Current Concepts of Pathogenesis and Treatment of Philadelphia Chromosome-Negative Myeloproliferative Neoplasms.

Philadelphia chromosome-negative myeloproliferative neoplasms are hematopoietic stem cell disorders characterized by dysregulated proliferation of mature myeloid blood cells. They can present as polycythemia vera, essential thrombocythemia, or myelofibrosis and are characterized by constitutive activation of JAK2 signaling. They share a propensity for thrombo-hemorrhagic complications and the risk of progression to acute myeloid leukemia. Attention has also been drawn to JAK2 mutant clonal hematopoiesis of indeterminate potential as a possible precursor state of MPN. Insight into the pathogenesis as well as options for the treatment of MPN has increased in the last years thanks to modern sequencing technologies and functional studies. Mutational analysis provides information on the oncogenic driver mutations in JAK2, CALR, or MPL in the majority of MPN patients. In addition, molecular markers enable more detailed prognostication and provide guidance for therapeutic decisions. While JAK2 inhibitors represent a standard of care for MF and resistant/refractory PV, allogeneic hematopoietic stem cell transplantation remains the only therapy with a curative potential in MPN so far but is reserved to a subset of patients. Thus, novel concepts for therapy are an important need, particularly in MF. Novel JAK2 inhibitors, combination therapy approaches with ruxolitinib, as well as therapeutic approaches addressing new molecular targets are in development. Current standards and recent advantages are discussed in this review.

Human Amnion Chorion Membrane Allografts in the Treatment of Chronic Diabetic Foot Ulcers: A Literature Review.

OBJECTIVE: To discuss human amnion chorion (placental) membrane allograft (HACMA) use for the treatment of chronic diabetic foot ulcers (DFUs) and to evaluate the effectiveness, cost, and product waste of this therapy. DATA SOURCES: PubMed, Cochrane, and OVID databases. STUDY SELECTION: Twenty-four articles pertaining to HACMA and DFUs published from 2016 to 2020 were selected. DATA EXTRACTION: The data collected included type of wound care product, study design, study size, baseline size of DFU, cost, product wastage, number of applications, and wound healing outcomes. DATA SYNTHESIS: Human amnion chorion membrane allografts in the treatment of chronic DFUs have led to a reduction in healing time and increased the overall percentage of healing, making them more effective in treating DFUs compared with standard of care. These products are offered in multiple sizes with various shelf lives and methods of storage, making them accessible, easy to use, less wasteful, and lower in cost compared with other commercially available products. Promising evidence demonstrates that HACMAs are beneficial in treating complex, high-grade DFUs with exposed tendon or bone. CONCLUSIONS: Human amnion chorion membrane allografts are effective in treating chronic DFUs with a greater percentage of complete wound closure and a reduction in healing time versus standard of care.

Evolution of a Novel Tissue Preservation Protocol to Optimize Osteochondral Transplantation Outcomes.

OBJECTIVE: Osteochondral allograft transplantation is a procedure to treat focal osteochondral lesions (OCLs), but is limited by tissue availability, the quality of transplanted tissue, and inconsistent storage protocols. The objective of this study was to assess the clinical outcomes of a novel tissue procurement, storage, and quality control protocol in treating OCLs. DESIGN: Prospective case series. Donor cadaveric tissue was processed, stored, and the tissue quality analyzed using the unique tissue preservation protocol developed at our institution. Advanced cross-sectional imaging was used to size match donor tissue with recipient patients. Osteochondral allografts were transplanted using the Arthrex Allograft OATS. Patients were evaluated with the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Knee injury and Osteoarthritis Outcome Score (KOOS), visual analog scale (VAS), and 36-Item Short Form Survey (SF-36) preoperatively and at 1 year and 2 years postoperatively. RESULTS: Twenty patients (17 knees, 3 shoulders) were included in the study. There was a significant improvement in the following scores: overall WOMAC score, WOMAC function and pain subcategories; KOOS pain, knee-related symptoms, activities of daily living, sports and recreation, and quality of life; SF-36 physical functioning, physical role, pain, and social functioning subcategories; and VAS at all time points postoperatively. There was a significant improvement in WOMAC stiffness at 2 years postoperatively. There were 2 failures, defined by graft subsidence and persistent pain requiring reoperation. CONCLUSION: The protocol developed at our institution for OAT resulted in significant clinical improvement in patients with OCLs and is an improvement on existing tissue storage techniques.

