5′-deoxy-5′-methylthioadenosine (MTA) is an endogenous compound produced through the metabolism of polyamines. The therapeutic potential of MTA has been assayed mainly in liver diseases and, more recently, in animal models of multiple sclerosis. The aim of this study was to determine the neuroprotective effect of this molecule in vitro and to assess whether MTA can cross the blood brain barrier (BBB) in order to also analyze its potential neuroprotective efficacy in vivo.
Neuroprotection was assessed in vitro using models of excitotoxicity in primary neurons, mixed astrocyte-neuron and primary oligodendrocyte cultures. The capacity of MTA to cross the BBB was measured in an artificial membrane assay and using an in vitro cell model. Finally, in vivo tests were performed in models of hypoxic brain damage, Parkinson's disease and epilepsy.
MTA displays a wide array of neuroprotective activities against different insults in vitro. While the data from the two complementary approaches adopted indicate that MTA is likely to cross the BBB, the in vivo data showed that MTA may provide therapeutic benefits in specific circumstances. Whereas MTA reduced the neuronal cell death in pilocarpine-induced status epilepticus and the size of the lesion in global but not focal ischemic brain damage, it was ineffective in preserving dopaminergic neurons of the substantia nigra in the 1-methyl-4-phenyl-1,2,3,6-tetrahydro-pyridine (MPTP)-mice model. However, in this model of Parkinson's disease the combined administration of MTA and an A2A adenosine receptor antagonist did produce significant neuroprotection in this brain region.
MTA may potentially offer therapeutic neuroprotection.
Hematopoietic stem cell transplant (HSCT) recipients are at significant risk for BKV reactivation, hemorrhagic cystitis (HC) and renal dysfunction. We prospectively monitored 98 HSCT by serial BKV PCR in the urine through Day (D) +100 to analyze the relationship between BKV viruria and HC, serum creatinine (Cr) and creatinine clearance (CrCl) through D +180 or death. Patients, median age 52 years, range 20-73, received T-cell depleted (50%) or cord blood allografts (21%). Median pre-HSCT BKV IgG titers were 1:10,240. Incremental increase in BKV IgG titers correlated with developing BKV viruria ≥ 107 copies/mL. By D +100, 53 (54%) patients had BKV viruria. BKV viral load in the urine increased at engraftment and persisted throughout D +100. HC developed in 10 patients (10%); 7/10 with BKV viruria. In competing risk analyses, BKV viruria ≥ 107 copies/mL, older age, CMV reactivation and foscarnet use were risk factors for HC. Cr and CrCl at 2, 3 and 6 months post-HSCT were similar between patients with and without BKV viruria.
The encouragement of healthy lifestyles for obesity prevention in young people is a public health priority. The European Youth Tackling Obesity (EYTO) project is a multicentric intervention project with participation from the United Kingdom, Portugal, the Czech Republic and Spain. The general aim of the EYTO project is to improve lifestyles, including nutritional habits and physical activity practice, and to prevent obesity in socioeconomically disadvantaged and vulnerable adolescents. The EYTO project works through a peer-led social marketing intervention that is designed and implemented by the adolescents of each participating country. Each country involved in the project acts independently. This paper describes the “Som la Pera” intervention Spanish study that is part of the EYTO project.
In Spain, the research team performed a cluster randomised controlled intervention over 2 academic years (2013–2015) in which 2 high-schools were designated as the control group and 2 high-schools were designated as the intervention group, with a minimum of 121 schoolchildren per group.
From the intervention group, 5 adolescents with leadership characteristics, called “Adolescent Challenge Creators” (ACCs), were recruited. These 5 ACCs received an initial 4 h training session about social marketing principles and healthy lifestyle theory, followed by 24 sessions (1.30 h/session) divided in two academic years to design and implement activities presented as challenges to encourage healthy lifestyles among their peers, the approximately 180–200 high-school students in the intervention group. During the design of the intervention, it was essential that the ACCs used the 8 social marketing criteria (customer orientation, behaviour, theory, insight, exchange, competition, segmentation and methods mix). The expected primary outcomes from the Spanish intervention will be as follows: increases in the consumption of fruits and vegetables and physical activity practice along with reductions in TV/computer/game console use. The secondary outcomes will be as follows: increased breakfast consumption, engagement with local recreation and reduced obesity prevalence. The outcomes will be measured by the Health Behaviour in School-aged Children Study (HBSC) survey at baseline and at the end of the intervention.
