Risk Of Primary Graft Failure Research Articles

(752) - Ex-Vivo Heart Perfusion Using the Transmedics Organ Care System - A Single Center Experience

Single flush antegrade perfusion and cold storage is a simple and economic way for donor heart preservation. However, the ischemic tolerance is limited by cellular energy resources. Due to the increasing organ shortage an increasing number of marginal donor hearts with an increased risk of primary graft failure (PGF) is used. Ex-vivo perfusion using oxygenated warm blood perfusion of the heart during transport might offer a possible solution to increase the utility of donor organs and decrease the risk of PGF.

Chimerism status after unrelated donor bone marrow transplantation with fludarabine-melphalan conditioning is affected by the melphalan dose and is predictive of relapse.

Little is known regarding the chimerism status after reduced-intensity conditioning transplantation when bone marrow is used as a stem cell source. We prospectively analyzed lineage-specific chimerism and retrospectively evaluated clinical outcomes in 80 adult patients who underwent unrelated donor bone marrow transplantation (URBMT) with fludarabine plus melphalan (FM) as the conditioning regimen. Mixed donor chimerism (MDC) was seen in 43 and 10% of patients at days 14 and 28, respectively. Melphalan at ≤130mg/m(2) was associated with an increased incidence of MDC at day 28 (P = 0.03). Patients with MDC at day 14 showed a marginally increased risk of primary graft failure and a marginally decreased risk of graft-versus-host disease. In multivariate analysis, MDC at day 14 was associated with higher overall mortality (hazard ratio (HR) = 2.1; 95% confidence interval (CI), 1.1-4.2; P = 0.04) and relapse rate (HR = 3.0; 95% CI, 1.2-7.5; P = 0.02), but not with non-relapse mortality (HR = 1.8; 95% CI, 0.70-4.6; P = 0.23). Thus, the FM regimen yields prompt complete donor chimerism after URBMT, but the melphalan dose significantly impacts the kinetics of chimerism. Chimerism status evaluation at day 14 may be instrumental in predicting relapse after URBMT with the FM regimen.

Real-Time Immunophenotyping of Peripheral Blood Early Post Myeloablative Cord Blood Transplant Can Identify Patients at Risk for Primary Graft Failure

