Delayed Graft Failure Research Articles

Outcomes After Exoscopic Versus Microscopic Ossicular Chain Reconstruction.

To analyze the outcomes of exoscopic versus microscopic ossicular chain reconstruction (OCR). Retrospective chart review. Tertiary care otology-neurotology practice. Adult subjects with a diagnosis of ossicular discontinuity from 2018 to 2022. Exoscopic or microscopic primary OCR (without mastoidectomy) with a partial ossicular replacement prosthesis (PORP) or total ossicular replacement prosthesis (TORP). Audiometric outcomes at 3 months and 1 year postoperatively including bone and air pure tone averages (PTA), air-bone gap (ABG), change in ABG, speech reception threshold (SRT), and word recognition score (WRS). Secondary outcomes included operative time and complication rates of primary and delayed graft failure, tympanic membrane lateralization, prosthesis extrusion, cerebrospinal fluid leak, facial nerve injury, profound hearing loss, persistent tinnitus, and persistent vertigo. Sixty ears underwent primary OCR and were subdivided based on prosthesis type (PORP and TORP) and surgical approach (exoscope vs microscope). Exoscopic OCR was performed on 30 ears (21 PORP, 9 TORP), and microscopic OCR was performed on 30 ears (19 PORP, 11 TORP). In the overall group (PORP + TORP) and in the PORP and TORP subgroups, there were no significant differences in 1) demographics, 2) intraoperative findings, and 3) audiometric outcomes of bone and air PTA, ABG, change in ABG, SRT, and WRS at 1 year postoperatively. Operative time was 64.7 and 59.6 minutes for the exoscopic and microscopic group, respectively ( p = 0.4, 95% CI [-16.4, 6.1], Cohen's D = 0.2). Audiometric and surgical outcomes after exoscopic and microscopic OCR are comparable.

Defining optimal blood pressure control for pre-transplant end-stage renal disease patients: scoping review.

Strict blood pressure control is essential to prevent cardiovascular disease and is associated with decreased mortality. However, in patients with end-stage renal disease awaiting renal transplantation, the level of optimal blood pressure control is not yet defined. Following the PRISMA Extension for Scoping Reviews, we searched MEDLINE and EMBASE for all peer-reviewed articles using keywords including 'end-stage renal disease', 'blood pressure', and 'pre-transplant' from their inception to 7 August 2022. Seven observational studies, including one population-based study, were included in the review. Most studies investigated factors associated with post-transplant graft failure or mortality. There was considerable heterogeneity in defining optimal pre-transplant blood pressure measurement frequency among studies (average of three measurements vs. single measurement). One study suggested that low pre-transplant diastolic blood pressure (<50 mmHg) was associated with lower odds of delayed graft failure and mortality. Two studies noted that pre-transplant hypertension, or clinical criteria of hypertension that were present prior to transplant, was associated with post-transplant adverse outcomes. In contrast, one study noted that pre-transplant sustained hypotension with mean blood pressure <80 mmHg, was associated with a higher frequency of delayed graft failure. This systematic review summarizes the current evidence regarding the relationship between pre-transplant blood pressure control and post-transplant outcomes in end-stage renal disease patients. While the results from the included studies are mixed, more stringent blood pressure control than currently practiced may be beneficial to decrease graft failure and mortality in this patient population.

Corneal Regeneration Using Gene Therapy Approaches.

One of the most remarkable advancements in medical treatments of corneal diseases in recent decades has been corneal transplantation. However, corneal transplants, including lamellar strategies, have their own set of challenges, such as graft rejection, delayed graft failure, shortage of donor corneas, repeated treatments, and post-surgical complications. Corneal defects and diseases are one of the leading causes of blindness globally; therefore, there is a need for gene-based interventions that may mitigate some of these challenges and help reduce the burden of blindness. Corneas being immune-advantaged, uniquely avascular, and transparent is ideal for gene therapy approaches. Well-established corneal surgical techniques as well as their ease of accessibility for examination and manipulation makes corneas suitable for in vivo and ex vivo gene therapy. In this review, we focus on the most recent advances in the area of corneal regeneration using gene therapy and on the strategies involved in the development of such therapies. We also discuss the challenges and potential of gene therapy for the treatment of corneal diseases. Additionally, we discuss the translational aspects of gene therapy, including different types of vectors, particularly focusing on recombinant AAV that may help advance targeted therapeutics for corneal defects and diseases.

Exceeding the Limits of Static Cold Storage in Limb Transplantation Using Subnormothermic Machine Perfusion.

