Older Donors Research Articles

Psychological and physical side effects during G-CSF mobilization in related donors of allo-HCT.

The psychological side effects of granulocyte colony-stimulating factor mobilization in related donors of allogeneic hematopoietic cell transplantation (allo-HCT) and impacts of psychological/physical side effects on harvest outcomes remain largely unknown. We prospectively analyzed 349 consecutive related peripheral blood stem cell (PBSC) donors for allo-HCT at the First Affiliated Hospital, Zhejiang University, School of Medicine from March 2021 to August 2023. Higher baseline peripheral blood white blood cell counts (p = 0.046), monocyte counts (p < 0.001), platelet counts (p = 0.001), and hemoglobin (p < 0.001) had a positive correlation to CD34+ cell counts in the first leukapheresis, while female donors (male vs. female, p < 0.001) and older age (> 40 vs. < = 40, p = 0.003) were negatively related to CD34+ cell counts. Bone pain was the most observed physical side effect and was more frequent in female donors (p = 0.032). The incidence of fatigue was higher in female donors and older donors (female vs. male, p = 0.016; > 40 vs. < = 40, p = 0.015). Donor depression (pre vs. during mobilization, p < 0.001), anxiety (pre vs. during mobilization, p = 0.043) and insomnia (pre vs. during mobilization, p = 0.011) scores increased during the mobilization period. Donors with higher depression, anxiety and stress scores at admission were more likely to experience nausea. At 1 month after the last leukapheresis, the counts of white blood cell, neutrophil, monocyte and hemoglobin were significant lower than baseline counts, while the platelet counts recovered to baseline. The mobilization and harvest process can increase the depression, anxiety and insomnia scores. Poor psychological status of the donor can aggravate the occurrence of physical side effects.

Detection of Nucleocapsid Antibodies Associated with Primary SARS-CoV-2 Infection in Unvaccinated and Vaccinated Blood Donors.

Nucleocapsid antibody assays can be used to estimate SARS-CoV-2 infection prevalence in regions implementing spike-based COVID-19 vaccines. However, poor sensitivity of nucleocapsid antibody assays in detecting infection after vaccination has been reported. We derived a lower cutoff for identifying previous infections in a large blood donor cohort (N = 142,599) by using the Ortho VITROS Anti-SARS-CoV-2 Total-N Antibody assay, improving sensitivity while maintaining specificity >98%. We validated sensitivity in samples donated after self-reported swab-confirmed infections diagnoses. Sensitivity for first infections in unvaccinated donors was 98.1% (95% CI 98.0-98.2) and for infection after vaccination was 95.6% (95% CI 95.6-95.7) based on the standard cutoff. Regression analysis showed sensitivity was reduced in the Delta compared with Omicron period, in older donors, in asymptomatic infections, <30 days after infection, and for infection after vaccination. The standard Ortho N antibody threshold demonstrated good sensitivity, which was modestly improved with the revised cutoff.

Tuscany Normothermic Regional Perfusion Mobile Teams for Controlled Donation After Circulatory Death.

To facilitate the implementation of controlled donation after circulatory death (cDCD) programs even in hospitals not equipped with a local extracorporeal membrane oxygenation (ECMO) team, some countries have launched a local cDCD network with an ECMO mobile team for normothermic regional perfusion (NRP). In the Tuscany region, in 2021, the Regional Transplant Authority launched a cDCD program to make the cDCD pathway feasible even in peripheral hospitals with NRP mobile teams, which were "converted" existing ECMO mobile teams, composed of highly skilled and experienced personnel. We describe the Tuscany cDCD program, (2021-2023), for cDCD from peripheral hospitals with NRP mobile teams. Twenty-six cDCDs (26/40, 65%) came from peripheral hospitals. Following the launch of the cDCD program, cDCDs from peripheral hospitals increased, from 33% (2021) to 75% (2022 and 2023) of the overall cDCDs. The mean age was 63 years, with older donors (>75 years) in half the cases. The median warm ischemia time was 45 min (20 min are required by the Italian law for death certification), ranging from 35 to 59 min. Among the 20 livers retrieved and 18 kidneys retrieved, 16 livers, and 11 kidneys (single kidney transplantation) were transplanted, after ex vivo reperfusion, respectively. The use of NRP mobile teams proved to be feasible and safe in the management of cDCD in peripheral hospitals. No complications were reported with NRP despite the advanced age of most cDCDs.