In the control group, no intervention was implemented, but the outcome measurements were collected in parallel with the intervention group.
This study described a new methodology to improve lifestyles and to address adolescent obesity.
ClinicalTrials.gov: NCT02157402. Registered 03 June 2014.
Electronic supplementary material
The online version of this article (doi:10.1186/s12889-015-1920-1) contains supplementary material, which is available to authorized users.
Adolescents; Youth; Peer-led; Healthy lifestyles; Obesity; Social marketing; Study protocol
Osteosarcoma is the most common primary malignant tumour of bone. The oncologic surgery of a proximal femur osteosarcoma affecting the hip joint can be very challenging. We present an 8-year-old boy with a 5-month history of right hip pain. Radiographs and magnetic resonance imaging (MRI) showed a lytic lesion of the proximal femur extending 13 cm to the diaphysis. Histological evaluation was consistent with high-grade osteoblastic osteosarcoma. After completing chemotherapy we performed an extra-articular resection of the hip. Reconstruction was accomplished by reimplanting the acetabulum after irradiation and modular proximal femur megaprosthesis. Endoprosthetic reconstruction following proximal femur resection is a good treatment alternative achieving good postoperative function. Extra-articular resection of the hip using a periacetabular osteotomy technique enabled us to achieve wide margins and leave an intact posterior column to optimize acetabular reconstruction stability. Extracorporeal irradiation and reimplantation is a valuable treatment option in a situation such as this where allograft geometric fit is a priority. We conclude that an extra-articular resection of the hip, followed by reconstruction with an extracorporeally irradiated acetabulum and a proximal femur modular megaprosthesis, is a useful combined treatment option for malignant lesions involving the hip joint, especially in paediatric patients.
Cord blood transplantation (CBT) is a known risk factor for human herpesvirus-6 (HHV-6) infection. We analyzed the nature of HHV-6 infections in 125 double-unit CBT recipients (median age 42 years) transplanted for hematologic malignancies with calcineurin-inhibitor/ mycophenolate mofetil prophylaxis and no anti-thymocyte globulin (ATG). One-hundred and seventeen (94%) patients reactivated HHV-6 by quantitative plasma PCR (median peak 7,600 copies/mL, range 100-160,000) at a median of 20 days (range 10-59) after transplantation. HHV-6 encephalitis occurred in 2 patients (1.6%), of whom one died and the other recovered with therapy. There was no association between high level HHV-6 viremia (≥ 10,000 or ≥ 25,000 copies/mL) and age, diagnosis, conditioning intensity, or dominant unit characteristics, or between high level viremia and transplant outcomes (engraftment, cytomegalovirus reactivation, day 100 grade II-IV acute graft-versus-host disease, day 100 transplant-related mortality, or 1-year disease-free survival). HHV-6 therapy delayed the onset of cytomegalovirus reactivation. Interestingly, HHV-6 resolution was observed in untreated patients, and resolution of viremia correlated with absolute lymphocyte count recovery. We observed a low incidence of encephalitis and no association with CBT outcomes. Our data suggests therapy in uncomplicated viremia may not be warranted. However, further investigation of the risk-benefit of HHV-6 viremia treatment and standardization of PCR testing is required.
Background and Purpose
NINDS Stroke Genetics Network (SiGN) is an international consortium of ischemic stroke studies that aims to generate high quality phenotype data to identify the genetic basis of etiologic stroke subtypes. This analysis characterizes the etiopathogenetic basis of ischemic stroke and reliability of stroke classification in the consortium.
Fifty-two trained and certified adjudicators determined both phenotypic (abnormal test findings categorized in major etiologic groups without weighting towards the most likely cause) and causative ischemic stroke subtypes in 16,954 subjects with imaging-confirmed ischemic stroke from 12 US studies and 11 studies from 8 European countries using the web-based Causative Classification of Stroke System. Classification reliability was assessed with blinded re-adjudication of 1509 randomly selected cases.
