"Take it or leave it": Analysis of pediatric heart offers for transplantation in Switzerland

BACKGROUND

There is a shortage of donor hearts in Switzerland, especially for pediatric recipients. However, the rate and reason for refusals of pediatric donor hearts offered in Switzerland has not been systematically analyzed.

METHODS

The national transplant database, Swiss Organ Allocation System, was searched for all hearts from Swiss and foreign donors younger than 16 years from 2015 to 2020. The numbers of accepted and refused hearts and early outcome were assessed, and the reasons for refusal were retrospectively analyzed.

RESULTS

A total of 136 organs were offered to the three Swiss pediatric heart centers and foreign donor procurement organizations. Of these, 26/136 (19%) organs were accepted and transplanted: 18 hearts were transplanted in Switzerland, and 13 of these were foreign. Reasons for refusal were (1) no compatible recipient due to blood group or weight mismatch, 89.4%; (2) medical, meaning organ too marginal for transplantation, 7.4%; (3) logistic, 1.4%; and (4) other, 1.8%. Five organs were refused in Switzerland by one center but later accepted and successfully transplanted by another center. Hearts from outside Switzerland were transplanted significantly less than Swiss hearts (n = 16/120 vs. 10/16, p < .001).

CONCLUSION

The most common reason for refusing a pediatric donor heart is lack of compatibility with the recipient. Few hearts are refused for medical reasons. A more generous acceptance seems to be justified in selected patients. Switzerland receives a high number of foreign offers, but their rate of acceptance is lower than that of Swiss donations.

Effects of donor smoking history on early post-transplant lung function measured by oscillometry

Introduction

Prior studies assessing outcomes of lung transplants from cigarette-smoking donors found mixed results. Oscillometry, a non-invasive test of respiratory impedance, detects changes in lung function of smokers prior to diagnosis of COPD, and identifies spirometrically silent episodes of rejection post-transplant. We hypothesise that oscillometry could identify abnormalities in recipients of smoking donor lungs and discriminate from non-smoking donors.

Methods

This prospective single-center cohort study analysed 233 double-lung recipients. Oscillometry was performed alongside routine conventional pulmonary function tests (PFT) post-transplant. Multivariable regression models were constructed to compare oscillometry and conventional PFT parameters between recipients of lungs from smoking vs non-smoking donors.

Results

The analysis included 109 patients who received lungs from non-smokers and 124 from smokers. Multivariable analysis identified significant differences between recipients of smoking and non-smoking lungs in the oscillometric measurements R5-19, X5, AX, R5z and X5z, but no differences in %predicted FEV1, FEV1/FVC, %predicted TLC or %predicted DLCO. An analysis of the smoking group also demonstrated associations between increasing smoke exposure, quantified in pack years, and all the oscillometry parameters, but not the conventional PFT parameters.

Conclusion

An interaction was identified between donor-recipient sex match and the effect of smoking. The association between donor smoking and oscillometry outcomes was significant predominantly in the female donor/female recipient group.

Donor KIR genotype based outcome prediction after allogeneic stem cell transplantation: no land in sight

Optimizing natural killer (NK) cell alloreactivity could further improve outcome after allogeneic hematopoietic cell transplantation (alloHCT). The donor's Killer-cell Immunoglobulin-like Receptor (KIR) genotype may provide important information in this regard. In the past decade, different models have been proposed aiming at maximizing NK cell activation by activating KIR-ligand interactions or minimizing inhibitory KIR-ligand interactions. Alternative classifications intended predicting outcome after alloHCT by donor KIR-haplotypes. In the present study, we aimed at validating proposed models and exploring more classification approaches. To this end, we analyzed samples stored at the Collaborative Biobank from HLA-compatible unrelated stem cell donors who had donated for patients with acute myeloid leukemia (AML) or myelodysplastic neoplasm (MDS) and whose outcome data had been reported to EBMT or CIBMTR. The donor KIR genotype was determined by high resolution amplicon-based next generation sequencing. We analyzed data from 5,017 transplants. The median patient age at alloHCT was 56 years. Patients were transplanted for AML between 2013 and 2018. Donor-recipient pairs were matched for HLA-A, -B, -C, -DRB1, and -DQB1 (79%) or had single HLA mismatches. Myeloablative conditioning was given to 56% of patients. Fifty-two percent of patients received anti-thymocyte-globulin-based graft-versus-host disease prophylaxis, 32% calcineurin-inhibitor-based prophylaxis, and 7% post-transplant cyclophosphamide-based prophylaxis. We tested several previously reported classifications in multivariable regression analyses but could not confirm outcome associations. Exploratory analyses in 1,939 patients (39%) who were transplanted from donors with homozygous centromeric (cen) or telomeric (tel) A or B motifs, showed that the donor cen B/B-tel A/A diplotype was associated with a trend to better event-free survival (HR 0.84, p=.08) and reduced risk of non-relapse mortality (NRM) (HR 0.65, p=.01). When we further dissected the contribution of B subtypes, we found that only the cen B01/B01-telA/A diplotype was associated with a reduced risk of relapse (HR 0.40, p=.04) while all subtype combinations contributed to a reduced risk of NRM. This exploratory finding has to be validated in an independent data set. In summary, the existing body of evidence is not (yet) consistent enough to recommend use of donor KIR genotype information for donor selection in routine clinical practice.

Donor Electrocardiogram Associations With Cardiac Dysfunction, Heart Transplant Use, and Survival: The Donor Heart Study

BACKGROUND

Potential organ donors often exhibit abnormalities on electrocardiograms (ECGs) after brain death, but the physiological and prognostic significance of such abnormalities is unknown.

OBJECTIVES

This study sought to characterize the prevalence of ECG abnormalities in a nationwide cohort of potential cardiac donors and their associations with cardiac dysfunction, use for heart transplantation (HT), and recipient outcomes.

METHODS

The Donor Heart Study enrolled 4,333 potential cardiac organ donors at 8 organ procurement organizations across the United States from 2015 to 2020. A blinded expert reviewer interpreted all ECGs, which were obtained once hemodynamic stability was achieved after brain death and were repeated 24 ± 6 hours later. ECG findings were summarized, and their associations with other cardiac diagnostic findings, use for HT, and graft survival were assessed using univariable and multivariable regression.

RESULTS

Initial ECGs were interpretable for 4,136 potential donors. Overall, 64% of ECGs were deemed clinically abnormal, most commonly as a result of a nonspecific St-T-wave abnormality (39%), T-wave inversion (19%), and/or QTc interval >500 ms (17%). Conduction abnormalities, ectopy, pathologic Q waves, and ST-segment elevations were less common (each present in ≤5% of donors) and resolved on repeat ECGs in most cases. Only pathological Q waves were significant predictors of donor heart nonuse (adjusted OR: 0.39; 95% CI: 0.29-0.53), and none were associated with graft survival at 1 year post-HT.

CONCLUSIONS

ECG abnormalities are common in potential heart donors but often resolve on serial testing. Pathologic Q waves are associated with a lower likelihood of use for HT, but they do not portend worse graft survival.

Influence of donor characteristics on the milk donation volume and microbiological quality of donated human milk in first 3 years of work of the Croatian human milk bank-retrospective observational study

OBJECTIVES

Donated human milk is the best possible alternative when mother's own milk is not available. The aim of this study is to investigate whether there are differences in the milk donation volumes and microbiological quality of donated milk depending on human milk donors (HMDs) characteristics.

METHODS

We analyzed data on the HMDs who donated milk in the first three years of work of human milk bank (HMB) - November 2019 to January 2023. The data on the volume of donated milk in L and suitable microbiological quality assessed by the number and isolated species of bacteria were collected from questionnaires filled out by HMDs and documentation administered by HMB employees and are presented using descriptive and comparative statistics.

RESULTS

Two hundred HMDs were included in this study. The majority of them are between 26 and 35 years of age, reside in capital city or the surrounding county, have given birth to a full-term child vaginally, and express surplus milk through a breast pump. Donor mothers of preterm born infants (14.5 %) donated greater quantities, there is statistically significant difference in the median of volume of milk donated (9.6 vs. 6.4, p=0.026). Milk expressed manually shows better results in microbiological quality (median percentage 100 vs. 82 vs. 100, p=0.040), while by comparing other characteristics of the donors, no difference was found between the groups.

CONCLUSIONS

It is important to be aware of the characteristics of previous HMDs in order to direct the HMB future promotional and educational activities.

Donor specific anti-HLA antibodies in hematopoietic stem cell transplantation. Single Center prospective evaluation and desensitization strategies employed

BACKGROUND

In the setting of mismatched-hematopoietic stem cells transplantation, the detection of antibodies directed against donor-specific HLA allele(s) or antigen(s) (DSA) represents a barrier for engraftment. It is thus necessary to plan an immunosuppressive strategy, or to select an alternative donor. This prospective study aimed at evaluating the efficacy of our strategy for testing DSAs and the efficacy of the desensitization strategy (DS) employed between November 2017 and November 2020.

