List For Kidney Transplantation Research Articles

#1390 Differences in the detection of anti-HLA antibodies between two single antigen bead methods in kidney transplantation patients

Abstract Background and Aims Two semiquantitative single-antigen bead (SAB) methods are currently available for the detection of anti-HLA antibodies and the estimation of their activity, depending on complement binding. However, data on accordance of the two methods on specificities detection and their reactivity evaluation are scarce. The purpose of this study is to compare the two methods in terms of anti-HLA antibodies specificities detection and of their complement binding capacity Method Sera from 97 patients with a positive Panel Reactive Antibody Test (>5%) was tested by two SAB methods, Immucor (IC) and One-lambda (OL), for class I and II anti-HLA antibody specificities and their ability to bind complement. The patients were either on a waiting list for kidney transplantation or transplanted patients tested routinely or after a clinical event. Statistical analysis of the results and comparison of the two methods followed. Results OL detected more class I positive specificities per patient [25 (9-34) vs. 18 (7-28) with IC, p < 0.001], while the two methods showed no difference in class II anti-HLA antibodies. IC detected 1608 out of 8148 and 1136 out of 7275 totally examined, positive anti-HLA class I and II antibody specificities respectively, with a median mean fluorescence intensity (MFI) of 4195 (1995-11272) and 6706 (2647-13184) respectively. Similarly, OL detected 1942/8148 and 1247/7275 positive specificities of anti-HLA class I and II antibodies respectively, with MFI 6185 (2855-12099) and 9498 (3630-17702)] respectively. In the IC method, 428/1608 [MFI 13900 (9540-17999)] and 409/1136 [MFI 11832 (7128-16531)] positive class I and II specificities, respectively, bound the C3d fraction of complement. Similarly, OL detected 485/1942 [MFI 15452 (9369-23095)] and 298/1247 [MFI 18852 (14415-24707)] class I and II specificities respectively that bound the C1q fraction of complement. In the analysis of the specificities that were positive by both methods, MFI showed a strong positive linear correlation between the two methods (r = 0.61, p < 0.001 and r = 0.54, p = 0.001 for classes I and II respectively). Accordingly, data were analyzed with Principal Components Analysis, in which negative results were also included. In the projection of the plane defined by the first two principal components the vector corresponding to the IC method for class I antibodies was congruent with the vectors of the complement binding detection methods, C3d and C1q. In contrast, the OL vector was nearly perpendicular to the other vectors, indicating the existence of non-complement-binding specificities that are not detected by IC. A similar picture was found for antibodies against HLA class II (Figure). Conclusion OL was more sensitive for detecting class I and II anti-HLA antibodies despite the fact that there was no difference in the number of class II specificities per patient. However, the additional specificities detected by OL, potentially do not bind complement. The MFI of the complement binding specificities were higher in both methods. The two methods were equivalent in detecting complement-binding class I specificities, however the C3d IC method was more sensitive in detecting complement-binding class II anti-HLA antibodies.

#1216 Comparable outcomes for old, older and very old deceased donors in old kidney transplant recipients