Contemporary prevalence and practice patterns of out-of-sequence kidney allocation

Since 2021, the Organ Procurement and Transplantation Network has reported a nearly 10-fold rise in out-of-sequence (OOS) kidney allocation, generating concern and halting development of continuous distribution policies. We report contemporary (2022-2023) practice patterns in OOS allocation using Organ Procurement and Transplantation Network data. We examined in sequence vs OOS donors with multivariable logistic regression and skipped vs OOS-accepting recipients with conditional logistic regression. Nearly 20% of kidney placements were OOS, varying from 0% to 43% acsoss organ procurement organizations; the 5 highest OOS-organ procurement organizations accounted for 29% of all OOS. Of OOS kidneys, 33% were declined ≥100 times in the standard allocation sequence and 51% were declined by ≥10 centers before OOS allocation began; 4.5% were made without any in-sequence declines. Nearly, all OOS offers were open offers. OOS kidneys were more likely to be from female, Black, older, donation after cardiac death, hypertensive, diabetic, and elevated creatinine donors. Candidates receiving OOS kidneys were more likely female, Asian, and older than skipped candidates. Higher-volume centers and centers with more White, fewer Hispanic, and more educated waiting list patients underwent transplantation disproportionately with more OOS kidneys. These findings suggest that the current, highly variable, discretionary use of OOS might exacerbate disparities, yet the impact of OOS on organ utilization cannot be determined with data now collected.

Assessment of Tie2-Rejuvenated Nucleus Pulposus Cell Transplants from Young and Old Patient Sources Demonstrates That Age Still Matters.

Cell transplantation is being actively explored as a regenerative therapy for discogenic back pain. This study explored the regenerative potential of Tie2+ nucleus pulposus progenitor cells (NPPCs) from intervertebral disc (IVD) tissues derived from young (<25 years of age) and old (>60 years of age) patient donors. We employed an optimized culture method to maintain Tie2 expression in NP cells from both donor categories. Our study revealed similar Tie2 positivity rates regardless of donor types following cell culture. Nevertheless, clear differences were also found, such as the emergence of significantly higher (3.6-fold) GD2 positivity and reduced (2.7-fold) proliferation potential for older donors compared to young sources. Our results suggest that, despite obtaining a high fraction of Tie2+ NP cells, cells from older donors were already committed to a more mature phenotype. These disparities translated into functional differences, influencing colony formation, extracellular matrix production, and in vivo regenerative potential. This study underscores the importance of considering age-related factors in NPPC-based therapies for disc degeneration. Further investigation into the genetic and epigenetic alterations of Tie2+ NP cells from older donors is crucial for refining regenerative strategies. These findings shed light on Tie2+ NPPCs as a promising cell source for IVD regeneration while emphasizing the need for comprehensive understanding and scalability considerations in culture methods for broader clinical applicability.

A Cross-Sectional Study of Measles-Specific Antibody Levels in Australian Blood Donors-Implications for Measles Post-Elimination Countries.

Passive immunisation with normal human immunoglobulin (NHIG) is recommended as post-exposure prophylaxis (PEP) for higher-risk measles contacts where vaccination is contraindicated. However, the concentration of measles-specific antibodies in NHIG depends on antibody levels within pooled donor plasma. There are concerns that measles immunity in the Australian population may be declining over time and that blood donors' levels will progressively decrease, impacting levels required to produce effective NHIG for measles PEP. A cross-sectional study of Australian plasmapheresis donors was performed using an age-stratified, random sample of recovered serum specimens, collected between October and November 2019 (n = 1199). Measles-specific IgG antibodies were quantified by ELISA (Enzygnost anti-measles virus IgG, Siemens), and negative and equivocal specimens (n = 149) also underwent plaque reduction neutralisation testing (PRNT). Mean antibody levels (optical density values) progressively decreased from older to younger birth cohorts, from 2.09 [±0.09, 95% CI] to 0.58 [±0.04, 95% CI] in donors born in 1940-1959 and 1990-2001, respectively (p < 0.0001). This study shows that mean measles-specific IgG levels are significantly lower in younger Australian donors. While current NHIG selection policies target older donors, as younger birth cohorts become an increasingly larger proportion of contributing donors, measles-specific antibody concentrations of NHIG will progressively reduce. We therefore recommend monitoring measles-specific antibody levels in future donors and NHIG products in Australia and other countries that eliminated measles before the birth of their youngest blood donors.

