Renal Graft Outcome Research Articles

Reproducibility and prognostic ability of chronicity parameters in kidney biopsy – Comprehensive evaluation comparing microscopy and artificial intelligence in digital pathology

IntroductionSemi-quantitative scoring of various parameters in renal biopsy is accepted as an important tool to assess disease activity and prognostication. There are concerns on the impact of interobserver variability in its prognostic utility, generating a need for computerized quantification. MethodsWe studied 94 patients with renal biopsies, 45 with native diseases and 49 transplant patients with index biopsies for Polyomavirus nephropathy. Chronicity scores were evaluated using two methods. A standard definition diagram was agreed after international consultation and four renal pathologists scored each parameter in a double-blinded manner. Interstitial fibrosis (IF) score was assessed with five different computerized and AI-based algorithms on trichrome and PAS stains. ResultsThere was strong prognostic correlation with renal function and graft outcome at a median follow-up ranging from 24 to 42 months respectively, independent of moderate concordance for pathologists scores. IF scores with two of the computerized algorithms showed significant correlation with estimated glomerular filtration rate (eGFR) at biopsy but not at the end of follow-up. There was poor concordance for AI based platforms. ConclusionChronicity scores are robust prognostic tools despite interobserver reproducibility. AI-algorithms have absolute precision but are limited by significant variation when different hardware and software algorithms are used for quantification.

High Rate of Kidney Graft Failure after Simultaneous Heart-Kidney Transplantation.

The indications and outcomes of Simultaneous heart-kidney transplantation (SHKT) remain sub-optimally defined. Risk factors for renal graft failure after SHKT also remain poorly defined. We analyzed the renal graft outcomes among SHKT recipients using United Network for Organ Sharing database from 2015-2020. To evaluate for factors associated with poor renal outcomes, we compared SHKT and kidney transplantation alone (KTA) recipients using propensity score matching. Among SHKT recipients, rate of primary non-function (PNF) of kidney graft was 3%, 30-day kidney graft failure rate was 7.0%, and the 30-day post-transplant mortality rate was 4.1%. The incidence of delayed kidney graft function (KDGF) was 27.5%. Kidney graft failure was seen early post-SHKT with most common causes of patient death (43.9%) and PNF of kidney graft (41.5%). One-year and two-year patient survival was 89.2% and 86.5%, and one-year and two-year freedom from kidney graft failure was 85.4% and 82.7%, respectively. In subgroup analysis of SHKT recipients, use of pre-transplant mechanical cardiac support (adjusted Odds Ratio (aOR) 2.57, P=0.017), higher cPRA (aOR 1.76, P=0.016), and older donor age per 10 years (aOR 1.94, P=0.001) were associated with PNF. Pre-transplant extracorporeal membrane oxygenation support was associated with the increased risk of 30-day recipient mortality (aOR 5.55, P=0.002). Increased 30-day graft failure was seen in SHKT recipients with pre-transplant mechanical cardiac support (aOR 1.77, P=0.038) and dialysis at time of transplant (aOR 1.72, P=0.044). Multivariable Cox-Hazard analysis demonstrated that SHKT, when compared to KTA, is associated with increased kidney graft failure (Hazard Ratio, 2.56, P<0.001) and recipient mortality (Hazard Ratio: 2.65, P<0.001). SHKT is associated with high rates of kidney graft failure. Identification of risk factors for renal graft failure can help optimize recipient selection for SHKT vs Kidney after HT, especially after introduction of the new safety-net policy.

SP5.12 Pancreas Graft Outcome dictates the Renal Graft outcomes and overall patient survival in Simultaneous Kidney Pancreas (SPK) Transplant recipients. A UNOS/OPTN Transplant Registry Big Data Analysis over the last 20 years. An Epidemiology In Transplant Study Group (ETrSG) Initiative