The distribution of etiologic categories varied by study, age, sex, and race (p<0.001 for each). Overall, only 40% to 54% of cases with a given major ischemic stroke etiology (phenotypic subtype) were classified into the same final causative category with high confidence. There was good agreement for both causative (kappa 0.72, 95%CI:0.69-0.75) and phenotypic classifications (kappa 0.73, 95%CI:0.70-0.75).
This study demonstrates that etiologic subtypes can be determined with good reliability in studies that include investigators with different expertise and background, institutions with different stroke evaluation protocols and geographic location, and patient populations with different epidemiological characteristics. The discordance between phenotypic and causative stroke subtypes highlights the fact that the presence of an abnormality in a stroke patient does not necessarily mean that it is the cause of stroke.
etiology; classification; phenotype; stroke subtype
Cyclotides are head-to-tail cyclized
peptides comprising a stabilizing
cystine-knot motif. To date, they are well known for their diverse
bioactivities such as anti-HIV and immunosuppressive properties. Yet
little is known about specific molecular mechanisms, in particular
the interaction of cyclotides with cellular protein targets. Native
and synthetic cyclotide-like peptides from Momordica plants are potent and selective inhibitors of different serine-type
proteinases such as trypsin, chymotrypsin, matriptase, and tryptase-beta.
This study describes the bioactivity-guided isolation of a cyclotide
from Psychotria solitudinum as an inhibitor of another
serine-type protease, namely, the human prolyl oligopeptidase (POP).
Analysis of the inhibitory potency of Psychotria extracts
and subsequent fractionation by liquid chromatography yielded the
isolated peptide psysol 2 (1), which exhibited an IC50 of 25 μM. In addition the prototypical cyclotide kalata
B1 inhibited POP activity with an IC50 of 5.6 μM.
The inhibitory activity appeared to be selective for POP, since neither
psysol 2 nor kalata B1 were able to inhibit the proteolytic activity
of trypsin or chymotrypsin. The enzyme POP is well known for its role
in memory and learning processes, and it is currently being considered
as a promising therapeutic target for the cognitive deficits associated
with several psychiatric and neurodegenerative diseases, such as schizophrenia
and Parkinson’s disease. In the context of discovery and development
of POP inhibitors with beneficial ADME properties, cyclotides may
be suitable starting points considering their stability in biological
fluids and possible oral bioavailability.
Hematopoietic cell; transplantation; Leukemia; Lymphoma; Myeloma
15N longitudinal relaxation rates are extensively used for the characterization of protein dynamics; however, their accurate measurement is hindered by systematic errors. 15N CSA/1H–15N dipolar cross-correlated relaxation (CC) and amide proton exchange saturation transfer from water protons are the two main sources of systematic errors in the determination of 15N R1 rates through 1H–15N HSQC-based experiments. CC is usually suppressed through a train of 180° proton pulses applied during the variable 15N relaxation period (T), which can perturb water magnetization. Thus CC cancellation is required in such a way as to minimize water saturation effects. Here we examined the level of water saturation during the T period caused by various types of inversion proton pulses to suppress CC: (I) amide-selective IBURP-2; (II) cosine-modulated IBURP-2; (III) Watergate-like blocks; and (IV) non-selective hard. We additionally demonstrate the effect of uncontrolled saturation of aliphatic protons on 15N R1 rates. In this paper we present an optimized pulse sequence that takes into account the crucial effect of controlling also the saturation of the aliphatic protons during 15N R1 measurements in non-deuterated proteins. We show that using cosine-modulated IBURP-2 pulses spaced 40 ms to cancel CC in this optimized pulse program is the method of choice to minimize systematic errors coming from water and aliphatic protons saturation effects.
Electronic supplementary material
The online version of this article (doi:10.1007/s10858-015-9937-4) contains supplementary material, which is available to authorized users.