For 50 years, static cold storage (SCS) has been the gold standard for solid organ preservation in transplantation. Although logistically convenient, this preservation method presents important constraints in terms of duration and cold ischemia-induced lesions. We aimed to develop a machine perfusion (MP) protocol for recovery of vascularized composite allografts (VCA) after static cold preservation and determine its effects in a rat limb transplantation model. Partial hindlimbs were procured from Lewis rats and subjected to SCS in Histidine-Tryptophan-Ketoglutarate solution for 0, 12, 18, 24, and 48 hours. They were then either transplanted (Txp), subjected to subnormothermic machine perfusion (SNMP) for 3 hours with a modified Steen solution, or to SNMP + Txp. Perfusion parameters were assessed for blood gas and electrolytes measurement, and flow rate and arterial pressures were monitored continuously. Histology was assessed at the end of perfusion. For select SCS durations, graft survival and clinical outcomes after transplantation were compared between groups at 21 days. Transplantation of limbs preserved for 0, 12, 18, and 24-hour SCS resulted in similar survival rates at postoperative day 21. Grafts cold-stored for 48 hours presented delayed graft failure (p = 0.0032). SNMP of limbs after 12-hour SCS recovered the vascular resistance, potassium, and lactate levels to values similar to limbs that were not subjected to SCS. However, 18-hour SCS grafts developed significant edema during SNMP recovery. Transplantation of grafts that had undergone a mixed preservation method (12-hour SCS + SNMP + Txp) resulted in better clinical outcomes based on skin clinical scores at day 21 post-transplantation when compared to the SCS + Txp group (p = 0.01613). To date, VCA MP is still limited to animal models and no protocols are yet developed for graft recovery. Our study suggests that ex vivo SNMP could help increase the preservation duration and limit cold ischemia-induced injury in VCA transplantation.

CD34+ -selected hematopoietic stem cell transplant conditioned with a myeloablative regimen in patients with advanced myelofibrosis.

Allogeneic hematopoietic stem cell transplantation (Allo-HCT) remains the only curative treatment for myelofibrosis (MF). Transplantation in patients with MF is mostly done using a reduced intensity conditioning regimen with calcineurin inhibitors for graft versus host disease (GVHD) prophylaxis. Here we sought to evaluate outcomes of patients who underwent an ex vivo CD34+ -selected allo-HCT using myeloablative conditioning (MAC). Twenty-seven patients were included in this retrospective analysis. All patients were conditioned with busulfan, melphalan and fludarabine and antithymocyte globulin to prevent graft rejection. G-CSF mobilized peripheral blood stem cell grafts were depleted of T-cells using immunomagnetic CD34+ selection by CliniMACS device. Median follow-up among survivors was 50.6 months. The estimated 3-year overall survival, relapse free survival and the combined endpoint of GVHD/relapse free survival were 88% (95% CI, 75-100%), 80% (95% CI, 66-98%) and 74% (95% CI, 59-93%), respectively. The cumulative incidence of grade II-IV acute GVHD at day 100 was 33.3% (95% CI 16.4-51.3%), and two patients suffered chronic GVHD. There were no cases of primary graft failure. However, delayed graft failure occurred in two patients. We conclude that CD34+ selected allo-HCT with a MAC resulted in high survival rates in this cohort of patients with MF.

QS7: Effect Of Static Cold Storage On Vascularized Composite Allografts

Purpose:The current gold standard in organ storage is static cold storage (SCS) at 4°C in a preservation solution (UW, HTK). While kidneys can be stored for 24 hours in SCS, Vascularized Composite Allografts (VCA) have been transplanted up to 12 hours in this condition. We aimed to determine the limits of VCA viability with SCS. We used a partial heterotopic hindlimb transplantation model on rodent to assess VCA survival at various durations of SCS.Methods:Right partial hind limbs in Lewis rats were procured and a 24G Angiocath inserted in the femoral artery. Limbs were flushed with 2ml of heparin saline (100UI/ml) at room temperature and then 5ml of ice cold HTK solution. The limbs were then immersed in HTK in a sterile bag and stored at 4°C for a period of 12(group 1), 18(group 2), 24(group 3), 48 (group 4) or 0 hours (fresh controls Group 5), before microsurgical transfer to the opposite groin. Graft weight was assessed before and after cold storage. At post-operative day (POD) 21, VCAs were harvested for histological analysis.Results:In all groups, there was no significant difference of weight gain in SCS groups after extended SCS times. In group 1 (n=4), 3 rats survived until POD21; clinical evolution showed a limited epidermolysis (<1/3 donor skin surface) in 2 grafts. In group 2 (n=4), 2 rats survived until POD21 without complication. In group 3 (n=6), 3 rats survived until POD21; 1 showed partial superficial necrosis on 50% of the donor skin surface that led to late wound healing. In group 4 (n=4), 3 rats survived; all but one showed extended superficial necrosis over more than 2/3 of the donor skin surface; findings at end of study revealed patent arterial supply but venous thrombosis in 2 rats, inflammatory tissues around the graft and necrotic muscles. There was no difference in the VCA survival rate between the groups 1, 2 and 3 compared to the control group 5. Group 4 demonstrated delayed graft failure.Conclusion:SCS provides a safe and simple method of organ storage but is very time limited. Cooling an organ down to 4°C aims to reduce cell metabolism 10-fold but does not make it zero. Hence, VCA hypothermic storage is limited by the remaining metabolism of the skeletal muscle. In our study, rat VCA can be stored in SCS for 24hours without significantly impacting its survival rate but an increase in muscular atrophy and epidermal necrosis correlates with longer hypothermic storage durations. We hypothesize that rat tissues are particularly resistant to SCS thus we need to scale up to a large animal model to better understand ischemic injuries on human tissues.

