Donor-recipient Matching Research Articles

Outcome of pediatric-to-adult liver transplantation:a single-center study in China

Objective: To explore the outcome of the pediatric-to-adult liver transplantation, including postoperative complications and relevant factors which affecting graft survival. Methods: Data of 55 patients undergoing pediatric-to-adult liver transplantation at the First Affiliated Hospital of Zhejiang University between January 2015 and August 2021 were retrospectively analyzed. The donors consisted of 34 males and 21 females, and the age was (11.8±4.7) years (range: 1 to 17 years). Among the cases,17 cases (30.9%) were donation of brain death,32 cases (58.2%) were donation of cardiac death, and 6 cases (10.9%) were donation after brain death plus cardiac death. The recipients consisted of 32 males and 23 females, and the age was (51.6±10.1) years (range: 27 to 70 years). Among the recipients,10 cases (18.2%) were ABO-incompatible liver transplantation.The influencing factors of early graft survival were analyzed by Student t test,Mann-Whitney U test or χ2 test,respectively.Survival curve was drawn by Kaplan-Meier method.Logistic multivariate analysis was used to analyze the independent relevant factors of early postoperative graft loss. Results: Up to October 31,2021,the follow-up time (M(IQR)) was 36.0(43.1)months(range:5.9 to 81.7 months).There were 13 cases with graft loss (two of them underwent re-transplantation due to acute liver failure).The monofactor analysis indicated that cold ischemia time and donor-recipient blood group matching were the relevant factors affecting the early graft survival rate(both P<0.05).Logistic multivariate analysis showed that cold ischemia time and history of recipient gastrointestinal bleeding were independent relevant factors(both P<0.05).Postoperative hepatic artery thrombosis occurred in 3 cases(5.5%), portal vein thrombosis diagnosed in 4 cases(7.3%), portal vein stenosis occurred in 2 cases(3.6%),biliary complications diagnosed in 7 cases(12.7%), and small liver syndrome was found in 8 cases(14.5%). Conclusions: Adult liver transplantation with pediatric donor liver is an effective method to treat end-stage liver disease.Cold ischemia time and history of recipient gastrointestinal bleeding were independent relevant factors for the early graft survival.

Determining Clinical Thresholds for Donor HLA Eplet Compatibility to Predict Best Outcomes Following Lung Transplantation.

Background.Currently, the assessment of immunological risk in lung transplantation (LTx) does not completely consider HLA compatibility at the molecular level. We have previously demonstrated the association of HLA eplets in predicting chronic lung allograft dysfunction following LTx; however, the associations between HLA eplet mismatch (epMM) loads and overall survival are unknown.Methods.In this retrospective, single-center study, 277 LTx donor-recipient pairs were high resolution HLA typed and analyzed for HLA epMMs using HLAMatchmaker (version 3.1). LTx pairs were also assessed for the presence of the previously described risk epitope mismatches DQ2-DQA1*05 and DQ7-DQA1*05.Results.HLA class I epMMs were not associated with deleterious outcomes; however, lower HLA class II (≤19), DQA1 (≤2), and combined HLA class I and II (≤29) epMM demonstrated an association with increased time to chronic lung allograft dysfunction and improved overall survival. The presence of a risk epitope mismatch was not associated with worse clinical outcomes.Conclusions.HLA epMM can risk-stratify LTx recipients and potentially guide donor-recipient matching and immunosuppression strategies.