15N relaxation; Longitudinal relaxation; R1; Water saturation; 15N CSA/1H–15N dipolar cross-correlated relaxation (CC); Radiation damping (RD)
The response of a murine macrophage cell line exposed to a library of seven metal and metal oxide nanoparticles was evaluated via High Throughput Screening (HTS) assay employing luciferase-reporters for ten independent toxicity-related signaling pathways. Similarities of toxicity response among the nanoparticles were identified via Self-Organizing Map (SOM) analysis. This analysis, applied to the HTS data, quantified the significance of the signaling pathway responses (SPRs) of the cell population exposed to nanomaterials relative to a population of untreated cells, using the Strictly Standardized Mean Difference (SSMD). Given the high dimensionality of the data and relatively small dataset the validity of the SOM clusters was established via a consensus clustering technique. Analysis of the SPR signatures revealed two cluster groups corresponding to (i) sub-lethal pro-inflammatory responses to Al2O3, Au, Ag, SiO2 nanoparticles possibly related to ROS generation, and (ii) lethal genotoxic responses due to exposure to ZnO and Pt nanoparticles at a concentration range of 25 μg/mL-100 μg/mL at 12 h exposure. In addition to identifying and visualizing clusters and quantifying similarity measures, the SOM approach can aid in developing predictive quantitative-structure relations; however, this would require significantly larger datasets generated from combinatorial libraries of engineered nanoparticles.
Nanotoxicity; Self-organizing map; clustering; HTS; cell signaling pathway
The impact of human leukocyte antigen (HLA) donor-specific antibodies (DSA) upon cord blood (CB) engraftment is controversial. We evaluated the influence of pre-existing HLA-antibodies (HLA-Abs) on engraftment in 82 double-unit CB recipients (median age 48 years) transplanted for hematologic malignancies. Of 28 patients (34%) with HLA-Abs, 12 had DSA (median MFI 5,255, range 1,057–9,453). DSA patients had acute leukemia (n = 11) or myelodysplasia (n = 1) and all received either high-dose or reduced intensity (but myeloablative) conditioning. After myeloablative CBT (n = 67), sustained donor engraftment was observed in 95% without HLA-Abs (median 23 days), 100% with non-specific HLA-Abs (median 23 days), and 92% with DSA (median 31 days, p = 0.48). Of 6 patients with HLA-Abs to one unit, 3 engrafted with that unit and 3 with the other. Of 6 patients with HLA-Abs against both units, one had graft failure despite being 100% donor, and 5 engrafted with one unit. Successful donor engraftment is possible in patients with DSA after myeloablative double-unit CBT. Our data suggest potential deleterious effects of DSA can be abrogated in patients with hematologic malignancies.
Washing cord blood (CB) grafts involves product manipulation and may result in cell loss. We investigated double-unit CB transplantation (CBT) using red blood cell (RBC) depleted units diluted with albumin-dextran in patients with hematologic malignancies. One-hundred thirty-six patients [median 43 years (range 4–71) and 69 kilograms (kg) (range 24–111)] were transplanted with a 4–6/6 HLA-matched graft. Patients ≤ 20 kg were excluded as they only received washed units. Units were diluted a median of 8 fold to a median volume of 200 ml/unit. The median infused TNC doses were 2.7 (larger unit) and 2.0 (smaller unit) × 107/kg respectively, and the median post-thaw recovery was 86%. Units were infused consecutively (median 45 minutes/unit). While only 17 patients (13%) had no infusion reactions, reactions in the remaining 119 patients were almost exclusively mild-moderate (by CTCAE v4 criteria 12 grade 1, 43 grade 2, 63 grade 3) and only 1 patient (< 1%) had a severe (grade 4) reaction. Moreover, most were easily treated. Grade 2–3 hypertension was the most common in 101 (74%) patients. The cumulative incidence of sustained donor-derived neutrophil engraftment was high: 95% in myeloablative and 94% in non-myeloablative CBT recipients. With appropriate supportive care, double-unit CBT with RBC-depleted grafts infused after albumin-dextran dilution is safe with high rates of engraftment in patients > 20 kg.
Outcomes of patients with acute myeloid leukemia (AML) who are refractory to high-dose Cytarabine (HiDAC)-based induction are dismal. Allogeneic hematopoietic stem cell transplantation (AHSCT) as initial salvage may be effective and potentially superior to conventional salvage chemotherapy.
Eighteen percent (285 of 1597) of AML patients were primary refractory to HiDAC-based regimens at the MD Anderson Cancer Center between 1995 and 2009. AHSCT was the initial salvage in 28 cases. These patients were compared against 149 patients who received salvage chemotherapy, but never received AHSCT.
