.57 (95% CI: 0.26-1.26; P=0.17) for OS and PFS, respectively, when 14bp-del/del was compared with 14bp-ins/X. Further exploratory analysis revealed a significant association between T/C at p3003 and improved OS (P=0.05) and PFS (P=0.006) compared with T/T. To our knowledge this is the first study on HLA-G and outcome after HSCT for a solid malignancy. After a coordinated multicenter study, we found that the more tolerogenic polymorphisms (14bp-del/del) is associated with better PFS and OS. The finding on p3003 deserves further investigation.

What is the outcome in patients with acute leukaemia who survive severe acute graft-versus-host disease?

BACKGROUND: Acute graft-versus-host disease (aGVHD) is a major complication of allogeneic haematopoietic stem cell transplantation (HSCT). With new promising therapies, survival may improve for severe aGVHD. OBJECTIVES: We wanted to analyze the long-term outcome in patients who survive severe aGVHD. METHODS: This study was a landmark analysis of 23 567 patients with acute Leukaemia who survived for more than 6 months after HSCT, 2002-2014. Patients alive after severe aGVHD (n = 1738) were compared to controls. RESULTS: Patients with severe aGVHD had higher non-relapse mortality (NRM) and higher rate of extensive chronic GVHD (cGVHD) than the controls (P < 10-5 ). The probability of relapse was significantly lower in the severe aGVHD group, but Leukaemia-free survival (LFS) and overall survival were significantly lower than for the controls (P < 10-5 ). Five-year LFS in patients with severe aGVHD was 49%, as opposed to 61% in controls with no or mild GVHD and 59% in patients with moderate GVHD. CONCLUSIONS: HSCT patients who survive severe aGVHD have higher risk of developing extensive cGVHD, a higher NRM, a lower relapse probability, and lower LFS than other HSCT patients. This study is a platform for outcome analysis in patients treated with novel therapies for acute GVHD.

GvHD after umbilical cord blood transplantation for acute leukemia: an analysis of risk factors and effect on outcomes.

Using the Center for International Blood and Marrow Transplant Research (CIBMTR) registry, we analyzed 1404 umbilical cord blood transplantation (UCBT) patients (single (<18 years)=810, double (⩾18 years)=594) with acute leukemia to define the incidence of acute GvHD (aGvHD) and chronic GvHD (cGvHD), analyze clinical risk factors and investigate outcomes. After single UCBT, 100-day incidence of grade II-IV aGvHD was 39% (95% confidence interval (CI), 36-43%), grade III-IV aGvHD was 18% (95% CI, 15-20%) and 1-year cGvHD was 27% (95% CI, 24-30%). After double UCBT, 100-day incidence of grade II-IV aGvHD was 45% (95% CI, 41-49%), grade III-IV aGvHD was 22% (95% CI, 19-26%) and 1-year cGvHD was 26% (95% CI, 22-29%). For single UCBT, multivariate analysis showed that absence of antithymocyte globulin (ATG) was associated with aGvHD, whereas prior aGvHD was associated with cGvHD. For double UCBT, absence of ATG and myeloablative conditioning were associated with aGvHD, whereas prior aGvHD predicted for cGvHD. Grade III-IV aGvHD led to worse survival, whereas cGvHD had no significant effect on disease-free or overall survival. GvHD is prevalent after UCBT with severe aGvHD leading to higher mortality. Future research in UCBT should prioritize prevention of GvHD.

Is there a stronger graft-versus-leukemia effect using HLA-haploidentical donors compared with HLA-identical siblings?