Abstract Background and Aims Old patients (≥ 65 years) make up almost 1/3 of the waiting list for kidney transplantation in the Netherlands, and this proportion continues to rise. These patients have a high waitlist mortality and benefit from early transplantation, even with kidneys from older or ‘marginal’ donors. Transplanting marginal donor kidneys may help to cut the proportion of elderly patients on the waiting list and improve clinical outcomes. More epidemiological support regarding the graft outcomes of old, older and very old donor kidneys is needed to support clinicians in accepting these kidneys. We therefore studied the outcomes of these kidneys in old recipients. Method Retrospective cohort study of all kidney transplant recipients ≥ 65 years with a deceased donor ≥ 65 years in the Netherlands between 2005 and 2022. Discarded kidneys from deceased donors ≥ 65 years in the same time period were included as well. Donors were categorized into old (65-69 years, OD), older (70-74, OD+) and very old (75+, OD++). Results We included 1301 transplantations from donors ≥ 65 years, of which 435 from an OD+ and 90 from an OD++. Median recipient age was 69 years (66 - 72), 67% was male. The transplanted OD+ and OD++ kidneys were more often from DBD donors (OD 42%, OD+ 51.3%, OD++ 70%, P < 0.01) with lower nadir creatinine compared to the OD kidneys (61.0 umol/l [51.0, 74.0] vs. OD+ 59.0 [49.0, 72.0] P = .034, vs OD++ 58.0 [49.0, 64.5] P = .021). Patient survival was similar for recipients of OD, OD+ and OD++ kidneys at one year (91% vs 89% vs 93%, respectively; Plog-rank = 0.3) and at five years (60% vs 60% vs 64%; Plog-rank = 0.2) after transplantation. Additionally, in multivariable Cox regression, donor age category was not associated with recipient mortality risk (Ref = OD. OD+: P = .7; OD++: P = .2). Death-censored graft survival was ≥92% in all groups after 1 year, and did not differ significantly between donor age categories (PGray's = 0.2). Results remained non-significant in multivariate Cox regression (Ref = OD, OD+: P = .942; OD++: p = 0.403). Kidneys offered but not accepted for transplantation (before procurement) had a higher serum nadir creatinine in comparison with transplanted kidneys (68 umol/L [56 - 84] vs 61 umol/L [51 - 78], P < .001), and were more often from DCD donors (79% vs 53%, P < .001). However, donor characteristics of many discarded kidneys resembled that of successfully transplanted kidneys. Conclusion Recipient and graft survival are good and similar for old patients receiving kidneys from old, older and very old deceased donors. These findings may contribute to a wider acceptance of kidneys from these donors.

WCN24-1301 Social factors and entry to the waiting list for kidney transplantation

WCN24-1301 Social factors and entry to the waiting list for kidney transplantation

Kidney Transplantation During COVID-19 Outbreak: Data From Public and Non-Public Dialysis Network

COVID-19 pandemic highly influenced on medical services in Poland. All restrictions, and additional procedures as well as numerous infections among medical staff highly affected transplantation in the country.Authors analyzed reports prepared by Polish Transplant Coordination Center Poltransplant and internal Fresenius Nephrocare Poland reports to assess difference in number of patients qualified for kidney transplantation and transplanted in pandemic period in comparison in pre-pandemic year.During SARS-CoV-2 outbreak number of qualified and transplanted patients was significantly lower comparing with pre-pandemic period. The most worsened data concerns the new qualifications which was significantly lower in the first year of pandemic as the effect of all restrictions implemented.The number of Kidney Tx procedures provided during 2-years pandemic period decreased significantly (-20.8%) in 2020 and in the second year the negative trend has been continued (-0.8%).Situation of private dialysis provider concerning number of active patients on waiting list for kidney transplantation was a bit better – decreased from 265 to 239 in 2020 (-9.8%) and increased to 259 in 2021 (+8.4%).The decline in the number of patients treated in Fresenius Nephrocare dialysis centers transplanted was deeper and felt down 27.8% in 2020 in comparison with 2019. In 2021 number of transplanted patients slightly increase about 2.5%.Results – decreased number of qualified and transplanted patients during SARS-CoV-2 outbreak clearly show the need of undertake multidisciplinary discussion among all stakeholders to create new procedures and processes which will help to protect the healthcare system and patients in case of future crisis situation.

Iron Management and Anemia in Patients on the Active Kidney Transplant List

IntroductionIron metabolism disorders and anemia are one of the main complications of end-stage renal disease that may affect the evaluation process for kidney transplantation. The study aimed to assess the iron metabolism in hemodialysis patients in relation to waiting list status. Study MethodThe study included 5068 hemodialysis patients, including those on the active waiting list (N = 449) and those who were not eligible for the waitlist (N = 4619). Demographic and biochemical data, Charlson's comorbidity index, duration of hemodialysis therapy and, respectively, hemoglobin, ferritin, and transferrin saturation levels were compared in both groups of patients. ResultsPatients on the active waiting list were significantly younger −53.2 vs 67.2 years (P < .001), with a lower Charlson comorbidity index score: 3.33 vs 4.42 (P < .001). The duration of hemodialysis therapy was similar: 66.0 vs 63.2 months (P = .416), the incidence of anemia according to World Health Organization (90.6%, vs 91.2%) and KDIGO (72.4% vs 70.4%). The degree of anemia correction in terms of hemoglobin concentration and transferrin saturation was comparable in both groups and amounted to an average of 10.9 g/dL (P = .349) for hemoglobin concentration and 32.7% vs 33.4% (P = .513) for transferrin saturation. However, there was a statistically significant difference in ferritin concentration: 554 ug/L vs 733 ug/L (P = .001). ConclusionsPatients on the active list have significantly lower ferritin levels despite similar duration of hemodialysis treatment and comparable hemoglobin values. This may be due to lower inflammation, and less frequent blood transfusions, and lead to a lower risk of immunization and an increased chance of potential kidney transplantation.