Interplay between donor age and HLA-DP matching in 10/10 HLA-matched unrelated donor HCT

AbstractIn 10/10 HLA-matched unrelated donor (MUD) hematopoietic cell transplantation (HCT) with calcineurin-inhibitor (CNI)-based prophylaxis, T-cell epitope DP-matched and permissive mismatched donors are associated with similar overall survival (OS) whereas donors with nonpermissive mismatches should be avoided. Younger unrelated donors are also favored over older donors. We explored outcomes associated with different combinations of DP-matching and donor age (dichotomized at 35 years) to further guide donor selection. Using a Center for International Blood and Marrow Transplant Research data set, we categorized 10 783 patients into 6 groups: DP-matched/younger donor (n = 1591), DP-matched/older donor (n = 526), permissive-mismatched/younger donor (n = 3845), permissive-mismatched/older donor (n = 1184), nonpermissive mismatched/younger donor (n = 2659), and nonpermissive mismatched/older donor (n = 978). We noted that younger donor age, rather than DP matching, was associated with better OS. Younger donors with permissive mismatches were associated with improved OS compared with older matched donors. Furthermore, younger donors with nonpermissive mismatches were associated with improved OS compared with older donors with permissive mismatches. Our study adds further information about the association of DP matching and donor age with HCT outcomes. Donor age should be prioritized over DP matching in patients undergoing 10/10 HLA-MUD with CNI prophylaxis. Among those with younger donors, permissive-mismatched or DP-matched donors are preferred over nonpermissive mismatched donors.

Normothermic Machine Perfusion Is Associated With Improvement in Mortality and Graft Failure in Donation After Cardiac Death Liver Transplant Recipients in the United States.

Use of normothermic machine perfusion (NMP) may help to expand the liver transplantation (LT) donor pool by potentially increasing the utilization of donation after circulatory death (DCD) organs. The aim of this study was to assess the impact of NMP on LT from DCD organs. Data among DCD adult LT recipients in the United Network for Organ Sharing between January 2016 and December 2022 were analyzed. Outcomes were compared between 2 groups: NMP versus non-MP using propensity score matching. During the study period, 4217 DCD LT recipients (NMP: 257 and non-MP: 3960) were identified. compared with non-MP, DCD LT recipients in NMP group were older (median recipient age: 61 versus 59 y, P = 0.013), had lower model for the end-stage liver disease score, longer wait time (126 versus 107 d, P = 0.028), and received organs from older donors (median age: 42 versus 38 y, P < 0.01) with longer preservation time (9.9 versus 5.3 h, P < 0.001). Two-year overall survival (NMP 94.4% versus non-MP 89.7%, P = 0.040) and 2-y graft survival (NMP 91.3% versus non-MP 84.6%, P = 0.017) were better in the NMP group. After propensity score matching, 2-y overall survival (NMP 94.2% versus non-MP 88.0%, P = 0.023) and graft survival (NMP 91.3% versus non-MP 81.6%, P = 0.004) were better in the NMP group. On multivariable cox regression analysis, NMP was an independent factor of protection against mortality (hazard ratio, 0.43; 95% confidence interval: 0.20-0.91; P = 0.029) and against graft failure (hazard ratio, 0.26; 95% confidence interval: 0.11-0.61; P = 0.002). Use of NMP for LT from DCD donors was associated with improved posttransplant patient and graft survival.

Prediction of Renal Graft Function 1 Year After Adult Deceased-Donor Kidney Transplantation Using Variables Available Prior to Transplantation.