MATERIALS AND METHODS

The anti-HLA antibody search was performed using the Luminex bead assays (Lifecode ID and LSA I/II-Immucor) and expressed as mean fluorescence intensity (MFI >1,000 positive). If the patient had DSAs and no alternative donors, a DS was employed with rituximab (day -15), 2 single volume plasmaphereses (PP; days -9 and -8), intravenous immunoglobulins (day -7) and infusion of HLA selected platelets, if persistent DSAs were directed against class I HLA. DS was scheduled with or without PP, according to the DSA MFI (>1,000 or <5,000) and FCXM (flow cytometry crossmatch).

RESULTS

Twenty-two out of 126 patients (17.46%) showed anti-HLA antibodies, 5 of them DSAs (3.97% of total); 3 patients underwent DS obtaining engraftment. Female gender (p=0.033) and a history of previous pregnancies or miscarriages (p=0.009) showed a statistically significant impact on alloimmunization. Factors associated with a delayed neutrophil engraftment were patient's female gender (p=0.039), stem cell source (p=0.025), and a high HSCT-specific comorbidity index (p=0.028). None of the analyzed variables, including the DSA detection, influenced engraftment.

CONCLUSIONS

Our study confirms the importance to test DSAs in mismatched-hematopoietic stem cells transplantation The DS used proved successful in removing DSAs. Prospective multicenter studies are needed to better define and validate consensus strategies on DSA management in HSCT.

Impact of deceased organ donor marijuana use on donor culture positivity and solid organ transplant recipient outcomes

With the increasing prevalence of marijuana use in the US, many deceased organ donors have a history of marijuana use, raising concerns about infectious risks to transplant recipients. We performed a multicenter retrospective cohort study in which exposed donors were those with recent marijuana use (in the prior 12 months) and unexposed donors were those with no recent marijuana use. Primary outcomes included the following: (1) positive donor cultures for bacteria or fungi, (2) recipient infection due to bacteria or fungi within 3 months posttransplant, and (3) recipient graft failure or death within 12 months posttransplant. Multivariable regression was used to evaluate the relationship between donor marijuana use and each outcome. A total of 658 recipients who received organs from 394 donors were included. Recent marijuana use was not associated with donor culture positivity (aOR: 0.84, 95% CI: 0.39-1.81, P = .65), recipient infection (aHR: 1.02, 95% CI: 0.76-1.38, P = .90), or recipient graft failure or death (aHR: 1.65, 95% CI: 0.90-3.02, P = .11). Our data suggest that organs from donors with a history of recent marijuana use do not pose significant infectious risks in the early posttransplant period.

Morphology Control for Efficient Nonfused Acceptor-Based Organic Photovoltaic Cells

Non-fused electron acceptors have huge advantages in fabricating low-cost organic photovoltaic (OPV) cells. However, morphology control is a challenge as non-fused C─C single bonds bring more molecular conformations. Here, by selecting two typical polymer donors, PBDB-TF and PBQx-TF, the blend morphologies and its impacts on the power conversion efficiencies (PCEs) of non-fused acceptor-based OPV cells are studied. A selenium-containing non-fused acceptor named ASe-5 is designed. The results suggest that PBQx-TF has a lower miscibility with ASe-5 when compared with PBDB-TF. Additionally, the polymer networks may form earlier in the PBQx-TF:ASe-5 blend film due to stronger preaggregation performance, leading to a more obvious phase separation. The PBQx-TF:ASe-5 blend film shows faster charge transfer and suppressed charge recombination. As a result, the PBQx-TF:ASe-5-based device records a good PCE of 14.7% with a higher fill factor (FF) of 0.744, while the PBDB-TF:ASe-5-based device only obtains a moderate PCE of 12.3% with a relatively low FF of 0.662. The work demonstrates that the selection of donors plays a crucial role in controlling the blend morphology and thus improving the PCEs of non-fused acceptor-based OPV cells.

Effects of plasmapheresis frequency on health status and exercise performance in men: A randomized controlled trial

BACKGROUND AND OBJECTIVES

Most research studies on the effects of repeated plasma donation are observational with different study limitations, resulting in high uncertainty on the link between repeated plasma donation and health consequences. Here, we prospectively investigated the safety of intensive or less intensive plasma donation protocols.

MATERIALS AND METHODS

Sixty-three male subjects participated in this randomized controlled trial and were divided into low-frequency (LF, once/month, n = 16), high-frequency (HF, three times/month, n = 16), very high-frequency (VHF, two times/week, n = 16) and a placebo (P, once/month, n = 15) groups. Biochemical, haematological, clinical, physiological and exercise-related data were collected before (D0), after 1½ months (D42) and after 3 months (D84) of donation.

RESULTS

In VHF, red blood cells, haemoglobin and haematocrit levels decreased while reticulocyte levels increased from D0 to D84. In both HF and VHF, plasma ferritin levels were lower at D42 and D84 compared to D0. In VHF, plasma levels of albumin, immunoglobulin G (IgG), immunoglobulin A (IgA) and immunoglobulin M (IgM) dropped from D0 to D42 and remained lower at D84 than at D0. In HF, plasma IgG, IgA and IgM were lower at D42, and IgG and IgM were lower at D84, compared to D0. Few adverse events were reported in HF and VHF. Repeated plasma donation had no effect on blood pressure, body composition or exercise performance.

CONCLUSION

VHF plasmapheresis may result in a large reduction in ferritin and IgG levels. HF and VHF plasmapheresis may result in little to no difference in other biochemical, haematological, clinical, physiological and exercise-related parameters.

One Year Outcomes Following Transplantation with COVID-19-Positive Donor Hearts: A National Database Cohort Study

The current understanding of the safety of heart transplantation from COVID-19+ donors is uncertain. Preliminary studies suggest that heart transplants from these donors may be feasible. We analyzed 1-year outcomes in COVID-19+ donor heart recipients using 1:3 propensity matching. The OPTN database was queried for adult heart transplant recipients between 1 January 2020 and 30 September 2022. COVID-19+ donors were defined as those who tested positive on NATs or antigen tests within 21 days prior to procurement. Multiorgan transplants, retransplants, donors without COVID-19 testing, and recipients allocated under the old heart allocation system were excluded. A total of 7211 heart transplant recipients met the inclusion criteria, including 316 COVID-19+ donor heart recipients. Further, 290 COVID-19+ donor heart recipients were matched to 870 COVID-19- donor heart recipients. Survival was similar between the groups at 30 days (p = 0.46), 6 months (p = 0.17), and 1 year (p = 0.07). Recipients from COVID-19+ donors in the matched cohort were less likely to experience postoperative acute rejection prior to discharge (p = 0.01). National COVID-19+ donor heart usage varied by region: region 11 transplanted the most COVID-19+ hearts (15.8%), and region 6 transplanted the fewest (3.2%). Our findings indicate that COVID-19+ heart transplantation can be performed with safe early outcomes. Further analyses are needed to determine if long-term outcomes are equivalent between groups.

Assessment of renal quality with quantitative contrast-enhanced ultrasound (CEUS) for differentiating kidney histopathology before procurement

Purpose: This study aimed to investigate the use of contrast-enhanced ultrasonography (CEUS) to assess the kidneys' quality before procurement. Methods: This prospective study included 74 donors and 148 recipients of kidneys. 119 kidneys underwent quantitative analysis. Before organ procurement, potential kidney donors underwent CEUS, though organ procurement involved a zero-point puncture biopsy. CEUS parameters of the renal cortex and medulla were evaluated, including rise time (RT), time to peak (TTP), the area under the curve (AUC), wash-in slope (WIS), peak intensity (PI), and mean transit time (MTT). Donors' kidneys were classified based on their pathological. Additionally, short-term clinical indicators of renal recipients were collected and analyzed to determine whether the patients had delayed recovery of renal allograft function. Results: This experiment included 148 cases of kidney information, divided into two groups based on the Remuzzi score of the kidneys. However, 29 kidneys were excluded from the quantitative analysis due to loss or low quality of CEUS images. Comparing the time-intensity curve (TIC) of renal cortical region of interest (ROI), we found that the group with lower pathological scores exhibited higher PI (P=0.002), AUC(P=0.003), and WIS (P=0.009). TIC comparison results for renal medulla ROI revealed that the group with lower pathological scores had higher PI (P=0.010), AUC (P=0.023), and WIS (P=0.024). Conclusions: This study highlighted the potential of CEUS as a non-invasive, safe, and real-time examination method that correlates with the Remuzzi score and renal pathology. Therefore, it can be used as a prospective preoperative non-invasive evaluation method for the donor's kidney.