Waiting time for kidney transplantation based on calculated panel reactive antibodies: experience of a southern Brazilian center.

The aim of this study was to analyze the waiting list for kidney transplantation in our hospital according to candidate's panel reactive antibodies (cPRA) and its outcomes. One thousand six hundred forty patients who were on the waiting list between 2015 and 2019 were included. For the analysis, hazard ratios (HR) for transplant were estimated by Fine and Gray's regression model according to panel reactivity and HR for graft loss and death after transplantation. The mean age was 45.39 ± 18.22 years. Male gender was predominant (61.2%), but the proportion decreased linearly with the increase in cPRA (p < 0.001). The distribution of patients according to panels were: 0% (n = 390), 1% - 49% (n = 517), 50% - 84% (n = 269), and ≥ 85% (n = 226). Transplantation was achieved in 85.5% of the sample within a median time of 8 months (CI 95%: 6.9 - 9.1). The estimated HRs for transplantation during the follow-up were 2.84 (95% CI: 2.51 - 3.34), 2.41(95%CI: 2.07 - 2.80), and 2.45(95%CI: 2.08 - 2.90) in the cPRA range of 0%, 1%-49%, and 50%-84%, respectively, compared to cPRA ≥ 85 (p < 0.001). After transplantation, the HR for graft loss was similar in the different cPRA groups, but the HR for death (0.46 95% CI 0.24-0.89 p = 0.022) was lower in the 0% cPRA group when adjusted for age, gender, and presence of donor specific antibodies (DSA). Patients with cPRA below 85% are more than twice as likely to receive a kidney transplantation with a shorter waiting time. The risk of graft loss after transplantation was similar in the different cPRA groups, and the adjusted risk of death was lower in nonsensitized recipients.

Survival of patients with kidney failure awaiting transplantation stratified by age and ethnicity: population-based cohort analysis.

Kidney transplantation is the treatment of choice for people living with kidney failure who are suitable for surgery, but survival benefits for older and/or ethnic minority candidates are unclear. To inform decision-making, the survival of patients on a waiting list for kidney transplantation was assessed. A retrospective study was undertaken of registry data for patients with kidney failure listed for transplantation in the UK. From 1 January 2000 until 30 September 2019, all patients listed for a first kidney-alone transplant were included. The primary outcome was all-cause mortality. After testing for violations of the proportional hazards assumption, an extended Cox regression model factoring in transplantation as a time-dependent variable according to the intention-to-treat principle was developed. The study cohort included 47 917 patients on a waiting list for kidney transplantation, of whom 34 558 (72.1%) subsequently received a transplant. Transplantation compared with remaining on dialysis was associated with an overall survival benefit (HR 0.17, 95% c.i. 0.16 to 0.18; P < 0.001), occurring immediately within 30 days, and observed regardless of ethnicity. For White kidney transplant candidates aged at least 65 or at least 70 years, a significant survival benefit was observed within 6 months (HR 0.49, 0.29 to 0.82) and 1 year (HR 0.45, 0.25 to 0.79) after transplantation respectively, which contrasted with 3 years after kidney transplantation for candidates from ethnic minorities aged at least 65 years (HR 0.53, 0.36 to 0.78) or at least 70 years (HR 0.53, 0.36 to 0.78). Although time-to-survival benefits are stratified by age and ethnicity, all kidney transplant candidates on the waiting list are better off with transplantation compared with remaining on dialysis. The absence of any early postoperative mortality suggests that some high-risk patients with kidney failure may not be receiving transplantation opportunities.

Spatial analysis of care for patients undergoing dialysis therapy in the state of Minas Gerais, Brazil, between 2015 and 2019.