▪Introduction: Primary graft failure (PGF) is a potentially life threatening complication following hematopoietic cell transplantation. Patients undergoing cord blood transplantation (CBT) are at higher risk for PGF and also experience delayed hematopoietic recovery. The ability to distinguish between PGF and delayed engraftment is critical for correct clinical management. Limited data exists analyzing the kinetics of engraftment of specific circulating cell lineages within 14 days after double CBT (dCBT). Herein, we investigate the potential for real time immunophenotyping (RTIP) of day 7 and day 14 post-transplant peripheral blood (PB) samples as an effective and economically feasible tool to distinguish PGF versus delayed engraftment.Methods: Between Feb 2013 and Jun 2014, 26 patients underwent a myeloablative dCBT at our institute. Heparinized PB samples (30 ml) were obtained from patients on days 7 and 14 post-transplant. PB mononuclear cells (PBMCs) were isolated by density gradient separation and total cell number was counted. RTIP with 9-color flow cytometry was performed at each time point using isolated fresh PBMC.Results: Median time to engraftment was 19 days (range 12-51) in 23 evaluable patients. The remaining 3 patients had no documented hematopoietic recovery by routine daily CBCs. Two patients were declared PGFs when day 21 PB chimerism results demonstrated 100% host T cells followed by confirmation of 0% donor engraftment on day 28. The third patient never had sufficient quantity of circulating cells to obtain RTIP results and died on day 28 with no hematopoietic recovery. Excluding this patient, we were able to quantify the absolute number of PBMC at day 7 (median: 3.1/µl; 95% CI: 2.6-4.6) and day 14 (median: 26/µl; 95% CI: 33-103) in all other patients. There was an increase in the absolute number of PBMC from day 7 to 14 in all patients except the two who experienced PGF. Furthermore, RTIP of day 7 PBMC revealed a predominance of T cells that were donor-derived, while day 14 RTIP of PBMC demonstrated a decreased frequency of T cells and increased frequency of predominantly donor-derived monocytes and NK cells. In contrast to the engrafting patients, the two PGF patients displayed a markedly different pattern in RTIP with minimal evidence of circulating monocytes in the day 14 samples (Fig 1A). Importantly, RTIP demonstrated that day 7 PBMC contained a higher frequency of CD14+CD16- monocytes and CD56brightCD16- NK cells than were infused, suggesting these specific cells were generated de novo and were not representative of cells infused with the graft (data not shown).Correlations between day 7 or day 14 cell subset numbers and time to engraftment were analyzed. The median absolute number of monocytes at day 7 was 0.075/µl (95% CI: 0.03-0.153). Patients with day 7 monocyte counts above the median demonstrated earlier engraftment than patients below the median (17.5 vs 26.5 days; p= 0.011). Using linear regression with engraftment as the variable of interest and the absolute number of day 7 monocytes as the predictor, the coefficient was 0.6 (95% CI: 0.075- 0.78, P=0.025) (Fig 1B). As expected, higher day 14 monocytes also correlated with earlier engraftment. With respect to the NK cell subset, the absolute number of NK cells at day 7 was not significantly correlated with engraftment time, but day 14 NK cell numbers were predictive of engraftment kinetics. The median number of NK cells at day 14 was 2.78/µl (95% CI: 1.87-5.79). Patients with day 14 NK counts above the median had earlier engraftment than those below the median (16 vs 26.5 days; (P=0.0034). The regression coefficient was 0.5 (95% CI, 0.077- 0.77; P=0.024). Finally, although total T cell numbers at day 7 and day 14 had no correlation with engraftment time, the two evaluable PGF patients had a greater inversion of CD4:CD8 ratio (0.038 & 0.058) than others (median: 0.71, 95% CI: 0.22-1.42) at day 14.Conclusions: This study provides the first clear evidence that RTIP of PBMC at days 7 and 14 can detect the kinetics of circulating de novo generated monocytes and NK cells and also reflects the in vivo immune environment in patients following dCBT. Importantly, detecting and measuring specific cell subsets using RTIP permits earlier identification of patients at high risk of graft failure versus patients with delayed engraftment and warrants further development as a clinically feasible diagnostic method to guide clinical intervention. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Size and Gender Matching in Heart Transplantation – Optimizing Donor Utilization in an Era of Changing Donor and Recipient Characteristics

Heart transplantation is limited by donor organ availability. Increased use of marginal donor organs, combined with increased recipient complexity, has increased the risk of primary graft failure. These changes in donor and recipient characteristics have led to a renewed focus on modifiable donor–recipient characteristics that have historically been shown to impact on post-transplant outcomes, namely size and gender matching. Recently published analyses of large registries have found that the use of body weight to size donor organs for transplantation fails to predict post-transplant outcomes, whereas newer methods such as predicted heart mass (utilizing height, age, and gender as well as weight) correlate well with a number of post-transplant outcomes, including survival. The well recognized risks of under-sizing in female donor:male recipient transplants and in recipients with increased pulmonary vascular resistance are reinforced by recent studies. Over-sizing is not associated with increased risk or survival benefit versus ideally matched adult donor hearts.

Superior Donor Heart Preservation Using Hypothermic Oxygenated Perfusion.