165-OR: Antioxidant-Based Encapsulation Strategies to Enhance Islet Allotransplantation

The destruction of insulin-producing cells is a hallmark of type 1 diabetes (T1D) and results in a loss of glycemic control. Islet transplantation can restore glucose homeostasis and prevent hypoglycemic events; however, long-term graft survival is low. Oxidative stress mediates islet transplant rejection. Therefore, suppressing oxidative stress with nanothin encapsulation materials comprised of alternating layers of tannic acid (TA), an immunomodulatory antioxidant, and poly(N-vinylpyrrolidone) (PVPON), a scaffold polymer, may allow for improved graft survival. We hypothesize that (PVPON/TA)-encapsulation of islets will prolong graft function and delay allotransplantation rejection in the absence of systemic immunosuppression. We recently published that allogeneic transplantation of encapsulated C57BL/6 islets into NOD mice significantly delayed graft failure, decreased free radical-adduct formation, and reduced infiltrating immune cell effector responses. These data suggest local immunosuppression with (PVPON/TA)-encapsulation may be a promising technique to prolong islet graft function in islet allotransplants. To enhance immunosuppression, we conjugated CTLA-4-Ig to the outer surface of (PVPON/TA) layers. (PVPON/TA/CTLA-4)-encapsulated islets display significantly delayed allograft rejection compared to (PVPON/TA) controls. Flow cytometry analysis demonstrated reduced CD80/CD86 costimulatory receptor and MHC-II expression on innate immune populations, enhanced FOXP3+ regulatory T cells, and enhanced PD1+ CD8 T cells within (PVPON/TA/CTLA-4)-encapsulated grafts. To monitor graft integrity in vivo, we conjugated (PVPON/TA) layers with the fluorophore Cy5.5. Transplantation of (PVPON/TA/Cy5.5)-encapsulated islets restored glucose tolerance and was detected in vivo for up to eight weeks post-transplant. The ability to modify our (PVPON/TA) coatings opens the door for endless possibilities to improve clinical islet transplantation. Disclosure J. Barra: None. V. Kozlovskaya: None. E. Kharlampieva: None. H. M. Tse: None. Funding National Science Foundation (1608728); National Institute of Diabetes and Digestive and Kidney Diseases (DK-099550); JDRF (SRA-2016-270-S-B, 2-SRA-2019-692-S-B)

Immediate ECMO Initiation Leads to Graft Recovery in Delayed Graft Failure after Heart Transplant

<h3>Introduction</h3> Graft failure is a leading cause of thirty-day mortality for heart transplant (HTx). Primary graft dysfunction, defined as occurring within 24 hours of transplantation, is the most frequent cause of graft failure. We present a rare case of delayed graft failure, which occurred on postoperative day (POD) 9, of unknown cause successfully recovered by immediate veno-arterial extracorporeal membrane oxygenation (VA-ECMO) initiation and subsequent biventricular assist device (BiVAD) support. <h3>Case Report</h3> A 55-year-old male with end stage heart failure from ischemic cardiomyopathy and severe peripheral vascular disease (PVD) underwent successful HTx surgery. On POD 6, he was transferred out of the ICU in stable condition. His POD 6 transthoracic echocardiogram (TTE) showed left ventricular ejection fraction (LVEF) of 60% with mild-moderately reduced right ventricular (RV) function. On POD 9, the patient went into sudden cardiac arrest, with return of spontaneous circulation after cardiopulmonary resuscitation. VA-ECMO was initiated immediately afterward, with right axillary arterial percutaneous cannulation due to severe PVD. A subsequent TTE showed LVEF of 5%, and a nearly akinetic RV, concerning for delayed graft failure. The patient was transitioned to extracorporeal BiVAD support on POD 21. A biopsy taken POD 21 showed non-infective myocarditis with no evidence of rejection. Prior to BiVAD explant (POD 78), TTE showed improved heart function: LVEF of 45% and only moderately reduced RV function. The BiVAD was explanted after 63 days of support. He was discharged 34 days after BiVAD explant; the presumed cause of delayed graft failure was secondary to residual pulmonary hypertension post-HTx. <h3>Summary</h3> In a case of rare delayed graft failure of unknown cause, immediate VA-ECMO initiation, followed by proper MCS management successfully rescued graft function.