Haploidentical hematopoietic stem cell transplants (HSCTs) are increasingly used, but it is unknown whether they have a stronger graft-versus-leukemia (GVL) effect. We analyzed 10 679 acute leukemia patients who underwent HSCT from an HLA-matched sibling donor (MSD, n=9815) or a haploidentical donor (⩾2 HLA-antigen disparity, n=864) between 2007 and 2012, reported to the European Group for Blood and Marrow Transplantation. In a Cox regression model, acute and chronic graft-versus-host disease (GVHD) was added as time-dependent variables. There was no difference in probability of relapse between recipients of haploidentical and MSD grafts. Factors of importance for relapse after T-cell-replete grafts included remission status at HSCT, Karnofsky score ⩽80, acute GVHD of grade II or higher and chronic GVHD (P<10(-5)). Patients with post-transplant cyclophosphamide (n=194) had similar outcome as other T-cell-replete haploidentical transplants (n=369). Non-relapse mortality was significantly higher in the haploidentical group compared with that in MSD patients (P<10(-5)). Leukemia-free survival was superior in the MSD patients receiving T-cell-replete (P<10(-5)) or T-cell-depleted grafts (P=0.0006). The risk of relapse was the same in acute leukemia patients who received haploidentical donor grafts as in those given MSD transplants, suggesting a similar GVL effect.

Primary graft failure after myeloablative allogeneic hematopoietic cell transplantation for hematologic malignancies.

Clinical outcomes after primary graft failure (PGF) remain poor. Here we present a large retrospective analysis (n=23,272) which investigates means to prevent PGF and early detection of patients at high risk. In patients with hematologic malignancies, who underwent their first myeloablative allogeneic hematopoietic cell transplantation, PGF was reported in 1278 (5.5%), and there was a marked difference in PGFs using peripheral blood stem cell compared with bone marrow grafts (2.5 vs 7.3%; P<0.001). A fourfold increase of PGF was observed in myeloproliferative disorders compared with acute leukemia (P<0.001). Other risk factors for PGF included recipient age <30, HLA mismatch, male recipients of female donor grafts, ABO incompatibility, busulfan/cyclophosphamide conditioning and cryopreservation. In bone marrow transplants, total nucleated cell doses ⩽2.4 × 10(8) per kg were associated with PGF (odds ratio 1.39; P<0.001). The use of tacrolimus-based immunosuppression and granulocyte colony-stimulating factor were associated with decreased PGF risk. These data, allow clinicians to do more informed choices with respect to graft source, donor selection, conditioning and immunosuppressive regimens to reduce the risk of PGF. Moreover, a novel risk score determined on day 21 post transplant may provide the rationale for an early request for additional hematopoietic stem cells.

Superselective intra-arterial umbilical cord blood administration to BM in experimental animals.

Umbilical cord blood (UCB) as a source of hematopoietic stem cells for transplantation is limited by the low number of cells and delayed engraftment. UCB cells are infused i.v. for transplantation, although only a proportion of the cells reach the BM. We investigated whether UCB could be administered safely using superselective intra-arterial (i.a.) injection. We injected human UCB (5 × 10(6)) into the aorta in rats, into the iliac artery in mice and into the femoral nutrient artery (FNA) in rabbits. We used angiography, immunohistochemistry, intravital microscopy and qPCR to assess safety end points and the distribution of injected cells. All animals showed normal behavior. No evidence of organ infarction was noted. UCB injected into the FNA of rabbits did not change the flow rates, measured by angiography. By qPCR, we found significantly higher fold-change values in the injected BM compared with i.v. injection (P=0.0087). Using intravital microscopy we visualized the mouse capillary bed during i.a. injection without cellular congestion. In summary, we show that i.a. infusion of UCB is safe and reaches an eightfold increase in engraftment in the BM compared with i.v. infusion. These studies lay the foundation for clinical trials.

Hematopoietic SCT: a useful treatment for late metachromatic leukodystrophy.