Purpose Hypothermic machine perfusion of donor hearts enables continuous aerobic metabolism and washout of toxic metabolic byproducts. We evaluated the effect of machine perfusion on cardiac myocyte integrity in hearts preserved for 4 hours in a novel device that provides pulsatile oxygenated hypothermic perfusion (Paragonix Sherpa PerfusionTM Cardiac Transport System). Methods All pig hearts were perfused with 1L of cold Celsior® solution after aortic cross-clamping, and then harvested. They were stored conventionally in Celsior® solution on ice for 4 hours (Celsior® storage [CS], n=6) or placed in the Sherpa device for 4 hours (pulsatile perfusion [PP], n=6). After cold preservation, hearts were evaluated hemodynamically using a Langendorff system. Systolic function was measured by +dP/dt; and diastolic function was measured by -dP/dt and EDP. Three control swine hearts were also re-perfused and evaluated immediately after harvest on the Langendorff system. Biopsies were taken from the LV apex at the time of harvest, after storage (when relevant), and after reperfusion for ultra-structural analysis using electron microscopy. Results CS, PP, and control hearts did not show any significant differences in systolic or diastolic function (+dP/dt, -dP/dt, EDP). CS hearts had more arrhythmias (supraventricular and ventricular) compared to PP and control hearts. Electron microscopy revealed endothelial cell rupture and damaged muscle fibers in the CS group after reperfusion, while the cell structures were preserved in the PP group and the control group. After preservation, PP hearts showed mild edema, which was not present in CS hearts, but after reperfusion, both groups had a similar grade of interstitial edema. Conclusions Hypothermic pulsatile perfusion of donor hearts during the storage interval is a simple technique that leads to better preservation of cell structure, as compared to a conventional cold storage method. This may lead to less risk of primary graft failure after orthotopic heart transplantation. Donor hearts preserved with pulsatile perfusion also appear less prone to arrhythmias during the reperfusion period. DISCLOSURES:Anderson, L.: Other, Paragonix Technologies, President. Madsen, J.: Grant/Research Support, Paragonix Technologies.

Hypothermic storage or organ culture?

AbstractCurrently there are two storage practices for the cornea, both use liquids based on cell culture medium: the hypothermic storage at 2‐6°C, and organ culture at 30‐37°C. Hypothermic storage seems to offer donor tissues of good quality comparable to that obtained by organ culture, provided that the storage time is kept short. Indeed, according to the literature, the risk of primary graft failure increases significantly after storage longer than 7 days. Furthermore, corneas stored longer than 7 days display epithelial alterations that may hinder the surgical procedure or delay the full recovery of the graft. The organ culture storage method consists of a storage period in culture medium at 30‐37C°, and a shorter de‐swelling and transportation phase at 30‐37C° and room temperature in the same medium supplemented with 4‐8% dextran. Organ culture solutions contain fetal calf serum as a source of growth factors to limit endothelial cell loss. The serum must be obtained from prion‐free countries. A storage period of 30 days can be achieved without significant loss of endothelial cells. The endothelium shows reparative phenomena during storage. Organ culture offers a longer storage time, a less restricted donor supply on beforehand, corneal endothelium with a better defined quality, and a pre‐operative microbiologic control. Cultured corneas always display an epithelium made up of 2‐3 layers of viable cells. The 30 days storage period allows an efficient use of valuable donor tissue: planning of operations is easier, allowing sufficient time for the allocation. The disadvantages of this method are the relative technical complexity and the need for qualified staff to perform tissue culture and selection of the corneas. The studies comparing the effect of the storage methods on outcome demonstrate similar graft survival and post‐operative decline in endothelial cell density. Corneas stored by organ culture are at least comparable with those stored hypothermically for shorter periods.

Role of Donor-Recipient Match in Determining the Risk for Primary Graft Failure after Heart Transplantation