Hematopoietic Stem Cell Transplantation in Sickle Cell Disease: A Multidimentional Review

While exagamglogene autotemcel (Casgevy) and lovotibeglogene autotemcel (Lyfgenia) have been approved by the US Food and Drug Administration (FDA) as the first cell-based gene therapies for the treatment of patients 12 years of age and older with sickle cell disease (SCD), this treatment is not universally accessible. Allogeneic hematopoietic stem cell transplant (HSCT) has the potential to eradicate the symptoms of patients with SCD, but a significant obstacle in HSCT for SCD is the availability of suitable donors, particularly human leukocyte antigen (HLA)-matched related donors. Furthermore, individuals with SCD face an elevated risk of complications during stem cell transplantation due to SCD-related tissue damage, endothelial activation, and inflammation. Therefore, it is imperative to consider optimal conditioning regimens and investigate HSCT from alternative donors. This review encompasses information on the use of HSCT in patients with SCD, including the indications for HSCT, conditioning regimens, alternative donors, and posttransplant outcomes.

Donor/recipient ascending aortic diameter ratio as a novel potential metric for donor selection and improved clinical outcomes in heart transplantation: a propensity score-matched study

Background

Donor/recipient size matching is paramount in heart transplantation. Body weight, height, body mass index, body surface area, and predicted heart mass (PHM) ratios are generally used in size matching. Precise size matching is important to achieve better clinical outcomes. This study aims to determine the donor/recipient ascending aortic diameter (AAoD) ratio as a metric for donor selection and its effect on postoperative clinical outcomes in heart transplant patients.

Methods

We retrospectively reviewed all consecutive patients who underwent heart transplantation from January 2015 to December 2018. A cutoff value of 0.8032 for the donor/recipient AAoD ratio (independent variable for the primary endpoint during unmatched cohort analysis) was determined for predicting in-hospital mortality. The patients were divided into two groups based on the cutoff value. Group A, AAoD < 0.8032 (n = 96), and Group B, AAoD > 0.8032 (n = 265). A propensity score-matched (PSM) study was performed to equalize the two groups comprising 77 patients each in terms of risk. A Cox regression model was developed to identify the independent preoperative variables affecting the primary end-point. The primary endpoint was all-cause in-hospital mortality.

Results

A total of 361 patients underwent heart transplantation during the given period. On the multivariate analysis, donor/recipient PHM ratio [HR 16.907, 95% confidence interval (CI) 1.535-186.246, P = 0.021], donor/recipient AAoD ratio < 0.8032 (HR 5.398, 95% CI 1.181-24.681, P = 0.030), and diabetes (HR 3.138, 95% CI 1.017-9.689, P = 0.047) were found to be independent predictors of in-hospital mortality. Group A had higher 3-year mortality than Group B (P = 0.022). The surgery time was longer and postoperative RBC, plasma, and platelets transfusion were higher in Group A (P < 0.05). Although not statistically significant the use of continuous renal replacement therapy (P = 0.054), and extracorporeal membrane oxygenation (P = 0.086), was realatively higher, and ventilation time (P = 0.079) was relatively longer in Group A.

Conclusions

The donor/recipient AAoD ratio is a potential metric for patient matching and postoperative outcomes in heart transplantation. A donor/recipient AAoD ratio > 0.8032 could improve post-heart transplantation outcomes and donor heart utilization.

Unedited allogeneic iNKT cells show extended persistence in MHC-mismatched canine recipients

Allogeneic invariant natural killer T cells (allo-iNKTs) induce clinical remission in patients with otherwise incurable cancers and COVID-19-related acute respiratory failure. However, their functionality is inconsistent among individuals, and they become rapidly undetectable after infusion, raising concerns over rejection and limited therapeutic potential. We validate a strategy to promote allo-iNKT persistence in dogs, an established large-animal model for novel cellular therapies. We identify donor-specific iNKT biomarkers of survival and sustained functionality, conserved in dogs and humans and retained upon chimeric antigen receptor engineering. We reason that infusing optimal allo-iNKTs enriched in these biomarkers will prolong their persistence without requiring MHC ablation, high-intensity chemotherapy, or cytokine supplementation. Optimal allo-iNKTs transferred into MHC-mismatched dogs remain detectable for at least 78 days, exhibiting sustained immunomodulatory effects. Our canine model will accelerate biomarker discovery of optimal allo-iNKT products, furthering application of MHC-unedited allo-iNKTs as a readily accessible universal platform to treat incurable conditions worldwide.

Total ventricular mass oversizing +50% or greater was a predictor of worse 1-year survival after heart transplantation

OBJECTIVES

Current donor-recipient size matching guidelines rely primarily on body weight, with no specified oversizing cutoff values. Recent literature has explored predicted total ventricular mass matching over body weight matching. We aim to explore the impact of total ventricular mass oversizing on heart transplant outcomes.

METHODS

The United Network for Organ Sharing database was queried for adults who underwent primary heart transplant from 1997 to 2017. By using validated equations, donor-recipient total ventricular mass mismatch was calculated. Donor-recipient pairs were divided into 3 groups by total ventricular mass mismatch. Post-heart transplant 1-year survival was analyzed using the Kaplan-Meier method and Cox proportional hazards models. We also investigated post-heart transplant complications, independent predictors for mortality, donor-recipient sex mismatch, and donor-recipient body habitus in total ventricular mass mismatch greater than +50%.

RESULTS

A total of 34,455 donor-recipient pairs were included. Fractional polynomial regression demonstrated increased the risk of mortality with higher total ventricular mass mismatch. Total ventricular mass mismatch of +48.3% maximized the Youden Index. Donor-recipient pairs were subsequently grouped by total ventricular mass mismatch as -20% to +30%, +30% to +50%, and greater than +50%. Total ventricular mass mismatch greater than +50% was an independent risk factor for 1-year mortality (hazard ratio, 1.40, P = .004) and was associated with increased postoperative stroke (P = .002). Some 80.3% of these recipients were smaller female patients with male donors. Total ventricular mass mismatch from +30% to +50% was not associated with worse survival (P = .17).

CONCLUSIONS

Total ventricular mass mismatch greater than +50% is associated with worse 1-year survival, although this group comprises a small portion of heart transplant. total ventricular mass mismatch from +30% to +50% is not associated with worse survival. These outcomes should be considered in selecting donors and in efforts to expand the potential donor pool.

Dynamic Changes of Regulatory T Cells/CD4⁺ T Cells in Peripheral Blood of Adult Kidney Transplant Recipients: A Comparison of Pediatric and Adult Kidney Donors

BACKGROUND Inducing transplantation tolerance and monitoring the recipient's immune status to improve allograft survival remains the main goal for kidney transplantation (KTx). MATERIAL AND METHODS A total of 53 renal transplantation patients and 20 healthy individuals were assigned to the post-transplantation and healthy groups, respectively; 10 recipients with stable renal function for 2 years after kidney transplantation were assigned to Group C. Eleven kidney transplantation recipients were hospitalized due to lung infection. Flow cytometry was used to measure levels of Tregs/CD4⁺ T cells. RESULTS The Tregs/CD4⁺ T cells ratio reached homeostasis 6 months after KTx, with no significant difference between Group D (healthy control group) and pre-surgery or Group C (2 years after KTx group). The pediatric donor group and the adult donor group reached immune homeostasis 3 months after the operation. Immune homeostasis is maintaining a balance between immune tolerance and immunogenicity. There was no significant difference in graft function between the pediatric and adult donor groups before surgery, 1 day after surgery, 1 week after surgery, 2 weeks after surgery, and 1 month after surgery; however, graft function was significantly better in the pediatric donor group compared with the adult donor group at 3 mouths (eGFR: 51.7 (40.4-66.2) vs 73.0 (55.7-90.2), P=0.008<0.05) and 6 months (eGFR: 52.2 (37.5-62.8) vs 80.5 (64.1-90.4), P<0.001) after surgery. Pediatric donor kidneys reached immune homeostasis 3 months after surgery, with better graft function at this time compared with adult donor kidneys. The proportion of Tregs/CD4⁺ T cells in recipients with a pulmonary infection after KTx was lower than in those with infection recovery. CONCLUSIONS Expanding the use of pediatric kidneys should be further explored by the transplantation community. The proportion of Tregs/CD4⁺ T cells in recipients with a pulmonary infection after KTx was lower than in those with infection recovery.

Impact of Donor Hemodynamics on Recipient Survival in Heart Transplantation

BACKGROUND

Heart transplantation is the gold-standard therapy for end-stage heart failure, but rates of donor-heart use remain low due to various factors that are often not evidence based. The impact of donor hemodynamics obtained via right-heart catheterization on recipient survival remains unclear.

METHODS

The United Network for Organ Sharing registry was used to identify donors and recipients from September 1999-December 2019. Donor hemodynamics data were obtained and analyzed using univariate and multivariable logistical regression, with the primary endpoints being 1- and 5-year post-transplant survival.

RESULTS

Of the 85,333 donors who consented to heart transplantation during the study period, 6573 (7.7%) underwent right-heart catheterization, of whom 5531 eventually underwent procurement and transplantation. Donors were more likely to undergo right-heart catheterization if they had high-risk criteria. Recipients who had donor hemodynamic assessment had 1- and 5-year survival rates similar to those without donor hemodynamic assessment (87% vs 86%, 1 year). Abnormal hemodynamics were common in donor hearts but did not impact recipient survival rates, even when risk-adjusted in multivariable analysis.