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A comparison of contiguous two-level anterior cervical discectomy and fusion using a structural allograft versus a Polyetheretherketone (PEEK) cage: the results of a three-year follow-up.

BACKGROUND: Allografts and polyetheretherketone (PEEK) cages are the two most commonly used materials in anterior cervical discectomy and fusion (ACDF). However, their effectiveness in two-level ACDF remains controversial. The primary aim of this retrospective study was to compare the clinical and radiological outcomes of two-level ACDF with plate fixation using either a structural allograft or a PEEK cage. METHODS: From 2010 to 2015, 88 consecutive patients underwent two-level ACDF, of whom 53 received an allograft and 35 patients received a PEEK cage. All PEEK cages were filled with local autografts. All clinical outcomes were prospectively collected before and six months and two years after surgery. Clinical efficacy was evaluated using a visual analogue scale for neck pain and limb pain, the Neck Pain and Disability Score, the Neck Disability Index, the Neurogenic Symptom Score, and the Japanese Orthopedic Association score. Radiological outcomes were assessed preoperatively, immediately after surgery, and at the final follow-up. RESULTS: A preoperative comparison revealed no difference between the two patient groups in terms of age, sex, body mass index, smoking status, preoperative symptoms, operation level, or follow-up (mean = 42.8 months). No differences in the improvements in clinical outcomes were observed between the two groups. Both groups showed significant improvement in mean disc height, segmental height, and segmental lordosis postoperatively. The fusion rate for the PEEK cage was 100% at both levels, while the fusion rate for the allograft group was 98.1% at the cephalad level and 94.2% at the caudad level (p > 0.05). Subsidence at the cephalad level occurred in 22.9% (8/35) of segments in the PEEK group and 7.7% (4/52) of segments in the allograft group (p = 0.057). At the caudal level, a higher incidence of cage subsidence was noted in the PEEK group than in the allograft group [37.1% (13/35) versus 15.4% (8/52)] (p = 0.02). Overall, subsidence was noted in 30% (21/70) of the PEEK group and in 11% (12/104) of the allograft group (p <  0.05). CONCLUSION: The use of PEEK cages resulted in a higher rate of subsidence in two-level ACDF than the use of allografts. Two-level ACDF using either allografts or PEEK cages resulted in similar clinical outcomes, radiological improvements in alignment and fusion rates.

Transcriptome Analysis in Renal Transplant Biopsies Not Fulfilling Rejection Criteria.

The clinical significance of renal transplant biopsies displaying borderline changes suspicious for T-cell mediated rejection (TCMR) or interstitial fibrosis and tubular atrophy (IFTA) with interstitial inflammation has not been well defined. Molecular profiling to evaluate renal transplant biopsies using microarrays has been shown to be an objective measurement that adds precision to conventional histology. We review the contribution of transcriptomic analysis in surveillance and indication biopsies with borderline changes and IFTA associated with variable degrees of inflammation. Transcriptome analysis applied to biopsies with borderline changes allows to distinguish patients with rejection from those in whom mild inflammation mainly represents a response to injury. Biopsies with IFTA and inflammation occurring in unscarred tissue display a molecular pattern similar to TCMR while biopsies with IFTA and inflammation in scarred tissue, apart from T-cell activation, also express B cell, immunoglobulin and mast cell-related genes. Additionally, patients at risk for IFTA progression can be identified by genes mainly reflecting fibroblast dysregulation and immune activation. At present, it is not well established whether the expression of rejection gene transcripts in patients with fibrosis and inflammation is the consequence of an alloimmune response, tissue damage or a combination of both.

Liver Transplantation with "Hors Tour" Allocated Versus Standard MELD Allocated Grafts: Single-Center Audit and Impact on the Liver Pool in France.