To analyze the spatial flow of care for patients undergoing dialysis therapy in the health regions of the State of Minas Gerais. Ecological study whose population was patients undergoing dialysis therapy in public, philanthropic institutions or whose treatment was paid for by the Unified Health System in private clinics in partnership, in the State of Minas Gerais. Patients were grouped by health region of residence. The proportions of patients who underwent dialysis were calculated, as well as enrollment on the kidney transplant list in their own region of residence or outside it. Person correlations of these proportions with socioeconomic and care indicators of the health regions were estimated. Spatial exploratory techniques estimated general (Moran's I) and local (LISA) spatial correlation coefficients. Regions with higher GDP had a higher number of nephrologists and a higher proportion of registrations in the region of residence. A cluster of regions with low GDP was identified further to the northeast of the State (also with lower nephrologist ratio values), a cluster with a high proportion of those registered on the transplant list in the center of the State, and a cluster with a low proportion of dialysis in the same region of residence further southeast. Regional disparities were evident in relation to the proportion of patients registered on the waiting list for kidney transplantation, the proportion of patients undergoing dialysis in the same region of residence and the proportion of patients registered on the waiting list for kidney transplantation in the same region of residence. residence.

Differences in the epidemiology, management and outcomes of kidney disease in men and women.

Improved understanding of differences in kidney disease epidemiology, management and outcomes in men and women could help nephrologists to better meet the needs of their patients from a sex- and gender-specific perspective. Evidence of sex differences in the risk and outcomes of acute kidney injury is mixed and dependent on aetiology. Women have a higher prevalence of chronic kidney disease (CKD) stages 3-5 than men, whereas men have a higher prevalence of albuminuria and hence CKD stages 1-2. Men show a faster decline in kidney function, progress more frequently to kidney failure and have higher mortality and risk of cardiovascular disease than women. However, the protective effect of female sex is reduced with CKD progression. Women are less likely than men to be aware of, screened for and diagnosed with CKD, started on antiproteinuric medication and referred to nephrologist care. They also consistently report a poorer health-related quality of life and a higher symptom burden than men. Women experience greater barriers than men to access the waiting list for kidney transplantation, particularly with respect to older age and obesity. However, women also have longer survival than men after transplantation, which may partly explain the comparable prevalence of transplantation between the sexes.

Cardiovascular risk trajectory and its associated factors among candidates on the waiting list for deceased-donor kidney transplantation: a longitudinal study

Cardiovascular risk trajectory and its associated factors among candidates on the waiting list for deceased-donor kidney transplantation: a longitudinal study

Chronological Changes in Emotional Status and Vaccine Implementation Rate Among Patients on the Waiting List for Deceased-Donor Kidney Transplantation During the Prolonged COVID-19 Pandemic

To investigate the emotional attributes and vaccine implementation rate of patients waiting for kidney transplants during the prolonged COVID-19 pandemic. We included 145 patients who were on the waiting list at our institution. Clinical information was obtained from medical charts, and emotional changes were assessed using a telephone questionnaire comprising 13 questions, including vaccine implementation. We also investigated factors affecting the decision to accept or decline deceased-donor kidney transplantation during the COVID-19 pandemic. Of the 145 patients, 121 (83.4%) provided informed consent and completed the questionnaire. The median age at registration on the waiting list for deceased-donor kidney transplantation and the median waiting period was 45.5 years and 103 months, respectively. This cohort comprised 84 males and 37 females. Twenty patients (16.5%) were diagnosed with COVID-19, and 15 (12.4%) were more curious about deceased-donor kidney transplantation. One hundred patients (82.6%) were vaccinated against COVID-19 more than thrice. Thirty patients (24.8%) declined, and 91 patients (75.2%) accepted an organ transplant offer during the COVID-19 pandemic. Multivariate analysis revealed that the long-term waiting period (P=.038) and anxiety about COVID-19, such as visiting the transplant facility (P < .0001) and prudence over time (P < .0001), were independent factors influencing the decline of a kidney transplant offer. Our findings suggest that some patients hesitated to undergo deceased-donor kidney transplantation during the pandemic. There is a need to develop an appropriate system to ensure safe and secure kidney transplantation during prolonged pandemics.