P9.33: Prevention Strategies Against CMV-Infection After Liver Transplantation

Background: There is a variety of prevention strategies against cytomegalovirus (CMV) viremia/ disease after liver transplantation (LT). Thus, this retrospective cohort study performed in a prospective manner with a 1-year follow-up has been performed comparing anti-CMV immunoglobulins (IGs) with Valganciclovir. Patients and Methods: A total of 257 patients underwent LT between January 2008 and May 2020. While 134 patients received anti-CMV-IGs (7500 IU for 4 days) between 2008 and October 2016, 111 patients were treated with Valganciclovir (up to 900 mg/d for 3-6 months dependent on renal function and side effects) since November 2016. Patients with viremia in both groups were treated at least for 14 days with Ganciclovir or Valganciclovir. Primary endpoint of the study was CMV viremia within 1 year after LT. Secondary endpoints were leukopenia, renal function, patient and graft survival. Results: Demographics were comparable in both groups (i.e. age (56.6 +/- 11.2 years), gender (78.8% male)). Viremia was 36.7% (n=90) within 1 year after LT with 43.3% (n=58) after anti-CMV IGs vs. 28.8% (n=32) after Valganciclovir (p>0.05). The incidence of viremia was dependent of the donor-recipient match with 39.6% (n=21) and 60,6% (n=20) in D-/R+ and D+/R+ after anti-CMV IGs, and 12.0% (n=3) and 25,7% (n=9) after Valganciclovir (p=0.018; p=0.007), respectively. The overall 1-year mortality rate was comparable in both groups with 13.1% (n=32). Kidney function based on serum creatinine was significantly improved with anti-CMV IGs at 1 year after LT. Conclusion: While Valgancyclovir protected nicely CMV positive recipients from CMV viremia the effect of anti-CMV IGs was inferior in this constellation without any impact on CMV disease; however, anti-CMV IGs are in favor to a better side effect profile especially concerning renal function and thus it should be the preferred prevention strategy.

1035 Gender Equality in Heart Transplantation: A Single Centre Study

Abstract Background International Society for Heart and Lung Transplantation catergoirises female gender in donor/recipient, as a significant risk factor for mortality after heart transplantation. Further, donor-recipient gender mismatch is also reported to be a determinant of post-transplant morbidity/mortality. To examine the effect of gender in survival outcomes, we conducted a retrospective study. Method Population comprised of 298 patients undergoing heart transplantation from 2001 to 2021, divided into four groups on the basis of donor and recipient matching. Group A consisted of men who received male donor-hearts, group B of women who received female donor-hearts, group C of women who received male donor-hearts, and group D of men who received female donor-hearts. Standard heart transplantation protocols were applied to all patient groups for graft preservation, surgical technique, donor-recipient size matching, induction &amp; immunosuppressive therapy. Results The study groups were found to be homogeneous to the major preoperative- risk- factors (aetiology, transplantation status, donor-recipient-age, total ischemic time). Donor gender, recipient gender and donor-recipient gender mismatching did not significantly modify the short and mid-term survivals, functional recovery, and primary graft dysfunction post-surgery. Conclusions Even though previous reports suggest that gender negatively affects survival, this proved to have no influence on the outcomes in our study. These results can be explained by a correct donor-recipient size matching. The well-documented female recipients’ tendency to more frequent and fatal rejection was not confirmed in our experience. The patient's age at transplantation, the routine use of induction therapy and an aggressive immunosuppressive regimen may be the substrate of these findings.

1036 Gender Equality in Heart Transplantation: A Single Centre Study

Abstract Background International Society for Heart and Lung Transplantation categorises female gender in donor/recipient, as a significant risk factor for mortality after heart transplantation. Further, donor-recipient gender mismatch is also reported to be a determinant of post-transplant morbidity/mortality. To examine the effect of gender in survival outcomes, we conducted a retrospective study. Method Population comprised of 298 patients undergoing heart transplantation from 2001 to 2021, divided into four groups on the basis of donor and recipient matching. Group A consisted of men who received male donor-hearts, group B of women who received female donor-hearts, group C of women who received male donor-hearts, and group D of men who received female donor-hearts. Standard heart transplantation protocols were applied to all patient groups for graft preservation, surgical technique, donor-recipient size matching, induction &amp; immunosuppressive-therapy. Results The study groups were found to be homogeneous to the major preoperative- risk- factors (aetiology, transplantation status, donor-recipient-age, total ischemic time). Donor gender, recipient gender and donor-recipient gender mismatching did not significantly modify the short and mid-term survivals, functional recovery, and primary graft dysfunction post-surgery. Conclusions Even though previous reports suggest that gender negatively affects survival, this proved to have no influence on the outcomes in our study. These results can be explained by a correct donor-recipient size matching. The well-documented female recipients’ tendency to more frequent and fatal rejection was not confirmed in our experience. The patient's age at transplantation, the routine use of induction therapy and an aggressive immunosuppressive regimen may be the substrate of these findings.