BACKGROUND Kidney transplantation is still the best therapy for patients with end-stage renal disease, but the demand for donor organs persistently surpasses the supply. A prognostic model using pre-transplant data for the prediction of renal graft function would be helpful to optimize organ allocation and avoid futile transplantations. MATERIAL AND METHODS Retrospective data of 2431 patients who underwent kidney transplantation between January 01, 2000, and December 31, 2012 with subsequent ten-year clinical follow-up in our transplant center were analyzed. Of these, 1172 patients met the inclusion criteria. Multivariable regression modelling was used to develop a prognostic model for the prediction of graft function after 1 year utilizing only pre-transplant data. The final model was assessed with the area under the receiver operating characteristic (AUROC) curve. RESULTS Donor age, donor serum creatinine, recipient body mass index, re-transplantations beyond the second kidney transplantation, and cold ischemia time had an independent, significant influence on graded renal graft function 1 year after kidney transplantation. AUROC analysis of the prognostic model was >0.700 for all GFR categories except KDIGO G5, indicating high sensitivity and specificity of prediction. CONCLUSIONS For improvement of renal graft function, organs from older donors or donors with high serum creatinine should not be used in obese recipients and for re-transplantations beyond the second one. Cold ischemia time should be as short as possible.

The impact of donor-recipient age difference on graft survival after heart transplant in adults with congenital heart disease

BackgroundThe impact of donor-recipient age difference in adult congenital heart disease (ACHD) patients undergoing heart transplant (HT) is unknown. MethodsACHD patients (≥18 years old) who underwent HT (2000-2020) were identified using the United Network for Organ Sharing database. Graft survival through 10 years based on donor-recipient age difference was evaluated by comparing outcomes of donors >5 years older than recipient (Older), donors within 5 years of recipient age (Equal Age), and donors >5 years younger than recipient (Younger, reference group). Cox multivariable analysis was performed to evaluate the effect of donor-recipient age difference on early and late graft survival. ResultsA total of 1,275 ACHD patients underwent HT (60% male, median 35 years-old (interquartile range 24-46) with median graft survival of 13.7 years (95% confidence interval [CI] 11.7-16.0). Compared to Younger donors (n=306 [24%]), graft survival was similar with Equal Age donors (n=698 [55%]; Log rank p=0.61), though significantly reduced with Older donors (n=271 [21%]; Log rank p=0.03). In multivariable analysis, late graft survival was similar with Equal Age donors but lower with Older donors (adjusted hazard ratio [aHR] 1.63, 95% CI 1.16-2.28, p=0.005), with a trend of reduced survival with Older donors in recipients <30 or ≥40 years-old. ConclusionsGraft survival in ACHD patients undergoing HT was similar for those with Younger and Equal Age donors. Recipients with Older donors had reduced 10-year survival, possibly related to increased risk in those <30 and ≥40 years-old. These data help inform optimal donor age for ACHD patients requiring HT.

Impact of Age of Heart Transplant Program on Patient Survival and Post-Transplant Outcomes.

The relationship between age of a heart transplant (HT) program and outcomes has not been explored. We performed a retrospective cohort analysis of the United Network for Organ Sharing database of all adult HTs between 2009 and 2019. For each patient, we created a variable that corresponded to program age: new (<5), developing (≥5 but <10) and established (≥10) years. Of 20 997 HTs, 822 were at new, 908 at developing, and 19 267 at established programs. Patients at new programs were significantly more likely to have history of cigarette smoking, ischemic cardiomyopathy, and prior sternotomy. These programs were less likely to accept organs from older donors and those with a history of hypertension or cigarette use. As compared to patients at new programs, transplant patients at established programs had less frequent rates of treated rejection during the index hospitalization (HR 0.43 [95% CI, 0.36-0.53] p<0.001) and at 1 year (HR 0.58 [95% CI, 0.49-0.70], p<0.001), less frequently required pacemaker implantations (HR 0.50 [95% CI, 0.36-0.69], p<0.001), and less frequently required dialysis (HR 0.66 [95% CI, 0.53-0.82], p<0.001). However, there were no significant differences in short- or long-term survival between the groups (log-rank p = 0.24). Patient and donor selection differed between new, developing, and established HT programs but had equivalent survival. New programs had increased likelihood of treated rejection, pacemaker implantation, and need for dialysis. Standardized post-transplant practices may help to minimize this variation and ensure optimal outcomes for all patients.