Cardiovascular risk trajectory and its associated factors among candidates on the waiting list for deceased-donor kidney transplantation: A longitudinal study

BackgroundCardiovascular disease is a significant cause of morbidity and mortality for wait-listed kidney transplant candidates. Since cardiovascular risk is related to a variety of factors and may change with time, longitudinal changes in cardiovascular risk and related factors in candidates need to be investigated. ObjectivesThis study aimed to examine the trajectory of the cardiovascular risk score and its related factors in patients on the waiting list for deceased-donor kidney transplantation (DDKT). MethodsThis longitudinal study enrolled 144 patients who were registered as candidates for a DDKT at a transplant center in South Korea. During the 5-year follow-up period, 3 candidates on the waiting list were transferred to other hospitals, 19 candidates died, and 31 candidates received kidney transplantation. ResultsApproximately 26.6 % of the candidates had a high level of cardiovascular risk, and this increased to 53.2 % after 5 years. A high risk of psychosocial status (β=0.351, p=.026) was the most significant predictor of cardiovascular risk, followed by higher comorbidity (β=0.263, p<.001). Comorbidities were a significant factor associated with cardiovascular risk throughout the 5-year period, whereas the duration of dialysis and waiting time were significant only within 1 year after baseline. ConclusionCardiovascular risk during 5 years on the waiting list for DDKT was associated with multidimensional factors, including psychosocial status before transplantation, comorbidity, waiting time for transplantation, and the duration of dialysis. In addition to managing comorbid conditions, shortening the waiting time and duration of dialysis is important for reducing cardiovascular risk during the long-term care of candidates on the waiting list for DDKT.

Renal transplant: gender differences

Renal transplantation represents the best treatment for end-stage kidney disease, leading to improved quality of life and life-expectancy for most of the patients. However, gender disparities are evident both in access and in outcomes of kidney transplantation. Women on dialysis are less likely to be on the waiting list for kidney transplantation and to receive an organ from a deceased donor or living donor. Several biological and sociocultural aspects could explain this disparity. On the contrary, more women than men are living kidney donors. Italian women are the first organ donors for living transplants in Europe. The gender difference in living donation is certainly affected by different comorbidities, but such a marked trend highlights a greater predisposition to donate of women, especially in the family context. Some differences are also found in kidney outcomes, even not fully understood. Our paper analyzes the main differences in different aspects of kidney transplantation related to gender, including nutritional aspects.

Age Disparities in Access to First and Repeat Kidney Transplantation.

Evidence suggests that older patients are less frequently placed on the waiting list for kidney transplantation (KT) than their younger counterparts. The trends and magnitude of this age disparity in access to first KT and repeat KT (re-KT) remain unclear. Using the US Renal Data System, we identified 2 496 743 adult transplant-naive dialysis patients and 110 338 adult recipients with graft failure between 1995 and 2018. We characterized the secular trends of age disparities and used Cox proportional hazard models to compare the chances of listing and receiving first KT versus re-KT by age (18-64 y versus ≥65 y). Older transplant-naive dialysis patients were less likely to be listed (adjusted hazard ratio [aHR] = 0.18; 95% confidence interval [CI], 0.17-0.18) and receive first KT (aHR = 0.88; 95% CI, 0.87-0.89) compared with their younger counterparts. Additionally, older patients with graft failure had a lower chance of being listed (aHR = 0.40; 95% CI, 0.38-0.41) and receiving re-KT (aHR = 0.76; 95% CI, 0.72-0.81). The magnitude of the age disparity in being listed for first KT was greater than that for re-KT ( Pinteraction < 0.001), and there were no differences in the age disparities in receiving first KT or re-KT ( Pinteraction = 0.13). Between 1995 and 2018, the age disparity in listing for first KT reduced significantly ( P < 0.001), but the age disparities in re-KT remained the same ( P = 0.16). Age disparities exist in access to both first KT and re-KT; however, some of this disparity is attenuated among older adults with graft failure. As the proportion of older patients with graft failure rises, a better understanding of factors that preclude their candidacy and identification of appropriate older patients are needed.