Patients receiving salvage chemotherapy were older, had higher bone marrow blasts percentage, and higher incidence of unfavorable cytogenetics (P<0.001). Median time from induction to AHSCT was 76 days. Objective response was achieved in 23 of 28 patients (82%) undergoing AHSCT. The incidence of grade III/IV acute and chronic graft versus-host-disease was 11% and 29%, respectively. Median follow up for living patients is 80 months. Median overall survival (OS) was 15.7 months and 2.9 months for AHSCT and chemotherapy, respectively (P<0.001); the 3-year OS rates were 39% and 2%, respectively. ASHCT as initial salvage therapy was identified as an independent prognostic factor for survival in multivariate analysis (HR = 3.03; P < 0.001).
Initial salvage therapy with AHSCT in patients with primary HiDAC refractory AML is feasible and may yield superior outcomes to salvage chemotherapy.
acute myeloid leukemia; primary refractory; allogeneic transplantation
While knowledge of the composition and mode of action of bee and wasp venoms dates back 50 years, the therapeutic value of these toxins remains relatively unexploded. The properties of these venoms are now being studied with the aim to design and develop new therapeutic drugs. Far from evaluating the extensive number of monographs, journals and books related to bee and wasp venoms and the therapeutic effect of these toxins in numerous diseases, the following review focuses on the three most characterized peptides, namely melittin, apamin, and mastoparan. Here, we update information related to these compounds from the perspective of applied science and discuss their potential therapeutic and biotechnological applications in biomedicine.
bee; wasp; venom; melittin; apamin; mastoparan
The aim of this prospective phase II trial was to determine the safety and efficacy of a nonmyeloablative (NMA) conditioning program incorporating peri-transplant-rituximab in patients with CD20+ B-cell non-Hodgkin lymphoma (B-NHL) receiving an allogeneic stem cell transplant (allo-SCT). Fifty-one adult B-NHL patients, with a median age of 54 years, were treated with cyclophosphamide, fludarabine and 200 cGy of total body irradiation (TBI). Rituximab 375 mg/m2 was given on d-8 and in 4 weekly doses beginning d+21. Equine anti-thymocyte globulin (eATG) was given to recipients of volunteer unrelated donor grafts. Graft-versus-host disease (GVHD) prophylaxis consisted of cyclosporine and mycophenolate mofetil and tacrolimus, sirolimus and methotrexate in 8 and 43 patients respectively. Thirty-three patients received grafts from unrelated donors and 18 received grafts from matched related donors. All patients engrafted. Full donor chimerism in bone marrow and peripheral T cells was seen in 92% and 89% of patients respectively at 3 months post-allo-SCT. The cumulative incidence (CI) of grade II-IV acute GVHD (aGVHD) at 6-months was 25% (95% CI: 13-38%) and grade III-IV was 11% (95% CI: 2-20%). The 2-year CI of chronic GVHD (cGVHD) was 29% (95% CI: 15-44%). The 2-year event-free (EFS) and overall (OS) survival for all patients was 72% (95% CI: 59-85%) and 78% (95% CI: 66-90%) respectively. The 2-year EFS for chemosensitive patients was 84% (95% CI: 72- 96%) compared to 30% (95% CI: 2 - 58%) for chemorefractory patients pre-allo-SCT (p<0.001). This NMA regimen, with peri-transplant rituximab, is safe and effective in patients with B-NHL.
Reduced-intensity conditioning (RIC) regimens for allogeneic stem cell transplantation (allo-SCT) have used alemtuzumab to abrogate the risk of graft-versus-host disease (GVHD). Thirty-eight advanced lymphoma patients underwent a prospective phase II study of melphalan, fludarabine and alemtuzumab containing RIC allo-SCT from 20 matched related and 18 unrelated donors with cyclosporin-A as GVHD prophylaxis. The cumulative incidence of grade II-IV acute GVHD at 3 months was 10.5% and three evaluable patients experienced chronic GVHD. Progression-free (PFS) and overall (OS) survival at 5 years is 25% (95% CI: 13-40) and 44% (95% CI: 28-59%) respectively. Previous high-dose therapy and autologous stem cell transplantation (HDT-ASCT) and elevated LDH at the time of allo-SCT resulted in inferior OS. Within this cohort of high-risk lymphoma patients, alemtuzumab containing RIC resulted in a low risk of GVHD and a high incidence of POD, especially in those with poor-risk features defined by elevated LDH pre-allo-SCT and previous HDT-ASCT.