P1717OUTCOMES OF INCREASED INTRA-ABDOMINAL PRESSURE AFTER KIDNEY TRANSPLANTATION

Abstract Background and Aims Increased intra-abdominal pressure (IAP) is commonly found among post-surgical patients and can induce organ dysfunction. However, its prevalence and impact after kidney transplantation have not been adequately described. We aimed to study the prevalence of increased IAP after kidney transplantation and its consequences on transplant outcomes. Method IAP was prospectively measured in 121 kidney transplant recipients every 8h during the first 72h after surgery using the urinary bladder technique (UnoMeter Abdo-Pressure kit). Mean IAP values during the first 24h (24h-IAP) were used in this analysis. Grading of intra-abdominal hypertension was defined according to WSACS guidelines. Patients were followed for at least 12 months or until graft failure or death. The study was approved by the local ethics committee and informed consent was obtained in all cases. Results 24h-IAP was 12.6±3.5 mmHg. 84.2% of subjects presented with intra-abdominal hypertension during the first 72h after kidney transplantation. Body mass index (OR: 1.35, 95% CI 1.12-1.63; P=0.002), male sex (OR: 3.34, 95% CI 1.1-10.3; P=0.032) and hemodialysis as renal replacement therapy before transplantation (OR: 4.35, 95% CI 1.32-14.4; P=0.016) were independent determinants of intra-abdominal hypertension. IAP was an independent risk factor for delayed graft function (*model adjusted for recipient age, sex, history of previous kidney transplants, recipient comorbidities, donor terminal serum creatinine and comorbidities, number of HLA mismatches &amp;gt;4, cold ischemia time and donation after cardiac death status), graft failure and death (**model adjusted for all variables included in the previous model plus delayed graft failure) (Figure). Conclusion Increased IAP was highly common after transplant surgery and was associated with higher rates of delayed graft function, graft failure and death. Routine IAP monitoring should be considered after transplantation to facilitate early identification of complications and initiation of the appropriate treatment to stop its effects.

1685-P: Islet Encapsulation with Tannic Acid Delays Allogeneic Islet Graft Rejection

Type 1 diabetes (T1D) is defined by the destruction of insulin-producing cells. Islet transplantation can restore glucose homeostasis and prevent serious hypoglycemic events; however, long-term graft survival is low. Oxidative stress can mediate islet transplantation rejection and suppressing oxidative stress with nanothin islet encapsulation materials comprised of alternating layers of tannic acid (TA), an immunomodulatory antioxidant, and poly(N-vinylpyrrolidone) (PVPON), a scaffold polymer, may allow for improved graft survival without systemic immunosuppression. We hypothesize that (PVPON/TA)-encapsulation of islets will prolong graft function following allotransplantation into immunocompetent recipients without utilizing systemic immunosuppression. Allogeneic transplantation of encapsulated C57BL/6 islets into diabetic non-obese diabetic (NOD) mice (n=12) significantly delayed graft failure by more than 90 days compared to controls and significantly reduced free radical-adduct formation produced by neutrophils and macrophages at the graft site. Gene expression displayed a 5- and 20-fold increase of anti-inflammatory genes Retnla and Arg1, respectively, and 3-fold reductions in Ccl5, Cxcl10, Prf1, and Grzmb mRNA accumulation in (PVPON/TA) versus control grafts. Flow cytometry analysis of encapsulated grafts contained fewer numbers of infiltrating dendritic cells and CD8 T cells and reduced frequencies of CCL5+, CXCR3+, MHC-II+ macrophages and perforin+ CD8 T cells by 3-fold compared to controls. Encapsulated grafts also reduced the frequencies of TNF+ and MHC-II+ dendritic cells by 2-fold. Additionally, encapsulation increased the frequency of arginase-1+ and CD206+ alternatively-activated macrophages 4-fold, suggesting that (PVPON/TA)-encapsulation may be a promising technique to prolong clinical islet graft function by skewing macrophage phenotypes and suppressing cytotoxic T cell effector responses in the absence of systemic immunosuppression. Disclosure J. Barra: None. V. Kozlovskaya: None. E. Kharlampieva: None. H.M. Tse: None. Funding National Institute of Diabetes and Digestive and Kidney Diseases (R01DK099550); JDRF (SRA-2016-270-S-B, JDRF 2-SRA-2019-692-S-B); National Science Foundation (NSF-DMR 1608728); National Institute of General Medical Sciences (T32GM008111)

Effect of Perioperative Optimization of Arterial Oxygen Content and Perfusion Pressure on the Function of the Transplanted Kidney in the Retrospective Study of Excretory Function and Assessment of New Markers of Kidney Damage: IL-18, Neutrophil Gelatinase-Associated Lipocalin, and Clusterin

