Normal Graft Research Articles

Early and late assessment of renal allograft dysfunction using intravoxel incoherent motion (IVIM) and diffusion-weighted imaging (DWI): a prospective study.

To evaluate the ability of the Intravoxel Incoherent Motion (IVIM) and monoexponentially ADC in renal allograft function in the early and late phases of transplantation, and to predict their effectiveness in discrimination of the graft pathology. This is a prospective study included participants scanned with quantitative diffusion and perfusion sequences on a 3-T MR scanner (Philips, Ingenia); the ADC and IVIM parameters; were calculated. Correlations and regression analysis with the eGFR, transplantation periods, and pathology were assessed. This study included 105 renal allograft recipients (85 males, and 20 females with mean age = 32.4 ± 11.9years and age range = 22-61years). There was a significant positive correlation between the whole parameters of the ADC and IVIM with eGFR however, the cortical parameters showed higher significant correlation coefficients (p < 0.001). Regression analysis revealed the most significant model can predict eGFR groups included cortical pseudo diffusion (D*) and cortical ADC (p < 0.001). In graft dysfunction eGFR was 61.5ml/min and normal graft was 64ml/min. This model demonstrates a high performance of an AUC 96% [0.93-0.97]. In the late transplantation, there is a higher correlation with D* compared to ADC, p-values = 0.001. IVIM and ADC Values are significant biomarkers for renal allograft function assessment, cortical ADC, and D* had the highest performance even in situations with mild impairment that is not affect the eGFR yet as cases of proteinuria with normal eGFR. Furthermore, D* is superior to ADC in the late assessment of the renal transplant.

#1492 Metabolic switch in CD8+ T cells may influence immune response in chronic antibody-mediated rejection (CAMR)

Abstract Background and Aims CAMR is the main cause of chronic graft injury and subsequent graft loss, but its pathogenesis is still largely unclear. Our group demonstrated an increase in CD8+ T cells infiltrating biopsies from CAMR patients (PMID: 20595199), but their role remains to be defined. Recently, immunometabolism has emerged as a field connecting cell energy metabolism with the immune cell differentiation and functions. Particularly, the permanent aerobic glycolysis of CD8+ lymphocytes induces their transition from naïve to activated state and effector T cells (PMID: 37315709). Thus, the aim of the study was to investigate the molecular mechanisms underlying the development of CAMR by the analysis of gene expression profiles of CD8+ T lymphocytes in conjunction with their metabolic state. Method We enrolled 14 patients with biopsy-proven CAMR and 12 stable transplant recipients with normal graft histology and function (control group). CD8+ T cells were purified by CD8 MicroBeads (Miltenyi Biotec) then counted (TC20™ Automated Cell Counter). Gene expression profiles of CD8+ T lymphocytes isolated from both groups were assessed using Agilent microarrays. Data obtained were statistically and functionally evaluated (IPA software) and validated by qPCR. Oxygen consumption rate (OCR) in CD8+ and CD8- cells was measured by a Resipher oxygen sensing lid (Lucid Scientific Inc., USA). The contribution of mitochondrial respiration to OCR was investigated in isolated CD8+ T cells from CAMR and controls treated with rotenone/antimycin A (Rot/AA), oligomycin (Olygo) or carbonyl cyanide-p-trifluoromethoxyphenylhydrazone (FCCP) to evaluate spare respiratory capacity (SRC), ATP-linked respiration, proton leak and maximal respiration. Results Gene expression profiles of CD8+ T cells showed a characteristic alteration of lipid metabolism in CAMR patients with the triglyceride biosynthesis pathway (p = 2.69E-3) as the most altered pathway and several genes de-regulated all potentially involved in the altered metabolic state of CD8+ T cells. Among others, we validated the increased expression of Nicotinamide Phosphoribosyltransferase (NAMPT) (FC = +2.39), the rate-limiting enzyme of nicotinamide adenine dinucleotide (NAD+) salvage pathway involved in the glycolysis progression, mostly activated in effector T cells. We then decided to evaluate the OCR and the metabolic state of CD8+T cells. Basal OCR was higher in CD8+ rather than CD8- cells, but with different trends among cells isolated from control and CAMR patients. Indeed, CD8+ cells from CAMR patients showed higher OCR compared to control, while OCR was lower in CD8- from CAMR rather than control patients. CD8+ OCR from both CAMR and control patients was mostly dependent on mitochondrial respiration, since it was deeply reduced by Rot/AA treatment. Interestingly, inhibitory response to Oligo treatment by CD8+ cells from CAMR patients was modest, while OCR was noticeably stimulated by FCCP in these cells, suggesting that mitochondrial oxygen uptake was not ATP linked but rather associated with increased uncoupling. These data suggest that CD8+ T cells from CAMR patients are activated effector T cells primarily utilizing aerobic glycolysis. To confirm this hypothesis, we evaluated the gene expression levels of: i) HIF1a, which involves permanent dependence on glycolysis even in the presence of oxygen (Warburg effect); ii) fatty acid transporter CD36, whose levels mimic an energy dependence on the beta oxidation of fatty acids, a process activated in memory T cells. We confirmed an increased expression of HIF1a and a reduced expression of CD36 in CD8+T cells from CAMR patients compared to controls (p&amp;lt;0.05), that confirm the T effector phenotype. Conclusion Our data suggest that CD8+ T cell from CAMR patients showed permanent dependency on glycolysis leading to altered immune phenotype and response, thus indicating novel opportunities to modulate the immune system for therapeutic purposes in kidney transplanted patients and reduce graft rejection.

