Role of mesenchymal stem cell conditioned medium on wound healing using a developed 3D skin model.

Alternative 3-dimensional (3D) skin models that replicate in vivo human skin are required to investigate important events during wound healing, such as collective cell migration, epidermal layer formation, dermal substrate formation, re-epithelialisation and collagen production. In this study, a matched human 3D skin equivalent model (3D-SEM) was developed from human skin cells (fibroblast and keratinocytes), characterised using haematoxylin and eosin, immunofluorescence staining and microRNA profiling. The 3D-SEM was then functionally tested for its use in wound healing studies. Mesenchymal stem cells (MSCs) were isolated and characterised according to the criteria stipulated by the International Society for Cell Therapy. Cytokine and growth factor secretions were analysed by enzyme-linked immunosorbent assay. MSC-conditioned medium (MSC-CM) was then tested for wound healing capacity using the developed 3D-SEM at different timepoints i.e., at one, two and four weeks. The constructed 3D-SEM showed consistent development of skin-like structures composed of dermal layers and epidermal layers, with the ability to express epidermal differentiation markers and full stratification. They also showed prolonged longevity in culture media, retaining full differentiation and stratification within the four weeks. MicroRNA profiling revealed a strong correlation in microRNA expression between the developed 3D-SEM and the original native skin (p<0.001; R=0.64). Additionally, MSC-CM significantly enhanced migration, proliferation and differentiation of epidermal cells in the wounded models compared to control models at the different timepoints. In conclusion, in this study, the developed 3D-SEM mimicked native skin at the cellular and molecular levels, and clearly showed the important stages of skin regeneration during the healing process. MSC secretome contains growth factors that play a pivotal role in the healing process and could be used as a therapeutic option to accelerate skin healing.

Autophagy gene Atg16L1 prevents lethal T cell alloreactivity mediated by dendritic cells.

Atg16L1 mediates the cellular degradative process of autophagy and is considered a critical regulator of inflammation based on its genetic association with inflammatory bowel disease. Here we find that Atg16L1 deficiency leads to an exacerbated graft-versus-host disease (GVHD) in a mouse model of allogeneic hematopoietic stem cell transplantation (allo-HSCT). Atg16L1-deficient allo-HSCT recipients with GVHD displayed increased T cell proliferation due to increased dendritic cell (DC) numbers and costimulatory molecule expression. Reduced autophagy within DCs was associated with lysosomal abnormalities and decreased amounts of A20, a negative regulator of DC activation. These results broaden the function of Atg16L1 and the autophagy pathway to include a role in limiting a DC-mediated response during inflammatory disease, such as GVHD.

An in vitro human assay for evaluating immunogenic and sensitization potential of a personal care and cosmetic product.

With the reduction or elimination of animal testing, manufacturers are left with limited options, as few robust in vitro tests are available and human studies are costly. Recently, concerns have been raised regarding potential adverse health effects associated with use of WEN by Chaz Dean (WCD) cleansing conditioners. The purpose of this study was to evaluate the immunogenic potential of a WCD hair cleansing conditioner by utilizing a novel in vitro human skin explant test. Peripheral blood mononuclear cells (PBMCs) and human skin biopsies were obtained from healthy volunteers. Monocyte derived dendritic cells (MoDCs) were generated, primed by 0.01% WCD cleansing conditioner exposure for 24 h, co-cultured with autologous lymphocytes for 4 days, and then cultured with skin biopsies for 3 days. The skin biopsies then underwent histopathological evaluation, and T cell proliferation and IFNγ levels were determined. Overall, this study showed that treatment with 0.01% WCD cleansing conditioner resulted in a negative prediction for in vivo immune response. Further, this analysis shows that the skin explant test is a viable alternative to animal testing for complex mixtures or commercially available products.

The influence of glucocorticoid receptor single nucleotide polymorphisms on outcome after haematopoietic stem cell transplantation.