Abstract Purpose Pancreatic graft outcomes affect the cumulative outcomes of SPK transplant, yet the impact of pancreas graft loss on renal graft and overall patient survival is yet to be reported. Methods We harmonized the UNOS/OPTN SPK Transplant data (1996-2019) reported to the U.S. Dept. of Health and Human Services to analyze survival outcomes of recipients who had all cause pancreas graft loss. The demographics report and survival analysis (renal graft/ patient survival) at 1,3, and 5 years post-transplant were data mined. Logistic Regression was done to identify predictors of survival. Results N=7036 all-cause pancreatic graft losses were reported from a cohort of N=64815 SPK Transplant recipients during the first five years of transplant. The renal graft survival was 99%, 97%, and 95% in functioning SPK transplant; 77%, 68%, and 54% in recipients with pancreatic graft loss at 1,3, and 5 years respectively. (Log-rank &amp;lt;0.001). The overall patient survival was 84%, 75%, and 66% in recipients with pancreatic graft loss at 1,3, and 5 years, respectively (Log-rank &amp;lt;0.001). Recipient age &amp;gt;45 years (p=0.008), recipient smoking history ( p&amp;lt;0.001), recipient history of hypertension ( p&amp;lt; 0.001), Recipient BMI &amp;gt;30 (p=0.01), cardiac events ( p=0.02) were the variables of importance on univariate analysis affecting renal graft and patient survival. Recipients with functioning Pancreas had a renal transplant survival benefit (0.22; 0.45) at 1 and 5 years &amp; overall patient survival (0.15; 0.33) at 1 and 5 years respectively. Conclusions Functioning pancreas graft confers survival benefit to renal graft and overall patient survival. The survival deteriorates over time since pancreas graft failure.

Impact of Resolved Preformed, Persistent Preformed, and De Novo Anti-HLA Donor-Specific Antibodies in Kidney Transplant Recipients on Long-Term Renal Graft Outcomes.

The post-transplant evolution of antihuman leukocyte antigen donor-specific antibodies (anti-HLA DSAs) includes three clinical patterns: resolved preformed DSAs, persistent preformed DSAs, and de novo DSAs. The aim of this retrospective study was to analyze the impact of resolved preformed, persistent preformed, and de novo anti-HLA-A, -B, and -DR DSAs in kidney transplant recipients on long-term renal allograft outcomes. This is a post hoc analysis of the study conducted in our transplant center. One hundred eight kidney transplant recipients were included in the study. Patients were followed for a minimum of 24 months after allograft biopsy, which was performed 3 to 24 months after kidney transplantation. The identification of persistent preformed DSAs at the time of biopsy was the most significant predictor of the combined endpoint of the study (>30% decline in estimated glomerular filtration rate or death-censored graft loss; HR = 5.96, 95% CI 2.041-17.431, p = 0.0011), followed by the occurrence of de novo DSAs (HR = 4.48, 95% CI 1.483-13.520, p = 0.0079). No increased risk was observed in patients with resolved preformed DSAs (HR = 1.10, 95% CI 0.139-8.676, p = 0.9305). Patients with resolved preformed DSAs have similar graft prognoses as patients without DSAs, therefore, the persistence of preformed DSAs and development of de novo DSAs are associated with inferior long-term allograft outcomes.

Biostatistical Analysis of Relation between HLA-A/B and HLA-DR Eplet Mismatches and Renal Graft Outcome

Abstract: Despite all the clinical interventions that happened during the last 2 decades, the unavailability of a potent donor for renal transplantation remains a concern in the field of transplantation immunology. Recent studies promise the establishment of an effective clinical method to find a potent renal transplant donor, in the near future. Combining the use of molecular techniques with biostatistical methods can be a great tool for clinicians in choosing a potent donor. The present study was conducted from a cohort of 1144 (n=572 pair) renal transplant recipients and their donors to analyse eplet matches and mismatches. Initial observation of increased serum creatinine level which ranged from 2.0 to 21.0 mg/dL in patients treated for end-stage renal disease implied a single event of graft rejection. The statistical correlation between eplet mismatches and graft survival was observed to be significant with P value 0.003. A value of -0.215 at 0.01 significance showed the positive linear correlation between the increased numbers of HLA DR eplet mismatches towards chronic renal graft rejection. The correlation coefficient of -0.888 observed between the number of HLA DR eplet mismatches and days of graft survival clearly implies the effect of increased HLA DR eplet mismatch delayed graft rejection. The study gives an idea on the minimization of class II HLA DR eplet mismatches to decreased frequency of graft rejection as indicated by increased survival rate.

Is There Any Association Between Triglyceride–Glucose Index and Graft Function in Kidney Transplant Recipients?