#1844 Pregnancy outcome among kidney transplant recipients

Abstract Background and Aims Background The possibility of a term pregnancy is one of the benefits of solid organ transplantation for women. The gonadal dysfunction, caused by the failure of the kidney or another organ, is reverted within a few months after normal graft function. Unplanned pregnancies in transplant recipients, however, may compromise graft function and survival, and may also risk unnecessary fetal exposure to immunosuppressive medications. Aims To study the prevalence of pregnancy and pregnancy related complication after kidney transplantation (KT). Method Retrospective cohort study conducted on 236 patients out of 3000 kidney transplant recipient who underwent renal transplantation (RT) at Mansoura Urology and Nephrology Centre between March 1976 and December 2019. divided into group I; 118 kidney transplant female's recipient experienced pregnancy at any time after kidney transplant and group II; 118 kidney transplant female's recipients who didn`t experience pregnancy after renal transplantation, they were matched according to age and duration of renal transplantation and comparable in primary immunosuppressant drugs. all kidney recipients were reviewed for preoperative &amp; operative and post-operative details also we record maternal and fetal complication. Results Prevalence of pregnancy in our center is 191 pregnancies in 118 women who had underwent kidney transplantation between 1976 and 2019. We have found that the mean age of pregnancy between (26.27 ± 4.37-29.89 ± 4.6), the mean gestational age between (33.69 ± 6.4 – 33 ± 7.5) weeks, the live birth rate is 126 (66%). Preterm delivery rate in our study is 85 (44.5%), neonatal death 8 (4.1%), miscarriage 59 (30.9%), intrauterine fetal death 6 (3.1%) and birth defect 4 (2%). The prevalence rates of gestational hypertension is 87 (45.5%), pre-eclampsia 48 (25.1%), gestational diabetes 19 (9.9%), urinary tract infection 36 (18.8%), and graft rejection 8 (4.1%) during pregnancy. caesarean section is the most common method of delivery in our study 133 (69.6%). Kidney transplant recipients who aged more than or equal to 30 years at time of pregnancy are at higher risk for having non live-birth outcome (OR: 3.2, p value: 0.05). Proteinuria more than or equal to 0.5 g/day before pregnancy is a significant risk factor for having non live-birth outcome (OR: 4.7, p value: 0.009). Also, proteinuria ≥0.5 g/day during pregnancy is associated with increases risk for non-live-birth (OR: 10.2, p value: 0.013). Gesatational hypertension is associated with increases risk for non-live-birth (OR: 8.3, p value: 0.010).Preeclampsia is associated with increases risk for non-live-birth (OR: 4.6, p value: 0.005). Conclusion Although the outcome of live births is favourable, the risks of maternal and fetal complications are high in kidney transplant recipients including pregnancy-induced hypertension, increased rates of preeclampsia, gestational diabetes, and caesarean section rates. The risk of miscarriage, prematurity, and low birth rate is also high.

#2252 Outcome of pregnancy after kidney transplantation

Abstract Background and Aims Background The possibility of a term pregnancy is one of the benefits of solid organ transplantation for women. The gonadal dysfunction, caused by the failure of the kidney or another organ, is reverted within a few months after normal graft function. Unplanned pregnancies in transplant recipients, however, may compromise graft function and survival, and may also risk unnecessary fetal exposure to immunosuppressive medications. Aims To study the prevalence of pregnancy and pregnancy related complication after kidney transplantation (KT). Method Retrospective cohort study conducted on 236 patients out of 3000 kidney transplant recipient who underwent renal transplantation (RT) at Mansoura Urology and Nephrology Centre between March 1976 and December 2019. divided into group I; 118 kidney transplant female's recipient experienced pregnancy at any time after kidney transplant and group II; 118 kidney transplant female's recipients who didn't experience pregnancy after renal transplantation, they were matched according to age and duration of renal transplantation and comparable in primary immunosuppressant drugs. all kidney recipients were reviewed for preoperative &amp; operative and post-operative details also we record maternal and fetal complication. Results Prevalence of pregnancy in our center is 191 pregnancies in 118 women who had underwent kidney transplantation between 1976 and 2019. We have found that the mean age of pregnancy between (26.27 ± 4.37 - 29.89 ± 4.6), the mean gestational age between (33.69 ± 6.4 - 33 ± 7.5) weeks, the live birth rate is 126 (66%). Preterm delivery rate in our study is 85 (44.5%), neonatal death 8 (4.1%), miscarriage 59 (30.9%), intrauterine fetal death 6 (3.1%) and birth defect 4 (2%). The prevalence rates of gestational hypertension is 87 (45.5%), pre-eclampsia 48 (25.1%), gestational diabetes 19 (9.9%), urinary tract infection 36 (18.8%), and graft rejection 8 (4.1%) during pregnancy. caesarean section is the most common method of delivery in our study 133 (69.6%). Kidney transplant recipients who aged more than or equal to 30 years at time of pregnancy are at higher risk for having non live-birth outcome (OR: 3.2, p value: 0.05). Proteinuria more than or equal to 0.5 g/day before pregnancy is a significant risk factor for having non live-birth outcome (OR: 4.7, p value: 0.009). Also, proteinuria ≥0.5 g/day during pregnancy is associated with increases risk for non-live-birth (OR: 10.2, p value: 0.013). Gestational hypertension is associated with increases risk for non-live-birth (OR: 8.3, p value: 0.010).Preeclampsia is associated with increases risk for non-live-birth ( OR: 4.6, p value: 0.005). Conclusion Although the outcome of live births is favourable, the risks of maternal and fetal complications are high in kidney transplant recipients including pregnancy-induced hypertension, increased rates of preeclampsia, gestational diabetes, and caesarean section rates. The risk of miscarriage, prematurity, and low birth rate is also high.