Reduced-intensity; allogeneic transplantation; alemtuzumab; lymphoma
The feasibility of selecting cord blood (CB) units at high-resolution human leukocyte antigen (HLA)-match has not been investigated. We analyzed the high-resolution donor-recipient HLA-match of 100 double-unit 4–6/6 HLA-A,-B antigen, -DRB1 allele-matched CB grafts (units 1a and 1b) and their back-up units (n = 377 units in total). The median cryopreserved graft dose was 2.9 × 107/kg/unit, and at high-resolution these units had a median donor-recipient HLA-allele match of 5/8 (range 2–8/8) and 6/10 (range 2–9/10), respectively. We then evaluated how often use of high-resolution HLA-match criteria would change the original graft selection to substitute one or both of the back-up units for units 1a and/or 1b. Using a model in which both a higher 8-allele HLA-match and cell dose ≥ 2.0 × 107/kg/unit were required, graft selection changed in 33% of transplants with minimal effect on cell dose (8.3% reduction). In summary, while units chosen based on HLA-A,-B antigen, -DRB1 allele-match have substantial mismatch at higher resolution, CB selection based on high-resolution HLA-match is possible in a significant proportion of patients without compromise in cell dose.
cord blood transplantation; human leukocyte antigen allele match; unit selection
Lenalidomide is an agent that has shown great activity in patients with multiple myeloma. However, studies have suggested that this drug negatively affects subsequent stem cell collection. To investigate whether lenalidomide impairs stem cell mobilization and collection, we reviewed data for patients with multiple myeloma who underwent mobilization with filgrastim. Predictors of mobilization failure were evaluated using logistic regression analysis. In 26 (9%) of 302 myeloma patients, stem cell mobilization failed. Mobilization failed in 25% of patients who had previously received lenalidomide, compared with 4% of patients who had not received lenalidomide (P < .001). In a multivariate analysis, prior lenalidomide use (odds ratio, 5.9; 95% CI, 2.4 to 14.3) and mobilization more than 1 year after diagnosis (odds ratio, 4.6; 95% CI, 1.9 to 11.1) were significantly associated with failed mobilization. Twenty-one of 26 patients in whom mobilization with filgrastim failed underwent remobilization with chemotherapy and filgrastim; in 18 (86%) of these 21 patients, stem cells were successfully mobilized and collected. In patients with multiple myeloma, prior lenalidomide therapy is associated with failure of stem cell mobilization with filgrastim. Remobilization with chemotherapy and filgrastim is usually successful in these patients.
Leukemic transformation (LT) from myelofibrosis has a very poor prognosis with the current treatment strategies. We hypothesized that allogeneic stem cell transplantation (ASCT) can improve outcomes for patients with LT, and reviewed 55 consecutive patients that were treated for myelofibrosis with ASCT at our institution. Fourteen patients (25%) were identified to have LT. Thirteen of these patients received induction chemotherapy and 6 achieved remission at the time of transplant. Conditioning regimen was melphalan (Mel)-based in 9 patients. All patients engrafted and achieved remission after transplant, whereas 4 subsequently relapsed. After a median follow-up of 31 months, 6 patients (49%) survived long term. Although limited by a small number of patients, this study suggests that patients with myelofibrosis and LT may achieve long-term remission after induction chemotherapy and ASCT.
Myelofibrosis; Leukemic transformation; Allogeneic stem cell transplantation
The purpose of this study was to determine the effect of alemtuzumab on treatment-related mortality (TRM), relapse, overall survival (OS), and disease-free survival (DSF) in patients with acute myelogenous leukemia (AML) and myelodysplastic syndromes (MDS) undergoing reduced intensity conditioning (RIC). We compared the outcome of 95 patients treated at the University of Chicago with fludarabine melphalan (Flu + Mel) + alemtuzumab conditioning and 59 patients treated at the M.D. Anderson Cancer Center with Flu + Mel conditioning. Both groups had similar patient and donor characteristics. There were no significant differences in TRM, relapse, survival, and DFS between the 2 groups. The incidence of acute graft-versus-host disease (aGVHD) grade II–IV (relative risk [RR] 5.5, P <.01) and chronic GVHD (cGVHD) (RR 6.6, P <.01) were significantly lower in patients receiving alemtuzumab. The addition of alemtuzumab to an RIC regimen dramatically reduces the incidence of aGVHD and cGVHD in patients with AML and MDS undergoing allogeneic transplantation. TRM, relapse risk, OS and DFS are not affected.