Validation of predicted heart mass equations by measurement of donor heart mass at time of heart transplantation.

Predicted heart mass (PHM) equations may be used in donor-recipient size matching in heart transplantation. We compared PHM and actual heart mass in 25 consecutive DBD heart transplants. There was a moderate positive correlation between actual heart mass and PHM. There was a similar moderate correlation between actual heart mass and donor weight or donor body surface area but not donor height. PHM was lower than actual heart mass for all donor hearts. Bland-Altman analysis showed a systematic bias between PHM and actual heart mass, with a mean difference of 190.9±66.4g. The utility of PHM equations is likely to be part of a multi-parametric assessment of the relative differences between donor and recipient, so the absolute difference is likely to be unimportant.

The interplay of gut microbiota between donors and recipients determines the efficacy of fecal microbiota transplantation

ABSTRACT Fecal microbiota transplantation (FMT) is a promising treatment for microbiota dysbiosis associated diseases, such as Clostridioides difficile infection (CDI) and inflammatory bowel disease (IBD). The engraftment of donor bacteria is essential for the effectiveness of FMT, which to some extent depends on the matching of donors and recipients. However, how different types of donor-derived bacteria affect FMT efficacy has not been fully dissected. We recruited two longitudinal IBD cohorts of 103 FMT recipients and further analyzed 1,280 microbiota datasets from 14 public CDI and IBD studies to uncover the effect of donor-derived microbiota in recipients. We found that two enterotypes, RCPT/E and RCPT/B (dominated by Enterobacteriaceae and Bacteroides, respectively), consistently exist in both CDI and IBD patients. Based on a time-course-based multi-cohort analysis of FMT fecal samples, we observed the interplay between recipient and donor-derived microbiota during FMT, in which the FMT outcome was significantly associated with the enterotype and microbiota distance between donor and recipient after FMT. We proposed a new measurement, the ratio of colonizers to residents after FMT (C2R), to quantify the engraftment of donor-derived bacteria in the recipients, and then constructed an enterotype-based statistical model for donor-recipient matching, which was validated by both cross-validation and an additional IBD FMT cohort (n = 42). We believe that with the accumulation of FMT multi-omics datasets, machine learning-based methods will be helpful for rational donor selection for improving efficacy and precision FMT practices.

Viability testing during liver preservation.

Viability assessment is one of the main indications for machine perfusion (MP) in liver transplantation. This review summarizes the rationale, evolution and limitations of proposed viability criteria and suggests a framework for future studies. Liver viability is most frequently assessed during normothermic MP by combining parameters relative to perfusate and bile composition, vascular flows and macroscopic aspect. Assessment protocols are largely heterogeneous and have significantly evolved over time, also within the same group, reflecting the ongoing evolution of the subject. Several recent preclinical studies using discarded human livers or animal models have explored other approaches to viability assessment. During hypothermic MP, perfusate flavin mononucleotide has emerged as a promising biomarker of mitochondrial injury and function. Most studies on the subject suffer from limitations, including low numbers, lack of multicenter validation, and subjective interpretation of some viability parameters. MP adds a further element of complexity in the process of assessing the quality of a liver graft. Understanding the physiology of the parameters included in the different assessment protocols is necessary for their correct interpretation. Despite the possibility of assessing liver viability during MP, the importance of donor-recipient matching and operational variables should not be disregarded.

Artificial Intelligence: Present and Future Potential for Solid Organ Transplantation.

Artificial intelligence (AI) refers to computer algorithms used to complete tasks that usually require human intelligence. Typical examples include complex decision-making and- image or speech analysis. AI application in healthcare is rapidly evolving and it undoubtedly holds an enormous potential for the field of solid organ transplantation. In this review, we provide an overview of AI-based approaches in solid organ transplantation. Particularly, we identified four key areas of transplantation which could be facilitated by AI: organ allocation and donor-recipient pairing, transplant oncology, real-time immunosuppression regimes, and precision transplant pathology. The potential implementations are vast—from improved allocation algorithms, smart donor-recipient matching and dynamic adaptation of immunosuppression to automated analysis of transplant pathology. We are convinced that we are at the beginning of a new digital era in transplantation, and that AI has the potential to improve graft and patient survival. This manuscript provides a glimpse into how AI innovations could shape an exciting future for the transplantation community.