IntroductionThe concept of anesthesia, in which kidney perfusion is optimized, the use of nephrotoxic drugs is avoided, and general anesthesia with protective and preconditioning properties of the graft is applied, is a key element of the therapeutic strategy in kidney transplantation (KTx). Material and methodA total of 86 patients (mean age: 49.4 ± 14.0 years, 66% men) with end-stage renal disease who underwent KTx between 2012 and 2015 were included in this retrospective study. Our aim was to assess the effect of oxygen content in arterial blood and selected hemodynamic parameters on the graft function and the occurrence of delayed graft failure. ResultsNo differences were found in baseline characteristics, indication for transplantation, and surgical technique used among study population. No correlation was found between oxygen delivery exponents and both standard markers of renal function and new biochemical markers (eg, IL-18, clusterin, and neutrophil gelatinase-associated lipocalin [NGAL]). DiscussionIn our study, hemodynamic parameters measured at scheduled intervals did not exceed the physiological range, which might have been the reason for the lack of correlation between the function of graft and the described hemodynamic conditions. At the same time, in the observed ranges of perfusion pressure during optimization of the oxygen content, no correlations were found with the postoperative function of the transplanted kidney. That observation could be a valuable conclusion for reducing the tendency of maintaining high blood pressure with the abuse of catecholamines, especially vasoconstrictors, and volume therapy, whose negative effect on tissue perfusion is unequivocal.

Assessment of Hemoglobin Levels in Patients Qualified for Kidney Transplantation in the Perioperative Period and Its Impact on the Occurrence of Delayed Graft Function

BackgroundAnesthesia in patients undergoing kidney transplantation (KTx) should be aimed at creating optimal hemodynamic conditions for the newly implanted kidney. Changes in of blood count, caused mainly by intraoperative hemodilution, may adversely affect the perioperative course by strengthening the pathologic mechanisms of ischemia-reperfusion syndrome. MethodsA total of 86 patients (mean age: 49.4 ± 14.0 years, 66% men) with end-stage renal disease who underwent KTx between 2012 and 2015 were included in this retrospective study. Our aim was to assess the hemoglobin level and the effect of fluctuations caused by the implemented fluid therapy on graft function and the occurrence of delayed graft failure. ResultsThere was no difference in baseline characteristics, indication for transplantation, and surgical technique used among study population. Among the whole observation group, no correlation was found between fluid therapy causing hemodilution with a decrease in hemoglobin concentration and the occurrence of delayed graft failure. ConclusionsIn our observations, we paid special attention to the problem of hemodilution in patients undergoing KTx. It is important to emphasize the importance of proper preparation of the patient for KTx by earlier implementation of anemia therapy, thus preventing exacerbation of anemia in the postoperative period, especially because the perioperative use of blood products is associated with numerous complications and a worse prognosis for the newly implanted kidney.

HLA-mismatched donor and high ferritin level showed poor clinical outcomes after allogeneic hematopoietic cell transplantation in patients with advanced myelofibrosis.

Background:Preconditioning intensity, donor choice and graft-versus-host disease (GVHD) prophylaxis of allogeneic hematopoietic cell transplantation (allo-HCT) for advanced myelofibrosis (MF) have not been fully elucidated.Methods:Thirty-five patients with advanced MF were treated with reduced-intensity conditioning (RIC) allo-HCT. We searched for matched sibling donors first, followed by matched or mismatched unrelated donors and familial mismatched donors. Preconditioning regimen consisted of fludarabine (total 150 mg/m2) and busulfan (total 6.4 mg/kg) with total body irradiation ⩽400cGy.Results:All showed engraftments, but four showed either leukemic relapse or delayed graft failure. Two-year overall survival (OS) and non-relapse mortality (NRM) was 60.0% and 29.9%, respectively. Acute GVHD was observed in 19 patients, and grade III–IV acute GVHD (eight grade III and four grade IV) was higher in human leukocyte antigen (HLA)-mismatched donor HCT compared with HLA-matched HCT (70% versus 20%). Chronic GVHD was observed in 16 patients, and a cumulative incidence of severe chronic GVHD was 33% in HLA-mismatched donor HCT and 7.7% in HLA-matched HCT. Significant hepatic GVHD was observed in nine patients (five acute, four chronic) and six of them died. Multivariate analysis revealed inferior OS in HLA-mismatched donor HCT (hazard ratio (HR) = 6.40, 95% confidence interval (CI) 1.6–25.7, p = 0.009) and in patients with high ferritin level at the time of pre-conditioning period (HR = 7.22, 95% CI 1.9–27.5, p = 0.004), which were related to higher incidence of hepatic GVHD with high NRM rate.Conclusion:RIC allo-HCT can be a valid choice providing graft-versus-fibrosis effect for advanced MF patients. However, HLA-mismatched donor and high pre-HCT ferritin level related to fatal hepatic GVHD should be regarded as poor-risk parameters.