In metachromatic leukodystrophy (MLD), the deficiency of the lysosomal enzyme arylsulfatase A (ARSA) leads to demyelination in the central and peripheral nervous system and ultimately to death. Allogeneic hematopoietic SCT (HSCT) is currently the only treatment for adult and late-onset juvenile MLD, although it is still in question because of insufficient follow-up. We wanted to determine whether HSCT could halt the progression of adult and late-onset juvenile MLD. Four treated unrelated patients and three untreated siblings were included in the study, and followed regularly for up to 18 years after transplantation. The patients were assessed from clinical examination, ARSA enzyme levels, magnetic resonance imaging of the brain and neuropsychological and neurophysiological tests. In the treated patients, ARSA levels were normal up to 18 years after transplantation. The parameters evaluated stabilized and remained stable after a latency period of 12-24 months. Two patients live normal lives, partially in a protected environment. The other two patients stabilized at a low cognitive and functional level. One of the controls is demented, one is in a vegetative state and one died. We conclude that, in comparison with their untreated siblings, HSCT halted the progression of the disease in our treated patients.

Stromal cells-are they really useful for GVHD?

Mesenchymal stromal cells (MSCs) have immunomodulatory effects and are increasingly being used for the treatment of acute and chronic GVHD. Although they seem immuno-privileged, they induce alloresponses, but the risk of immunization is poorly characterized. After infusion, they first reach the lungs, liver and spleen, and are then difficult to trace. Several mechanisms are involved in stromal cells suppressing alloreactivity, such as induction of regulatory T cells, but whether or not this will also affect leukemic relapse or increase infections is not known. Although several encouraging pilot studies have been published, there have been few prospective randomized trials. There may be a bias in the literature, as negative results are seldom published, and there have been few comparative studies with other immunosuppressive regimens. Most animal models have failed to show any effect on GVHD. Several questions remain to be answered for optimization of stromal cell therapy. Which source is optimal-BM, fat, cord or decidua? Can stromal cells be replaced by exosomes, which culture conditions are most appropriate and at what passage and how frequently should cells be administered? More research is required to move stromal cell therapy forward to become an established treatment for acute and chronic GVHD.

Prophylaxis and treatment of GVHD: EBMT-ELN working group recommendations for a standardized practice.

GVHD remains the major impediment to broader application of allogeneic haematopoietic SCT. It can be prevented completely, but at the expense of other complications, rejection, relapse or delayed immune reconstitution. No optimal prevention or treatment method has been defined. This is reflected by enormous heterogeneity in approaches in Europe. Retrospective comparisons between different policies, although warranted, do not give definite answers. In order to improve the present situation, an European Group for Blood and Marrow Transplantation and the European LeukemiaNet working group has developed in a Delphi-like approach recommendations for prophylaxis and treatment of GVHD in the most common allogeneic transplant setting, transplantation from an HLA-identical sibling or unrelated donor for standard risk malignant disease. The working group proposes these guidelines to be adopted as routine standard in transplantation centres and to be used as comparator in systematic studies evaluating the advantages and disadvantages of practices differing from these recommendations.

Increased risk of gastrointestinal acute GVHD following the addition of melphalan to busulfan/cyclophosphamide conditioning.

Risk factors associated with the development of aGVHD in the gastrointestinal tract have not been studied in depth. We retrospectively assessed 25 pediatric patients with MDS and JMML and compared the treatment outcome of two different conditioning regimens. Seventeen children (68%) underwent conditioning with busulfan (Bu), cyclophosphamide (Cy), and melphalan (Mel) and eight children (32%) with Bu and Cy. Gastrointestinal aGVHD stages II-IV (day 0-100) were observed in 47% (eight of 17) of the patients in the BuCyMel group and in none (0 of 8) in the BuCy group (p < 0.05). In patients who developed gastrointestinal aGVHD stages III-IV, a 24-h variation in the Bu concentration with a nighttime peak was noted. HC and liver aGVHD stages II-IV were observed in 47% (eight of 17) and 35% (six of 17) after BuCyMel conditioning and in 0% (0 of 17) and 12.5% (one of eight) after BuCy conditioning. The overall survival rate was 53% (nine of 17) in the BuCyMel group and 62.5% (five of eight) in the BuCy group. In conclusion, the addition of melphalan to the BuCy conditioning regimen resulted in severe gastrointestinal complications and did not improve overall survival.

A prospective randomized toxicity study to compare reduced-intensity and myeloablative conditioning in patients with myeloid leukaemia undergoing allogeneic haematopoietic stem cell transplantation.