ZBP1-mediated apoptosis and inflammation exacerbate steatotic liver ischemia/reperfusion injury.

Steatotic donor livers are becoming more and more common in liver transplantation. However, the current use of steatotic grafts is less acceptable than normal grafts due to their higher susceptibility to ischemia/reperfusion (I/R) injury. To investigate the mechanism underlying the susceptibility of steatotic liver to I/R injury, we detected cell death markers and inflammation in clinical donor livers and animal models. We found that caspase-8-mediated hepatic apoptosis is activated in steatotic liver I/R injury. However, ablation of caspase-8 only slightly mitigated steatotic liver I/R injury without affecting inflammation. We further demonstrated that RIPK1 kinase induces both caspase-8-mediated apoptosis and cell death-independent inflammation. Inhibition of RIPK1 kinase significantly protects against steatotic liver I/R injury by alleviating both hepatic apoptosis and inflammation. Additionally, we found that RIPK1 activation is induced by Z-DNA binding protein 1 (ZBP1) but not the canonical TNF-α pathway during steatotic liver I/R injury. Deletion of ZBP1 substantially decreases the steatotic liver I/R injury. Mechanistically, ZBP1 is amplified by palmitic acid-activated JNK pathway in steatotic livers. Upon I/R injury, excessive reactive oxygen species trigger ZBP1 activation by inducing its aggregation independent of the Z-nucleic acids sensing action in steatotic livers, leading to the kinase activation of RIPK1 and the subsequent aggravation of liver injury. Thus, ZBP1-mediated RIPK1-driven apoptosis and inflammation exacerbate steatotic liver I/R injury, which could be targeted to protect steatotic donor livers during transplantation.

Pre-Coronary Artery Bypass Grafting Computed Tomography-Based Fractional Flow Reserve Predicts Graft Failure: Implications for Planning Invasive Treatment of Coronary Artery Disease.

The aim of the study is to evaluate whether a pre-coronary artery bypass grafting (CABG) coronary computed tomography-based fractional flow reserve (FFR-CT) result at the site of a future anastomosis would predict the graft failure in patients undergoing CABG. In 43 patients who had coronary computed tomography angiography (CCTA) prior to the CABG, follow-up CCTA were acquired >12 months post-CABG procedure. The FFR-CT values were simulated on the basis of the pre-CABG CCTA. Based on follow-up CCTA, the anastomosis sites and the graft patency were determined. The graft failure was defined as either its stenosis >50% or occlusion. Ninety eight (44 saphenous, 54 left or right internal mammary artery) grafts were assessed. Eighteen grafts from 16 patients were dysfunctional on follow-up CCTA. The FFR-CT values at the location of future anastomosis were higher in dysfunctional than in normal grafts (0.77 [0.71-0.81] vs 0.60 [0.56-0.66], respectively, P = 0.0007). Pre-CABG FFR-CT (hazard ratio = 1.1; 95% CI: 1.012-1.1, P = 0.0230), and bypass graft to right coronary artery (hazard ratio = 3.7; 95% CI: 1.4-9.3 vs left anterior descending artery) were independent predictors of graft dysfunction during follow-up. The optimal threshold of FFR-CT to predict graft failure was >0.68 (sensitivity 88.9% (95% CI: 65.3-98.6), specificity 63.7% (95% CI: 52.2-74.2), positive predictive value 35.6% (95% CI: 28.3%-43.5%), negative predictive value 96.2% (95% CI: 87.2%-99.0%)). Pre-CABG functional FFR-CT predicts future coronary bypass graft failure. This shows utility of FFR-CT for guiding coronary revascularization and also suggests significance of physiological assessment prior to CABG.

Impact of hyperparathyroidism on allograft histology and function after kidney transplantation: Rethinking its causal role in graft dysfunction.