Donor to recipient age matching in lung transplantation: A European experience

BackgroundThe age profile of organ donors and patients on lung transplantation (LT) waiting lists have changed over time. In Europe, the donor population has aged much more rapidly than the recipient population, making allocation decisions on lungs from older donors common. In this study we assessed the impact of donor and recipient age discrepancy on LT outcomes in the UK and France. MethodsA retrospective analysis of all adult single or bilateral LT in France and the UK between 2010 and 2021. Recipients were stratified into 3 age groups: young (≤ 30 years), middle-aged (30 to 60) and older (≥60). Their donors were also stratified into 2 groups <60, ≥ 60. Primary graft dysfunction (PGD) rates and recipient survival was compared between matched and mismatched donor and recipient age groups. Propensity matching was employed to minimize covariate imbalances and to improve the internal validity of our results. ResultsOur study cohort was 4,696 lung transplant recipients (LTRs). In young and older LTRs, there was no significant difference in 1 and 5-years post-transplant survival dependent on the age category of the donor. Young LTRs who received older donor grafts had a higher risk of severe grade 3 PGD. ConclusionOur findings show that clinically usable organs from older donors can be utilized safely in LT, even for younger recipients. Further research is needed to assess if the higher rate of PGD3 associated with use of older donors has an effect on long-term outcomes.

Differences in SARS-CoV-2 antibodies depending on age, blood group, and sex in a Swedish blood donor cohort

This study aimed to describe differences in prevalence and the long-term presence of nucleocapsid antibodies (N-antibodies) elicited by SARS-CoV-2 infection in a Swedish blood donor population not subjected to lockdown. We tested 20,651 blood donor samples for nucleocapsid antibodies from the beginning of March 2020 and 27 months onwards using the Roche Elecsys Anti-SARS-CoV-2 assay. The proportion of positive SARS-CoV-2 antibody samples was determined each week. After the exclusions of one-time donors and subjects with incomplete data, 19,726 samples from 4003 donors remained. Differences in antibody prevalences stratified for age, sex, and blood groups (ABO and RhD) were determined, as well as antibody loss and recovery. Lower antibody prevalence was seen for older donors, blood group AB, and RhD-negative subjects. A significant decrease in antibody titer between the first and the second antibody-positive donation was seen for the whole study group, females, older subjects, blood group O, AB, and RhD-positive subjects. The titer waned below the detection limit in 60 (3.0%) of 1983 N-antibody-positive donors, and for 18 of these donors, a second episode with antibodies was detected. We showed that N-antibodies persist for months or years and that surprisingly few antibody-positive donors lost their antibodies. We also conclude that antibody prevalence in a Swedish population never subject to lockdown did not apparently differ from populations that were subject to stricter regulations.

Unlocking the benefits of transplantation with kidneys from older donors.

Unlocking the benefits of transplantation with kidneys from older donors.

Analysis of erythrocyte and iron study data among plateletpheresis donors in Hangzhou, China

BackgroundThe purpose of this study is to obtain the iron parameters level of blood donors and the population who need to pay attention to iron parameters level in this area. MethodsA total of 993 plateletpheresis donors were included in this study, including 798 males and 195 females. The results of erythrocyte and iron parameters of blood donors were compared and analyzed in different groups according to the gender, age and number of blood donations. ResultThe proportion of men and women with low serum ferritin (SF) levels was 10.8 % and 27.7 %, respectively. The mean levels of serum iron (SI), SF, transferrin saturation (Tfs), hemoglobin (Hb) and hematocrit (HCT) of male blood donors decreased with the increase of age groups, but there was no significant statistical difference between the results of female blood donors. The level of SI, SF, Tfs, Hb and HCT of male donors decreased with the increase of blood donations in the past year, while TRF and TIBC increased. The level of Hb, HCT and SF of female donors showed no significant downward trend, while the levels of TRF increased with increasing donations in the past year, excluding first-time donors. The SI of female donors trended down, and TIBC trended up with increasing donations. ConclusionBlood collection institutions need to focus on iron parameters levels in older and frequent male donors, and young fertile female donors.

Differential Responses to Aging Among the Transcriptome and Proteome of Mesenchymal Progenitor Populations.