BACKGROUND: To our knowledge, no randomized toxicity studies have been conducted to compare myeloablative conditioning (MAC) and reduced-intensity conditioning (RIC) in allogeneic haematopoietic stem cell transplantation (HSCT). METHODS: Adult patients ≤60 years of age with myeloid leukaemia were randomly assigned (1 : 1) to treatment with RIC (n = 18) or MAC (n = 19) in this Phase II single-centre toxicity study. RESULTS: There was a maximum median mucositis grade of 1 in the RIC group compared with 4 in the MAC group (P < 0.001). Haemorrhagic cystitis occurred in eight of the patients in the MAC group and none in the RIC group (P < 0.01). Results of renal and hepatic tests did not differ significantly between the two groups. RIC-treated patients had faster platelet engraftment (P < 0.01) and required fewer erythrocyte and platelet transfusions (P < 0.001) and less total parenteral nutrition (TPN) than those treated with MAC (P < 0.01). Cytomegalovirus (CMV) infection was more common in the MAC group (14/19) than in the RIC group (6/18) (P = 0.02). Donor chimerism was similar in the two groups with regard to CD19 and CD33, but was delayed for CD3 in the RIC group. Five-year transplant-related mortality (TRM) was approximately 11% in both groups, and rates of relapse and survival were not significantly different. Patients in the MAC group with intermediate cytogenetic acute myeloid leukaemia had a 3-year survival of 73%, compared with 90% among those in the RIC group. CONCLUSION: Reduced-intensity conditioning had several advantages compared with MAC, including less mucositis, less haemorrhagic cystitis, faster platelet engraftment, the need for fewer transfusions and less TPN, and fewer CMV infections. Both regimens were tolerated and TRM was low.

Effects of spleen status on early outcomes after hematopoietic cell transplantation.

To assess the impact of spleen status on engraftment, and early morbidity and mortality after allogeneic hematopoietic cell transplantation (HCT), we analyzed 9,683 myeloablative allograft recipients from 1990 to 2006; 472 had prior splenectomy (SP), 300 splenic irradiation (SI), 1,471 with splenomegaly (SM), and 7,440 with normal spleen (NS). Median times to neutrophil engraftment (NE) and platelet engraftment (PE) were 15 vs 18 days and 22 vs 24 days for the SP and NS groups, respectively (P<0.001). Hematopoietic recovery at day +100 was not different across all groups, however the odds ratio of days +14 and +21 NE and day +28 PE were 3.26, 2.25 and 1.28 for SP, and 0.56, 0.55, and 0.82 for SM groups compared to NS (P<0.001), respectively. Among patients with SM, use of peripheral blood grafts improved NE at day +21, and CD34+ cell dose >5.7 × 10(6)/kg improved PE at day+28. After adjusting variables by Cox regression, the incidence of GVHD and OS were not different among groups. SM is associated with delayed engraftment, whereas SP prior to HCT facilitates early engraftment without having an impact on survival.

Graft failure in the modern era of allogeneic hematopoietic SCT.

Graft failure may contribute to increased morbidity and mortality after allogeneic hematopoietic SCT (allo-HSCT). Here, we present risk factors for graft failure in all first allo-HSCTs performed at our center from 1995 to mid-2010 (n=967). Graft failure was defined as >95% recipient cells any time after engraftment with no signs of relapse, or re-transplantation because of primary or secondary neutropenia (<0.5 × 10(9)/L) and/or thrombocytopenia (<30 × 10(9)/L). Fifty-four patients (5.6%) experienced graft failure. The majority were because of autologous reconstitution (n=43), and only a few patients underwent re-transplantation because of primary (n=6) or secondary (n=5) graft failures. In non-malignant disorders, graft failure had no effect on survival, whereas in malignant disease graft failure was associated with reduced 5-year survival (22 vs 53%, P<0.01). In multivariate analysis, ex vivo T-cell depletion (relative risk (RR) 8.82, P<0.001), HLA-mismatched grafts (RR 7.64, P<0.001), non-malignant disorders (RR 3.32, P<0.01) and reduced-intensity conditioning (RR 2.58, P<0.01) increased the risk for graft failure, whereas graft failures were prevented by total nucleated cell doses of ≥ 2.5 × 10(8)/kg (RR 0.36, P<0.01). In conclusion, graft failure was only associated with inferior survival in malignant disease. Non-malignant disorders, HLA match, conditioning intensity, immunosuppression regimen and cell dose all influenced graft failure risk.