Managing uncertainty in multidisciplinary renal team meetings: decision-making processes and complex challenges in kidney transplant listing

Multidisciplinary team (MDT) meetings are common to many fields of medicine and widely established internationally. They are intended to ensure higher-quality decision-making and improved patient outcomes. For patients with end-stage kidney disease (ESKD), decisions on whether to place marginally suitable candidates on the kidney transplantation waiting list can be challenging and as such they are supported by MDT meetings. Uncertainty in terms of the best course of action can be linked with a dearth of knowledge or evidence on specific medical conditions and likely implications for successful transplantation, but also on unforeseen outcomes influenced by patient behaviours. In this project, we observed how MDT meetings work in practice in kidney transplant listing, unpacking issues of risk and uncertainty in transplant decision-making processes. Our findings indicate that a central value of MDT meetings is managing medical uncertainty and psychosocial risks, and distributing responsibility for complex transplant listing decisions to ensure equity of access to transplantation as well as an efficient use of scarce kidneys. This sheds light on strategies enacted to mitigate these risks and uncertainties, and the role played by different types of knowledge (experiential versus scientifically evidence-based) in the overall decision-making process.

The Association of Dialysis Facility Payer Mix With Access to Kidney Transplantation

Insurance coverage for patients with end-stage kidney disease has shifted toward more commercially insured patients at dialysis facilities. The associations among insurance status, facility-level payer mix, and access to kidney transplantation are unclear. To determine the association of dialysis facility commercial payer mix and 1-year incidence of wait-listing for kidney transplantation, and to delineate the association of commercial insurance at the patient vs facility level. This retrospective population-based cohort study used data from the United States Renal Data System from 2013 to 2018. Participants included patients aged 18 to 75 years initiating chronic dialysis between 2013 and 2017, excluding patients with a prior kidney transplant or with major contraindications to kidney transplant. Data were analyzed from August 2021 and May 2023. Dialysis facility commercial payer mix, calculated as the proportion of patients with commercial insurance per facility. The primary outcome was patients added to a waiting list for kidney transplant within 1 year of dialysis initiation. Multivariable Cox regression, censoring for death, was used to adjust for patient-level (demographic, socioeconomic, and medical) and facility-level factors. A total of 233 003 patients (97 617 [41.9%] female patients; mean [SD] age, 58.0 [12.1] years) across 6565 facilities met inclusion criteria. Participants included 70 062 Black patients (30.1%), 42 820 Hispanic patients (18.4%), 105 368 White patients (45.2%), and 14 753 patients (6.3%) who identified as another race or ethnicity (eg, American Indian or Alaskan Native, Asian, Native Hawaiian or Pacific Islander, and multiracial). Of 6565 dialysis facilities, the mean (SD) commercial payer mix was 21.2% (15.6 percentage points). Patient-level commercial insurance was associated with increased incidence of wait-listing (adjusted hazard ratio [aHR], 1.86; 95% CI, 1.80-1.93; P < .001). At the facility-level and before covariate adjustment, higher commercial payer mix was associated with increased wait-listing (fourth vs first payer mix quartile [Q]: HR, 1.79; 95% CI, 1.67-1.91; P < .001). However, after covariate-adjustment, including adjusting for patient-level insurance status, commercial payer mix was not significantly associated with outcome (Q4 vs Q1: aHR, 1.02; 95% CI, 0.95-1.09; P = .60). In this national cohort study of patients newly initiated on chronic dialysis, although patient-level commercial insurance was associated with higher access to the kidney transplant waiting lists, there was no independent association of facility-level commercial payer mix with patients being added to waiting lists for transplant. As the landscape of insurance coverage for dialysis evolves, the potential downstream impact on access to kidney transplant should be monitored.