The biological aging of stem cells (exhaustion) is proposed to contribute to the development of a variety of age-related conditions. Despite this, little is understood about the specific mechanisms which drive this process. In this study, we assess the transcriptomic and proteomic changes in 3 different populations of mesenchymal progenitor cells from older (50-70 years) and younger (20-40 years) individuals to uncover potential mechanisms driving stem cell exhaustion in mesenchymal tissues. To do this, we harvested primary bone marrow mesenchymal stem and progenitor cells (MPCs), circulating osteoprogenitors (COP), and adipose-derived stem cells (ADSCs) from younger and older donors, with an equal number of samples from men and women. These samples underwent RNA sequencing and label-free proteomic analysis, comparing the younger samples to the older ones. There was a distinct transcriptomic phenotype in the analysis of pooled older stem cells, suggestive of suppressed proliferation and differentiation; however, these changes were not reflected in the proteome of the cells. Analyzed independently, older MPCs had a distinct phenotype in both the transcriptome and proteome consistent with altered differentiation and proliferation with a proinflammatory immune shift in older adults. COP cells showed a transcriptomic shift to proinflammatory signaling but no consistent proteomic phenotype. Similarly, ADSCs displayed transcriptomic shifts in physiologies associated with cell migration, adherence, and immune activation but no proteomic change with age. These results show that there are underlying transcriptomic changes with stem cell aging that may contribute to a decline in tissue regeneration. However, the proteome of the cells was inconsistently regulated.

FTO deficiency in older livers exacerbates ferroptosis during ischaemia/reperfusion injury by upregulating ACSL4 and TFRC

Older livers are more prone to hepatic ischaemia/reperfusion injury (HIRI), which severely limits their utilization in liver transplantation. The potential mechanism remains unclear. Here, we demonstrate older livers exhibit increased ferroptosis during HIRI. Inhibiting ferroptosis significantly attenuates older HIRI phenotypes. Mass spectrometry reveals that fat mass and obesity-associated gene (FTO) expression is downregulated in older livers, especially during HIRI. Overexpressing FTO improves older HIRI phenotypes by inhibiting ferroptosis. Mechanistically, acyl-CoA synthetase long chain family 4 (ACSL4) and transferrin receptor protein 1 (TFRC), two key positive contributors to ferroptosis, are FTO targets. For ameliorative effect, FTO requires the inhibition of Acsl4 and Tfrc mRNA stability in a m6A-dependent manner. Furthermore, we demonstrate nicotinamide mononucleotide can upregulate FTO demethylase activity, suppressing ferroptosis and decreasing older HIRI. Collectively, these findings reveal an FTO-ACSL4/TFRC regulatory pathway that contributes to the pathogenesis of older HIRI, providing insight into the clinical translation of strategies related to the demethylase activity of FTO to improve graft function after older donor liver transplantation.

Shorter donor leukocyte telomere length is associated with poor peripheral blood stem cell mobilization induced by granulocyte colony-stimulating factor

Background/purposeInsufficient numbers of peripheral blood stem cells (PBSC) after granulocyte colony-stimulating factor (G-CSF) mobilization occurs in a significant proportion of PBSC collections, often from older age donors. Telomere length (TL) is often used as an indicator of an individual's biological age. This study aimed to investigate the relationship between donors' leukocyte TL and the outcome of G–CSF–induced PBSC mobilization in healthy unrelated donors. MethodsDonors’ leukocyte TLs and the outcome of G–CSF–induced PBSC mobilization, as assessed by pre-harvest CD34+ cell counts, were analyzed in 39 healthy PBSC donors. TL in a non-mobilized general population (n = 90) was included as a control group. G-CSF mobilization effect was categorized into three groups according to pre-harvest CD34+ cell count: poor (≤25/μL, PMD), intermediate (between 25 and 180/μL), and good (≥180/μl, GMD). ResultsLeukocyte TL of PBSC donors correlated well with pre-harvest CD34+ cell counts (r = 0.645, p < 0.001). Leukocyte TLs of PMDs (n = 8) were significantly shorter than those of GMDs (n = 9) and non-mobilization controls (p < 0.05). Moreover, all PMD TLs were below the 50th percentile, and 62.5% of PMDs had TLs below the 10th percentile of age-matched control participants. In contrast, no GMD TLs were below the 10th percentile; in fact, 33.3% (3/9) of them were above the 90th percentile. ConclusionOur results indicate that shorter donor leukocyte TL is associated with poor G–CSF–induced PBSC mobilization. TL, which represents a donor's biological age, could be a potential predictor for mobilization outcome.