Analysis of tissues following mesenchymal stromal cell therapy in humans indicates limited long-term engraftment and no ectopic tissue formation.

Mesenchymal stromal cells (MSCs) are explored as a novel treatment for a variety of medical conditions. Their fate after infusion is unclear, and long-term safety regarding malignant transformation and ectopic tissue formation has not been addressed in patients. We examined autopsy material from 18 patients who had received human leukocyte antigen (HLA)-mismatched MSCs, and 108 tissue samples from 15 patients were examined by PCR. No signs of ectopic tissue formation or malignant tumors of MSC-donor origin were found on macroscopic or histological examination. MSC donor DNA was detected in one or several tissues including lungs, lymph nodes, and intestine in eight patients at levels from 1/100 to <1/1,000. Detection of MSC donor DNA was negatively correlated with time from infusion to sample collection, as DNA was detected from nine of 13 MSC infusions given within 50 days before sampling but from only two of eight infusions given earlier. There was no correlation between MSC engraftment and treatment response. We conclude that MSCs appear to mediate their function through a "hit and run" mechanism. The lack of sustained engraftment limits the long-term risks of MSC therapy.

Bone marrow or peripheral blood stem cell transplantation from unrelated donors in adult patients with acute myeloid leukaemia, an Acute Leukaemia Working Party analysis in 2262 patients.

BACKGROUND: No survival benefit of using blood stem cells instead of bone marrow (BM) has been shown in matched unrelated donor (MUD) transplantation. DESIGN AND METHODS: In a retrospective registry analysis, we compared the use of blood stem cells (n = 1502) and BM (n = 760) from unrelated donors in patients aged 18-60 years with acute myeloid leukaemia (AML) undergoing myeloablative conditioning between 1997 and 2008. The blood stem cell recipients were older (P < 0.01), had more advanced disease (P < 0.0001) and received less total body irradiation (P < 0.0001) and more antithymocyte globulin (P = 0.01). RESULTS: Recovery of neutrophils and platelets was faster with blood stem cells (P < 0.0001). The incidence of acute graft-versus-host disease (GVHD) was similar, but there was more chronic GVHD in the blood stem cell group [hazard ratio (HR) = 1.29, P = 0.02]. There were no significant differences in nonrelapse mortality (NRM), relapse incidence and leukaemia-free survival (LFS) between the two groups amongst patients with AML in remission. In patients with advanced leukaemia, NRM was lower (HR = 0.61, P = 0.02) and LFS was prolonged (HR = 0.67, P = 0.002) when blood stem cells were used. At 3 years, LFS for all patients, regardless of remission status, was 41% for both treatment groups. The outcome was not affected after multivariable analysis adjusted for confounders. CONCLUSION: Blood stem cells compared with BM in MUD transplantation for patients with AML in remission resulted in the same rates of LFS. In patients with advanced leukaemia, the blood stem cell group had reduced NRM and improved LFS.

Stromal cells from term fetal membrane are highly suppressive in allogeneic settings in vitro.