BACKGROUND: The French transplant governing system defined "Rescue" (the so-called "Hors Tour") livers as those livers which were declined for the five top-listed patients. This study compares the outcomes following liver transplantation (LT) in patients who received a donor liver through a rescue allocation (RA) procedure or according to MELD score priority (standard allocation, SA) and evaluates the impact on the graft pool of a proactive policy to accept RA grafts. METHODS: Data from all consecutive patients who underwent LT with SA or RA grafts from 2011 to 2015 were compared in terms of short- and long-term outcomes. RESULTS: The 249 elective first LTs were performed with 64 (25.7%) RA and 185 (74.3%) SA grafts. RA grafts were obtained from older donors and were associated with a longer cold ischemia time. Recipients of RA livers were older and had lower MELD scores. The rates of delayed graft function, primary nonfunction, retransplantation, complications, and mortality were similar between the RA and SA groups. At 1 and 3 and 5 years, graft and patient survival rates were similar between the groups. These results were maintained after matching on recipient characteristics. Our proactive policy to accept RA grafts increased the liver pool for elective first transplantation by 25%. CONCLUSIONS: RA livers can be safely transplanted into selected recipients and significantly expand the liver pool.

Chronic Kidney Disease After Liver Transplantation: Impact of Extended Criteria Grafts.

The use of extended criteria donor (ECD) grafts has been associated with acute kidney injury (AKI) after liver transplantation. However, the relation between graft quality and development of chronic kidney disease (CKD) remains unknown. Therefore, the aim of this study was to analyze the impact of ECD grafts for CKD after liver transplantation. All patients (2007-2015) transplanted for end-stage liver disease at our center were assessed. Longterm kidney function was divided into 4 groups: no CKD (estimated glomerular filtration rate [eGFR], ≥60 mL/minute/1.73 m2 ), mild CKD (eGFR, 30-59 mL/minute/1.73 m2 ), severe CKD (eGFR, 15-29 mL/minute/1.73 m2 ), and end-stage renal disease (ESRD). Marginal donation after brain death (DBD) grafts (donor age, >70 years; body mass index, >35 kg/m2 ; cold storage, >12 hours) and donation after circulatory death (DCD) grafts were considered ECD grafts. Overall, 926 patients were included, and 43% received an ECD graft (15% marginal DBD; 28% DCD). After 5 years, 35% developed CKD; severe CKD and ESRD occurred in only 2% and 1%, respectively. CKD rates were comparable for all 3 graft groups (standard group, 36%; marginal DBD group, 29%; DCD group, 35%; standard versus marginal DBD groups, P = 0.16; standard versus DCD group, P = 0.80). None of the ECD criteria were identified as independent risk factors in a Cox regression model for CKD. Risk factors included recipient age, female sex, and preoperative kidney function. Furthermore, recipients who had severe acute kidney injury (AKI; Kidney Disease: Improving Global Outcomes stages 2 and 3) had a 1.8-fold increased risk for CKD. Longterm kidney function of recipients with severe AKI depended on the recovery of kidney function in the first postoperative week. In conclusion, there is no direct relation between the use of ECD grafts and CKD after liver transplantation. However, caution should be taken in recipients who experience severe AKI, regardless of graft type.

Association of baseline histopathology and kidney donor risk index with graft outcomes in deceased donor kidney transplantation
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BACKGROUND: Donor organ quality is a key determinant of graft outcomes in deceased donor kidney transplantation (DDKT). The predictive values of baseline histopathology and several clinical scoring systems for long-term graft outcomes have been evaluated, but the results remain controversial. MATERIALS AND METHODS: We screened 167 patients who underwent DDKT at Ulsan University Hospital from April 2003 to June 2016. Among them, 66 patients who underwent baseline kidney biopsy and whose kidney donor risk index (KDRI) was available were included in this analysis. All baseline biopsies were rescored according to the updated Banff classification. RESULTS: Median follow-up was 22 months. Mean age of recipients and donors was 51.4 and 44.7 years, respectively. Mean KDRI was 1.40 ± 0.44. During follow-up, delayed graft function and biopsy-proven acute rejection (BPAR) developed in 7 and 11 patients, respectively. Graft failure occurred in 2 patients. In Cox regression analysis, interstitial fibrosis/tubular atrophy (IFTA) (hazard ratio (HR) = 3.59; p = 0.049) was a significant risk factor for BPAR. In multivariate linear regression, age (standardized ß (SB) = -0.282; p = 0.002), BPAR (SB = -0.406; p < 0.001), KDRI (SB = -0.277; p = 0.003), and IFTA (SB = -0.298; p = 0.001) were significant predictors of last-visit estimated glomerular filtration rate (eGFR). CONCLUSION: Several clinical and pathologic parameters, such as KDRI and IFTA, may be helpful for predicting long-term graft outcomes, including BPAR and last-visit eGFR, in DDKT.
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Comparison of synthetic bone graft ABM/P-15 and allograft on uninstrumented posterior lumbar spine fusion in sheep.