Haematopoietic stem cell transplantation (HSCT) remains the only cure for most haematological malignancies, however, the mortality rate remains high. Complications after HSCT include relapse, graft versus host disease (GvHD), graft rejection and infection. Over the last few years several groups, have demonstrated that non-HLA gene polymorphisms can be predictive of outcome after HSCT. Since the glucocorticoid cortisol is pivotal in the regulation of the immune system, we decided to examine single nucleotide polymorphisms (SNPs; rs6198, rs33388 and rs33389) within the glucocorticoid receptor (GR) and correlate with HSCT outcome. The training set consisted of patients (n = 458) who underwent HSCT for acute leukaemia between 1983 and 2005. In the recipients, the absence of the ACT haplotype and absence of the T allele of rs33388 were associated with decreased OS and the absence of the ACT haplotype, the absence of the T allele of rs33388 and the presence of the ATA haplotype were associated with increased risk of relapse. In addition, the presence of the ACT haplotype in the recipient showed a trend to be associated with increased risk of chronic graft versus host disease (cGvHD). The patients in this cohort received mainly myeloablative conditioning (n = 327). The SNPs in the glucocorticoid receptor were then investigated in a validation set (n = 251) of HSCT patients transplanted for acute leukaemia from 2006. This cohort contained significantly more patients that had received reduced intensity conditioning (RIC). Some of the results could be validated in these patients. However, contrary to the training set, the absence of the haplotype ACT in the donor in this cohort was associated with increased risk of cGvHD. Differences in the conditioning were shown to influence the results. These results are the first to associate GR SNPs with HSCT outcome and demonstrate the inherent problems of replicating SNP association studies in HSCT, due to different pre-transplant regimens.

Impact of Alemtuzumab Scheduling on Graft-versus-Host Disease after Unrelated Donor Fludarabine and Melphalan Allografts.

Alemtuzumab conditioning is highly effective at reducing the incidence of acute and chronic graft-versus-host disease (GVHD) in reduced-intensity fludarabine and melphalan transplantation with cyclosporine monotherapy. Less frequent and lower dose scheduling may be used with sibling donors, but an optimal regimen for matched unrelated donors has not been defined. In this retrospective observational study of 313 patients, the incidence and severity of GVHD was compared in patients receiving 3 different dose schedules: the standard 100-mg regimen (20 mg on days -7 to -3), 60 mg (30 mg on days -4 and -2), or 50 mg (10 mg on days -7 to -3). Patients treated with 100 mg, 60 mg, or 50 mg developed acute GVHD grades I to IV with an incidence of 74%, 65%, and 64%, respectively, whereas 36%, 32%, and 41% developed chronic GHVD. An excess of severe acute grades III/IV GVHD was observed in the 50-mg cohort (15% versus 2% to 6%; P = .016). The relative risk of severe acute grade GVHD remained more than 3-fold higher in the 50-mg cohort compared with the 100-mg cohort after adjustment for differences in HLA match, age, gender mismatch, cytomegalovirus risk, and diagnosis (P = .030). The findings indicate that the 60-mg alemtuzumab schedule was comparable with the 100-mg schedule, but more attenuated schedules may increase the risk of severe grade GVHD.

Regulation of advanced therapy medicinal products in Europe and the role of academia.

BACKGROUND AIMS: Advanced therapy medicinal products (ATMP) are gene therapy, somatic cell therapy or tissue-engineered products regulated under (EC) No. 1394/2007 to ensure their free movement within the European Union while guaranteeing the highest level of health protection for patients. Academic good manufacturing practice (GMP) centers are major contributors in the development of ATMPs and this study assessed the impact of regulations on them. METHODS: European academic and non-industrial facilities (n = 747) were contacted, and a representative sample of 50 replied to a detailed questionnaire. Experienced centres were further selected in every Member State (MS) for semi-structured interviews. Indicators of ATMP production and development success were statistically assessed, and opinions about directive implementation were documented. RESULTS: Facilities experienced in manufacturing cell therapy transplant products are the most successful in developing ATMPs. New centres lacking this background struggle to enter the field, and there remains a shortage of facilities in academia participating in translational research. This is compounded by heterogeneous implementation of the regulations across MS. CONCLUSIONS: GMP facilities successfully developing ATMPs are present in all MS. However, the implementation of regulations is heterogeneous between MS, with substantial differences in the definition of ATMPs and in the approved manufacturing environment. The cost of GMP compliance is underestimated by research funding bodies. This is detrimental to development of new ATMPs and commercialization of any that are successful in early clinical trials. Academic GMP practitioners should strengthen their political visibility and contribute to the development of functional and effective European Union legislation in this field.