The causal relationship between hyperparathyroidism and kidney graft dysfunction remains inconclusive. Applying Bradford-Hill's temporality and consistency causation principles, we assessed the effect of parathyroid hormone (iPTH) on graft histology and eGFR trajectory on kidney transplant recipients (KTRs) with normal time-zero graft biopsies. Retrospective cohort study evaluating the effect of hyperparathyroidism on interstitial fibrosis and tubular atrophy (IF/TA) development in 1232 graft biopsies. Pre-transplant hyperparathyroidism was categorized by KDIGO or KDOQI criteria, and post-transplant hyperparathyroidism by iPTH>1× and>2× the URL 1 year after transplantation. We included 325 KTRs (56% female, age 38±13 years, follow-up 4.2 years [IQR: 2.7-5.8]). Based on pre-transplant iPTH levels, 26% and 66% exceeded the KDIGO and KDOQI targets, respectively. There were no significant differences in the development of>25% IF/TA between KTRs with pre-transplant iPTH levels above and within target range according to KDIGO (53%vs. 62%, P=.16, HR.94 [95% CI:.67-1.32]) and KDOQI (60%vs. 60%, P=1.0, HR 1.19 [95% CI:.88-1.60]) criteria. Similarly, there were no differences when using 1 year post-transplant iPTH cut-offs>88 pg/mL (58%vs. 64%, P=.33) and>176 pg/mL (55%vs. 62%, P=.19). After adjusting for confounders, no significant differences were observed in eGFR trajectories among the iPTH strata. In young KTRs who received a healthy graft, no association was found between increased pre- and post-transplant iPTH levels and graft dysfunction, as assessed histologically and through eGFR trajectory. The concept of hyperparathyroidism as a risk factor for graft dysfunction in recipients at low risk requires reevaluation.

Complications and Recurrences after Excision and Reconstruction of Eyelid Tumours.

The eyelids are a common site for skin tumours and account for 5-10% of all skin tumours. Treatment is mainly surgical and aims to preserve the anatomical structure of the eyelid, its function and not least its aesthetic appearance. Presentation of recurrence and complication rates of tumour-related eyelid surgery in a cohort of 450 tumours. Analysis of a cohort of 450 tumours operated on revealed 13 (2.8%) operations with recurrences and 32 (7%) with complications. The statistical significance of recurrences was observed for the involved and uninvolved ciliary margin. At the temporal canthus, 23.1% of recurrences occurred compared to 7.7% at the medial canthus. SGC has the highest recurrence rate. Complications include the following: ectropion, dehiscence, gross cicatrix with normal function, retraction, post-radiation damage, sub-graft haemorrhage and graft rejection. The recurrence rate of eyelid tumours is lower than that of complications. The choice of surgical technique determines the frequency of complications and histological control of the excised tissue, as well as the frequency of recurrences.

Mucosal-Type Chronic Otitis Media: Clinical Predictors of Postoperative Success.

Chronic otitis media (COM) remains a global disease, a burden, and a challenge. Predicting its treatment's postoperative success based on clinical presentation has not been reported, particularly for the mucosal (tubotympanic/safe) type. A prospective descriptive study of patients with mucosal-type COM was done to identify clinical predictors of improved postoperative hearing outcomes and successful graft uptakes. Among the 110 ears studied, tympanoplasty was performed in 76 and corticalmastoidectomy with tympanoplasty in 34, based on six weeks of discharge-free or persistent discharge, respectively; all were treated with postoperative intranasal steroid spray. Eustachian tube dysfunction was noted in 96.4%. All patients with a history of ear discharge over five years had ossicular discontinuity, and those with persistent discharge had nonpatent aditus. Normal postoperative hearing was attained in most patients with less than one year of ear discharge.Surgical intervention within a year achieved normal hearing and graft success of 100% with type I tympanoplasty using the fascia alone in discharge-free ears and cortical mastoidectomy with tympanoplasty using cartilage-fascia graft in discharging ears, despite Eustachian tube dysfunction. In the latter group, graft success in type II tympanoplasty was 76.9%. Ear discharge is the prime predictor of postoperative success in mucosal-type COM, as its duration and persistence dictate the time and type of surgical intervention.Duration of more than five years is directly proportional to pre-operative hearing loss with ossicular involvement and inversely proportional to postoperative hearing improvement, necessitating early surgical intervention, despite it being the mucosal or "safe type." Ear discharge-free for six weeks is an indicator of tympanoplasty. Persistent ear discharge, despite nonotogenic confounders, suggests aditus nonpatency, indicates the need for cortical mastoidectomy, and necessitates achieving its patency along with tympanoplasty. A surgical decision-making algorithm for the best possible surgical outcome in the chronic mucosal type of OM is also suggested.