#5940 CLINICAL UTILITY OF GENETIC TESTING IN A KIDNEY TRANSPLANT CLINIC

Abstract Background and Aims Inherited kidney disease (IKD) is one of the leading causes of end-stage of kidney disease. Genetic diagnosis plays an important role in the counseling and management of kidney transplant patients or those on the waiting list, as it makes it possible to identify the cause of CKD, help in the selection of living donors, carry out genetic counseling and find out the prognosis around the graft survival and the risk of recurrence of the primary disease. The objective of the following study is to analyze the prevalence of IKD in our kidney transplant population and those on the waiting list, the phenotypic characteristics, genetic findings, and the diagnostic reclassification performed after the genetic study. Method This retrospective study has incluyed all genetic test (by next-generation sequencing (NGS) until 529 genes associated with kidney disease) performance between January 2018 and January 2023 in kidney transplant patients or on the waiting list for kidney transplant at Doctor Peset Hospital, using a multidisciplinary team approach. The patients were considered for genomic evaluation if they met one of the inclusion criteria: CKD of unknown etiology, family history of CKD, glomerular disease or chronic tubulo–interstitial disease with no recognized cause, suspicion of aHUS, CKD and other extrarenal syndromic signs or with renal malformations or nephrocalcinosis. Demographic data, family burden and screening, CKD phenotype, urinary anormalities, hypertension, diabetes, results of genetic test, were analyzed. Results We performed genetic testing in 76 patients (43,4% women; 88% Caucasian). Median age at time of kidney failure was 37 years (range: 17–77), 62% of patients had a positive family history of CKD and 29% presented extrarenal manifestations. The majority were male patients (56.6%) and Caucasian patients (88.2%). Most patients presented with an original clinical diagnosis glomerular disease 52,6% (FSGS lesion on biopsy (8/27) and non-diagnostic histology (10/27)), followed by ciliopathy (13%), aHUS (10.5%), and chronic kidney disease of unknown cause (6.6%), tubulointerstitial nephritis (6.6%), and with congenital anomalies (6.6%). In 46 patients had a genetic diagnosis defined as finding a pathogenic or likely pathogenic gene variant that explained the patient's kidney disease. With majority being COL4 variants (26.3%), followed by autosomal dominant polycystic kidney disease (ADPKD) (10.5%), podocytopathy and autosomal dominant tubulointerstitial kidney diseases. There were confirmed within a clinical diagnostic in 28% (above all ADPKD) and resulted in reclassification of the clinical diagnosis in 33% (above all COL4-related nephropathy) and there are more frequently a negative result if clinical diagnosis was unknown etiology, congenital anomalies o aHUS until 60%. With this data, 78% of the patients could have avoided a biopsy and 50% a immunossuppresive treatment with the diagnosis by genetic test. A genetic cause was identified by family screening in 16 families comprising 19 patients. A genetic diagnosis were more likely to have a family history of kidney disease (47,4% versus 14,5%, P &amp;lt; 0.001). There was otherwise no statistically significant difference in any other clinical characteristic (age at onset of kidney disease, age at kidney failure, race, hypertension, diabetes, hematuria, renal cyst or stone). Conclusion Our study demonstrates the clinical utility of genetic study in kidney transplants with unknown etiology or glomerulonephritis or chronic tubule-interstitial disease with no recognized cause or with positive family history of kidney disease, getting a genetic diagnosis until 60%, with a reclassification of the clinical diagnosis in a one-third. A genetic diagnosis is necessary to evaluate to kidney transplant recipients, to identify the etiology of CKD, to perform a genetic counseling and to improve patient management and prognosis.

#4691 LAPAROSCOPIC NEPHRECTOMY IN PATIENTS WITH AUTOSOMAL DOMINANT POLYCYSTIC KIDNEY DISEASE

Abstract Background and Aims At the present, discussions continue on the indications and timing of performing kidney nephrectomy in patients with autosomal dominant polycystic kidney (ADPK) disease who are on the waiting list for kidney transplantation. Large sizes of kidneys, traumatic access, accompanying these operations cause a high incidence of postoperative complications, mortality and aggravate the severity of patients. The aim of the presented study was to find the preferred algorithm for preparing patients for kidney transplantation. Method The results of the nephrectomy of polycystic kidneys were analyzed in 28 patients (mean age 49±1.5 years, 16 men, 12 women), which were conditionally divided into two groups. The first group included 13 patients (46.4%) with open surgery using median laparotomy and lumbotomy, in the second group - 15 (53.6%) - laparoscopic nephrectomy. Surgical interventions for patients in both groups receiving renal replacement therapy dialysis, performed according to emergency and planned indications. Results The average duration of laparoscopic and open surgical interventions was 149±14 and 132±15 min, respectively. The maximum size of deleted polycystic-altered kidneys in the first group was 21.3±4.21 cm, in the second group it was 20.5±3.3 cm. The incidence of postoperative complications in the 1st and 2nd groups was 6 cases (46.1%) and 2 cases (13.3%), respectively. There was one fatal outcome (7.69%) in the 1st group as a result of septic complications. the average postoperative bed-day in the first group was 12-13 (12.7 ± 1.1), in the second - 8-9 (8.6±0.5). Patients after laparoscopic interventions are activated on the 2nd-3rd day (2.8±0.14), after open operations - on the 4th-5th (4.43±0.32). Conclusion The incidence of postoperative complications after laparoscopic nephrectomy in patients with ADPK does not exceed 13.3%. The use of laparoscopic technologies makes it possible to expand the possibilities of using nephrectomy for the treatment and preparation of patients with polycystic kidney transplantation.