Functional and Molecular Analysis of Human Osteoarthritic Chondrocytes Treated with Bone Marrow-Derived MSC-EVs.

Osteoarthritis (OA) is a degenerative joint disease, causing impaired mobility. There are currently no effective therapies other than palliative treatment. Mesenchymal stromal cells (MSCs) and their secreted extracellular vesicles (MSC-EVs) have shown promise in attenuating OA progression, promoting chondral regeneration, and modulating joint inflammation. However, the precise molecular mechanism of action driving their beneficial effects has not been fully elucidated. In this study, we analyzed MSC-EV-treated human OA chondrocytes (OACs) to assess viability, proliferation, migration, cytokine and catabolic protein expression, and microRNA and mRNA profiles. We observed that MSC-EV-treated OACs displayed increased metabolic activity, proliferation, and migration compared to the controls. They produced decreased proinflammatory (Il-8 and IFN-γ) and increased anti-inflammatory (IL-13) cytokines, and lower levels of MMP13 protein coupled with reduced expression of MMP13 mRNA, as well as negative microRNA regulators of chondrogenesis (miR-145-5p and miR-21-5p). In 3D models, MSC-EV-treated OACs exhibited enhanced chondrogenesis-promoting features (elevated sGAG, ACAN, and aggrecan). MSC-EV treatment also reversed the pathological impact of IL-1ß on chondrogenic gene expression and extracellular matrix component (ECM) production. Finally, MSC-EV-treated OACs demonstrated the enhanced expression of genes associated with cartilage function, collagen biosynthesis, and ECM organization and exhibited a signature of 24 differentially expressed microRNAs, associated with chondrogenesis-associated pathways and ECM interactions. In conclusion, our data provide new insights on the potential mechanism of action of MSC-EVs as a treatment option for early-stage OA, including transcriptomic analysis of MSC-EV-treated OA, which may pave the way for more targeted novel therapeutics.

Inducible heat shock protein 70 reduces T cell responses and stimulatory capacity of monocyte-derived dendritic cells.

Heat shock protein 70 (Hsp70) has gained a lot of attention in the past decade due to its potential immunoregulatory functions. Some of the described proinflammatory functions of Hsp70 became controversial as they were based on recombinant Hsp70 proteins specimens, which were later shown to be endotoxin-contaminated. In this study we used low endotoxin inducible Hsp70 (also known as Hsp72, HSPA1A), and we observed that after a 24-h incubation of monocyte-derived immature dendritic cells (mo-iDCs) with 20 µg/ml of low endotoxin Hsp70, their ability to stimulate allogenic T cells was reduced. Interestingly, low endotoxin Hsp70 also significantly reduced T cell responses when they were simulated with either IL-2 or phytohemagglutinin, therefore showing that Hsp70 could alter T cell responses independently from its effect on mo-iDCs. We also reported a greater response of Hsp70 treatment when activated versus nonactivated T cells were used. This effect of Hsp70 was similar for all tested populations of T cells that included CD3(+), CD4(+), or CD8(+). Taken together, our observations strongly suggest that Hsp70 might dampen, rather than provoke, T cell-mediated inflammatory reactions in many clinical conditions where up-regulation of Hsp70 is observed.

Differential expression of miRNAs from extracellular vesicles in chronic graft-versus-host disease: A preliminary study.

BACKGROUND: Chronic graft-versus-host disease (cGvHD) is a complex disorder that typically manifests after allogeneic hematopoietic stem cell transplantation (HSCT). It is a major cause of non-relapse mortality, which makes finding biomarkers associated with its occurrence a priority. Recent studies increasingly indicate that microRNAs (miRNAs, short regulatory RNA molecules) can be used as biomarkers of various disorders. They can circulate in patients' bodies encapsulated within extracellular vesicles (EVs). OBJECTIVES: To identify miRNAs associated with the occurrence of cGvHD in EVs isolated from the plasma of patients after allogeneic HSCT. MATERIAL AND METHODS: We performed global miRNA expression profiling in a pilot cohort of 3 cGvHD cases and 4 non-cGvHD patients without disease symptoms 90 days after the transplantation (control group). RESULTS: The 2 groups were naturally clustered according to their miRNA profiles using unsupervised hierarchical clustering analysis. We identified 3 miRNAs that were differentially expressed in the cGvHD patients compared to the non-cGvHD patients. The levels of hsa-miR-630 and hsa-miR-374b-5p were lower in the cGvHD patients: 4.1-fold (p = 0.002) and 2.7-fold (p = 0.044), respectively. In contrast, the levels of hsa-miR-29c-3p were 5.8-fold higher (p = 0.004). CONCLUSIONS: Our results suggest that miRNA profiles from plasma EVs may act as markers of cGvHD onset.