Diplopia as the presenting symptom of a post‐transplant lymphoproliferative disorder in a bilateral inferior lim transplanted young adult

Aims/Purpose: To present a unique case of post‐transplant lymphoproliferative disorder (PTLD) after bilateral inferior limb transplantation, which is still controversial due to the absence of precedents in the literature and the unclear risk–benefit ratio.Methods: Case report.Results: A 22‐year‐old male presented to the emergency room complaining of double vision. He had a history of bilateral inferior limb amputation 8 years ago and received a bilateral lower limb transplantation 2 years later. He had normal graft function and was receiving cytomegalovirus prophylaxis. During neurological examinations left abducens nerve (CN VI) palsy was noted. Other cranial nerves affected produced facial hypoesthesia (CN V) and mild paresis (CN VII), hearing loss and tinnitus in left side (CN VIII) and soft palate asymmetry (CN X). He was otherwise neurologically intact, alert and orientated. MRI revealed a lesion located at the facial colliculus at the floor of 4th ventricle. In the context of immunosuppression, the differential diagnosis included abscess versus PTLD. Biopsy of the lesion was performed. Morphologically atypical lymphocytic cells suggestive of B lymphoma were identified. Monoclonal rearrangement for heavy chain Igen and immunoglobulins were identified with molecular biology techniques. The histology features were consistent with a diagnosis of CNS B lineage primary lymphoma. Two days later, bilateral supracondylar amputation was performed. Following the explant, immunosuppression was withdrawn. His underlying condition was finally diagnosed as PTLD, for which he started a chemotherapeutic regimen with radical intention (methotrexate and cytosine arabinoside). The patient recovered fully and up to date, 10 years later, is doing well.Conclusions: Due to its diverse aetiologias, a proper workup must be done of the patients presenting with diplopia to the emergency room. PLTD must be a condition to always be considered in patients with history of solid organ transplant; since the early diagnosis is crucial for a successful management of this often‐fatal condition.

Association between heart failure and arteriovenous access patency in patients with end-stage renal disease on hemodialysis

BackgroundHeart disease and chronic kidney disease are often comorbid conditions owing to shared risk factors, including diabetes and hypertension. However, the effect of congestive heart failure (CHF) on arteriovenous fistula (AVF) and AV graft (AVG) patency rates is poorly understood. We hypothesize preexisting HF may diminish blood flow to the developing AVF and worsen patency. MethodsWe conducted a single-institution retrospective review of 412 patients with end-stage renal disease who underwent hemodialysis access creation from 2015 to 2021. Patients were stratified based on presence of preexisting CHF, defined as clinical symptoms plus evidence of reduced left ventricular ejection fraction (EF) (<50%) or diastolic dysfunction on preoperative echocardiography. Baseline demographics, preoperative measures of cardiac function, and dialysis access-related surgical history were collected. Kaplan-Meier time-to-event analyses were performed for primary patency, primary-assisted patency, and secondary patency using standard definitions for patency from the literature. We assessed differences in patency for patients with CHF vs patients without CHF, patients with a reduced vs a normal EF, and AVG vs AVF in patients with CHF. ResultsWe included 204 patients (50%) with preexisting CHF with confirmatory echocardiography. Patients with CHF were more likely to be male and have comorbidities including, diabetes, chronic obstructive pulmonary disease, hypertension, and a history of cerebrovascular accident. The groups were not significantly different in terms of prior fistula history (P = .99), body mass index (P = .74), or type of hemodialysis access created (P = .54). There was no statistically significant difference in primary patency, primary-assisted patency, or secondary patency over time in the CHF vs non-CHF group (log-rank P > .05 for all three patency measures). When stratified by preoperative left ventricular EF, patients with an EF of <50% had lower primary (38% vs 51% at 1 year), primary-assisted (76% vs 82% at 1 year), and secondary patency (86% vs 93% at 1 year) rates than those with a normal EF. Difference reached significance for secondary patency only (log-rank P = .029). AVG patency was compared against AVF patency within the CHF subgroup, with significantly lower primary-assisted (39% vs 87% at 1 year) and secondary (62% vs 95%) patency rates for AVG (P < .0001 for both). ConclusionsIn this 7-year experience of hemodialysis access creation, reduced EF is associated with lower secondary patency. Preoperative CHF (including HF with reduced EF and HF with preserved EF together) is not associated with significant differences in overall hemodialysis access patency rates over time, but patients with CHF who receive AVG have markedly worse patency than those who receive AVF. For patients with end-stage renal disease and CHF, the risks and benefits must be carefully weighed, particularly for those with low EF or lack of a suitable vein for fistula creation.

Functional MRI evaluation of blood oxygen dependent (BOLD) in renal allograft dysfunction: a prospective study.

Blood oxygen level dependent-magnetic resonance imaging (BOLD-MRI) is a non-invasive functional imaging technique that can be used to assess renal allograft dysfunction. To evaluate the diagnostic performance of BOLD-MRI using a 3-T scanner in discriminating causes of renal allograft dysfunction in the post-transplant period. This prospective study was conducted on 112 live donor-renal allograft recipients: 53 with normal graft function, as controls; 18 with biopsy-proven acute rejection (AR); and 41 with biopsy-proven acute tubular necrosis (ATN). Multiple fast-field echo sequences were performed to obtain T2*-weighted images. Cortical R2* (CR2*) level, medullary R2* (MR2*) level, and medullary over cortical R2* ratio (MCR) were measured in all participants. The mean MR2* level was significantly lower in the AR group (20.8 ± 2.8/s) compared to the normal group (24 ± 2.4/s, P <0.001) and ATN group (27.4 ± 1.7/s, P <0.001). The MCR was higher in ATN group (1.47 ± 0.18) compared to the AR group (1.18 ± 0.17) and normal functioning group (1.34 ± 0.2). Both MR2* (area under the curve [AUC] = 0.837, P <0.001) and MCR (AUC = 0.727, P = 0.003) can accurately discriminate ATN from AR, however CR2* (AUC = 0.590, P = 0.237) showed no significant difference between both groups. In early post-transplant renal dysfunction, BOLD-MRI is a valuable non-invasive diagnostic technique that can differentiate between AR and ATN by measuring changes in intra-renal tissue oxygenation.