CONCLUSIONS

Donors with abnormal hemodynamics may represent an opportunity to expand the pool of viable donor hearts.

Prevalence, Characteristics, and Prognostic Relevance of Donor-Transmitted Coronary Artery Disease in Heart Transplant Recipients

BACKGROUND

The reported prevalence of donor-transmitted coronary artery disease (TCAD) in heart transplantation (HT) is variable, and its prognostic impact remains unclear.

OBJECTIVES

The goal of this study was to characterize TCAD in a contemporary multicentric cohort and to study its prognostic relevance.

METHODS

This was a retrospective study of consecutive patients >18 years old who underwent HT in 11 Spanish centers from 2008 to 2018. Only patients with a coronary angiography (c-angio) within the first 3 months after HT were studied. Significant TCAD (s-TCAD) was defined as any stenosis ≥50% in epicardial coronary arteries, and nonsignificant TCAD (ns-TCAD) as stenosis <50%. Clinical outcomes were assessed by means of Cox regression and competing risks regression. Patients were followed-up for a median period of 6.3 years after c-angio.

RESULTS

From a cohort of 1,918 patients, 937 underwent c-angio. TCAD was found in 172 patients (18.3%): s-TCAD in 65 (6.9%) and ns-TCAD in 107 (11.4%). Multivariable Cox regression analysis did not show a statistically significant association between s-TCAD and all-cause mortality (adjusted HR: 1.44; 95% CI: 0.89-2.35; P = 0.141); however, it was an independent predictor of cardiovascular mortality (adjusted HR: 2.25; 95% CI: 1.20-4.19; P = 0.011) and the combined event cardiovascular death or nonfatal MACE (adjusted HR: 2.42; 95% CI: 1.52-3.85; P < 0.001). No statistically significant impact of ns-TCAD on clinical outcomes was detected. The results were similar when reassessed by means of competing risks regression.

CONCLUSIONS

TCAD was not associated with reduced survival in patients alive and well enough to undergo post-HT angiography within the first 3 months; however, s-TCAD patients showed increased risk of cardiovascular death and MACE.

Could retrograde reperfusion combined with washout technique broaden the applicability of marginal grafts in liver transplantation? Intra-operative and short-term outcomes of a prospective cohort

INTRODUCTION

many revascularization techniques were designed to reduce the imbalance of ischemia-reperfusion injury. This study's objective is to evaluate retrograde reperfusion (RR) compared to sequential anterograde reperfusion (AR), with and without the washout technique (WO).

METHOD

this prospective cohort study collected data from 94 deceased donor orthotopic liver transplants and divided it into three groups: RR with WO (RR+WO), AP with WO (AR+WO), and AP without WO (AR). This study did not assign the reperfusion technique to the participants. The primary outcome considered the early graft dysfunction, and secondary outcomes included post-reperfusion syndrome (PRS), post-reperfusion lactate, surgery fluid balance, and vasoactive drug dose during the surgery.

RESULTS

87 patients were submitted to the final analysis-29 in the RR+WO group, 27 in the AR+WO group, and 31 in the AR group. Marginal grafts prevalence was not significantly different between the groups (34% vs. 22% vs. 23%; p=0.49) and early graft dysfunction occurred at the same rate (24% vs. 26% vs. 19%; p=0.72). RR+WO reduced serum post-reperfusion lactate (p=0.034) and the incidence of significant PRS (17% vs. 33% vs. 55%; p=0.051), but norepinephrine dosing >0.5mcg/kg/min were not different during the surgery (20,7% vs. 29,6% vs. 35,5%, p=0.45).

CONCLUSIONS

primary outcome was not significantly different between the groups; however, intraoperative hemodynamic management was safer using the RR+WO technique. We theorized that the RR+WO technique could reduce the incidence of PRS and benefit marginal graft survival following diseased donor orthotopic liver transplantation.

Japanese national survey on declined liver allografts from brain-dead donors: High decline rate but promising outcomes in allografts with moderate steatosis

Aim

Liver allografts from brain-dead donors, which were declined and were eventually not transplanted due to accompanying marginal factors, have never been surveyed in Japan. We surveyed the declined allografts and discussed the graft potential focusing on various marginal factors.

Methods

We collected data on brain-dead donors between 1999 and 2019 from the Japan Organ Transplant Network. We divided their liver allografts into declined (nontransplanted) and transplanted ones, and then characterized declined ones focusing on their timepoints of decline and accompanying marginal factors. For each marginal factor, we calculated the decline rate from the number of declined and transplanted allografts, and assessed the 1-year graft survival rate from transplanted allografts.

Results

A total of 571 liver allografts were divided into 84 (14.7%) declined and 487 (85.3%) transplanted ones. In the declined allografts, a majority was declined after laparotomy (n = 55, 65.5%), most of which had steatosis and/or fibrosis (n = 52). Out of the moderate steatotic (without F ≥ 2 fibrosis) allografts (n = 33), 21 were declined and 12 were transplanted, leading to a 63.6% decline rate. The latter 12 achieved a 92.9% 1-year graft survival rate after transplantation. Comparison of donor background showed no significant difference between the declined and transplanted allografts.

Conclusion

Pathological abnormalities of steatosis/fibrosis seem to be the most common donor factor leading to graft decline in Japan. Allografts with moderate steatosis were highly declined; however, transplanted ones achieved promising outcomes. This national survey highlights the potential utility of liver allografts with moderate steatosis.

Donor selection for fecal bacterial transplantation and its combined effects with inulin on early growth and ileal development in chicks

AIMS

To select the best donor and investigate its combined effects with inulin on growth performance, and ileal health of chicks.

METHODS AND RESULTS

The chicks (Hy-line Brown) were treated with fecal microbiota suspension from different breeder hens to select the best donor. Treatment with fecal microbiota transplantation (FMT) alone or in combination with inulin found that it improved gut microbiome in chicks. The organ indexes were increased on 7d, especially the bursa of fabricius index (P < 0.05). On 14d, immune performance, ileal morphology, and barrier were improved, simultaneously, the concentration of short-chain fatty acids was also increased. In addition, for the expression of ileal barrier-related genes, Anaerofustis and Clostridium were positively correlated with them (P < 0.05), Blautia, Prevotella, Veillonella, and Weissella were the opposite (P < 0.05), and RFN20 showed a positive correlation with gut morphology (P < 0.05).

CONCLUSION

Combination of homologous FMT and inulin promoted early growth and intestinal health of chicks.

Development and validation of the lung donor (LUNDON) acceptability score for pulmonary transplantation

There is a chronic shortage of donor lungs for pulmonary transplantation due, in part, to low lung utilization rates in the United States. We performed a retrospective cohort study using data from the Scientific Registry of Transplant Recipients database (2006-2019) and developed the lung donor (LUNDON) acceptability score. A total of 83 219 brain-dead donors were included and were randomly divided into derivation (n = 58 314, 70%) and validation (n = 24 905, 30%) cohorts. The overall lung acceptance was 27.3% (n = 22 767). Donor factors associated with the lung acceptance were age, maximum creatinine, ratio of arterial partial pressure of oxygen to fraction of inspired oxygen, mechanism of death by asphyxiation or drowning, history of cigarette use (≥20 pack-years), history of myocardial infarction, chest x-ray appearance, bloodstream infection, and the occurrence of cardiac arrest after brain death. The prediction model had high discriminatory power (C statistic, 0.891; 95% confidence interval, 0.886-0.895) in the validation cohort. We developed a web-based, user-friendly tool (available at https://sites.wustl.edu/lundon) that provides the predicted probability of donor lung acceptance. LUNDON score was also associated with recipient survival in patients with high lung allocation scores. In conclusion, the multivariable LUNDON score uses readily available donor characteristics to reliably predict lung acceptability. Widespread adoption of this model may standardize lung donor evaluation and improve lung utilization rates.

Real-time transcription polymerase chain reaction cycle threshold values as criteria for utilization of incidental COVID-19 positive lung donors

Shortage of organ donors is an ongoing limiting factor in lung transplantation (LT). Despite increasing prevalence of asymptomatic COVID-19 infection, positive COVID-19 testing from a potential donor remains a contraindication at many LT centers. In this report, we present the outcomes of LT utilizing an algorithm based on donor clinical presentation, and COVID-19 real-time reverse transcription polymerase chain reaction (RT-PCR) with cycle threshold (Ct) values evaluation. The Ct value threshold for organ acceptance was >35. A total of 8 COVID-positive donors were included. No donor-to-recipient transmissions of COVID-19 were observed. Short-term outcomes were comparable to those reported in pre-COVID literature. Survival-to-date is 100% with median POD of 161 days. Our findings support the safety and efficacy of utilizing our algorithm including Ct value threshold for selection of donors with incidental COVID-19 positive testing.

