Citations

Regenerative medicine with the use of stem cells has appeared as a potential therapeutic alternative for many disease states. Despite initial enthusiasm, there has been relatively slow transition to clinical trials. In large part, numerous questions remain regarding the viability, biology and efficacy of transplanted stem cells in the living subject. The critical issues highlighted the importance of developing tools to assess these questions. Advances in molecular biology and imaging have allowed the successful non-invasive monitoring of transplanted stem cells in the living subject. Over the years these methodologies have been updated to assess not only the viability but also the biology of transplanted stem cells. In this review, different imaging strategies to study the viability and biology of transplanted stem cells are presented. Use of these strategies will be critical as the different regenerative therapies are being tested for clinical use.

Abstract The first two authors and last two authors contributed equally. Genome-wide association studies (GWAS) have identified risk loci for Acute Lymphoblastic Leukemia (ALL), Chronic Lymphoblastic Leukemia (CLL) and Non-Hodgkin Lymphoma, however an Acute Myeloid Leukemia (AML) GWAS has not been published to date. We performed a GWAS to identify AML and Myelodysplastic Syndrome (MDS) risk loci using a nested case-control study design in the DISCOVeRY-BMT cohorts which includes almost 2000 AML and MDS patients as cases and 2813 unrelated donors as controls. Genotyping was performed using the Illumina Human OmniExpress BeadChip and imputed using the Haplotype Reference Consortium, yielding > 8 million high-quality variants for statistical analysis. Logistic regression models with AML (de novo AML with normal cytogenetics, de novo AML with abnormal cytogenetics and therapy-related AML) and MDS cases and European American healthy donor controls adjusted for age and sex were used to test the association of each SNP with disease status. To identify the strongest association signal with disease we conducted a summary statistic SNP-based association analysis (ASSET) using non-overlapping AML and MDS cases implemented in R statistical software. ASSET uses an exhaustive search for SNPs with small but common pleiotropic effects across groups of traits while accounting for the multiple tests required by the subset search, as well as any shared controls between groups. This approach allowed us to further investigate the heterogeneity within AML subtypes and to gain increased power by pooling subtypes that show pleiotropic effects. ASSET genome wide (GW) significance is defined as P<5.0x10-8, however, we present results of each subset analysis. ASSET analyses identified an association of T allele at rs12203592, Interferon Regulatory Factor 4 (IRF4), with increased risk of de novo AML and MDS (Figure 1) (OR=1.37; 95% CI, 1.25-1.51, Pmeta=1.59x10-10). The variant has been reported significant in GWAS of skin pigmentation, hair color, non-melanoma skin cancer, squamous cell carcinoma, actinic keratosis, and childhood ALL; GW case-control studies of neuroblastoma and breast cancer show suggestive association signals (P<5 x 10-6). IRF4 belongs to the IRF family of transcription factors and is a key regulator of differentiation stages in hematopoiesis. The T allele at rs12203592 is associated with significantly increased expression of IRF4 in whole blood and lung tissue and in vitro mouse studies have shown the T allele to be associated with higher levels of IRF4 transcription. rs12203592 is <80bp from an IRF4 transcription start site and in an important position within NF-κB motifs in multiple blood and immune cell lines, supporting the hypothesis that this SNP modulates NF-κB repression of IRF4 expression. Another variant in the IRF4 regulatory region, rs62389423 (A allele), showed a putative association with subsets of de novo AML and MDS (OR=1.36; 95% CI,1.21-1.52, Pmeta=1.2x10-7). Although not in linkage disequilibrium with rs12203592, the A allele has also been previously associated with susceptibility to skin cancer and melanoma in multiple GWAS. Analysis of 596 UKbiobank CLL cases and >300,000 controls, shows the A allele correlates with a 50% increased risk of CLL (95% CI, 1.32-1.73, P= 2.4x10-9).Several other GWAS also show an association between additional IRF4 variants and CLL. Analyses in individual subtypes also revealed an intronic variant, rs10098598, in RAD21 to be associated with de novo AML (OR=2.18; 95% CI, 1.60-2.97; Pmeta=8.9x10-7). RAD21, on8q24, a region known to be associated with multiple cancer types, is involved in DNA double-stranded break repair and in chromatid cohesion in mitotic cells. Loss of function would theoretically lead to chromosomal instability and tumorigenesis. Components of the cohesion complex (including RAD21) are somatically mutated in ~12% of de novo AML and MDS patients, where it is frequently an early event. We provide the first GW evidence of association between a common variant and AML susceptibility. This SNP has been shown to be associated with multiple phenotypes, suggesting that there are pleiotropic effects at work. Our RAD21 finding is consistent with the role of cohesion in leukemogenesis and provides some evidence of its role in de novo AML susceptibility. Replication and further subset analyses with genome-wide data in >2000 AML cases are ongoing. Disclosures Griffiths: Alexion Inc.: Honoraria, Research Funding; Astex/Otsuka Pharmaceuticals: Honoraria, Research Funding; Celgene, Inc: Honoraria, Research Funding; Novartis, Inc.: Research Funding; Pfizer, Inc.: Research Funding. McCarthy:Bristol Myers Squibb: Consultancy, Honoraria; Celgene: Consultancy, Honoraria, Research Funding; Karyopharm: Consultancy, Honoraria; Takeda: Consultancy, Honoraria; Janssen: Consultancy, Honoraria.