BackgroundAlthough previous studies have illustrated the relationship between chronic kidney disease, coronary artery disease, erectile dysfunction, and the triglyceride–glucose index (TyGi), the relationship between this index and postoperative graft function in patients undergoing renal transplantation has yet to be investigated. In the present study, we aimed to reveal the association between the TyGi and renal graft outcomes in patients who underwent renal transplantation. MethodsWe retrospectively collected data on living and cadaveric kidney donor recipients between May 2019 and April 2022. The recipients’ age, sex, body mass index, preoperative fasting glucose and triglyceride levels, TyGi, estimated glomerular filtration rate (eGFR), and serum creatinine measurement data were recorded. The patients were divided into 2 groups according to their GFR values (group 1: GFR <60 mL/min/1.73 m2; group 2: GFR ≥60 mL/min/1.73 m2). Follow-up serum creatinine–eGFR levels and TyGi measurements were compared between the recipients in group 1 and group 2. ResultsThe mean TyGi measurements of the recipients were 8.79 ± 0.64 in group 1 and 8.83 ± 0.72 in group 2. There was no statistically significant difference in terms of the TyGi measurements between the 2 groups (P >. 05). No statistically significant correlation was found between the recipients’ creatinine, eGFR, and TyGi at 1st, 6th, and 12th postoperative months (P > .05). ConclusionsWe believe that the relationship between the TyGi and renal graft function can be more clearly understood in prospective studies that include a higher number of patients and a longer follow-up period.

Association of Circulating Anti-HLA Donor-Specific Antibodies and Their Characteristics, including C1q-Binding Capacity, in Kidney Transplant Recipients with Long-Term Renal Graft Outcomes

Post-transplant antihuman leukocyte antigen donor-specific antibodies (anti-HLA DSAs) monitoring in kidney transplant recipients remains unclear and is currently under investigation. The pathogenicity of anti-HLA DSAs is determined by antibody classes, specificity, mean fluorescent intensity (MFI), C1q-binding capacity, and IgG subclasses. The aim of this study was to investigate the association of circulating DSAs and their characteristics with renal allograft long-term outcomes. The study included 108 consecutive patients from our transplant center who underwent kidney allograft biopsy between November 2018 and November 2020, 3 to 24 months after kidney transplantation. At the time of biopsy, patients' sera were collected for analysis of anti-HLA DSAs. Patients were followed for a median time of 39.0 months (Q1-Q3, 29.8-45.0). Detection of anti-HLA DSAs at the time of biopsy (HR = 5.133, 95% CI 2.150-12.253, p = 0.0002) and their C1q-binding capacity (HR = 14.639, 95% CI 5.320-40.283, p ≤ 0.0001) were independent predictors of the composite of sustained 30% reduction from estimated glomerular filtration rate or death-censored graft failure. Identification of anti-HLA DSAs and their C1q-binding capacity could be useful in identifying kidney transplant recipients at risk for inferior renal allograft function and graft failure. Analysis of C1q is noninvasive, accessible, and should be considered in clinical practice in post-transplant monitoring.

Abstract 279: Ecpr, A New Source Of Organs

Purpose: The scarcity of renal grafts is a major public health problem. New strategies are sought to overcome the problem of organ shortage. Organ donation after brain death is a major source of renal grafts. In our center, extracorporeal cardiopulmonary resuscitation (ECPR) is used as a 2nd line of treatment for refractory cardiac arrest. Despite this treatment, some patients present brain death and become eligible to organ donation. To this day, information is scarce on the long-term outcome of renal grafts from these patients. The objective of this study was to evaluate this outcome. Methods: We conducted a monocentric retrospective observational study between 2011 and 2017. The study was validated by the local ethics committee. We included patients who were eligible to organ donation after diagnosis of brain death and from whom at least one organ graft was procured and transplanted. Among these patients we compared those who were treated by ECPR for refractory cardiac arrest (ECPR group) and those who were not (control group). Results: During the study period, 45 patients were included, respectively 23 and 22 in the control and ECPR groups. Patients from the ECPR group were younger with less comorbidities (respectively 41+/-13 vs 63+/-19 years in the ECPR and control groups, p&lt;0,044). However, they were more severe during their ICU stay, as shown by their SAPS II score which was significantly higher (80+/-13 vs 61+/-15 in the ECPR and control groups respectively, p&lt;0,001). A total of 68 renal grafts were procured, transplanted, and studied (34 in each group). There was no difference between the 2 groups in terms of graft survival at 1 year (94.1 vs 82.4% in the ECPR and control group respectively, p=0,52). Discussion-Conclusion: Our study outlines that kidneys harvested from patients treated with ECPR have similar long-term outcome to organs retrieved from patients developing brain death without ECPR. Younger age and absence of comorbidities seem to compensate patient severity after cardiac arrest. One could hypothesize on a protective effect of ECPR on kidney function due to continuous blood flow delivered in the descending aorta. With the increase of ECPR cases, this strategy could be an increasing source of organs to address the issue of organ shortage.