Allogeneic transplant; AML; MDS; T cell depletion; Alemtuzumab
While donor-specific anti-HLA antibodies (DSA) have been implicated in graft rejection in solid organ transplantation, their role in hematopoietic stem cell transplantation (HSCT) remains unclear.
To address the hypothesis that the presence of DSA contributes to the development graft failure, we tested 24 consecutive patients for the presence of anti-HLA antibodies determined by a highly sensitive and specific solid-phase/single-antigen assay. The study included a total of 28 haploidentical transplants, each with 2–5 HLA allele mismatches, at a single institution, from 9/2005 to 8/2008.
DSA were detected in five patients (21%). Three out of 4 (75%) patients with DSA prior to the first transplant failed to engraft, compared with 1 out of 20 (5%) without DSA (p=0.008). All 4 patients who experienced primary graft failure had second haploidentical transplants. One patient developed a second graft failure with persistent high DSA levels, while 3 engrafted, 2 of them in the absence of DSA. No other known factors that could negatively influence engraftment were associated with the development of graft failure in these patients.
These results suggest that donor-specific anti-HLA antibodies are associated with a high rate of graft rejection in patients undergoing haploidentical stem cell transplantation. Anti-HLA sensitization should be evaluated routinely in hematopoietic stem cell transplantation with HLA mismatched donors.
Donor-specific anti-HLA antibodies; primary graft failure; haploidentical stem cell transplantation
A total of 36 consecutive patients with AML in CR underwent reduced-intensity allogeneic hematopoietic SCT (RISCT) with fludarabine and melphalan conditioning. All patients were ineligible for myeloablative transplantation because of age or comorbidity. In total, 30 patients were in first CR and six patients were in second CR. Donors were siblings in 21 (58%) patients and were unrelated in 15 (42%) patients. Hematopoietic cell transplant specific comorbidity scores ≥3 were present in 26 (72%) patients. With a median follow-up of 52 months (range, 34–103 months), OS and PFS rates at 4 years were 71% (s.e., 8%) and 68% (s.e., 8%), respectively. At 4 years, the cumulative incidence of non-relapse mortality was 20% (s.e., 7%) and of relapse mortality was 8% (s.e., 5%). Neither OS nor PFS was affected by older age (>60 years), unrelated donor, melphalan dose, or comorbidity score. At last follow up, of the 24 surviving patients, 21 (88%) had performance status (ECOG) of 0 without any active chronic GVHD requiring steroids. Hence, RISCT with fludarabine and melphalan conditioning produces durable long-term remission in older patients with AML.
reduced intensity allogeneic transplantation; AML; hematopoietic SCT
In the 2nd NCI Workshop on the Biology, Prevention, and Treatment of Relapse After Hematopoietic Stem Cell Transplantation, the Scientific/Educational Session on the Prevention and Treatment of Relapse after Allogeneic Transplantation highlighted progress in developing new therapeutic approaches since the 1st Relapse Workshop. Recent insights that might provide a basis for the development of novel, practical clinical trials were emphasized, including utilization of newer agents, optimization of donor lymphocyte infusion (DLI), and investigation of novel cellular therapies. Dr. de Lima discussed preemptive and maintenance strategies to prevent relapse after transplantation, e.g., recent promising results suggestive of enhanced graft-versus-tumor activity with hypomethylating agents. Dr. Schmid provided an overview of adjunctive strategies to improve cell therapy for relapse, including cytoreduction prior to DLI, combination of targeted agents with DLI, and considerations in use of second transplants. Dr. Porter addressed strategies to enhance T-cell function, including ex-vivo activated T cells and T-cell engineering, and immunomodulatory approaches to enhance T-cell function in vivo, including exogenous cytokines and modulation of costimulatory pathways.