Purpose Non-functional recovery of the graft (primary graft failure, PGF) is still the major cause of early adverse outcome after heart transplantation (HT). While several donor- and recipient-related factors have been taken into account to explain PGF onset, few data are available analyzing how donor-recipient match may be optimized to reduce PGF occurrence. In this study, we explored PGF risk factors, aiming to identify specific donor-recipient matches associated with PGF onset. Methods and Materials We reviewed data from all adult patients transplanted between 1999 and 2011 at our center, including those with pre-HT laboratory and hemodynamic data availability. Study endpoint was occurrence of PGF defined as need of mechanical circulatory support with ECMO/intra-aortic balloon pump, or cardiac index Results Out of 370 patients included, 63(17%) presented PGF. Among all clinical and laboratory variables analyzed, recipient female sex (P Conclusions Female gender and high GTP independently predicted PGF onset. Allocation of donors died of cerebral hemorrhage to recipients with high RVP, or of undersized donors to female recipients, markedly increased PGF risk. Underscoring the importance of strategies directed at controlling reactive pulmonary hypertension before HT, this study suggests that development of customized allocation algorythms may signifcantly improve post-HT outcomes.

Circulation: Clinical Summaries

<i>Circulation:</i> Clinical Summaries

The Scandinavian Propaten ® Trial – 1-Year Patency of PTFE Vascular Prostheses with Heparin-Bonded Luminal Surfaces Compared to Ordinary Pure PTFE Vascular Prostheses – A Randomised Clinical Controlled Multi-centre Trial

Objective To compare 1-year potencies’ of heparin-bonded PTFE [(Hb-PTFE) (Propaten ®)] grafts with those of ordinary polytetraflouroethylene (PTFE) grafts in a blinded, randomised, clinically controlled, multi-centre study. Materials and methods Eleven Scandinavian centres enrolled 569 patients with chronic functional or critical lower limb ischaemia who were scheduled to undergo femoro–femoral bypass or femoro–poplitaeal bypass. The patients were randomised 1:1 stratified by centre. Patency was assessed by duplex ultrasound scanning. A total of 546 patients (96%) completed the study with adequate follow-up. Results Perioperative bleeding was, on average, 370 ml with PTFE grafts and 399 ml with Heparin-bonded PTFE grafts ( p = 0.32). Overall, primary patency after 1 year was 86.4% for Hb-PTFE grafts and 79.9% for PTFE grafts (OR = 0.627, 95% CI: 0.398; 0.989, p = 0.043). Secondary patency was 88% in Hb-PTFE grafts and 81% in PTFE grafts (OR = 0.569 (0.353; 0.917, p = 0.020)). Subgroup analyses revealed that significant reduction in risk (50%) was observed when Hb-PTFE was used for femoro–poplitaeal bypass (OR = 0.515 (0.281; 0.944, p = 0.030)), and a significant reduction in risk (50%) was observed with Hb-PTFE in cases with critical ischaemia (OR = 0.490 (0.249; 0.962, p = 0.036)). Conclusion The Hb-PTFE graft significantly reduced the overall risk of primary graft failure by 37%. Risk reduction was 50% in femoro–poplitaeal bypass cases and in cases with critical ischaemia.

Anti-HLA Antibodies and Graft Rejection In Hematopoietic Stem Cell Transplantation