#2741 The interplay between donor &amp; recipient factors, outcomes, and transplant artery flow volume as measured by phase-contrast magnetic resonance imaging

Abstract Background and Aims Cardiovascular health and kidney transplant health are inter-connected [1]. Phase-contrast magnetic resonance imaging (PC-MRI) is a non-invasive means of quantifying blood flow volume within vasculature. Its utility for the assessment of blood flow volumes within the transplant renal artery has not been explored. The aims of this study were to determine if: (A) flow in the transplant artery is influenced by donor and recipients factors, (B) flow in the transplant artery is related to or influences clinical outcomes for transplant recipients. Method Analysis of PC-MRI sequences obtained during 218 kidney transplant magnetic resonance angiograms (MRA) performed at a single centre between 2019 and 2021 was undertaken. All scans were clinically indicated and requested by clinicians to investigate for transplant renal artery stenosis (TRAS). Baseline clinical and demographic data and subsequent clinical outcome data were collected for all study participants. Median follow up was 49 (IQR 40–54) months. For Kaplan-Meier survival analyses, comparison of clinical outcomes by interquartile range of flow volumes was performed, whereby quartile one comprised subjects with the lowest transplant artery blood flow volumes. Statistical analysis was performed using MedCalc Statistical Software version 22.013. Results In this study of 218 subjects, 49 (22.4%) had features of possible TRAS identified on initial MRA. TRAS was subsequently confirmed via intra-arterial digital subtraction angiography in 19 (8.7%) cases. The majority of participants were male 150/218 (68.8%). The commonest cause of ESKD was diabetic kidney disease at 71/218 (32.6%). Living donor transplant recipients were 35/218 (11.5%) of the study population. The median donor age was 55 (IQR 44–65) years. The median time from ESKD to transplantation was 25 (IQR 9–53) months. The median time from transplantation to PC-MRI for all participants was 322 (IQR 81–1744) days; for participants who were ultimately diagnosed with TRAS it was 169 (IQR 76–262) days. The median age of recipients at time of PC-MRI was 56 (IQR 45–64) years. Overall, the mean transplant artery flow volume was 0.41 L/min (95% CI 0.39–0.45 L/min). Rank correlation between age of donor and flow in the transplant artery (L/min) showed r = −0.25 (95% CI −0.37 - −0.12) P = 0.0002. Rank correlation between age of recipient at time of PC-MRI and flow in the transplant artery (L/min) showed r = −0.37 (95% CI −0.48 to −0.25) P ≤ 0.0001. Rank correlation between flow in the transplant artery (L/min) and estimated glomerular filtration rate (mL/min/1.73 m2) showed r = 0.43 (95% CI 0.31–0.53) P &amp;lt; 0.0001. Univariable linear regression analysis of flow in the transplant artery (L/min) and estimated glomerular filtration rate (mL/min/1.73 m2) was R2 0.14, DF regression = 1 DF residual = 214, F = 34.7, P &amp;lt; 0.0001 (Fig. 1). Overall, 35 (16.1%) participants experienced kidney transplant failure and 42 (19.3%) participants died within the study follow up period. Kaplan-Meier analysis showed no significant difference in kidney transplant survival between four groups categorized according to transplant artery flow volumes, logrank test P = 0.93 (Fig. 2A). Subjects in the first quartile were at greater risk of death, logrank test P = 0.01, HR 4.36 (95% CI 1.77–10.74) compared with fourth quartile (Fig. 2B) Conclusion This study has demonstrated that both older donor age and older recipient age negatively correlate with transplant artery flow, and that transplant artery flow is positively correlated and predicts estimated glomerular filtration rate. Finally, recipients with low transplant artery flow volume are at greater risk of death. Neither cause nor effect of low blood flow volume have been elucidated in this study. However, improving transplant blood flow by optimising cardiovascular health may have a positive impact on outcomes for people with kidney transplants and warrants further study.

"Age ain't nothing but a number": Advanced perfusion is the key to increasing the usability of older DCD donor livers.

"Age ain't nothing but a number": Advanced perfusion is the key to increasing the usability of older DCD donor livers.