Liver Transplantation for Zellweger Syndrome.

Zellweger syndrome or cerebrohepatorenal syndrome is a rare, multisystem disorder occurring due to defect in metabolic pathway within the peroxisomes. Cirrhosis with portal hypertension is an important presentation of these patients. Given its progressive, multisystem nature, the role of liver transplantation (LT) in Zellweger syndrome remains undefined and controversial. An 11-y-old boy diagnosed with Zellweger syndrome presented to theauthors with decompensated cirrhosis along with bilateral proptosis. After a meticulous evaluation, he was offered an ABO incompatible liver transplantation with hismother being the donor. He had an uneventful post operative period. After a follow up of 24 mo, he has normal graft function,normal cognition along with resolution of proptosis. Therefore, in a group of carefully selected patients with Zellweger syndrome, a liver transplantation can be offered successfully with an excellent prognosis.

Diagnostic significance of TGF-β1 in kidney recipients with graft dysfunction

Development of minimally invasive diagnosis techniques for complications in recipients, based on analysis of the levels of molecular and genetic biomarkers, is an urgent task facing modern transplantology. Transforming growth factor beta 1 (TGF-β1), which has multiple effects in the body, among the potential indicators of complications.Objective: to assess the diagnostic significance of serum TGF-β1 in kidney recipients with graft dysfunction.Materials and methods. The study included 129 kidney recipients aged 17 to 68 years and 35 healthy subjects. Serum TGF-β1 levels in the recipients were determined by immunoenzyme technique.Results. Kidney recipients included 95 patients with laboratory and clinical signs of graft dysfunction, who underwent biopsy of the transplanted kidney, followed by morphological examination, and 34 recipients with normal graft function. Serum TGF-β1 levels in the kidney recipients were significantly higher than in their healthy counterparts (p = 0.00001); it did not correlate with most blood test parameters; with the glomerular filtration rate (GFR). Kidney recipients with graft dysfunction had significantly higher TGF-β1 levels than other recipients (p = 0.018). In recipients with graft dysfunction, morphological study revealed the following: acute tubular necrosis (ATN, n = 11), acute T-cell mediated rejection (ACR, n = 26), acute antibody-mediated rejection (AMR, n = 35), non-immune-mediated nephrosclerosis with signs of calcineurin inhibitor nephrotoxicity (CNI nephrotoxicity, n = 13), and recurrent glomerulonephritis (chronic graft rejection, n = 10). Recipients with immune-mediated graft injury (ACR, AMR and chronic rejection) had higher serum TGF-β1 levels than recipients with graft dysfunction resulting from other causes, p &lt; 0.0001. Kidney recipients with serum TGF-β1 levels above the threshold value of 94.3 ng/mL had a higher risk of immune-mediated graft dysfunction than other kidney recipients (RR = 2.2 ± 0.22 [95% CI 1.46–3.46]) with 77.5% test sensitivity and 60.3% specificity.Conclusion. The calculated threshold serum TGF-β1 level in kidney recipients can be considered as an auxiliary indicator of graft dysfunction resulting from acute or chronic rejection.

Non-invasive rejection surveillance in stable heart transplantation using local laboratory-run donor-derived cell-free DNA assay: two-centre European feasibility study