SP1.1.2 The significant impact of using virtual cross match on achieving 100% within-18 hour target of cold ischaemia time in transplanting kidneys from donors following brain death in a single centre in UK

Abstract Aims To evaluate the impact of virtual cross match in donation following brain death (DBD) kidney transplants on the cold ischaemia time (CIT) as one of the factors in achieving better renal graft outcomes. Methods Every patient on the deceased donor renal transplant waiting list in our centre was asked to give a blood sample to test for Human Leucocyte Antigen (HLA) antibodies. Our transplant coordinators ensured that this process is updated three monthly as part of the eligibility criteria to perform virtual cross match. Other factors contributing to CIT were intentionally ignored given that there are no significant changes in the kidney allocation scheme or kidney acceptance criteria. Comparison was made between CIT in the financial years 2014/ 2015 and 2020 /2021. Results Since the introduction of this strategy, our centre was the only centre in all 23 UK kidney transplant centres to achieve 100% transplantation within 18 hour CIT for DBD kidneys transplants in the financial year 2020/2021. This represented a significant improvement compared to 58% in the financial year 2014/2015. Conclusions Virtual cross match was a key factor in achieving the 18 hours target for DBD kidney transplant regardless of other contributing factors. It is highly recommended that a three-monthly screening for HLA Antibodies is regularly performed to achieve this result.

Impact of Tacrolimus Daily Dose Limitation in Renal Transplant Recipients Expressing CYP3A5: A Retrospective Study.

The pharmacokinetic variability of tacrolimus can be partly explained by CYP3A5 activity. Our objective was to evaluate a tacrolimus sparing policy on renal graft outcome according to CYP3A5 6986A>G genetic polymorphism. This retrospective study included 1114 recipients with a median follow-up of 6.3 years. Genotyping of the 6986A>G allelic variant corresponding to CYP3A5*3 was systematically performed. One year after transplantation, tacrolimus blood trough concentration (C0) target range was 5–7 ng/mL. However, daily dose was capped to 0.10 mg/kg/day regardless of the CYP3A5 genotype. A total 208 CYP3A5*1/- patients were included. Despite a higher daily dose, CYP3A5*1/- recipients exhibited lower C0 during follow-up (p < 0.01). Multivariate analysis did not show any significant influence of CYP3A5*1/- genotype (HR = 0.70, 0.46–1.07, p = 0.10) on patient-graft survival. Glomerular Filtration Rate (GFR) decline was significantly lower for the CYP3A5*1/- group (p = 0.02). The CYP3A5*1/- genotype did not significantly impact the risk of biopsy-proven acute rejection (BPAR) (HR = 1.01, 0.68–1.49, p = 0.97) despite significantly lower C0. Based on our experience, a strategy of tacrolimus capping is associated with a better GFR evolution in CYP3A5*1/- recipients without any significant increase of BPAR incidence. Our study raised some issues about specific therapeutic tacrolimus C0 targets for CYP3A5*1/- patients and suggests to set up randomized control studies in this specific population.

Association of Bw4/Bw6 mismatch across class I HLA loci with renal graft outcomes in first time transplants

Bw4 and Bw6 are strongly immunogenic epitopes routinely assigned based on HLA-B typing results per Organ Procurement and Transplantation Network (OPTN) policies. These public epitopes and their variants are shared by some cross-reactive HLA-A and -C antigens. Although epitope mismatch has been associated with poor transplant outcomes, previous studies did not find such associations for Bw4/6 mismatch as defined by HLA-B antigens only. We hypothesized that a broader definition for Bw4/Bw6 mismatch that includes cross-reactive HLA-A and -C antigens may reveal the risk associated with these epitopes. In this retrospective cohort study, we examined kidney transplantations between 2000 and 2016 in the OPTN database and determined the association of Bw4/6 mismatch across all class I HLA antigens and renal graft outcomes. Even by this broader definition, Bw4/6 mismatch was not independently associated with 1-year graft rejection (adjusted OR: 0.99, 95%CI 0.93–1.06) or death-censored graft survival (adjusted HR: 1.02, 95%CI 1.00–1.05). There was no significant association among recipients who were already sensitized at transplant either. Our findings suggest that Bw4/6 mismatch alone is not associated with poor renal graft outcomes despite their strong immunogenicity, and the load of epitope mismatches over a certain threshold is likely required to cause adverse clinical consequences.