Abstract Over the past decade, there have been numerous published candidate gene association studies of non-HLA variants, genes and/or pathways in relation to BMT survival outcomes. Most of these studies investigated a small number of candidate single nucleotide polymorphisms (SNPs), chosen based on known gene function, in a limited number of cases without replication. Here we test the association of previously reported SNPs with survival outcomes (overall survival (OS), progression-free survival (PFS), death due to disease (DD) or transplant-related mortality (TRM)) after URD BMT using data from the DISCOVeRY-BMT (Determining the Influence of Susceptibility Conveying Variants Related to one-Year mortality after BMT) study which included 2,052 European descent recipient-unrelated donor pairs (Cohort 1) and 763 recipient-unrelated donor pairs (Cohort 1) reported to the Center for International Blood and Marrow Transplant Research (CIBMTR) between 2000-2009 and 2009-2011, respectively. DISCOVeRY-BMT is a Genome Wide Association Study (GWAS) that includes over 9 million typed or imputed SNPs. This represents the largest study to date and is well powered to test both SNP and gene-based association hypotheses. We conducted an extensive literature review of PubMed using MESH terms related to transplant and hematologic disease which yielded 76 candidate gene association studies that investigated a total of 46 genes with any survival outcome. Of the 46 genes, 11 genes (CTLA4, CYP2B6, CYP2C19, GSTM1, GSTT1, IL23R, IL6, MTHFR, NOD2/CARD15, TNFSRF1B, and VDR) were studied in at least 2 publications. A total of 16 SNPs in 8 of these genes reported a significant (P< 0.05) association with at least one survival outcome (OS, PFS, DD or TRM). We tested these 16 SNPs for an association with the survival outcome originally reported in each article (Table 1). All association models included age at BMT, diagnosis (AML, ALL, MDS), disease status at BMT, cell source (blood, bone marrow) and year of BMT. P-values from Cohorts 1 and 2 were combined using a fixed-effects model in METAL software. Since the candidate gene studies have a gene-based hypothesis, we also performed gene-level testing using the VErsatile Gene-Based Association Study (VEGAS2) software to measure the aggregate effect of all available typed and imputed SNPs from our GWAS data in these 8 genes. The candidate gene association studies included heterogeneous patient populations of autologous and/or allogeneic (related or unrelated donors) BMT for a variety of hematologic diseases. Most candidate gene studies performed genotyping on both donors and recipients, and SNPs were tested either independently for donor or recipient genomes, or considering the total number of variant alleles the recipient-donor pair had at a given locus (0-4) (Table 1). The 16 SNPs from the previous candidate gene association studies were not significantly associated at a nominal P<0.05 to either the survival outcome reported in the original published paper, or to any survival outcome (Table 1). Likewise, the VEGAS2 gene-based analysis did not reveal any statistically significant associations for any of the 8 genes at P<0.05. Our study also corroborated prior reports of SNPs and genes that were not associated with survival outcomes. Candidate gene association studies use a priori biological knowledge to select genes that are likely associated with outcome and subsequently SNPs within the gene thought likely to affect function based on knowledge at the time of the investigation. Our findings suggest that neither the genetic variation tested in these candidate genes, nor other individual SNPs in the gene independently or collectively are not associated with survival outcomes in recipients of URD BMT. Our failure to replicate the prior candidate gene studies may be due to these SNPs being dependent on the underlying disease (ie. AML, ALL, etc), the donor relation (related, unrelated, autologous), or that there is no true association of these SNPs with the outcomes studied. #These authors contributed equally Table 1. Table 1. Disclosures McCarthy: Gamida Cell: Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Karyopharm: Honoraria, Membership on an entity's Board of Directors or advisory committees; Onyx: Honoraria, Membership on an entity's Board of Directors or advisory committees; Bristol Myers Squibb: Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; The Binding Site: Honoraria, Membership on an entity's Board of Directors or advisory committees; Sanofi: Honoraria, Membership on an entity's Board of Directors or advisory committees. Hahn:Novartis: Equity Ownership; NIH: Research Funding. Sucheston-Campbell:NIH/NCI: Research Funding.