Poor Outcomes of HLA-Mismatched Allogeneic Hematopoietic Cell Transplantation and High Ferritin Levels after a Reduced-Intensity Conditioning Regimen in Patients with Advanced Myelofibrosis

Allogeneic hematopoietic cell transplantation (allo-HCT) preconditioning intensity, donor choice, and graft-versus-host disease (GVHD) prophylaxis for advanced myelofibrosis (MF) have not been fully elucidated. Thirty-five patients with advanced MF were treated with reduced-intensity conditioning (RIC) allo-HCT. We searched for matched sibling (n=16) followed by matched (n=10) or mismatched (n=5) unrelated and familial mismatched donors (n=4). Preconditioning regimen consisted of fludarabine (total 150 mg/m2) and busulfan (total 6.4 mg/kg) with total body irradiation≤ 400cGy. All showed engraftments, but four (11.4%) showed either leukemic relapse (n=3) or delayed graft failure (n=1). Two-year overall survival (OS) and non-relapse mortality (NRM) was 60.0% and 29.9%, respectively. Acute GVHD was observed in 19 patients, and grade III-IV acute GVHD was higher with HLA-mismatch (70% vs. 20%, p=0.008). Significant hepatic GVHD was observed in nine patients (5 acute, 4 chronic), and six of them died. Multivariate analysis revealed inferior OS with HLA-mismatch (HR=6.40, 95%CI 1.6-25.7, p=0.009) and in patients with high ferritin level at post-HCT D+21 (HR=7.22, 95%CI 1.9-27.5, p=0.004), which were related to hepatic GVHD and high NRM. RIC allo-HCT can be a valid choice for advanced MF. However, HLA-mismatch and high post-HCT ferritin levels related to significant hepatic GVHD should be regarded as poor-risk parameters. Disclosures Kim: Handok: Honoraria; Amgen: Honoraria; Celgene: Consultancy, Honoraria; Astellas: Consultancy, Honoraria; Hanmi: Consultancy, Honoraria; AGP: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; SL VaxiGen: Consultancy, Honoraria; Novartis: Consultancy; Janssen: Honoraria; Daiichi Sankyo: Honoraria, Membership on an entity's Board of Directors or advisory committees; Otsuka: Honoraria; BL &amp; H: Research Funding; Chugai: Honoraria; Yuhan: Honoraria; Sanofi-Genzyme: Honoraria, Research Funding; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees. Lee:Alexion: Consultancy, Honoraria, Research Funding; Achillion: Research Funding.

260-OR: Encapsulation of Islets with Tannic Acid Enhances Islet Function

Islet transplantation can restore glucose homeostasis in patients with type 1 diabetes (T1D), however, limited islet availability, toxicity of immunosuppressants, and poor graft survival impede clinical application. We hypothesize that islet encapsulation with coatings consisting of tannic acid (TA), an immunomodulatory antioxidant, and poly(N-vinylpyrrolidone) (PVPON), will provide immunoprotection and maintain β-cell function after transplantation. (PVPON/TA)-encapsulated syngeneic islets (n=13) significantly delayed graft failure without immunosuppression after transplantation under the kidney capsule into diabetic non-obese diabetic (NOD) mice by more than 30 days compared to non-encapsulated grafts (n= 13; p=0.0021). Histology of islet engrafted kidneys demonstrated increased insulin, glucagon, and somatostatin positivity within encapsulated grafts compared to non-encapsulated grafts and was corroborated with enhanced glucose responsiveness following an intraperitoneal glucose tolerance test (n=9, p=0.0032). To define the immunoprotective properties of (PVPON/TA) coatings, flow cytometric analysis of islet grafts at day 7 post-transplantation displayed fewer MHC-II expressing cells compared to non-encapsulated controls. Gene expression of islet grafts at 5 days post-transplant displayed a significant increase in Ins2 (p&amp;lt;0.05), Arg1 (p&amp;lt;0.0001), and a decrease in Ccl5 (p=0.0006), Cxcl10 (p=0.043), and Grzmb (p=0.032) mRNA accumulation in encapsulated islet grafts in contrast to controls, suggesting that (PVPON/TA)-encapsulation reduces proinflammatory immune responses and elicits a shift toward an anti-inflammatory phenotype. To address limited islet availability, encapsulation of neonatal porcine islets restored euglycemia in diabetic NOD.scidmice for more than 200 days after xenotransplantation. Our results support the hypothesis that (PVPON/TA) coatings are immunomodulatory and may prolong islet graft function following transplantation. Disclosure J. Barra: None. V. Kozlovskaya: None. E. Kharlampieva: None. G. Korbutt: None. H.M. Tse: None. Funding American Diabetes Association (7-12-CD-11 to H.M.T.); JDRF (1-SRA-2015-42-A-N)