Simultaneous heart-kidney transplantation results in respectable long-term outcome but a high rate of early kidney graft loss in high-risk recipients \u2013 a European single center analysis

BackgroundIn spite of renal graft shortage and increasing waiting times for transplant candidates, simultaneous heart and kidney transplantation (HKTx) is an increasingly performed procedure established for patients with combined end-stage cardiac and renal failure. Although data on renal graft outcome in this setting is limited, reports on reduced graft survival in comparison to solitary kidney transplantation (KTx) have led to an ongoing discussion of adequate organ utilization.MethodsThis retrospective study was conducted to evaluate prognostic factors and outcomes of 27 patients undergoing HKTx in comparison to a matched cohort of 27 patients undergoing solitary KTx between September 1987 and October 2019 in one of Europe’s largest transplant centers.ResultsMedian follow-up was 100.33 (0.46–362.09) months. Despite lower five-year kidney graft survival (62.6% versus 92.1%; 111.73 versus 183.08 months; p = 0.189), graft function and patient survival (138.90 versus 192.71 months; p = 0.128) were not significantly inferior after HKTx in general. However, in case of prior cardiac surgery requiring sternotomy we observed significantly reduced early graft and patient survival (57.00 and 94.09 months, respectively) when compared to patients undergoing solitary KTx (183.08 and 192.71 months; p < 0.001, respectively) or HKTx without prior cardiac surgery (203.22 and 203.22 months; p = 0.016 and p = 0.019, respectively), most probably explained by the significantly increased rate of primary nonfunction (33.3%) and in-hospital mortality (25.0%).ConclusionsOur data demonstrates the increased rate of early kidney graft loss and thus significantly inferior graft survival in high-risk patients undergoing HKTx. Thus, we advocate for a “kidney-after-heart” program in such patients to ensure responsible and reasonable utilization of scarce resources in times of ongoing organ shortage crisis.

MO929KIDNEY TRANSPLANTATION IN MONOCLONAL IMMUNOGLOBULIN DEPOSITION DISEASE: A REPORT OF 6 CASES

Abstract Background and Aims Monoclonal immunoglobulin deposition disease (MIDD) is a systemic rare condition that usually leads to end stage renal disease. Treatment of patients with a bortezomib-based regimen followed by autologous stem cell transplantation (ASCT) has been increasingly used, with improvements in the response rates and the renal graft outcomes in kidney transplant recipients Method Retrospective study of 6 patients diagnosed of MIDD with complete response but not renal response after hematologic treatment that underwent kidney transplant in our institution between 2010 and 2019. Results A total of 6 patients (5 women) were analyzed, with mean age at diagnosis of 47 years (range 40-53). At presentation their mean eGFR was 18 mL/minute (range 9-25) and mean proteinuria of 5.5 g (range 0.290-12.5). The deposit was kappa type except in 1 case (heavy and light lambda type chains). In all of them there was an absence of monoclonal component in blood and urine but positive immunofixation in 5 cases (2 only in urine). 3 started chronic hemodialysis during admission and the others at 3, 5 and 44 months after diagnosis. As hematological treatment, all received bortezomib followed by ASCT, being under complete hematological response at the time of kidney transplant. It was performed at 28 months on average from ASCT (range 11-42), with mean kappa/lambda ratio of 2.6 (range 1.33-3.75). 3 patients received induction with thymoglobulin and 3 with basiliximab, followed by triple therapy with tacrolimus + prednisone + mTOR inhibitor (4 patients) or mycophenolate (2 patients). During a median follow-up of 20,5 months from kidney transplant and 54 months from ASCT, 1 patient experienced hematologic relapse and 2 had hematologic progression (one of them with MIDD relapse in the allograft) requiring treatment. The patient with organ relapse received Daratumumab monotherapy achieving complete hematologic response but graft failure. The other 5 patients had functional graft with median serum creatinine 1.68 mg/dl. Conclusion In patients with MIDD and sustained complete hematologic response, a kidney transplant can be considered. The optimal approach to treatment of hematologic relapse or recurrence of MIDD after kidney transplant remains to be determined