MicroRNA profiling of low concentration extracellular vesicle RNA utilizing NanoString nCounter technology.

Extracellular vesicles (EV) and the microRNAs that they contain are increasingly recognised as a rich source of informative biomarkers, reflecting pathological processes and fundamental biological pathways and responses. Their presence in biofluids makes them particularly attractive for biomarker identification. However, a frequent caveat in relation to clinical studies is low abundance of EV RNA content. In this study, we used NanoString nCounter technology to assess the microRNA profiles of n = 64 EV low concentration RNA samples (180-49125 pg), isolated from serum and cell culture media using precipitation reagent or sequential ultracentrifugation. Data was subjected to robust quality control parameters based on three levels of limit of detection stringency, and differential microRNA expression analysis was performed between biological subgroups. We report that RNA concentrations > 100 times lower than the current NanoString recommendations can be successfully profiled using nCounter microRNA assays, demonstrating acceptable output ranges for imaging parameters, binding density, positive/negative controls, ligation controls and normalisation quality control. Furthermore, despite low levels of input RNA, high-level differential expression analysis between biological subgroups identified microRNAs of biological relevance. Our results demonstrate that NanoString nCounter technology offers a sensitive approach for the detection and profiling of low abundance EV-derived microRNA, and may provide a solution for research studies that focus on limited sample material.

HSP70 natively and specifically associates with an N-terminal dermcidin-derived peptide that contains an HLA-A*03 antigenic epitope.

Tumor cells very often have elevated expression of HSP70, the anti-apoptotic properties of which contribute to overall tumor survival. Independent of its anti-apoptotic properties, HSP70 was also suggested to be involved in the antigen presentation process by chaperoning cytosolic peptides, thus protecting them from rapid degradation and securing the peptide pool for further processing. In this study, we identified a 33-amino acid N-terminal dermcidin (DCD)-derived peptide from the repertoire of in vivo HSP70-associated peptides isolated from a leukemic cell line, K562. The DCD peptide has been previously shown to be involved in tumorigenesis, to increase tumor survival rate, to improve tumor stress resistance, and to aid growth. We show that HSP70 is a specific binding partner for the DCD prosurvival peptide and define an ATP-dependent DCD-binding site (GNPCH). We also identify an HLA-A*03 antigenic epitope within the DCD peptide, which follows and partially overlaps the HSP70-binding site (CHEASAAQK). This study describes the interaction between HSP70 and the DCD-derived prosurvival peptide, an interaction that may direct the peptide toward antigen presentation and independently contribute to the prosurvival mechanism mediated by DCD.

The fate of human Langerhans cells in hematopoietic stem cell transplantation.

Langerhans cells (LC) and other antigen-presenting cells are believed to be critical in initiating graft versus host responses that influence the outcome of allogeneic hematopoietic stem cell transplantation. However, their fate in humans is poorly understood. We have sought to define the effect of conditioning regimes and graft versus host disease (GVHD) on the survival of recipient LC and reconstitution of donor cells after transplant. Confocal microscopy of epidermal sheets shows that full intensity transplant (FIT) depletes LC more rapidly than reduced intensity transplant (RIT) at day 0, although the nadir is similar in both at 14-21 d. Recovery occurs rapidly within 40 d in the absence of acute GVHD, but is delayed beyond 100 d when GVHD is active. LC chimerism was determined in sex-mismatched transplants using a two-step Giemsa/fluorescence in situ hybridization assay on isolated cells. Acquisition of donor chimerism at 40 d is more rapid after FIT (97%) than RIT (36.5%), irrespective of blood myeloid engraftment. At 100 d, all transplants achieve at least 90% LC donor chimerism and over half achieve 100%. Complete donor chimerism is associated with prior acute cutaneous GVHD, suggesting a role for allogeneic T cells in promoting LC engraftment.