Key PointsIKZF1 associations with high-risk B-ALL may differ by age and sex. A novel variant on chromosome 14, rs189434316, is associated with over a 3.5-fold risk of normal cytogenetic B-ALL.

The comprehensive microscopic, spectroscopic, and in vitro voltammetric analysis presented in this work, which builds on the well-studied properties of carbon-based materials, facilitates potential ways for improvement of carbon fiber microelectrodes (CFMs) for neuroscience applications. Investigations by both, scanning electron microscopy (SEM) and confocal Raman spectroscopy, confirm a higher degree of structural ordering for the fibers exposed to carbonization temperatures. An evident correlation is also identified between the extent of structural defects observed from SEM and Raman results with the CFM electrochemical performance for dopamine detection. To improve CFM physico-chemical surface stability and increase its mechanical resistance to the induced compressive stress during anticipated in vivo tissue penetration, successful coating of the carbon fiber with boron-doped diamond (BDD) is also performed and microspectroscopically analyzed here. The absence of spectral shifts of the diamond Raman vibrational signature verifies that the growth of an unstrained BDD thin film was achieved. Although more work needs to be done to identify optimal parameter values for improved BDD deposition, this study serves as a demonstration of foundational technology for the development of more sensitive electrochemical sensors, that may have been impractical previously for clinical applications, due to limitations in either safety or performance.

Abstract Background A cluster of severe lung disease occurred at a manufacturing facility making industrial machines. We aimed to describe disease features and workplace exposures. Methods Clinical, functional, radiologic, and histopathologic features were characterized. Airborne concentrations of thoracic aerosol, metalworking fluid, endotoxin, metals, and volatile organic compounds were measured. Facility airflow was assessed using tracer gas. Process fluids were examined using culture, polymerase chain reaction, and 16S ribosomal RNA sequencing. Results Five previously healthy male never‐smokers, ages 27 to 50, developed chest symptoms from 1995 to 2012 while working in the facility's production areas. Patients had an insidious onset of cough, wheeze, and exertional dyspnea; airflow obstruction (mean FEV 1 = 44% predicted) and reduced diffusing capacity (mean = 53% predicted); and radiologic centrilobular emphysema. Lung tissue demonstrated a unique pattern of bronchiolitis and alveolar ductitis with B‐cell follicles lacking germinal centers, and significant emphysema for never‐smokers. All had chronic dyspnea, three had a progressive functional decline, and one underwent lung transplantation. Patients reported no unusual nonoccupational exposures. No cases were identified among nonproduction workers or in the community. Endotoxin concentrations were elevated in two air samples; otherwise, exposures were below occupational limits. Air flowed from areas where machining occurred to other production areas. Metalworking fluid primarily grew Pseudomonas pseudoalcaligenes and lacked mycobacterial DNA, but 16S analysis revealed more complex bacterial communities. Conclusion This cluster indicates a previously unrecognized occupational lung disease of yet uncertain etiology that should be considered in manufacturing workers (particularly never‐smokers) with airflow obstruction and centrilobular emphysema. Investigation of additional cases in other settings could clarify the cause and guide prevention.