Ethical issues raised by uterus transplantation: A report from the People's Republic of China

The recent advances in assisted reproductive technology, such as hormonal stimulation, IVF, and intracytoplasmic sperm injection (ICSI), have made it possible to circumvent many causes of male and female factor infertility. However, uterine infertility is still considered an ''unconditionally infertile'' condition. Owing to the continued advances in organ transplantation, microvascular anastomosis techniques, and immunosuppressive medicine, the transplantation of organs is no longer restricted to the ones necessary for continued life. Quality-of-life enhancing types of transplantation, such as uterine transplantation, in recent years, have also entered the clinical arena. This undoubtedly brings new hope to such women, but also creates ethical challenges. Selection of the donor, the impact on the recipient and offspring, as well as challenges to moral and social norms are issues that cannot be ignored. In the present review, the ethical issues of transplantation of the uterus will be discussed in light of recent progress in the procedure.

Donor selection for adoptive immunotherapy with NK cells in AML patients: Comparison between analysis of lytic NK cell clones and phenotypical identification of alloreactive NK cell repertoire

Natural killer (NK) cell-based adoptive immunotherapy in leukemia patients is an emerging field of interest based on clinical evidence of efficacy and safety. Elderly acute myeloid leukemia (AML) patients have been successfully treated with NK cells from HLA-haploidentical donors, especially when high amounts of alloreactive NK cells were infused. The aim of this study was comparing two approaches to define the size of alloreactive NK cells in haploidentical donors for AML patients recruited in two clinical trials with the acronym "NK-AML" (NCT03955848), and "MRD-NK". The standard methodology was based on the frequency of NK cell clones capable of lysing the related patient-derived cells. The alternative approach consisted of the phenotypic identification of freshly derived NK cells expressing, as inhibitory receptors, only the inhibitory KIR(s) specific for the mismatched KIR-Ligand(s) (HLA-C1, HLA-C2, HLA-Bw4). However, in KIR2DS2⁺ donors and HLA-C1⁺ patients, the unavailability of reagents staining only the inhibitory counterpart (KIR2DL2/L3) may lead to an underestimated identification of the alloreactive NK cell subset. Conversely, in the case of HLA-C1 mismatch, the alloreactive NK cell subset could be overestimated due to the ability of KIR2DL2/L3 to recognize with low-affinity also HLA-C2. Especially in this context, the additional exclusion of LIR1-expressing cells might be relevant to refine the size of the alloreactive NK cell subset. We could also associate degranulation assays, using as effector cells IL-2 activated donor peripheral blood mononuclear cells (PBMC) or NK cells upon co-culture with the related patient target cells. The donor alloreactive NK cell subset always displayed the highest functional activity, confirming its identification accuracy by flow cytometry. Despite the phenotypic limitations and considering the proposed corrective actions, a good correlation was shown by the comparison of the two investigated approaches. In addition, the characterization of receptor expression on a fraction of NK cell clones revealed expected but also few unexpected patterns. Thus, in most instances, the quantification of phenotypically defined alloreactive NK cells from PBMC can provide data similar to the analysis of lytic clones, with several advantages, such as a shorter time to achieve the results and, perhaps, higher reproducibility/feasibility in many laboratories.

Donor's long-term quality of life following living-donor lobar lung transplantation

INTRODUCTION

Living-donor lobar lung transplantation is an alternative procedure to deceased donation lung transplantation. It involves graft donation from healthy donors; however, only a few reports have discussed its long-term prognosis in living lung donors and their associated health-related quality of life. This study aimed to examine living lung donors' health-related quality of life.

METHODS

In our cross-sectional survey of living lung donors, we assessed health-related quality of life-based on three key aspects (physical, mental, and social health) using the 36-Item Short Form Health Survey. We also evaluated chronic postoperative pain and postoperative breathlessness using the numeric rating scale and the modified Medical Research Council Dyspnea scale, respectively.

RESULTS

We obtained consent from 117 of 174 living lung donors. The average scores of the living lung donors on the 36-Item Short Form Health Survey were higher than the national average. However, some donors had poorer physical, mental, and social health, with lower summary scores than the national averages. Low mental component summary predictors included donor age (<40 years; odds ratio = 10.2; p < .001) and recipient age (<18 years; odds ratio = 2.73; p < .032). Low role-social component summary predictors included high lung allocation score (≥50; odds ratio = 3.94, p < .002) and recipient death (odds ratio = 3.64; p = .005). There were no predictors for a physical component summary. Additionally, many donors did not complain of pain or dyspnea.

CONCLUSIONS

Living lung donors maintained an acceptable long-term health-related quality of life after surgery. Potential donors should be informed of relevant risk factors, and high-risk donors should receive appropriate support.

Comparison of NK alloreactivity prediction models based on KIR-MHC interactions in haematopoeitic stem cell transplantation

The biological processes underlying NK cell alloreactivity in haematopoietic stem cell transplantation (HSCT) remain unclear. Many different models to predict NK alloreactivity through KIR and MHC genotyping exist, raising ambiguities in its utility and application for clinicians. We assessed 27 predictive models, broadly divided into six categories of alloreactivity prediction: ligand-ligand, receptor-ligand, educational, KIR haplotype-based, KIR matching and KIR allelic polymorphism. The models were applied to 78 NGS-typed donor/recipient pairs undergoing allogeneic HSCT in genoidentical (n=43) or haploidentical (n=35) matchings. Correlations between different predictive models differed widely, suggesting that the choice of the model in predicting NK alloreactivity matters. For example, two broadly used models, educational and receptor-ligand, led to opposing predictions especially in the genoidentical cohort. Correlations also depended on the matching fashion, suggesting that this parameter should also be taken into account in the choice of the scoring strategy. The number of centromeric B-motifs was the only model strongly correlated with the incidence of acute graft-versus-host disease in our set of patients in both the genoidentical and the haploidentical cohorts, suggesting that KIR-based alloreactivity, not MHC mismatches, are responsible for it. To our best knowledge, this paper is the first to experimentally compare NK alloreactivity prediction models within a cohort of genoidentical and haploidentical donor-recipient pairs. This study helps to resolve current discrepancies in KIR-based alloreactivity predictions and highlights the need for deeper consideration of the models used in clinical studies as well as in medical practice.

Utilization of COVID-19 positive donors for Heart transplantation and associated short-term outcomes

BACKGROUND

The safety and efficacy of using COVID-19 positive donors in heart transplantation (HT) are increasingly relevant, but not well established. The present study evaluated the characteristics and utilization of such donors and associated post-HT outcomes.

METHODS

All adult (≥18 years old) potential donors and HT recipients in the United States from April 21, 2020 to March 31, 2022 were included. Donor COVID-19 status was defined by the presence (or absence) of any positive test within 21 days of organ recovery. Donor and recipient characteristics and post-HT outcomes, including a primary composite of death, graft failure, and re-transplantation, were compared by donor COVID-19 status.

RESULTS

Of 967 COVID-19(+) potential donors, 19.3% (n = 187) were used for HT compared to 26.7% (n = 6277) of COVID-19(-) donors (p < 0.001). Transplanted COVID-19(+) vs COVID-19(-) donors were younger, but otherwise were similar. Recipients of hearts from COVID-19+ vs COVID-19(-) donors less frequently received pre-HT inotropes (24.1% vs 31.7%, p = 0.023) and ventricular assist device therapy (29.7% vs 36.8%, p = 0.040). There were no significant differences in any post-HT outcome by donor COVID-19 status, including the primary composite outcome at 90 days (5.4% vs 5.6%, p = 0.91). Among COVID-19(+) donors, the presence of a subsequent negative test prior to transplant was not associated with posttransplant outcomes.

CONCLUSIONS

Our results suggest that carefully selected COVID-19 positive donors may be used for HT with no difference in short-term post-transplant outcomes. Additional data regarding donor and recipient treatments and impact of vaccination should be collected to better inform our use of organs from COVID(+) donors.

Kidney nonprocurement in deceased donors with acute kidney injury

BACKGROUND

Acute kidney injury (AKI) is common in deceased organ donors and is associated with high rates of kidney discard by transplant centers. High discard rates may consequently drive nonprocurement of these kidneys by organ procurement organizations. We aimed to study the relationship between donor AKI and kidney nonprocurement.

METHODS

Using U.S. registry data, we identified donors with at least one organ recovered from 2008 to 2018. We compared characteristics of donors with no kidneys procured across AKI stages, and used multivariable logistic regression to evaluate the relationship between AKI severity and kidney nonprocurement.

RESULTS

Overall 14 543 kidneys from 7620 donors were not procured, among which 93% were from donors with AKI. For 6945 donors with no kidneys procured but an extrarenal organ recovered, most had stage 3 (51%), followed by stage 1 (27%) and stage 2 AKI (15%). Nonprocured stage 3 donors were the youngest and had the lowest Kidney Donor Risk Index of all nonprocured donors. Adjusted odds of kidney nonprocurement were 1.14 (95%CI 1.02-1.27) for stage 1, 1.25 (95%CI 1.12-1.41) for stage 2, and 10.37 (95%CI 9.30-11.56) for stage 3 donors, compared to non-AKI donors. Among donors with minimum creatinine <1.5 mg/dl, stage 2 and 3 AKI were still associated with significantly higher odds of nonprocurement.