P-774 Risks management in a donor program: application of Failure Mode and Effect Analysis from gamete matching to gamete thawing

Abstract Study question Is failure mode and effects analysis (FMEA) a useful and effective method of risk assessment in a gamete donor program? Summary answer The analysis of the potential failures, their causes and effects significantly improved the safety strategies previously adopted in our gamete donor program. What is known already At present, in Italy, the donation of fresh gametes is possible, but almost unmanageable due to the lack of donors and the refund to donors forbidden by law. As a result, many IVF Italian Centers established agreements with foreign gametes cryo-banks in order to meet the huge demand for donation treatments. The exchange of personal sensitive data and gametes between the sending and receiving centers represents a crucial aspect in a donor cycle. Each stage of this process, from gamete request to gamete thawing, is not error-free. FMEA represents a strategy to identify and mitigate potential failures before they occur. Study design, size, duration Fifty-eight oocyte and 4 sperm donation cycles were performed at our IVF facility from September 2019 to January 2021. Gametes came from a single Spanish cryo-bank. FMEA represents a proactive risk evaluation tool useful to identify real or potential failures and to develop actions to minimize risks. FMEA was conducted, in January 2021, by a team consisting of 2 gynaecologists, 3 embryologists and 2 quality managers and repeated 8 months later. Participants/materials, setting, methods Processes were analyzed to identify and score the potential failure modes using the risk priority number (RPN) scoring system. The calculation has been obtained by multiplying 3 factors: severity, occurrence and detectability scored from 1-5. After calculating the criticality of each failure mode, an action plan was prepared and then effectiveness of new process was monitored. Finally, FMEA was repeated and the improved RPN after the corrective actions was calculated. Main results and the role of chance In our gamete donation program, we mapped four phases: gamete request, donor-recipient matching, gamete delivery and gamete thawing. All the steps presented multiple failures and 11 different potential failure modes had been identified. Failure modes as the incorrect transcription of the recipient data, the acceptance of a donor proposal not well-matched with recipients and the receipt of gametes unsuitable for the couple correlate to high-risk scores with 30 RPN. These events may have severe consequences such as an incorrect matching between donor and recipient, and the subsequent birth of a child from a mismatched donor. Although gamete request, donor-recipient matching and receiving gametes phases are mainly characterized by document checking, the introduction of witnessing by another physician or embryologist, reduced the risk by 50%. Therefore, the introduction of double checking by a second operator represents an essential control measure to avoid errors. Limitations, reasons for caution This study is influenced by the general limitations of the FMEA approach, such as different personal experiences and skills of the participants since failures may be unrecognized, underestimated or overstated. Wider implications of the findings Performing a risk assessment in a donor program represents a valid strategy to mitigate risks of incorrect matching and loss of traceability. Since errors in data record and acceptance of donor proposal may cause important down streaming consequences, the double witnessing is strongly encouraged. Trial registration number NA

Primary Use of the Deep Inferior Epigastric Pedicle for Free-flap Phalloplasty: Rationale, Technique, and Outcomes.

Background:Most free-flap phalloplasty reports describe the femoral artery and great saphenous vein as recipient vessels, with the deep inferior epigastric artery and venae comitantes (DIEA/V) only rarely reported. We review our experience with preferentially using the DIEA/V as recipient vessels in gender-affirming free-flap phalloplasty, with DIEV as primary venous outflow.Methods:We retrospectively reviewed consecutive patients who underwent gender-affirming free-flap phalloplasty at our single institution from June 2017 through June 2021. The DIEA/V was used as recipient vessels, with the DIEA/V pedicle externalized via a passageway made through the external inguinal ring.Results:Thirty-eight consecutive free flaps (26 radial forearm free-flap phalloplasties, 10 anterolateral thigh phalloplasties, and two radial forearm free-flap urethroplasties) were performed. Mean age was 37.3 years; mean BMI was 25.7. Mean follow-up was 17.9 months. All flaps were anastomosed to the DIEA/V, without use of vein grafts. Most flaps (89.5%) had at least two veins anastomosed. To augment outflow, a saphenous vein branch was used in one of 38 (2.6%) cases and other superficial veins were used in two of 38 (5.3%) cases. One of 38 (2.6%) cases (early in our experience) resulted in total flap loss.Conclusions:Advantages of the DIEA/V as free-flap phalloplasty recipient vessels include a short, direct pathway for vessels, excellent donor-recipient vessel size match that allows end-to-end anastomoses, and elimination of risks associated with arterialized interposed veins. When venous outflow appears compromised, we recommend a low threshold to use additional local or saphenous veins, though this is rarely needed given the DIEV’s reliability.