Analysis of non-HLA genomic risk factors in HLA-matched unrelated donor hematopoietic cell transplantation for chronic myeloid leukemia.

BACKGROUND: Allogeneic hematopoietic cell transplantation is the main curative therapy for patients with chronic myeloid leukemia who do not respond to tyrosine kinase inhibitors. It has been proposed that non-human leukocyte antigen gene polymorphisms influence outcome after hematopoietic cell transplantation and could be used alongside traditional patient-donor and transplant characteristics to create a recipient risk profile associated with allogeneic hematopoietic cell transplantation. DESIGN AND METHODS: A previous study from the European Group for Blood and Marrow Transplantation showed that the absence of recipient tumor necrosis factor receptor II, absence of donor interleukin 10 ATA/ACC and presence of donor interleukin 1 receptor antagonist allele 2 genotypes were associated with decreased survival and increased non-relapse mortality in adult patients with chronic myeloid leukemia undergoing myeloablative human leukocyte antigen-identical sibling transplantation. To explore these associations in unrelated donor transplantation, these polymorphisms were genotyped in 383 adult patients with chronic myeloid leukemia who underwent hematopoietic cell transplantation from unrelated donors matched for 10/10 human leukocyte antigens. RESULTS: The polymorphisms were not associated with overall survival, non-relapse mortality, relapse or acute graft-versus-host disease in the unrelated donor cohort. Comparison of the unrelated donor and human leukocyte antigen-identical sibling cohorts showed differences in survival and clinical characteristics. CONCLUSIONS: We did not confirm that non-human leukocyte antigen polymorphisms were associated with outcomes in myeloablative unrelated donor hematopoietic cell transplantation for chronic myeloid leukemia, possibly because of the strong association between clinical variables and outcome which masked more subtle genetic effects.

Cell-based therapy in prophylaxis and treatment of chronic graft-versus-host disease.

Hematopoietic allogeneic stem cell transplantation (allo-SCT) is a curative option for patients with hematological malignancies. However, due to disparities in major and minor histocompatibility antigens between donor and recipient, severe inflammatory complications can occur, among which chronic graft-versus-host disease (cGVHD) can be life-threatening. A classical therapeutic approach to the prevention and treatment of cGVHD has been broad immunosuppression, but more recently adjuvant immunotherapies have been tested. This review summarizes and discusses immunomodulatory approaches with T cells, including chimeric antigen receptor (CAR) and regulatory T cells, with natural killer (NK) cells and innate lymphoid cells (ILCs), and finally with mesenchymal stromal cells (MSC) and extracellular vesicles thereof. Clinical studies and pre-clinical research results are presented likewise.

Fluorine labelling of therapeutic human tolerogenic dendritic cells for 19F-magnetic resonance imaging.

Tolerogenic dendritic cell (tolDC) therapies aim to restore self-tolerance in patients suffering from autoimmune diseases. Phase 1 clinical trials with tolDC have shown the feasibility and safety of this approach, but have also highlighted a lack of understanding of their distribution in vivo. Fluorine-19 magnetic resonance imaging (19F-MRI) promises an attractive cell tracking method because it allows for detection of 19F-labelled cells in a non-invasive and longitudinal manner. Here, we tested the suitability of nanoparticles containing 19F (19F-NP) for labelling of therapeutic human tolDC for detection by 19F-MRI. We found that tolDC readily endocytosed 19F-NP with acceptable effects on cell viability and yield. The MRI signal-to-noise ratios obtained are more than sufficient for detection of the administered tolDC dose (10 million cells) at the injection site in vivo, depending on the tissue depth and the rate of cell dispersal. Importantly, 19F-NP labelling did not revert tolDC into immunogenic DC, as confirmed by their low expression of typical mature DC surface markers (CD83, CD86), low secretion of pro-inflammatory IL-12p70, and low capacity to induce IFN-γ in allogeneic CD4+ T cells. In addition, the capacity of tolDC to secrete anti-inflammatory IL-10 was not diminished by 19F-NP labelling. We conclude that 19F-NP is a suitable imaging agent for tolDC. With currently available technologies, this imaging approach does not yet approach the sensitivity required to detect small numbers of migrating cells, but could have important utility for determining the accuracy of injecting tolDC into the desired target tissue and their efflux rate.