CONCLUSIONS

AKI severity is a strong risk factor for kidney nonprocurement. Efforts to address the organ shortage should focus on encouraging procurement and utilization of kidneys from deceased donors with severe AKI, given the large and rising prevalence of donor AKI and excellent transplant outcomes with these kidneys.

The Significance of the Nucleic Acid Test (NAT) to Prevent Viral Contamination in Musculoskeletal Tissue Transplantation

Objective  The present study aims to highlight the significance of the nucleic acid test (NAT) for musculoskeletal tissue donation and to compare the sensitivity of this test on the different available platforms.

Method  The present study is a retrospective survey in a human tissue bank database and an integrative literature review encompassing the last 10 years. The PubMed portal and the SCOPUS, CINAHL, and Web of Science databases were queried for articles.

Results  We found no specific studies on the use and sensitivity of NAT in braindead tissue donors. The information presented in the present study consists of specific contents intended for the Brazilian Blood Transfusion Network (Hemorrede Transfusional Nacional, in Portuguese) and internal retrospective data from a tissue bank located at a city in the state of São Paulo, Brazil.

Conclusions  The NAT is effective in blood samples from living patients. However, since biochemical reactions in braindead patients can be different, specific research, platforms, or both are crucial to tissue banks.

Radiologic Evaluation of Uterine Vasculature of Uterus Transplant Living Donor Candidates: DUETS Classification

Uterus transplantation is a treatment solution for women suffering from absolute uterine factor infertility. As much as 19.5% of uterus-transplanted patients underwent urgent graft hysterectomy due to thrombosis/hypoperfusion. The necessity to identify candidates with high-quality uterine vasculature is paramount. We retrospectively evaluated and compared the imaging results with actual vascular findings from the back table. In this article, we present a novel radiologic grading scale (DUETS classification) for evaluating both uterine arteries and veins concerning their suitability for uterus procurement and transplantation. This classification defines several criteria for arteries (caliber, tapering, atherosclerosis, tortuosity, segment, take-off, and course) and veins (caliber, tapering, plethora, fenestrations, duplication/multiplicity, dominant route of venous drainage, radiologist’s confidence with imaging and assessment). In conclusion, magnetic resonance angiography can provide reliable information on uterine venous characteristics if performed consistently according to a well-established protocol and assessed by a dedicated radiologist. The caliber of uterine arteries seems to be inversely related to the time passed since the last delivery. We recommend that the radiologist comments on the reliability and confidence of the imaging study. It cannot be over-emphasized that the most crucial aspect of surgical imaging is the necessity of high-quality communication between a surgeon and a radiologist.

Prediction of measured GFR after living kidney donation from pre-donation parameters

BACKGROUND

One of the challenges in living kidney donor screening is to estimate remaining kidney function after donation. Here we developed a new model to predict post-donation measured glomerular filtration rate (mGFR) from pre-donation serum creatinine, age and sex.

METHODS

In the prospective development cohort (TransplantLines, n = 511), several prediction models were constructed and tested for accuracy, precision and predictive capacity for short- and long-term post-donation 125I-iothalamate mGFR. The model with optimal performance was further tested in specific high-risk subgroups (pre-donation eGFR <90 mL/min/1.73 m2, a declining 5-year post-donation mGFR slope or age >65 years) and validated in internal (n = 509) and external (Mayo Clinic, n = 1087) cohorts.

RESULTS

In the development cohort, pre-donation estimated GFR (eGFR) was 86 ± 14 mL/min/1.73 m2 and post-donation mGFR was 64 ± 11 mL/min/1.73 m2. Donors with a pre-donation eGFR ≥90 mL/min/1.73 m2 (present in 43%) had a mean post-donation mGFR of 69 ± 10 mL/min/1.73 m2 and 5% of these donors reached an mGFR <55 mL/min/1.73 m2. A model using pre-donation serum creatinine, age and sex performed optimally, predicting mGFR with good accuracy (mean bias 2.56 mL/min/1.73 m2, R2 = 0.29, root mean square error = 11.61) and precision [bias interquartile range (IQR) 14 mL/min/1.73 m2] in the external validation cohort. This model also performed well in donors with pre-donation eGFR <90 mL/min/1.73 m2 [bias 0.35 mL/min/1.73 m2 (IQR 10)], in donors with a negative post-donation mGFR slope [bias 4.75 mL/min/1.73 m2 (IQR 13)] and in donors >65 years of age [bias 0.003 mL/min/1.73 m2 (IQR 9)].

CONCLUSIONS

We developed a novel post-donation mGFR prediction model based on pre-donation serum creatinine, age and sex.

Prevalence and risk factors of antibodies to HLA according to different cut-off values of mean fluorescence intensity in haploidentical allograft candidates: A prospective study of 3805 subjects

The importance of anti-HLA antibodies in transplantation settings, such as HLA-mismatched or haploidentical hematopoietic stem cell transplantation and platelet refractoriness, is widely recognized. In previous reports, it was mentioned that several cut-off values of donor-specific anti-HLA antibodies mean fluorescence intensity (MFI) were related to graft rejection in the environment of HLA mismatched stem cell transplantation and the aim of this study was to investigate the prevalence and risk factors of anti-HLA antibodies according to those cut-off values of MFI. A total of 3805 patients with hematologic disease were prospectively enrolled and analyzed. When using MFI of anti-HLA antibodies ≥500, ≥1000, ≥1500, ≥2000, ≥5000, and ≥ 10,000 as cut-off values for positivity, the prevalence of class I or II anti-HLA antibodies ranged from 4.6% to 20.2% in all cases. When the MFI cut-off value was ≥500 for positivity, multivariate analysis indicated that platelet transfusion, underlying disease, and pregnancy were the most important risk factors for the presence of anti-HLA antibodies for the total patients. Subgroup analysis according to age, gender, and underlying disease showed that pregnancy was the most important risk factor for the presence of anti-HLA antibodies. For all patients (n = 3805), when anti-HLA antibody positivity was defined according to different MFI cut-off values, including ≥1000, ≥1500, ≥2000, ≥5000, and ≥ 10,000, an association of platelet transfusion and pregnancy with anti-HLA antibodies was also demonstrated. Our results suggest that pregnancy and platelet transfusion are the main risk factors for the prevalence of anti-HLA antibodies in haploid allograft candidates, providing evidence for guiding the evaluation of anti-HLA antibodies and helping donor selection for HLA-mismatched transplant candidates.

Pearls and Pitfalls in Pediatric Kidney Transplantation After 5 Decades

Worldwide, over 1,300 pediatric kidney transplantations are performed every year. Since the first transplantation in 1959, healthcare has evolved dramatically. Pre-emptive transplantations with grafts from living donors have become more common. Despite a subsequent improvement in graft survival, there are still challenges to face. This study attempts to summarize how our understanding of pediatric kidney transplantation has developed and improved since its beginnings, whilst also highlighting those areas where future research should concentrate in order to help resolve as yet unanswered questions. Existing literature was compared to our own data of 411 single-center pediatric kidney transplantations between 1968 and 2020, in order to find discrepancies and allow identification of future challenges. Important issues for future care are innovations in immunosuppressive medication, improving medication adherence, careful donor selection with regard to characteristics of both donor and recipient, improvement of surgical techniques and increased attention for lower urinary tract dysfunction and voiding behavior in all patients.

Evolving Characteristics of Heart Transplantation Donors and Recipients: JACC Focus Seminar

Although the burden of end-stage heart failure continues to increase, the number of available organs for heart transplantation (HT) remains inadequate. The HT community has been challenged to find ways to expand the number of donor hearts available. Recent advances include use of hearts from donors infected with hepatitis C virus as well as other previously underutilized donors, including those with left ventricular dysfunction, of older age, and with a history of cocaine use. Concurrently, emerging trends in HT surgery include donation after circulatory death, ex vivo normothermic heart perfusion, and controlled hypothermic preservation, which may enable procurement of organs from farther distances and prevent early allograft dysfunction. Contemporary HT recipients have also evolved in light of the 2018 revision to the U.S. heart allocation policy. This focus seminar discusses recent trends in donor and recipient phenotypes and management strategies for successful HT, as well as evolving areas and future directions.

Association of Donor Brain Death Due to Stroke With Prognosis After Heart Transplantation

BACKGROUND

The proximate cause of donor brain death is not considered a conventional risk factor in modern heart transplantation.

OBJECTIVES

This study aimed to investigate the effect of the cause of donor brain death on recipients.

METHODS

Using the United Network for Organ Sharing registry, long-term mortality and allograft failure were compared in recipients who underwent heart transplantation in the United States from 2005 through 2018 between allograft recipients from donors with stroke as the cause of brain death (n = 3,761) vs nonstroke causes (n = 14,677). Inverse probability weighting was used for risk adjustment. Interactions were investigated between the cause of brain death and other conventional donor risk factors for recipient mortality.

RESULTS

There was an interaction between the cause of brain death and donor age (P_interaction = 0.008). When allografts were procured from donors aged 40 years or younger, stroke as the cause of brain death was associated with an increased risk of mortality (23% vs 19% at 5 years; HR: 1.17; 95% CI: 1.02-1.35) and allograft failure (HR: 1.30; 95% CI: 1.04-1.63). When donors were older than 40 years, the cause of brain death was not associated with outcomes.