Prognostic Factors Evaluation for Liver Transplant Mismatching: A New Way of Selecting and Allocating Organs

Liver transplant (LT) is the standard therapy for end-stage liver disease. Advances in surgical techniques and immunosuppression protocols improved the results of LT by increasing long-term survival. Nevertheless, an adequate match between the donor and recipient is paramount for avoiding futile liver transplants. We aimed to identify the prognostic factors in donor-recipient LT matching. Retrospective analysis of adult LT was conducted from January 2006 to December 2018, which included the following transplant modalities: deceased donor LT (DDLT), living donor LT (LDLT), combined liver-kidney transplant (CLKT), and domino LT (DLT). Among 1101 patients who underwent LT, 958 patients underwent DDLT, 92 patients underwent LDLT, 45 patients underwent CLKT, and 6 patients underwent DLT. The overall survival (OS) in 1, 5, and 10 years were 89%, 83%, and 82%, respectively. For DDLT, OS in 1, 5, and 10 years were 91%, 84%, and 82%, respectively. For LDLT, OS in 1, 5, and 10 years were 89%, 72%, and 69%, respectively. For CKLT, OS in 1, 5, and 10 years were 90%, 71%, and 71%, respectively. None of the DLT patients died. For DDLT, the factors that affected OS were the presence of fulminant liver failure (odds ratio [OR], 2.23; 95% CI, 1.18-4.18; P=.001), hemodialysis before LT (OR, 2.12; 95% CI, 1.27-3.5; P=.004), retransplant (OR, 4.74; 95% CI, 2.75-8.17; P=.000), and recipient age >60 years (OR, 1.86; 95% CI, 1.27-2.73; P=.001). For hospitalization before LT (due to an acute-on-chronic liver failure), the OR was 2.10 (95% CI, 1.29-3.42; P=.003). Donor intensive care unit time >7 days (OR, 1.46; 95% CI, 1.04-2.06; P=.02) was also associated with overall mortality. We identified prognostic factors in donor-recipient LT matching. Furthermore, we demonstrated that an adequate organ allocation with donor-recipient selection might increase graft survival and reduce waiting list mortality.

Septuagenarian Donors and Recipients in Deceased Donor Liver Transplantation: A Brazilian Single Center Experience and Literature Review

The number of elderly patients who have end-stage liver disease and require liver transplantation has dramatically increased. On the other hand, liver grafts from elderly donors have been offered more frequently for transplantation. The present study aims to analyze the results of liver transplants performed with donors and recipients aged ≥70 years. We performed a single-center retrospective study of deceased donors liver transplants that involved recipients aged ≥7070 years or recipients who received grafts from donors aged ≥70 years from 2011 to 2021. A literature review on the results of liver transplantation in elderly recipients was also performed. Thirty septuagenarian recipients were included; their overall 1- and 5-years survival was 80% and 76.6%, respectively. The prevalence of recipients aged ≥70 years in our department was 2.65%. Twenty recipients received grafts form septuagenarian donors; their overall 1- and 5-years survival was 75%. The prevalence of donors aged ≥70 years in our department was 1%. In the literature review, 17 articles were analyzed. The 5-years survival of recipients aged ≥70 years ranged from 47.1% to 78.5%. Septuagenarian recipients and patients who received grafts from elderly brain-dead donors present adequate overall survival after liver transplantation. Optimized donor-recipient matching is paramount for achieving good outcomes. The combination of high-risk donors with septuagenarian recipients should be avoided as well as using grafts of elderly donors that present others risk factors. Thus, the age of the donor or recipient alone cannot be considered an absolute contraindication for liver transplantation.