Early renal function trajectories, cytomegalovirus serostatus and long-term graft outcomes in kidney transplant recipients

BackgroundImproved recognition of factors influencing graft survival has led to better short-term kidney transplant outcomes. However, efforts to prevent long-term graft decline and improve graft survival have seen more modest improvements. The adoption of electronic health records has enabled better recording and identification of donor-recipient factors through the use of modern statistical techniques. We have previously shown in a prevalent renal transplant population that episodes of rapid deterioration are associated with graft loss.MethodsEstimated glomerular filtration rates (eGFR) between 3 and 27 months after transplantation were collected from 310 kidney transplant recipients. We utilised a Bayesian approach to estimate the most likely eGFR trajectory as a smooth curve from an average of 10,000 Monte Carlo samples. The probability of having an episode of rapid deterioration (decline greater than 5 ml/min/1.73 m2 per year in any 1-month period) was calculated. Graft loss and mortality data was collected over a median follow-up period of 8 years. Factors associated with having an episode of rapid deterioration and associations with long-term graft loss were explored.ResultsIn multivariable Cox Proportional Hazard analysis, a probability greater than 0.8 of rapid deterioration was associated with long-term death-censored graft loss (Hazard ratio 2.17; 95% Confidence intervals [CI] 1.04–4.55). In separate multivariable logistic regression models, cytomegalovirus (CMV) serostatus donor positive to recipient positive (Odds ratio [OR] 3.82; 95%CI 1.63–8.97), CMV donor positive (OR 2.06; 95%CI 1.15–3.68), and CMV recipient positive (OR 2.03; 95%CI 1.14–3.60) were associated with having a greater than 0.8 probability of an episode of rapid deterioration.ConclusionsEarly episodes of rapid deterioration are associated with long-term death-censored graft loss and are associated with cytomegalovirus seropositivity. Further study is required to better manage these potentially modifiable risks factors and improve long-term graft survival.

Subnormothermic Perfusion with H2S Donor AP39 Improves DCD Porcine Renal Graft Outcomes in an Ex Vivo Model of Kidney Preservation and Reperfusion

Cold preservation is the standard of care for renal grafts. However, research on alternatives like perfusion at higher temperatures and supplementing preservation solutions with hydrogen sulfide (H2S) has gained momentum. In this study, we investigated whether adding H2S donor AP39 to porcine blood during subnormothermic perfusion at 21 °C improves renal graft outcomes. Porcine kidneys were nephrectomized after 30 min of clamping the renal pedicles and treated to 4 h of static cold storage (SCS) on ice or ex vivo subnormothermic perfusion at 21 °C with autologous blood alone (SNT) or with AP39 (SNTAP). All kidneys were reperfused ex vivo with autologous blood at 37 °C for 4 h. Urine output, histopathology and RNAseq were used to evaluate the renal graft function, injury and gene expression profiles, respectively. The SNTAP group exhibited significantly higher urine output than other groups during preservation and reperfusion, along with significantly lower apoptotic injury compared to the SCS group. The SNTAP group also exhibited differential pro-survival gene expression patterns compared to the SCS (downregulation of pro-apoptotic genes) and SNT (downregulation of hypoxia response genes) groups. Subnormothermic perfusion at 21 °C with H2S-supplemented blood improves renal graft outcomes. Further research is needed to facilitate the clinical translation of this approach.

CON: Liver Transplant Alone.

CON: Liver Transplant Alone.

Renal Graft Outcomes in Simultaneous Kidney-Heart Transplant Recipients: Analysis of the UNOS Database from 1987-2018

Renal Graft Outcomes in Simultaneous Kidney-Heart Transplant Recipients: Analysis of the UNOS Database from 1987-2018