BACKGROUND: Spinal fusion is a commonly used procedure in spinal surgery. To ensure stable fusion, bone graft materials are used. ABM/P-15 (commercial name i-Factor™ Flex) is an available synthetic bone graft material that has CE approval in Europe. This peptide has been shown to improve bone formation when used in devices with fixation or on bone defects. However, the lack of external stability and large graft size make posterolateral lumbar fusion (PLF) a most challenging grafting procedure. This prospective randomized study was designed to evaluate early spinal fusion rates using an anorganic bovine-derived hydroxyapatite matrix (ABM) combined with a synthetic 15 amino acid sequence (P-15)-ABM/P-15 bone graft, and compared with allograft in an uninstrumented PLF model in sheep. The objective of this study was to assess fusion rates when using ABM/P-15 in uninstrumented posterolateral fusion in sheep. METHODS: Twelve Texas/Gotland mixed breed sheep underwent open PLF at 2 levels L2/L3 and L4/L5 without fixation instruments. The levels were randomized so that sheep received an ABM graft either with or without P15 coating. Sheep were euthanized after 4.5 months and levels were harvested and evaluated with a micro-CT scanner and qualitative histology. Fusion rates were assessed by 2D sections and 3D reconstruction images and fusion was defined as intertransverse bridging. RESULTS: There was 68% fusion rate in the allograft group and an extensive migration of graft material was noticed with a fusion rate of just 37% in the ABM/P-15 group. Qualitative histology showed positive osteointegration of the material and good correlation to scanning results. CONCLUSIONS: In this PLF fusion model, ABM/P15 demonstrated the ability to migrate when lacking external stability. Due to this migration, reported fusion rates were significantly lower than in the allograft group. The use of ABM/P15 as i-Factor™ Flex may be limited to devices with fixation and bone defects.

The Impact of Renal Tissue Procurement at Bedside on Specimen Adequacy and Best Practices.

Objectives: Renal biopsy is the gold standard for the diagnosis of both native and allograft renal diseases. We studied the impact of tissue procurement at bedside (TPB) omission on the adequacy of renal biopsies. Methods: We compared 120 renal biopsies collected during 2015 using TPB with 111 renal biopsies collected during 2016 when TPB was discontinued. Adequacy criteria were applied as follows: by light microscopy, 10 glomeruli and two arteries for allograft biopsies and seven glomeruli for native biopsies. At least one glomerulus was considered adequate for immunofluorescence and electron microscopy in both groups. Results: The rate of inadequacies in allograft biopsies increased significantly, from 12.50% to 21.61% (P < .05), when TPB was discontinued. Conclusions: Elimination of TPB service had a negative impact on allograft specimen adequacy. Repeat biopsies add cost and delay patient care. Institutions should take this into consideration when considering omission of TPB.

Renal allograft survival rates in kidneys initially declined for paediatric transplantation.