CONCLUSIONS

As the cause of donor brain death, stroke had a substantially different effect on recipient and allograft survival depending on donor age. In the case of younger donor ages, stroke was associated with higher recipient mortality and allograft failure than other causes of brain death. The strength of this association decreased with increasing donor age such that the increased hazard was no longer present in donors older than approximately 40 years.

Outcome of kidney transplantations from ≥65-year-old deceased donors with acute kidney injury

Kidney transplantation (KT) from donors with acute kidney injury (AKI) has been associated with delayed graft function (DGF) but similar graft survival compared with KT from donors without AKI. Kidneys from ≥65-year-old donors with comorbidities are more susceptible to cold ischemia time and DGF and it is unknown whether such elderly kidneys with AKI can also be transplanted with satisfactory outcomes. All KTs from ≥65-year-old donors performed at our centre from 1999 to 2019 (n = 233) were retrospectively analysed and short- as well as long-term outcomes were compared for KTs from donors with (n = 64) and without AKI (n = 169). There were no significant differences regarding the frequency of DGF as well as the estimated glomerular filtration rate (eGFR) one and three years post-transplant between the no-AKI and the AKI group (DGF: no-AKI 30.2% vs. AKI 40.6%, P = 0.17; eGFR at one-year: 31.9 ml/min/1.73m² vs. 35.5 ml/min/1.73m² , P = 0.32; at three-years: 33.8 ml/min/1.73m² vs. 40.9 ml/min/1.73m² , P = 0.18; respectively). Death-censored graft survival and patient survival were also not significantly different. Multivariable Cox regression analysis did not identify AKI as a significant risk factor for graft loss or death. Following careful donor and recipient selection, kidneys from ≥65-year-old AKI donors may potentially be transplanted with satisfactory outcomes. This article is protected by copyright. All rights reserved.

Impact of COVID-19 on blood donor deferral patterns during the COVID-19 pandemic: A retrospective analysis

BACKGROUND AND OBJECTIVES

Blood donor deferral is an essential tool for blood safety. The ongoing COVID-19 pandemic has adversely affected blood transfusion services all over the world. But its impact on donor deferral rate and the pattern is unclear in light of the new donor deferral policy due to the COVID-19 pandemic.

MATERIALS AND METHODS

This retrospective study was divided into pre-COVID and COVID (15 March 2019-14 March 2021). All the deferred donors were divided into six different categories: (1) medical causes, (2) surgical causes, (3) drugs and vaccination, (4) risk of transfusion-transmitted diseases, (5) miscellaneous causes and (6) flu-like symptoms. In addition, COVID-related deferrals were also incorporated. All these above categories along with the donor demography were analysed by SPSS software version 25.

RESULTS

The donor deferral rate was 17.03% and 12.74% during the pre-COVID and COVID periods, respectively. During the pre-COVID period, Category 3 deferrals and during COVID period, Category 6 deferrals were significantly higher. A reversal in pattern with increased blood pressure (40.2% vs. 24.04%) over-riding low haemoglobin (34.77% vs. 55.5%) was noted in the Category 1 deferral during the COVID period. Category 1 deferral was more in middle-aged adults as compared to young and old adults (p < 0.05). Among middle-aged adults, deferral due to flu-like symptoms was also significantly more during the COVID period (p < 0.05).

CONCLUSION

COVID-19 significantly affected the donor pool and changed the pattern of donor deferral. Understanding donor deferral patterns may help in identifying targeted donor populations and planning donor recruitment strategies in future pandemic crises.

Collection and administration of blood products in horses: Transfusion indications, materials, methods, complications, donor selection, and blood testing

BACKGROUND

Blood transfusion is a lifesaving treatment for horses with acute hemorrhage and other causes of anemia. Transfusions improve oxygen delivery to the tissues via increased blood volume and hemoglobin concentration. Certain aspects of equine blood transfusion are challenging, especially in the field situation, and practitioners may be unfamiliar or feel overwhelmed with the process. An understanding of the indications, materials, methods, and techniques as well as donor selection and possible complications will help practitioners successfully implement blood transfusion in clinical practice.

PROCEDURES

Blood transfusion involves several steps including appropriate donor selection, cross-matching, blood collection, and administration, as well as monitoring and handling of transfusion reactions. Guidance for each of these steps are detailed in this review.

SUMMARY

Blood transfusion is an effective and often lifesaving treatment for managing diseases of blood loss, hemolysis, and decreased RBC production. Equine practitioners require a thorough understanding of the indications for blood transfusion, the immunological principles behind compatibility testing and transfusion reactions, and the technical skills to aseptically collect and administer blood products KEY POINTS: Equine practitioners require a thorough understanding of the indications for blood transfusion, the immunological principles behind compatibility testing and transfusion reactions, and the technical skills to aseptically collect and administer blood products. Because there are over 400,000 possible equine RBC phenotypes, no universal donor exists, and some blood type incompatibilities are likely between any donor and recipient. Therefore, prior to any blood transfusion, donor and recipient blood should be cross-matched Inadequate delivery of oxygen (Do₂ ) to the tissues, resulting from low hemoglobin (Hb) concentration, is the most important indication for blood transfusion Neonatal isoerythrolysis most commonly occurs following an anamnestic response in late gestation; it rarely occurs following a primary exposure because the immune response is not strong enough to produce clinically significant alloantibody titers.

Cost-effectiveness and system-wide impact of using Hepatitis C-viremic donors for heart transplant

BACKGROUND

The advent of direct-acting antiviral therapy for Hepatitis C (HCV) has made using HCV-viremic donors a viable strategy to address the donor shortage in heart transplantation. We employed a large-scale simulation to evaluate the impact and cost-effectiveness of using HCV-viremic donors for heart transplant.

METHODS

We simulated detailed histories from time of listing until death for the real-world cohort of all adults listed for heart transplant in the United States from July 2014 to June 2019 (n = 19,346). This population was imputed using historical data and captures "real-world" heterogeneity in geographic and clinical characteristics. We estimated the impact of an intervention in which all candidates accept HCV+ potential donors (n = 472) on transplant volume, waitlist outcomes, and lifetime costs and quality-adjusted life years (QALYs).

RESULTS

The intervention produced 232 more transplants, 132 fewer delistings due to deterioration, and 50 fewer waitlist deaths within this 5-year cohort and reduced wait times by 3% to 11% (varying by priority status). The intervention was cost-effective, adding an average of 0.08 QALYs per patient at a cost of $124 million ($81,892 per QALY). DAA therapy and HCV care combined account for 11% this cost, with the remainder due to higher costs of transplant procedures and routine post-transplant care. The impact on transplant volume varied by blood type and region and was correlated with donor-to-candidate ratio (ρ = 0.71).

CONCLUSIONS

Transplanting HCV+ donor hearts is likely to be cost-effective and improve waitlist outcomes, particularly in regions and subgroups experiencing high donor scarcity.

Effect of donor characteristics on T cell-replete haploidentical stem cell transplantation over the last 10 years at a single institution

One of the most complex issues with haploidentical stem cell transplantation (haplo-SCT) is donor selection, given that multiple haploidentical donors are often available for a given recipient. To develop evidence-based guidance for donor selection in the setting of anti-thymocyte globulin-based haplo-SCT, we performed a prospective cohort study of 512 patients with haematological malignancies who had haplo-SCT to determine which donor variables were most important in favouring transplant outcomes. Increasing donor age was associated with poorer overall survival (OS) [hazard ratio (HR) 1·08, P = 0·044]. Female donors to male recipients was significantly associated with higher non-relapse mortality (NRM; HR 2·05, P = 0·006). Furthermore, increasing donor age had a higher risk of Grades 3-4 acute graft-versus-host disease (aGVHD; HR 1·17, P = 0·005), female donors to male recipients was associated with a higher risk of Grades 2-4 aGVHD (HR 1·50, P = 0·022). Sibling donors had superior OS, disease-free survival, and NRM than parental donors in patients aged <35 years. However, sibling donors had higher NRM than offspring donors in patients aged ≥35 years. A younger donor, usually a young sibling in younger recipients (aged <35 years) or a young offspring in older patients (aged ≥35 years) and avoiding female donors to male recipients should be preferred when multiple haploidentical donors are available.