PB2220 SURVIVAL OUTCOME OF HIGH‐RISK PATIENTS WITH MYELOFIBROSIS TREATED WITH ALLOGENEIC HEMATOPOIETIC CELL TRANSPLANTATION FOLLOWING REDUCED‐INTENSITY CONDITIONING REGIMENS

Background:Allogeneic hematopoietic cell transplantation (allo‐HCT) is the only curative treatment for myelofibrosis (MF), but substantial risk of transplantation‐related mortality (TRM) is a considerable obstacle especially in elderly patients or in patients with severe comorbidity. In the era of Janus kinase (JAK) inhibitors, transplantation may be delayed in good responders but cytopenia is a major complication, and we confront refractory patients who should be treated with allo‐HCT immediately.Aims:Here, we are going to show our experiences on high‐risk MF patients who were treated with reduced‐intensity conditioning (RIC) allo‐HCT.Methods:Here, we are going to show our experiences on high‐risk MF patients who were treated with reduced‐intensity conditioning (RIC) allo‐HCT.Results:All showed successful engraftment. Including 2 patients who were conditioned with nonmyeloablative regimen, total 6 (15.8%) showed delayed graft failure at a median 8 months post‐HCT (range, 3.8‐13.8). Two recovered after stem cell booster from the same donor, other 2 received donor lymphocyte infusion but showed progression, and 1 died after 2nd allo‐HCT. Among the 33 patients with post‐HCT bone marrow (BM) exam results, 29 (87.8%) showed significant improvement of BM fibrosis (range, 14‐661 days). After median follow‐up duration of 24.6 months (range, 6.1‐124.8), 2‐year OS was 64.6% (64.3% in triple‐negative subgroup), 2‐year nonrelapse mortality was 27.4%, and 2‐year graft‐and‐relapse‐free survival (GRFS) was 28.4%, which suggested there were fatal high‐grade GVHD in this cohort. Acute GVHD was observed in 18 patients (5 grade II, 7 grade III, 4 grade IV) and a cumulative incidence of grade III‐IV acute GVHD was 30.6%. Chronic GVHD was observed in 13 (4 mild, 2 moderate, 7 severe), and a cumulative incidence of severe chronic GVHD was 27.5%. Among them, severe hepatic GVHD was observed in 9 patients (5 acute, 4 chronic). Among 11 dead patients, 7 died due to fatal hepatic GVHD, 1 died of lung GVHD, and 3 died due to septic pneumonia. Multivariate analysis revealed 2‐year OS was significantly poorer in patients who suffered from hepatic GVHD (HR = 9.8, 95%CI 1.0‐94.7, p = 0.022) and the significant cause of fatal hepatic GVHD was unrelated or mismatched donor HCT.Summary/Conclusion:RIC allo‐HCT can be a valid choice providing graft‐versus‐myelofibrosis effect for advanced and triple‐negative MF patients, but fatal hepatic GVHD was frequently observed especially in unrelated or mismatched donor transplants which should be overcome in the future.

Ultrastructural findings in graft failure after Descemet membrane endothelial keratoplasty (DMEK) and new triple procedure

To investigate factors that influence graft failure after Descemet membrane endothelial keratoplasty (DMEK) based on transmission electron microscopy results.Retrospective observational case series.This single center study included 16 eyes of 16 patients with penetrating keratoplasty (n = 14) or repeat DMEK (n = 2) following graft failure after DMEK. The main outcome measures were ultrastructural changes in the explanted graft on transmission electron microscopy, best-corrected visual acuity, and central corneal thickness.The mean preoperative and postoperative best-corrected visual acuity was 1.01 ± 0.54 logMAR and 0.56 ± 0.37 logMAR. The mean central corneal preoperative and postoperative thickness was 667 ± 187 μm and 511 ± 42 μm. Visual acuity and central corneal thickness improved significantly (P = .001/P = .003) after repeat surgery. Electron microscopy showed that 3 of 14 corneas showed upside down transplantation, and 3 corneas had pigmented cells or pigment granules at the Descemet–stroma interface. Further, 9 of 16 specimens showed a posterior collagenous layer deposited onto the Descemet membrane (average thickness 5.1 ± 6.2 μm; ranged 0.65–20 μm); this did not correlate significantly with the time between the original and repeat keratoplasty. Of 16 original grafts, 7 showed ultrastructural anomalies of the Descemet membrane, but one excised cornea showed no Descemet membrane pathologies.The majority of eyes with graft failure after DMEK showed ultrastructural changes in the Descemet membrane. It is crucial to assess donor tissue quality and to conduct graft marking before surgery to avoid immediate or delayed graft failure after DMEK. Nevertheless, repeat keratoplasty provided significant improvement in central corneal thickness and visual acuity.