BACKGROUND: The outcome of organs which have been declined for paediatric recipients is not known. This study aimed to determine the outcome of kidneys initially declined for paediatric recipients and establish renal allograft survival in kidneys that were eventually transplanted. METHODS: Data were obtained from the UK Transplant Registry for all donation after brain death (DBD) kidneys offered and declined to paediatric recipients (< 18 years) in the UK from 2009 to 2014. RESULTS: Eighty-two percent (503/615) of kidneys initially declined for paediatric transplantation were eventually transplanted, 7% (46/615) of kidneys went to paediatric recipients and 62% (384/615) of kidneys went to adult (kidney only) recipients. The remainder were used for multiple organ transplants. In the 46 kidneys that went to paediatric recipients, 1 and 3-year renal allograft survivals were 89% (95% CI 75.8-95.3%) and 82% (95% CI 67.1-90.6%), respectively. In the 384 kidneys given to adult kidney-only recipients, 1 and 3-year renal allograft survivals were 96% (95% CI 93.5-97.6%) and 94% (95% CI 90.7-96.1%), respectively. Eighty-four percent of the 204 children who initially had an offer declined on their behalf were eventually transplanted and have a functioning graft at a median 3-year follow-up. CONCLUSIONS: This study reports acceptable short-term renal allograft survival in kidneys that were initially declined for paediatric recipients and subsequently transplanted. Evidence-based guidelines are required to ensure that the most appropriate kidneys are selected for paediatric recipients.

A randomized trial of normothermic preservation in liver transplantation.

Liver transplantation is a highly successful treatment, but is severely limited by the shortage in donor organs. However, many potential donor organs cannot be used; this is because sub-optimal livers do not tolerate conventional cold storage and there is no reliable way to assess organ viability preoperatively. Normothermic machine perfusion maintains the liver in a physiological state, avoids cooling and allows recovery and functional testing. Here we show that, in a randomized trial with 220 liver transplantations, compared to conventional static cold storage, normothermic preservation is associated with a 50% lower level of graft injury, measured by hepatocellular enzyme release, despite a 50% lower rate of organ discard and a 54% longer mean preservation time. There was no significant difference in bile duct complications, graft survival or survival of the patient. If translated to clinical practice, these results would have a major impact on liver transplant outcomes and waiting list mortality.

The New Era of Transplant Oncology: Liver Transplantation for Nonresectable Colorectal Cancer Liver Metastases.

Colorectal cancer (CRC) is the third most incident cancer worldwide. Most of CRC patients will develop distant metastases, mainly to the liver, and liver resection is the only potential chance for cure. On the other hand, only a small proportion of patients with hepatic CRC metastasis are candidates for upfront liver resection. Liver transplantation (LT) is an attractive option for patients with nonresectable CRC liver metastases (NRCLM) without extrahepatic involvement. Initial experiences with LT for NRCLM achieved very poor outcomes, with a 5-year overall survival (OS) lower than 20%. However, these initial studies did not have a standardized patient selection or neoadjuvant or adjuvant therapies. With recent advances in the surgical and medical oncology fields, the landscape has changed. Recent studies from Norway have shown an encouraging 5-year OS of 50% when transplanting patients with NRCLM. Nevertheless, the main concern when expanding the indications for LT is organ shortage. To manage this organ shortage, strategies utilizing live donor liver transplantation are gaining favor. A few ongoing trials are assessing the impact of LT in NRCLM patient survival. Therefore, the aim of this paper is to review the current status of LT for NRCLM.

Split liver transplantation: Current developments.

In 1988, Rudolf Pichlmayr pioneered split liver transplantation (SLT), enabling the transplantation of one donor liver into two recipients - one pediatric and one adult patient. In the same year, Henri Bismuth and colleagues performed the first full right/full left split procedure with two adult recipients. Both splitting techniques were rapidly adopted within the transplant community. However, a SLT is technically demanding, may cause increased perioperative complications, and may potentially transform an excellent deceased donor organ into two marginal quality grafts. Thus, crucial evaluation of donor organs suitable for splitting and careful screening of potential SLT recipients is warranted. Furthermore, the logistic background of the splitting procedure as well as the organ allocation policy must be adapted to further increase the number and the safety of SLT. Under defined circumstances, in selected patients and at experienced transplant centers, SLT outcomes can be similar to those obtained in full organ LT. Thus, SLT is an important tool to reduce the donor organ shortage and waitlist mortality, especially for pediatric patients and small adults. The present review gives an overview of technical aspects, current developments, and clinical outcomes of SLT.

Testing feasibility of an accurate microscopic assessment of macrovesicular steatosis in liver allograft biopsies by smartphone add-on lenses.