AbstractAbstract 519We have previously identified a high risk of primary graft failure (PGF) in patients with DSA in T-cell depleted haploidentical transplantation (HaploSCT); 3/4 patients with DSA had PGF compared with 1/20 patients without DSA. All patients with DSA against anti-HLA A, B and DRB1 developed PGF, while 1 patient with anti-DP DSA did not. We now hypothesize that anti-DP antibodies may have a significant but less deleterious impact on engraftment. Methods:We evaluated the occurrence of PGF in 592 patients who received matched unrelated donor transplants at our institution after 1/2005. 88 % of the transplants were matched in 8/8 alleles of HLA-A,B,C,DRB1 in the HvG vector; approximately 75% of the transplants were mismatched in either DRB 3/4/5, DQB1 or DPB1. The presence of DSA was determined by testing the patients' sera with a panel of fluorescent beads coated with single HLA antigen preparations using a Luminex™ platform; results were interpreted as fluorescence intensity (FI) against DSA mismatch. All HLA loci were typed by high resolution methods. Results:19/592 patients (3%) had either PGF (N=9) or died early without engraftment (ED) (N=10). The only DSA identified were against the DP molecule in 8 patients matched in 8/8 HLA alleles with no apparent specificity. 3/8 (37.5%) patients had PGF/ED compared with 16/584 (2.7%) who did not have DSA (p=0.001, RR=23.3). One patient with PGF in the presence of anti-DP DSA had a second transplant in the absence of antibodies and engrafted cells from the same donor. In spite of common HLA sensitization (116/592, 19.6%) only 8 patients (1.4%) presented DSA in their pre-transplant specimens, mostly females (N=7) with a median age 49 years. DSA ranged from 1558 to 9845 FI, similar in patients with and without engraftment. Overall there was a 3% risk of PGF/ED without HLA antibodies, 6% risk in the presence of antibodies but not DSA, and 37.5% risk in the presence of DSA. Multivariate analysis revealed that DSA (p=0.0001) and ABO mismatch (p=0.04) were the only variables associated with graft failure. There was a significant association between female gender and allosensitization, 30.8% of females had anti HLA antibodies vs. 12.1% males (p<0.0001). While no difference in the incidence of HLA antibodies was observed between females with no prior pregnancies and males (p=0.24), this became apparent when allosensitization was evaluated in males vs. females with one pregnancy (p=0.008) and females with 2 or more pregnancies (p=0.0003). Conclusions:These results, combined with our previous findings in HaploSCT, suggest that DSA are associated with graft rejection in hematopoietic stem cell transplantation. Graft failure occurs less often with anti-DP DSA (3/9) compared with DSA against high expression HLA molecules (3/3, HLA-A, B or DRB1) and may confer a lower risk for graft rejection. The differences may reside in the lower levels of DP molecules expressed on cell surface. DSA screening is warranted when considering donors with HLA mismatches as strategies for donor selection and/or antibody level reduction may be needed to decrease the risk of PGF in allogeneic HSCT from partially HLA-matched donors. Disclosures:No relevant conflicts of interest to declare.

205: The risk of primary allograft failure using hearts from older donors

Expansion of donor pool is concerning as it increases the risk of primary graft failure (PGF) in recipients of organs from older donors. Using data obtained from the Scientific Registry of Transplant Recipients we sought to identify donor risk factors associated with PGF in heart transplant (HT) recipients.

Risk factors for primary graft failure after pediatric cardiac transplantation: importance of recipient and donor characteristics

Background Primary graft failure, or circulatory insufficiency immediately after transplantation, frequently occurs after pediatric cardiac transplantation and is the most common cause of death after infant transplantation. Risk factors for pediatric primary graft failure are poorly defined. Methods We retrospectively reviewed donor, procedural and recipient characteristics for primary graft failure in 165 pediatric cardiac transplant recipients (median age at transplant 1.1 years) by multivariatle logistic regression. Primary graft failure was defined as the need for mechanical circulatory support or use of multiple intravenous inotrope/pressors, including epinephrine, for circulatory support within the first 24 hours after transplantation. Results Primary graft failure occurred in 54 patients (33%); 24 patients (15%) required mechanical support for their graft failure; and primary graft failure was the cause of death or graft loss in 10 patients. Recipient risk factors associated with an increased risk of primary graft failure included diagnosis of congenital heart disease and a need for mechanical support before transplantation. Ventilator support before transplantation and maximal pulmonary vascular resistance index were risk factors for the development of isolated right ventricular graft failure. Donor risk factors associated with an increased risk for primary graft failure included increasing donor recipient weight and body surface area ratios; increasing donor ischemic time; anoxia as a cause of death; and increasing cardiopulmonary resuscitation time. Donor blood type O + and hyperdynamic donor systolic function were associated with a decreased risk of primary graft failure. Conclusions Multiple donor, recipient and procedural risk factors, including the type and severity of heart disease in the recipient before transplantation, are associated with primary graft failure after pediatric cardiac transplantation. Avoidance of matching high-risk donors to high-risk recipients may improve morbidity and mortality after transplantation.