Are MELD and MELDNa Still Reliable Tools to Predict Mortality on the Liver Transplant Waiting List?

Liver transplantation is the only curative treatment for end-stage liver disease. Unfortunately, the scarcity of donor organs and the increasing pool of potential recipients limit access to this life-saving procedure. Allocation should account for medical and ethical factors, ensuring equal access to transplantation regardless of recipient's gender, race, religion, or income. Based on their short-term prognosis prediction, model for end-stage liver disease (MELD) and MELD sodium (MELDNa) have been widely used to prioritize patients on the waiting list for liver transplantation resulting in a significant decrease in waiting list mortality/removal. Recent concern has been raised regarding the prognostic accuracy of MELD and MELDNa due, in part, to changes in recipients' profile such as body mass index, comorbidities, and general condition, including nutritional status and cause of liver disease, among others. This review aims to provide a comprehensive view of the current state of MELD and MELDNa advantages and limitations and promising alternatives. Finally, it will explore future options to increase the donor pool and improve donor-recipient matching.

Donor-Recipient Weight Match in Pediatric Heart Transplantation: Liberalizing Weight Matching with Caution.

(1) Background: To expand the donor pool, greater donor hearts tended to be used in heart transplantation. However, the data about the feasibility of expanding the donor and recipient weight ratios (DRWRs. All donor and recipient weight ratio (DRWR) in this study or cited from other articles were converted to the DRWR calculated by ((donor weight-recipient weight)/recipient weight) × 100%.) to >30% was still scant in China’s pediatric heart transplantation (HTx). The potential risk increased along with the further expansion of the appropriate range of DRWR to >30% and its upper limit was still in debate. (2) Methods: Seventy-eight pediatric patients (age < 18 years) undergoing HTx between 2015 and 2020 at our center were divided into two groups based on the DRWR (>30% and ≤30%). Variables were summarized and analyzed via univariate analyses and multivariate analyses. A Kaplan-Meier methodology was used to calculate survival and conditional survival. (3) Results: No significant difference was found in one-year, three-year or five-year survival between the two groups. (4) Conclusions: The expansion of DRWR to >30% was acceptable for China’s pediatric HTx. Notably, continuously liberalizing of the upper DRWR boundary to more than 200% could be used as a stop-loss option but should be applied with caution.

Expanding donor age in liver transplantation using liver grafts from nonagenarian donors.

Satisfactory outcomes in a series of liver transplantations (LT) with octogenarian liver grafts have been reported, as well as several cases of LT using nonagenarian liver grafts with short follow-up. From October 2013 to December 2019, we performed 426 LT. Six LTs used nonagenarian livers (case group) and 49 used octogenarian livers (control group). A comparative analysis was performed between groups. Median donor age was significantly higher in the nonagenarian group than in the octogenarian group (90.6years versus 83.4 years; (P<.001). There was a significant difference in LT indications (P=.026) between the groups, but not in perioperative recipient variables, morbidity, or mortality. The 1-, 3-, and 5-year patient survival rates were 67.7% in the recipients of nonagenarian livers and 85.7%, 78.0%, and 74.4%, respectively, in the recipients of octogenarian livers (P=.631). The 1-, 3-, and 5-year graft survival rates were 66.7% in the recipients of nonagenarian livers and 81.3%, 73.8%, and 70.3%, respectively, in the recipients of octogenarian livers (P=.745). The results of LT with nonagenarian liver grafts are not significantly different from those obtained with octogenarian donors, taking into consideration the small sample size and careful selection of donors and adequate donor-recipient matching.

In-Depth Analysis of Anti-HLA Antibodies Using C1q Assay

Alloantibodies are significant biomarkers of posttransplant kidney rejection. With solid-phase assays, the presence of alloantibodies and complement-binding capacities can be tested. It has been noted that complement-binding anti-HLA (C1q) correlates well with high titers of anti-HLA antibodies (single antigen bead, SAB), but we have recently shown that lower SAB titers may be associated with complement in the complement cytotoxicity test. If so, low titers of donor-specific antibodies could be stratified for complement binding and used for better donor-recipient matching. To study this, we tested 268 patients awaiting kidney transplantation for SAB and C1q and stratified them into positive (Allo+) and negative (Allo-) cohorts. Next, all assayed specificities of SAB were matched with the corresponding C1q in order to correlate mean fluorescence intensity levels. We found a strong correlation between SAB and C1q for all HLA loci apart from HLA-DP. Moreover, there was no strict cutoff for C1q prediction on SAB mean fluorescence intensity level. In addition, an unusual laboratory phenotype was found; that is, a positive C1q result without corresponding SAB specificity. We tested this phenomenon and found positive IgM SAB. CONCLUSIONS: Simultaneous C1q and SAB testing may serve as a tool for in-depth analysis of alloantibodies before transplantation.