Cardiac output-based fluid optimization for kidney transplant recipients: a proof-of-concept trial.

Intravenous fluid management for deceased donor kidney transplantation is an important, modifiable risk factor for delayed graft function (DGF). The primary objective of this study was to determine if goal-directed fluid therapy using esophageal Doppler monitoring (EDM) to optimize stroke volume (SV) would alter the amount of fluid given. This randomized, proof-of-concept trial enrolled 50 deceased donor renal transplant recipients. Data collected included patient characteristics, fluid administration, hemodynamics, and complications. The EDM was used to optimize SV in the EDM group. In the control group, fluid management followed the current standard of practice. The groups were compared for the primary outcome of total intraoperative fluid administered. There was no difference in the mean (standard deviation) volume of intraoperative fluid administered to the 24 control and 26 EDM patients [2,307 (750) mL vs 2,675 (842) mL, respectively; mean difference, 368 mL; 95% confidence interval (CI), -87 to +823; P=0.11]. The incidence of complications in the control and EDM groups was similar (15/24 vs 17/26, respectively; P=0.99), as was the incidence of delayed graft failure (8/24 vs 11/26, respectively; P=0.36). Goal-directed fluid therapy did not alter the volume of fluid administered or the incidence of complications. This proof-of-concept trial provides needed data for conducting a larger trial to determine the influence of fluid therapy on the incidence in DGF in deceased donor kidney transplantation. www.clinicaltrials.gov (NCT02512731). Registered 31 July 2015.

Long-term Complications and Surgical Failures After Ossiculoplasty.

To study long-term complications after ossiculoplasty. Case series with chart review. Tertiary care referral center otology practice. One hundred ninety-five patients (18-88 yr of age) undergoing ossiculoplasty with tympanoplasty or tympanomastoidectomy using cartilage tympanic membrane grafts, retrograde mastoidectomy with canal wall reconstruction, or mastoid obliteration techniques between July 1998 and July 2012. The studied patients all had at least 3 years of clinical follow-up. Incidence of long-term complications, including need for revision surgery, need for secondary ventilation tube placement, recurrence of conductive hearing loss (and related etiologies), recurrent cholesteatoma, and delayed graft failure (recurrent tympanic membrane perforation). Long-term complications were observed in 10.3% (20/195) of patients. 8.2% (16/195) required revision surgery, 10.2% (17/195) required secondary ventilation tube placement, 3.6% (7/195) experienced recurrence of conductive hearing loss, 4.1% (8/195) had delayed failure of tympanic membrane graft, and 1.5% (3/195) had recurrence of cholesteatoma. Recurrence of conductive hearing loss was caused by the displacement of prosthesis in 3 of 7 patients and extensive scar tissue formation without prosthesis displacement in 4 of 7 patients. Seventy-two percent obtained a postoperative pure-tone average - air-bone gap < 20 dB. Forty-eight percent (93/195) obtained a hearing result worse than expected based on the ossiculoplasty outcome parameter staging index. Long-term complications are a significant consideration in all the patients undergoing ossiculoplasty. Our data suggest that tobacco smoking, Eustachian tube dysfunction, and an unexpectedly poor hearing result on the first postoperative audiogram are all important risk factors for the development of significant complications.

Elevated ischaemia-associated lysyl oxidase activity in delayed graft failure 6-12months after renal transplantation.

What is the central question of this study? What potential biochemical changes are associated with renal parenchyma 6-12months after renal transplantation and delayed graft failure? What is the main finding and its importance? Tissue fibrosis, mediated by tissue ischaemia-induced induction of hypoxia-inducible factor-1α and fibronectin and consequent activation of lysyl oxidase, is a major underlying pathophysiological mechanism that contributes to delayed graft failure several months after renal transplantation. The present investigation was undertaken to evaluate the potential biochemical changes associated with renal parenchyma 6-12months after renal transplantation and delayed graft failure. Serum concentrations of transforming growth factor-β in these subjects always remained elevated. In addition, examination of tissue from needle biopsies confirmed that there were consistent changes in the enzyme lysyl oxidase, which functions as an amine oxidase, modifies lysine residues on collagen and cross-links in a process of modulation of the extracellular matrix. Parenchymal levels of hypoxia-inducible factor-1α and fibronectin were elevated, as detected by Western blotting. These findings indicate an ongoing ischaemic insult, which might result from increased tissue fibrosis or, in some cases, might be additive with pre-existing pathophysiological factors that constrain proper renal haemodynamics. Thus, increased lysyl oxidase activity, which we assayed, is a potential unfavourable mechanism occurring in these kidneys that are undergoing failure and probably causes increased fibrosis within the organ and causes ischaemia, renovascular hypertension and a cascade leading to renal dysfunction and failure.