Bone marrow-derived mesenchymal stromal cells (BM-MSCs) have immunosuppressive properties and have been used to treat steroid-refractory acute graft-versus-host disease (GVHD) in stem cell transplant patients. Cells with similar capacities can also be found in term placental tissue. We have isolated stromal cells from term fetal membrane (FMSCs), umbilical cords (UCSCs) and placental villi (PVSCs) as well as from bone marrow and compared their immunoregulatory capacity in allogeneic settings. We found that FMSCs and UCSCs suppressed proliferation significantly in mixed lymphocyte reactions (MLRs), whereas PVSCs showed inconsistent suppressive effects. When added to MLR cultures, FMSCs suppressed the production of interferon (IFN)-γ and interleukin (IL)-17, whereas UCSCs and PVSCs promoted the production of IL-17 instead. Secretion of IL-10 was increased after addition of FMSCs and UCSCs. In this setting, BM-MSCs had no significant effect on secretion of IFN-γ, IL-17 or IL-10 in MLR cultures. When analysing the expression of adhesion markers, we noted that FMSCs expressed the highest levels of CD29 (ß1), CD49d (α4) and CD54 (ICAM-1) compared to the other types of stromal cells. Thus, our data indicate that stromal cells isolated from term fetal membrane have great immunosuppressive capacity in terms of proliferation and production of proinflammatory cytokines from alloreactive T cells, and also promote anti-inflammatory IL-10. They express high levels of integrins that may be of importance in homing to inflamed tissues. Fetal membrane may provide a valuable source of cells with immunosuppressive properties and could possibly be used for treatment of acute GVHD and other inflammatory disorders.

Different impact of intermediate and unfavourable cytogenetics at the time of diagnosis on outcome of de novo AML after allo-SCT: a long-term retrospective analysis from a single institution.

Karyotype of myeloblasts at the time of AML diagnosis has been shown to be prognostic significant for pre-remission outcome and outcome after allo-SCT, but the latter requires further studies. We conducted a retrospective analysis of the impact of intermediate and unfavourable cytogenetics at the time of primary diagnosis on outcome after allo-SCT in de novo AML. The study included 169 patients who underwent allo-SCT at Karolinska University Hospital between 1980 and 2010. Intermediate and unfavourable cytogenetics were found in 129 (76%) and 40 patients (24%), respectively. Myeloablative and reduced-intensity conditioning were given to 120 (71%) and 49 (29%) patients, respectively. Allo-SCT was performed in CR1 in 122 patients (72%). TRM was 16% in both cytogenetics groups. Relapse occurred in 29% patients with intermediate and in 45% patients with unfavourable cytogenetics (P=0.01). The probabilities of 5-year OS for patients with intermediate and unfavourable cytogenetics were 60 and 43%, respectively (P=0.02). Multivariate analysis revealed intermediate cytogenetics, chronic GVHD, and recipient CMV-negative serostatus as variables associated with favourable OS. Our study showed that outcome after allo-SCT in de novo AML differs depending on cytogenetic risk-group; however its position in post-remission therapy of eligible AML patients is not threatened.

Disturbances in dental development and craniofacial growth in children treated with hematopoietic stem cell transplantation.

OBJECTIVES: To investigate the correlation between age, degree of disturbances in dental development, and vertical growth of the face in children treated with hematopoietic stem cell transplantation (HSCT). PATIENTS: 39 long-term survivors of HSCT performed in childhood and transplanted before the age of 12, at a mean age of 6.8±3.3 years. METHODS: Panoramic and cephalometric radiographs were taken at a mean age of 16.2 years. For each patient two age- and sex-matched healthy controls were included. The area of three mandibular teeth was measured and a cephalometric analysis was performed. RESULTS: The mean area of the mandibular central incisor, first and second molar was significantly smaller in the HSCT group, and the vertical growth of the face was significantly reduced, especially in the lower third, compared to healthy controls. A statistically significant correlation between age at HSCT, degree of disturbances in dental development, and vertical growth of the face was found. Children subjected to pre-HSCT chemotherapy protocols had significantly more growth reduction in vertical craniofacial variables compared to children without pre-HSCT chemotherapy. Conditioning regimens including busulfan or total body irradiation had similar deleterious effects on tooth area reduction and craniofacial parameters. CONCLUSIONS: The younger the child is at HSCT, the greater the impairment in dental and vertical facial development. This supports the suggestion that the reduction in lower facial height found in SCT children mainly is a result of impaired dental development and that young age is a risk factor for more severe disturbances.