The role of donor-recipient gender matching in lung transplantation: a systematic review.

Donor to recipient (D-R) matching in lung transplantation (LTx) is firstly directed by blood group (identity or compatibility), immunological status and morphological criteria. Sex matching is ignored and impact on outcome less investigated. Systematic review of English literature using PubMed (1990-2019) was performed to evaluate the potential role of D-R matching in determining long-term outcome in patients after LTx. Search terms included (LTx) AND (sex) OR (gender) OR (matching) OR (mismatch) OR (donor characteristics) and were restricted to articles' title. Only articles directly reporting LTx survival outcome according to gender match/mismatch and D-R gender combination in LTx were included. Two authors independently extracted articles using predefined data fields, including study quality indicators. MOOSE Guidelines for Meta-Analyses and Systematic Reviews of Observational Studies applied. Nine articles were analyzed and included into this study. All studies analyzed the effect of the different D-R gender combinations on survival while seven of them investigated exclusively the role of sex matching on LTx outcome. In this latter group two out of seven showed a trend towards an overall survival advantage for sex matching LTx combination. The worst survival results were reported for F to M gender combination in 3 studies and for M to F gender combination by 1 study. No differences were reported in remaining 4 studies. This systematic review suggests that sex matching and several gender combinations could play a role in determining overall survival rate after LTx. Data deriving from unbiased studies supported that matching female-female (F-F) and male-male (M-M) could improve LTx outcome while FD-MR combination should be avoided. Unfortunately, a good part of the analyzed data are affected by bias due to confounding factors. Up-to-date immunological, hormonal and morphological factors could explain the gender-based difference in LTx outcome. Further investigations should clarify their role and importance to define the effects of gender combinations on survival.

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

ObjectivesCurrent 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. MethodsThe 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%. ResultsA 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). ConclusionsTotal 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.

Artificial Intelligence for the Prognostication and Management of Heart Transplant: A Scoping Review

<h3>Purpose</h3> Current clinical guidelines related to the identification and management of heart transplant (HT) outcomes are based on small studies or expert consensus. With a growing interest in artificial intelligence (AI) to optimize prognostication and management of patients post-HT, our scoping review aims to summarize the current state of AI in the setting of HT, and its potential impact on clinical practice. <h3>Methods</h3> We systematically searched MEDLINE, Embase, and Inspec for observational and interventional studies that applied AI methodologies to a HT population. Blinded abstract screening and full text review were completed in duplicate. Disagreements were resolved by consensus or independent third-party adjudication. <h3>Results</h3> A total of 1351 publications were initially identified. Among these, 78 met our inclusion criteria, primarily addressing themes of prognosis (n=53), diagnosis (n=23), and management (n=2) of HT patients (Fig 1A). AI models were applied to various clinical applications, including the classification and prediction of pre- and post-HT outcomes (e.g., graft function, hospitalization, re-HT, and survival), detection of acute cellular rejection and cardiac allograft vasculopathy, and modelling of blood levels of immunosuppressive agents. In 18 studies, AI models were directly compared against conventional logistic regression, and in half of these studies AI outperformed conventional models. Of note, 31% (n=24) of the included studies were full manuscripts, whereas 69% (n=54) were peer-reviewed conference abstracts (Fig 1B). <h3>Conclusion</h3> AI presents a unique opportunity to enhance organ allocation, donor-recipient matching, and post-HT survival and management. Unfortunately, with the current state of evidence, there is a lack of primary studies that transition from abstract presentation to manuscript publication, perhaps suggesting more robust validation is required prior to the ubiquitous integration of AI into clinical practice.