Making a Killer: Selecting the Optimal Natural Killer Cells for Improved Immunotherapies

Over the past 20 years natural killer (NK) cell-based immunotherapies have emerged as a safe and effective treatment option for patients with relapsed or refractory leukemia. Unlike T cell-based therapies, NK cells harbor an innate capacity to eliminate malignant cells without prior sensitization and can be adoptively transferred between individuals without the need for extensive HLA matching. A wide variety of therapeutic NK cell sources are currently being investigated clinically, including allogeneic donor-derived NK cells, stem cell-derived NK cells and NK cell lines. However, it is becoming increasingly clear that not all NK cells are endowed with the same antitumor potential. Despite advances in techniques to enhance NK cell cytotoxicity and persistence, the initial identification and utilization of highly functional NK cells remains essential to ensure the future success of adoptive NK cell therapies. Indeed, little consideration has been given to the identification and selection of donors who harbor NK cells with potent antitumor activity. In this regard, there is currently no standard donor selection criteria for adoptive NK cell therapy. Here, we review our current understanding of the factors which govern NK cell functional fate, and propose a paradigm shift away from traditional phenotypic characterization of NK cell subsets towards a functional profile based on molecular and metabolic characteristics. We also discuss previous selection models for NK cell-based immunotherapies and highlight important considerations for the selection of optimal NK cell donors for future adoptive cell therapies.

Significance of regional population HLA immunogenetic datasets in the efficacy of umbilical cord blood banks and marrow donor registries: a study of Cretan HLA genetic diversity

BACKGROUND AIMS

The high genetic diversity of HLA across populations significantly confines the effectiveness of a donor or umbilical cord blood search for allogeneic hematopoietic stem cell transplantation (HSCT). This study aims to probe the HLA immunogenetic profile of the population of Crete, a Greek region with specific geographic and historical characteristics, and to investigate potential patterns in HLA distribution following comparison with the Deutsche Knochenmarkspenderdatei (DKMS) donor registry. It also aims to highlight the importance of regional public cord blood banks (PCBBs) in fulfilling HSCT needs, especially in countries with significant genetic diversity.

METHODS

A cohort of 1835 samples representative of the Cretan population was typed for HLA class I (HLA-A, HLA-B, HLA-C) and class II (HLA-DRB1, HLA-DQB1, HLA-DPB1) loci by high-resolution second field next-generation sequencing. Data were compared with the respective HLA profiles of 12 DKMS populations (n = 20 032). Advanced statistical and bioinformatics methods were employed to assess specific intra- and inter-population genetic indexes associated with the regional and geographic distribution of HLA alleles and haplotypes.

RESULTS

A considerable HLA allelic and haplotypic diversity was identified among the Cretan samples and between the latter and the pooled DKMS cohort. Even though the HLA allele and haplotype frequency distribution was similar to regions of close geographic proximity to Crete, a clinal distribution pattern from the northern to southern regions was identified. Significant differences were also observed between Crete and the Greek population of DKMS.

CONCLUSIONS

This study provides an in-depth characterization of the HLA immunogenetic profile in Crete and reveals the importance of demographic history in HLA heterogeneity and donor selection. The novel HLA allele and haplotype frequency comparative data between the Cretan and other European populations signify the importance of regional PCBBs in prioritizing HLA diversity to efficiently promote the HSCT program at the national level and beyond.

Impact of cardiopulmonary resuscitation on outcome of kidney transplantations from braindead donors aged ≥65 years

Patients with a history of cardiopulmonary resuscitation (CPR) and subsequent brain death are frequently evaluated for organ donation. Whether kidneys from ≥65-year-old braindead donors with a history of CPR can be transplanted with satisfactory outcomes is unknown. All kidney transplants (KT) from ≥65-year-old donors performed at our centre from 1999 to 2018 (n = 185) were retrospectively analysed and outcome was compared for KTs from donors with and without a history of CPR (n = 27 and n = 158, respectively). No significant differences in the incidence of delayed graft function (DGF) as well as one- and three-year graft function were observed between the CPR and the no-CPR group (DGF: 26.0% vs 31.0%, P = 0.76; one-year serum creatinine: 150.4 μmol/l vs 177.0 μmol/l, P = 0.11; three-year serum creatinine: 150.4 μmol/l vs 168.2 μmol/l, P = 0.52, respectively). Death-censored graft survival was comparable after one and five years (CPR group: 81.5% and 76.7% vs no-CPR group: 86.6% and 75.7%, P = 0.70). Likewise, patient survival was not significantly different. Multivariable Cox regression analysis also did not identify CPR as a significant risk factor for graft loss or death. Our study suggests that, following stringent donor selection, the outcome of KTs from ≥65-year-old braindead donors with and without a history of CPR is comparable. This article is protected by copyright. All rights reserved.

Assessment of the global practice of living donor liver transplantation

Criteria that drive the selection and utilization of living liver donors are limited. Herein, the global availability of living donor liver transplantation (LDLT) and components of donor selection and utilization were assessed via an international survey. There were 124 respondents representing 41 countries, including 47 from Asia/Middle East (A/ME), 20 from Europe, and 57 from the Americas. Responses were obtained from 94.9% of countries with ≥10 LDLT cases/year. Most centers (82.3%) have defined donor age criteria (median 18-60 years), while preset recipient MELD cutoffs (median 18-30) were only reported in 54.8% of programs. Overall, 67.5% of programs have preset donor BMI (body mass index) ranges (median 18-30), and the mean acceptable macrosteatosis was highest for A/ME (20.2 ± 9.2%) and lowest for Americas (16.5 ± 8.4%, P = 0.04). Americas (56.1%) and European (60.0%) programs were more likely to consider anonymous donors versus A/ME programs (27.7%, P = 0.01). There were no differences in consideration of complex anatomical variations. Most programs (75.9%) perform donor surgery via an open approach, and A/ME programs are more likely to use microscopic arterial reconstruction. Despite variations in practice, key aspects of living donor selection were identified. These findings provide a contemporary reference point as LDLT continues to expand into areas with limited access to liver transplantation.

Humanized Mouse Model as a Novel Approach in the Assessment of Human Allogeneic Responses in Organ Transplantation

The outcome of organ transplantation is largely dictated by selection of a well-matched donor, which results in less chance of graft rejection. An allogeneic immune response is the main immunological barrier for successful organ transplantation. Donor and recipient human leukocyte antigen (HLA) mismatching diminishes outcomes after solid organ transplantation. The current evaluation of HLA incompatibility does not provide information on the immunogenicity of individual HLA mismatches and impact of non-HLA-related alloantigens, especially in vivo. Here we demonstrate a new method for analysis of alloimmune responsiveness between donor and recipient in vivo by introducing a humanized mouse model. Using molecular, cellular, and genomic analyses, we demonstrated that a recipient's personalized humanized mouse provided the most sensitive assessment of allogeneic responsiveness to potential donors. In our study, HLA typing provided a better recipient-donor match for one donor among two related donors. In contrast, assessment of an allogeneic response by mixed lymphocyte reaction (MLR) was indistinguishable between these donors. We determined that, in the recipient's humanized mouse model, the donor selected by HLA typing induced the strongest allogeneic response with markedly increased allograft rejection markers, including activated cytotoxic Granzyme B-expressing CD8+ T cells. Moreover, the same donor induced stronger upregulation of genes involved in the allograft rejection pathway as determined by transcriptome analysis of isolated human CD45+cells. Thus, the humanized mouse model determined the lowest degree of recipient-donor alloimmune response, allowing for better selection of donor and minimized immunological risk of allograft rejection in organ transplantation. In addition, this approach could be used to evaluate the level of alloresponse in allogeneic cell-based therapies that include cell products derived from pluripotent embryonic stem cells or adult stem cells, both undifferentiated and differentiated, all of which will produce allogeneic immune responses.

An Immunologic Compatibility Testing Was Not Useful for Donor Selection in Fecal Microbiota Transplantation for Ulcerative Colitis

Fecal microbiota transplantation (FMT) is an effective procedure against Clostridioides difficile infection (CDI), with promising but still suboptimal performance in other diseases, such as ulcerative colitis (UC). The recipient’s mucosal immune response against the donor’s microbiota could be relevant factor in the effectiveness of FMT. Our aim was to design and validate an individualized immune-based test to optimize the fecal donor selection for FMT. First, we performed an in vitro validation of the test by co-culturing lymphocytes obtained from the small intestine mucosa of organ donor cadavers (n=7) and microbe-associated molecular patterns (MAMPs) obtained from the feces of 19 healthy donors. The inflammatory response was determined by interleukin supernatant quantification using the Cytometric Bead Array kit (B&D). We then conducted a clinical pilot study with 4 patients with UC using immunocompetent cells extracted from rectal biopsies and MAMPs from 3 donor candidates. We employed the test results to guide donor selection for FMT, which was performed by colonoscopy followed by 4 booster instillations by enema in the following month. The microbiome engraftment was assessed by 16S rDNA massive sequencing in feces, and the patients were clinically followed-up for 16 weeks. The results demonstrated that IL-6, IL-8, and IL-1ß were the most variable markers, although we observed a general tolerance to the microbial insults. Clinical and colonoscopy remission of the patients with UC was not achieved after 16 weeks, although FMT provoked enrichment of the Bacteroidota phylum and Prevotella genus, with a decrease in the Actinobacteriota phylum and Agathobacter genus. The most relevant result was the lack of Akkermansia engraftment in UC. In summary, the clinical success of FMT in patients with UC appears not to be influenced by donor selection based on the explored recipient’s local immunological response to FMT, suggesting that this approach would not be valid for FMT fecal donor optimization in such patients.