Abstract Background Monitoring adverse events is crucial after heart transplantation (HTx). Allograft rejection is a major etiological factor of graft dysfunction, hospitalisation, and death posttransplant. Endomyocardial biopsy (EMB) is the standard method of monitoring rejection; however, there are risks and limitations associated with it. The ISHLT guidelines for the care of HTx recipients have included non-invasive surveillance such as testing for donor-derived cell-free DNA (dd-cfDNA). While major studies have been conducted with patient cohorts and centralised testing in the USA, hereby we explored a European two-site cohort where dd-cfDNA was quantified at local centres by next-generation sequencing-based CE-marked assay. Purpose Our objective was to assess feasibility of assay and evaluate dd-cfDNA values in clinically stable HTx recipients. Methods HTx patients were enrolled at their scheduled visits in this cross-sectional study in 2 European HTx centres. Serial data after HTx, including clinical status, maintenance immunosuppression therapy and drug levels, diagnostic tests (blood tests, echocardiograms, coronary angiograms, EMBs), and adverse events were collected. Venous blood specimens were drawn in Streck cfDNA blood collection tubes for quantification of dd-cfDNA levels. We analysed dd-cfDNA fraction in plasma using AlloSeq cfDNA assay. For analysis, clinical stability was defined as asymptomatic patients &amp;gt;28 days post-HTx with normal graft function, without cytomegalovirus infection, history of rejection, or allograft vasculopathy. Results Between July 2021 and December 2022, 50 HTx recipients were enrolled at a median of 274 (112–395) days posttransplant. The median age at enrolment was 55.5 years. Of the total 82 dd-cfDNA results, 34 samples were excluded as they did not meet stability criteria. The median dd-cfDNA value of stable patients was 0.11% (95% CI 0.08%–0.13%). Median levels of dd-cfDNA did not differ between samples drawn in the first year after HTx (n=40) and at later time (n=8) [0.11% vs. 0.11%; p=0.41]. Of the 48 dd-cfDNA samples, 7 had values at risk based on the dd-cfDNA cut-off values from previous clinical validation trials: 4 at the injury cut-off of ≥0.20% and 3 at the severe injury threshold of ≥0.35%. Comparing clinical variables of samples with dd-cfDNA ≥0.20% (n=7) and &amp;lt;0.20% (n=41), we observed a 3-fold, non-significant increase in rate of de novo DSA formation (33.3% vs. 10.8%; p=0.19). Conclusions Our data show feasibility to analyse dd-cfDNA at the local level. In our two-site European reference cohort, dd-cfDNA is present at low levels (median 0.11%) which is within former reported ranges for clinically stable HTx recipients. Levels of dd-cfDNA do not vary beyond the first post-HTx year. The fact that in patients with de novo DSA higher dd-cfDNA levels are found; although, not statistically significant, suggests that dd-cfDNA may be a marker of subclinical rejection and requires further study.

Abstract 12560: Single Cell RNA Sequencing Signature of Cardiac Allograft Vasculopathy

Background: Cardiac allograft vasculopathy (CAV) is one of the major causes of death after heart transplantation (HTx). However, immunological mechanisms of CAV remain incompletely understood. This study aimed to determine distinct immune profiles of CAV compared to HTx patients with normal graft function (CONTROL). Methods: Peripheral blood mononuclear cells (PBMC) obtained from the International Society for Heart and Lung Transplant grade 2 or 3 CAV (n=6), and CONTROL (n=12) patients were analyzed using single cell RNA sequencing (498 genes) on the BD Rhapsody platform combined with 56 protein markers (CITE-seq) and VDJ-seq. Cells were clustered into major cell types using 18 protein markers. Targeted clustering was then performed to determine subclusters using proteomic and transcriptomic data. Results: Proportions of memory B cell (0.5±0.4% vs 1.4±0.8%, p=0.01) and CD16+CD56+ TEMRA CD8 T cell (0.5±0.3% vs 1.0±1.7%, p=0.007) were decreased and proportion of C1q+ nonclassical monocyte (1.0±0.5% vs 0.4±0.3%, p=0.01) was increased in CAV patients compared to CONTROL. In Th1 effector memory CD4 T cell cluster, CAV had a significantly higher proportion of clonally expanded cells (24.1±10.0% vs 11.3±9.2%, p=0.01) characterized by higher expression of NKG7, GZMH, CCL5, and CST7 compared to non-expanded cells in this cluster. Signature genes with the highest positive coefficients determined by LASSO regression to predict CAV (72.2% accuracy) included IFITM3, LAIR2, CD52, IFITM2, NKG7, NAMPT, CD74, F13A1, IL3RA, and RNASE2. IFITM3 and LAIR2 were the best positive predictors for CAV and overexpressed predominantly in CD4 T and CD8 T cells (Figure). Conclusion: CAV demonstrates distinct immune cellular and transcriptomic phenotypes compared to CONTROL. IFITM3 and LAIR2 overexpression in PBMCs may predict severe CAV in HTx patients.

Pre-CABG assessment of coronary stenosis with FFR-CT predicts future graft failure

Abstract Funding Acknowledgements Type of funding sources: Public Institution(s). Main funding source(s): National Institute of Cardiology grant. Objectives To evaluate, whether a pre-CABG coronary computed tomography based FFR (FFR-CT) result at the site of a future anastomosis would predict the graft failure in patients undergoing CABG. Background Functional guidance of surgical coronary revascularization remains debatable. Recently FFR-CT is recognized as suitable for the diagnosis of vessel-specific ischemia. Methods In 43 patients (mean age 65.14y (± 9.91), 15 women) who had CCTA performed less than 6 months prior to the isolated CABG, follow-up CCTA were acquired &amp;gt;12 months post CABG procedure (at median of 903[IQR:468–1669] days). Based on the pre-CABG CCTA, FFR-CT values were simulated. On the basis of follow-up CCTA the anastomosis sites and the graft patency were determined. The graft failure was defined as either its stenosis &amp;gt;50% or occlusion. Results 98 (44 saphenous, 54 LIMA/RIMA) grafts were assessed. 18 graft from 16 patients were dysfunctional on follow-up CCTA. FFR-CT values measured at the location of the future anastomosis were significantly higher in the dysfunctional than normal grafts (0.77[0.71–0.81] vs 0.60[0.56–0.66] respectively, p = 0.0007). According to multivariable Cox regression model pre-CABG FFR-CT (HR=1.1;95%CI:1.0–1.1, p = 0.0230), and bypass graft to RCA (HR=3.7; 95%CI:1.4–9.3 vs. LAD) were independent predictors of graft dysfunction during follow-up. The optimal threshold of FFR-CT to predict graft failure was &amp;gt;0.68 (sensitivity 88.9% (95%CI:65.3–98.6), specificity 63.7% (95%CI:52.2–74.2), PPV 35.6% (95%CI:28.3%-43.5%), NPV 96.2% (95%CI:87.2%-99.0%). Conclusions Pre-CABG functional FFR-CT predicts future coronary bypass graft failure. This shows utility of FFR-CT for guiding coronary revascularization and also suggests significance of physiological assessment prior to CABG.