In situ dissection of the graft-versus-host activities of cytotoxic T cells specific for minor histocompatibility antigens.

Minor histocompatibility antigens (mHags) are immunogenic peptides from polymorphic cellular proteins that induce strong T-cell responses after human leukocyte antigen (HLA)-matched, mHag-mismatched stem-cell transplantation. mHags with broad or limited tissue expression are target antigens for graft-versus-host (GvH) and graft-versus-leukemia (GvL) reactivities. Separation of these activities is crucial for adoptive immunotherapy of leukemia without GvH disease. Therefore, using a skin-explant assay we investigated the in situ activities of cytotoxic T lymphocytes (CTLs) specific for the ubiquitously expressed mHag H-Y and for the hematopoietic-restricted mHags HA-1 and HA-2. H-Y-specific CTLs, visualized by tetrameric HLA-mHag peptide complexes, infiltrated male skin sections within 24 hours, induced severe GvH reactions of grade III-IV and produced high levels of IFN-gamma. In contrast, CTLs specific for the hematopoietic system-specific mHags HA-1 and HA-2 induced no or low GvH reactions above background and produced little or no interferon-gamma, unless the skin sections were preincubated with HA-1/HA-2 synthetic peptides. These results provide the first in situ dissection of GvH effects by mHag-specific CTLs and show that ubiquitously expressed mHags are the prime targets of GvH disease.

Exploring the Extracellular Vesicle MicroRNA Expression Repertoire in Patients with Rheumatoid Arthritis and Ankylosing Spondylitis Treated with TNF Inhibitors.

Rheumatoid arthritis (RA) and ankylosing spondylitis (AS) belong to the most common inflammatory rheumatic diseases. MicroRNAs (miRNAs) are small 18-22 RNA molecules that function as posttranscriptional regulators. They are abundantly present within extracellular vesicles (EVs), small intercellular communication vesicles that can be found in bodily fluids and that have key functions in pathological and physiological pathways. Recently, EVs have gained much interest because of their diagnostic and therapeutic potential. Using NanoString profiling technology, the miRNA repertoire of serum EVs was determined and compared in RA and AS patients before and after anti-TNF therapy to assess its potential use as a diagnostic and prognostic biomarker. Furthermore, possible functional effects of those miRNAs that were characterized by the most significant expression changes were evaluated using in silico prediction algorithms. The analysis revealed a unique profile of differentially expressed miRNAs in RA and AS patient serum EVs. We identified 12 miRNAs whose expression profiles enabled differentiation between RA and AS patients before induction of anti-TNF treatment, as well as 4 and 14 miRNAs whose repertoires were significantly changed during the treatment in RA and AS patients, respectively. In conclusion, our findings suggest that extracellular vesicle miRNAs could be used as potential biomarkers associated with RA and AS response to biological treatment.

Profiling Tissue and Biofluid miR-155-5p, miR-155*, and miR-146a-5p Expression in Graft vs. Host Disease.