Objective: The aim of the study was to determine the rate, predictors, and impact of complete pathologic response (cPR) to pretransplant locoregional therapy (LRT) in a large, multicenter cohort of hepatocellular carcinoma (HCC) patients undergoing liver transplantation (LT). Background: LRT is used to mitigate waitlist dropout for patients with HCC awaiting LT. Degree of tumor necrosis found on explant has been associated with recurrence and overall survival, but has not been evaluated in a large, multicenter study. Methods: Comparisons were made among patients receiving pre-LT LRT with (n = 802) and without (n = 2637) cPR from the United States Multicenter HCC Transplant Consortium (UMHTC), and multivariable predictors of cPR were identified using logistic regression. Results: Of 3439 patients, 802 (23%) had cPR on explant. Compared with patients without cPR, cPR patients were younger; had lower Model for End-stage Liver Disease (MELD) scores, AFP levels, and neutrophil–lymphocyte ratios (NLR); were more likely to have tumors within Milan criteria and fewer LRT treatments; and had significantly lower 1-, 3-, and 5-year incidence of post-LT recurrence (1.3%, 3.5%, and 5.2% vs 6.2%, 13.5%, and 16.4%; P < 0.001) and superior overall survival (92%, 84%, and 75% vs 90%, 78%, and 68%; P < 0.001). Multivariable predictors of cPR included age, sex, liver disease diagnosis, MELD, AFP, NLR, radiographic Milan status, and number of LRT treatments (C-statistic 0.67). Conclusions: For LT recipients with HCC receiving pretransplant LRT, achieving cPR portends significantly lower posttransplant recurrence and superior survival. Factors predicting cPR are identified, which may help prioritize patients and guide LRT strategies to optimize posttransplant cancer outcomes.

The term “idiopathic calcifying tenosynovitis” (ICT) refers to a clinically and radiologically defined syndrome of pain and tendinous calcifications, most often involving the shoulder joint. A distinctive subset of ICT cases, termed “tenosynovitis with psammomatous calcifications” (TPC), occurs in the distal extremities and shows characteristic morphology, in particular psammomatous calcifications. As only 14 cases have been reported to date, TPC remains poorly recognized by both pathologists and clinicians. Twenty-three well-characterized cases of TPC along with all available radiologic and clinical information, including follow-up, were collected. Cases occurred in 21 females and 1 male (1 patient of unknown sex), aged 16 to 75 years (mean: 41), and almost exclusively involved the fingers and toes, except for one case in the elbow and one in the knee joint. The lesions ranged from 2 to 30 mm in size (mean: 10 mm). Pain was the most common presenting symptom (12/16 patients). A history of trauma or repetitive activity was present in 6 of 15 patients. None of the individuals was known to have disorders in calcium or phosphate metabolism. Radiographic studies showed a nonspecific, calcified mass. Typical morphologic features of TPC were invariably present, with degenerating tendinous tissue containing psammomatous calcifications, surrounded by a variably cellular, CD68/CD163/CD4-positive histiocyte-rich granulomatous host reaction. HUMARA assay in one case showed a polyclonal pattern. Clinical follow-up (19 patients; mean: 5.2 y; range: 1 to 14 y) showed no local recurrences. In this, the largest study of TPC to date, we confirm striking predilection of this distinctive pseudoneoplasm for the fingers and toes of young to middle-aged women. TPC should be rigorously distinguished from other forms of ICT, which typically involve large, proximal joints, and show simply dystrophic calcification involving tendinous tissues, and from tumoral calcinosis, which also involves large joints and often is associated with calcium and/or phosphate abnormalities. TPC appears to be related to trauma and/or repetitive activity and is cured with simple excision.