UROLITHIASIS IN RENAL TRANSPLANTATION RECIPIENTS

Objectives: Urinary stone formation is a rare complication in renal transplantation recipients. Unlike general population, the diagnosis is likely to be delayed due to graft denervation. And urolithiasis could lead to graft failure. In this study, we aimed to identify the incidence of urolithiasis and their characteristics. Methods: We retrospectively studied 1366 renal transplantation recipients who underwent transplantation surgery at Seoul St. Mary’s Hospital between 2009 and 2018. By medical record review, patients who were treated for urolithiasis were enrolled. Results: During study period, there were 12 patients who were diagnosed with symptomatic urolithiasis with functioning allograft. Overall incidence was 0.87%. Mean age of diagnosis was 53.4 years. Of 12 patients, 9 patient were males. Mean duration from transplantation to diagnosis of urolithiasis was 19 months. Stone compositon study was performed in 7 patients. Common composition of stones was uric acid stone (5 patients, 41.6% and 4 of them were mixed with calcium based stone). The other patients revealed calcium oxalate stone and struvite stone. In 5 patients, stone passed through after ESWL. And 5 patients received ureteroscopic removal procedure. 1 patient experience spontaneous stone passage and the other patient required cystoscopic stone removal because of large size of stone. Mean time from diagnosis to treatment was 9.8 days. No significant differences were observed between mean estimated glomerular filtration rate before and after treatment (p=0.071). Conclusions: Urinary stone formation in renal transplantation recipients is a rare complication (0.87%). Prompt diagnosis and treatment, and stone-preventive management can prevent adverse effects on renal graft outcome.

Β2-Microglobulin Post Kidney Transplantation as A Predictor of Subsequent Kidney Allograph Dysfunction

Background: Long-term outcome in renal transplantation is heterogeneous, and predicting success is challenging. Serum β2-microglobulin (β2MG), a novel marker of kidney function, predicts mortality and kidney failure in the general population, and its elevation following transplantation is a marker of acute rejection. Objective: To determine whether serum beta-2-micro-globulin one three-year post-transplant period could predict the decline in GFR over a follow-up period of six months. Patients and methods: This study was carried out at the National Institute of Nephrology and Urology, Cairo, Egypt. The patients were subjected to different demographic, clinical, biochemical, ultrasonographic, and endoscopic findings. In this study, 42 primary kidney transplant recipients were included. Results: The results showed a significant increase in serum β2-microglobulin level between renal transplant recipients with unstable kidney functions in comparison to renal transplant recipients with stable kidney function. The results showed serum β2-microglobulin level could be a good predictor of renal graft outcomes. Measurements of serum levels of beta 2 micro-globulin could be more sensitive and more specific than serum creatinine as renal function tests for early prediction of graft dysfunction. Conclusion: In this study, we found an association between serum level of β2MG in the late post-transplant period and a subsequent decline in kidney allograft function within a short time-frame. The overall results show that a higher serum level of β2MG after a single measurement at different intervals of the late post-transplant period independently predicts the lower eGFR. Thus, higher serum β2MG is a risk factor for graft function, particularly with longer follow-up.

C3d-positive donor-specific antibodies have a role in pretransplant risk stratification of cross-match-positive HLA-incompatible renal transplantation: United Kingdom multicentre study.

Anti-HLA-antibody characteristics aid to risk-stratify patients and improve long-term renal graft outcomes. Complement activation by donor-specific antibody (DSA) is an important characteristic that may determine renal allograft outcome. There is heterogeneity in graft outcomes within the moderate to high immunological risk cases (cross-match-positive). We explored the role of C3d-positive DSAs in sub-stratification of cross-match-positive cases and relate to the graft outcomes. We investigated 139 cross-match-positive living-donor renal transplant recipients from four transplant centres in the United Kingdom. C3d assay was performed on serum samples obtained at pretreatment (predesensitization) and Day 14 post-transplant. C3d-positive DSAs were found in 52 (37%) patients at pretreatment and in 37 (27%) patients at Day 14 post-transplant. Median follow-up of patients was 48months (IQR 20.47-77.57). In the multivariable analysis, pretreatment C3d-positive DSA was independently associated with reduced overall graft survival, the hazard ratio of 3.29 (95% CI 1.37-7.86). The relative risk of death-censored five-year graft failure was 2.83 (95% CI 1.56-5.13). Patients with both pretreatment and Day 14 C3d-positive DSAs had the worst five-year graft survival at 45.5% compared with 87.2% in both pretreatment and Day 14 C3d-negative DSA patients with the relative risk of death-censored five-year graft failure was 4.26 (95% CI 1.79, 10.09). In this multicentre study, we have demonstrated for the first time the utility of C3d analysis as a distinctive biomarker to sub-stratify the risk of poor graft outcome in cross-match-positive living-donor renal transplantation.