Introduction: Acute graft vs. host disease (aGvHD) is a frequent complication following allogeneic haematopoeitic transplantation (HSCT). Despite recent advances, there are no universally accepted biomarkers to determine development of aGvHD. MicroRNAs miR-146a and miR-155 have been previously associated with aGvHD and show promise as clinically translatable biomarkers. In this study, we performed comprehensive expression profiling of miR-146a, miR-155, and miR-155* expression in aGvHD target tissue and biofluids and relate expression to post-HSCT outcomes. Materials and Methods: MicroRNA expression was assessed by qRT-PCR in gastrointestinal (n = 31) and skin (n = 31) biopsies as well as serum (exploratory cohort n = 34, verification cohort n = 81, diagnostic cohort n = 65) and urine (exploratory cohort n = 30, verification cohort n = 56, diagnostic cohort n = 20) biofluids, including extracellular vesicle (EV) cohorts (serum EV n = 15, urine EV n = 30). Expression was related to aGvHD incidence, severity and overall survival. Results: In GI samples, expression of miR-155 (p = 0.03) and miR-146a (p = 0.03) was higher at aGvHD onset compared to patients with no GvHD. In skin biopsies, expression of miR-155 (p = 0.004) was upregulated in aGvHD patients compared to normal control skin. Expression of miR-146a was higher in aGvHD compared to no aGvHD biopsies (p = 0.002). In serum, miR-155 (p = 0.03) and miR-146a (p = 0.02) expression was higher at day 14 (D14), while in urine expression was elevated at D7 post-HSCT in patients who developed aGvHD compared to those disease-free. This was verified in an independent serum (miR-155 p = 0.005, miR-146a p = 0.003) and urine (miR-155 p = 0.02, miR-146a p = 0.04) cohort, where both microRNAs were also associated with aGvHD by ROC analysis. In serum and urine samples taken at the time of aGvHD symptoms, expression of miR-155 and miR-146a was also elevated (serum miR-155 p = 0.03, miR-146a p < 0.001; urine miR-155 p = 0.02, miR-146a p = 0.02). In contrast, miR-146a and miR-155 were downregulated at D14 in serum EVs and at D7 in urine EVs in patients who developed aGvHD compared to those that remained disease-free, in both an exploratory (serum miR-155 p = 0.02, miR-146a p = 0.06; urine miR-155 p = 0.02, miR-146a p = 0.07) and an independent cohort (serum miR-155 p = 0.01, miR-146a p = 0.02). Conclusions: These results further support a role for miR-155 and miR-146a as non-invasive, clinically relevant biomarkers for aGvHD. However, the link between their involvement in generalized inflammation and in specific pathophysiology requires further investigation at a systemic level.

Genome-wide association study identifies susceptibility loci for acute myeloid leukemia.

Acute myeloid leukemia (AML) is a hematological malignancy with an undefined heritable risk. Here we perform a meta-analysis of three genome-wide association studies, with replication in a fourth study, incorporating a total of 4018 AML cases and 10488 controls. We identify a genome-wide significant risk locus for AML at 11q13.2 (rs4930561; P = 2.15 × 10-8; KMT5B). We also identify a genome-wide significant risk locus for the cytogenetically normal AML sub-group (N = 1287) at 6p21.32 (rs3916765; P = 1.51 × 10-10; HLA). Our results inform on AML etiology and identify putative functional genes operating in histone methylation (KMT5B) and immune function (HLA).

Impact of genomic risk factors on outcome after hematopoietic stem cell transplantation for patients with chronic myeloid leukemia.

BACKGROUND: Non-HLA gene polymorphisms have been shown to influence outcome after allogeneic hematopoietic stem cell transplantation. Results were derived from heterogeneous, small populations and their value remains a matter of debate. DESIGN AND METHODS: In this study, we assessed the effect of single nucleotide polymorphisms in genes for interleukin 1 receptor antagonist (IL1RN), interleukin 4 (IL4), interleukin 6 (IL6), interleukin 10 (IL10), interferon (IFNG), tumor necrosis factor (TNF) and the cell surface receptors tumor necrosis factor receptor II (TNFRSFIB), vitamin D receptor (VDR) and estrogen receptor alpha (ESR1) in a homogeneous cohort of 228 HLA identical sibling transplants for chronic myeloid leukemia. Three good predictors of overall survival, identified via statistical methods including Cox regression analysis, were investigated for their effects on transplant-related mortality and relapse. Predictive power was assessed after integration into the established European Group for Blood and Marrow Transplantation (EBMT) risk score. RESULTS: Absence of patient TNFRSFIB 196R, absence of donor IL10 ATA/ACC and presence of donor IL1RN allele 2 genotypes were associated with increased transplantation-related mortality and decreased survival. Application of prediction error and concordance index statistics gave evidence that integration improved the EBMT risk score. CONCLUSIONS: Non-HLA genotypes were associated with survival after allogeneic hematopoietic stem cell transplantation. When three genetic polymorphisms were added into the EBMT risk model they improved the goodness of fit. Non-HLA genotyping could, therefore, be used to improve donor selection algorithms and risk assessment prior to allogeneic hematopoietic stem cell transplantation.