Simultaneous 3-way Paired Exchange Liver Transplantation Without Nondirected Donation: Novel Strategy to Expand the Donor Pool.

Simultaneous 3-way Paired Exchange Liver Transplantation Without Nondirected Donation: Novel Strategy to Expand the Donor Pool.

Quantification of extracellular matrix remodeling for the non-invasive identification of graft fibrosis after liver transplantation

Detecting patients with early post-transplant fibrosis after liver transplantation (LT) is very important. Non-invasive tests are needed to avoid liver biopsies. We aimed to detect fibrosis in liver transplant recipients (LTR) using extracellular matrix (ECM) remodeling biomarkers. ECM biomarkers for type III (PRO-C3), IV (PRO-C4), VI (PRO-C6) and XVIII (PRO-C18L) collagen formation and type IV collagen degradation (C4M) were measured by ELISA in prospectively collected, cryopreserved plasma samples (n = 100) of LTR with paired liver biopsies from a protocol biopsy program. Fibrosis ≥ F2 was present in 29% of patients (median 44 months post-LT). APRI and FIB-4 neither identified significant fibrosis nor were correlated with histopathological fibrosis scores, while ECM biomarkers (AUCs 0.67–0.74) did. The median levels of PRO-C3 (15.7 vs. 11.6 ng/ml; p = 0.002) and C4M (22.9 vs. 11.6 ng/ml; p = 0.006) levels were elevated in T-cell-mediated rejection compared to normal graft function. The median levels of PRO-C4 (178.9 vs. 151.8 ng/ml; p = 0.009) and C4M (18.9 vs. 16.8 ng/ml; p = 0.004) levels were increased if donor-specific antibodies were present. PRO-C6 had the highest sensitivity (100%), NPV (100%) and negative likelihood-ratio (0) for graft fibrosis. To conclude, ECM biomarkers are helpful in identifying patients at risk of relevant graft fibrosis.

A clinical study of using ROC to compare the efficiency of ASL and BOLD in diagnosis of renal allograft function.

This retrospective study aims to evaluate the effectiveness of renal transplantation function by comparing arterial spin labeling (ASL) and blood oxygen level dependent (BOLD) imaging with the receiver operating characteristic (ROC) curve. According to the estimated glomerular filtration rate (eGFR) values, 42 patients with normal kidney grafts (the normal kidney graft group, eGFR <60 mL/min/1.73 m2) and 93 patients with injured grafts (the kidney graft injury group, eGFR <60 mL/min/1.73 m2) were included in the present study. Renal blood flow (RBF) and the effective transverse relaxation rate (R2*) were calculated by comparing ASL and BOLD imaging. The ROC curve and the youden index were used to evaluate the diagnostic performance of ASL, BOLD, and the combination of them. The results showed that all the clinical features of the patients, except for gender, differed significantly between the 2 groups (P<0.05). The mean RBF value of the renal transplant injury group (104.33±54.76 mL/100 g/min) was significantly lower than that of the normal group (191.84±63.96 mL/100 g/min, P<0.01). The mean medullary R2* value of the renal transplant injury group (27.91±3.35 1/s) was significantly higher than that of the normal group (25.22±2.94 1/s, P<0.01). Negative correlations were found between R2* and eGFR (r=-0.44), and RBF and R2* (r=-0.54; both P<0.01). The ROC analysis showed that both RBF and R2* reflected injured renal function [area under the curves (AUC) =0.86 and 0.72, respectively]. In addition, the AUC of RBF and R2* combined was 0.86, which was comparable to that of RBF alone (P=0.95), while combining R2* and RBF improved the diagnostic performance of R2* alone (AUC =0.86 versus 0.72, respectively; P<0.01). The youden index analysis showed that the diagnostic accuracy of ASL was 80.00%, better than 71.85% of BOLD; the sensitivity and specificity of ASL in diagnosing renal allograft dysfunction were 79.57% and 80.95%, superior to 77.42% and 59.52% of BOLD. Our results showed that the non-invasive assessment of ASL in clinical kidney transplant function is a more promising imaging technique than BOLD.