Light microscopy is an essential tool in histological examination of tissue samples. However, the required equipment for a correct and rapid diagnosis is sometimes unavailable. Smartphones and mobile phone networks are widespread, and could be used for diagnostic imaging and telemedicine. Macrovesicular steatosis (MS) is a major risk factor for liver graft failure, and is only assessable by microscopic examination of a frozen tissue section. The aim of this study was to compare the microscopic assessment of MS in liver allograft biopsies by a smartphone with eyepiece adaptor (BLIPS device) to standard light microscopy. Forty liver graft biopsies were evaluated in transmitted light, using an Iphone 5s and 4 different mini-objective, add-on lenses. A significant correlation was reported between the two different approaches for graft MS assessment (Spearman's correlation coefficient: rs = 0.946; p < .001). Smartphone with eyepiece adaptor had similar discriminatory power to identify MS in liver grafts than standard light microscopy. Based on these findings, a smartphone integrated with a low-cost eyepiece adaptor can achieve adequate accuracy in the assessment of MS in liver graft, and could be used as an alternative to standard light microscope when unavailable.

Comparison of allograft and polyetheretherketone (PEEK) cage subsidence rates in anterior cervical discectomy and fusion (ACDF).

Structural allografts and PEEK cages are commonly used interbody fusion devices in ACDF. The subsidence rates of these two spacers have not yet been directly compared. The primary aim of this study was to compare the subsidence rate of allograft and PEEK cage in ACDF. The secondary aim was to determine if the presence of subsidence affects the clinical outcome. We reviewed 67 cases (117 levels) of ACDF with either structural allograft or PEEK cages. There were 85 levels (48 cases) with PEEK and 32 levels (19 cases) with allograft spacers. Anterior and posterior disc heights at each operative level were measured at immediate and 6months post-op. Subsidence was defined as a decrease in anterior or posterior disc heights >2mm. NDI of the subsidence (SG) and non-subsidence group (NSG) were recorded. Chi-square test was used to analyze subsidence rates. T-test was used to analyze clinical outcomes (α=0.05). There was no statistically significant difference between subsidence rates of the PEEK (29%; 25/85) and allograft group (28%; 9/32) (p=0.69). Overall mean subsidence was 2.3±1.7mm anteriorly and 2.6±1.2mm posteriorly. Mean NDI improvement was 11.7 (from 47.1 to 35.4; average follow-up: 12mos) for the SG and 14.0 (from 45.8 to 31.8; average follow-up: 13mos) for the NSG (p=0.74). Subsidence rate does not seem to be affected by the use of either PEEK or allograft as spacers in ACDF. Furthermore, subsidence alone does not seem to be predictive of clinical outcomes of ACDF.

Hematopoietic Cell Transplantation Comorbidity Index Predicts Outcomes in Patients with Acute Myeloid Leukemia and Myelodysplastic Syndromes Receiving CD34+ Selected Grafts for Allogeneic Hematopoietic Cell Transplantation.

To evaluate the association between the hematopoietic cell transplantation-comorbidity index (HCT-CI) and the recently developed age-adjusted HCT-CI (HCT-CI/age) and transplant outcomes in the setting of CD34-selected allogeneic HCT, we analyzed a homogeneous population of patients undergoing allogeneic HCT with CD34-selected grafts for acute myeloid leukemia and myelodysplastic syndrome (n = 346). Median HCT-CI and HCT-CI/age scores were 2 (percentile 25 to 75, 1 to 4) and 3 (percentile 25 to 75, 1 to 5), respectively. Higher HCT-CI and HCT-CI/age scores were associated with higher nonrelapse mortality (NRM) and lower overall survival (OS). The HCT-CI distinguished 2 risk groups (0 to 2 versus ≥3), whereas, with the HCT-CI/age, there was a progressive increase in NRM and decrease in OS with increasing scores in all 4 groups (0 versus 1 to 2 versus 3 to 4 versus ≥5). Higher scores in both models were associated with lower chronic graft-versus-host disease relapse-free survival but not with higher relapse. Both models showed a promising predictive accuracy for NRM (c- = .616 for HCT-CI and c- = .647 for HCT-CI/age). In conclusion, the HCT-CI and HCT-CI/age predict transplant outcomes in CD34-selected allo-HCT, including NRM, OS, and chronic graft-versus-host disease relapse-free survival and may be used to select appropriate patients for this approach.