#5950 MAJOR HLA ALLELE AND HAPLOTYPE FREQUENCIES IN THE MALTESE KIDNEY TRANSPLANT REGISTRY

Abstract Background and Aims The human leukocyte antigens (HLA) are the most diverse and polymorphic genes in the human genome and matching them is of vital importance for maximising the survival of kidney transplants. The Maltese archipelago consists of three inhabited islands in the Mediterranean Sea, with a total population of just over half a million people. HLA polymorphisms in Malta have never been described. The aim of this study was to investigate allelic frequencies and determine the most common haplotypes for major HLA Class I and Class II groups in the Maltese kidney transplant registry. This will hopefully facilitate organ sharing with other European countries and improve the HLA matching for kidney transplant recipients. Method All patients of Maltese ethnicity on the national kidney transplant list between 2018 and 2022 were analysed retrospectively. HLA typing is routinely performed at medium to high resolution using polymerase chain reaction sequence specific oligonucleotide probes and Luminex technology at the HLA-A, HLA-B, HLA-C, HLA-DR, HLA-DQ and HLA-DP loci. Allele and haplotype frequencies were calculated by direct counting and simple percentages. Results A total of 191 patient samples were analysed yielding the following allele types: 16 HLA-A, 31 HLA-B, 17 HLA-C, 15 HLA-DRB1, 6 HLA-DP, 7 HLA-DQ, 5 HLA-DRB3, one HLA-DRB4 and one HLA DRB5. The most frequent allele groups for the HLA-A locus were HLA-A*02 (30.9%), HLA-A*24 (12.0%) and HLA-A*01 (11.8%) whilst for the HLA-B locus these were HLA-B*35 (16.2%), HLA-B*18 (11.5%) and HLA-B*51 (7.1%). The most prevalent allele groups for the HLA-DRB1 locus were HLA-DRB1*11 (24.1%), HLA-DRB1*04 (13.1%) and HLA-DRB1*07 (11.3%). The commonest allele group for each of HLA-C, HLA-DP and HLA-DR loci were HLA-C*07 (23.6%), HLA-DP4 (5.8%), HLA-DQ7 (31.2%) respectively. The five most frequently encountered haplotypes were HLA-A*02-B*13-DRB1*07 (2.1%), HLA-A*02-B*35-DRB1*04 (1.6%), HLA-A*02-B*18-DRB1*10 (1.3%), HLA-A*02-B*35-DRB1*11 (1.3%), HLA-A*24-B*35-DRB1*11 (1.3%). Conclusion This study provides the first data on the Major HLA allele and haplotype frequencies in Maltese kidney transplant candidates. Such data may be crucial in setting up international kidney exchange programmes.

#5815 INTERNATIONAL VARIATIONS IN TRANSITION OF CARE PRACTICES AND TWO-YEAR OUTCOMES IN ADVANCED CHRONIC KIDNEY DISEASE

Abstract Background and Aims The transition to kidney failure is the period of the highest risk for adverse outcomes in chronic kidney disease (CKD). A smooth and timely transition of care, assuring informed and patient-centric decision-making, is paramount to fostering better kidney care. We described the two-year incidence of clinical outcomes and nephrology practices among advanced CKD patients in CKDopps. Method CKDopps is a prospective cohort study designed to describe and evaluate variations in CKD practices and outcomes in nephrologist-led CKD clinics. For this analysis, we included CKDopps participants who reached a three-month average estimated glomerular filtration rate (eGFR) of less than 20 mL/min/1.73 m2 in the US, France, and Brazil. Time at risk for outcomes started at the end of the first three-month window in which the average eGFR was lower than 20 mL/min/1.73 m2 during study follow-up. Education was defined as participation in at least one educational session about KRT modalities. They were considered to have been referred to vascular access (VA) creation if reported in medical records. Education or VA referral happening before the start of follow-up were classified as occurring at baseline. Patients were considered waitlisted if they had been registered on a pre-emptive kidney transplant waiting list. Cumulative incidence functions adjusting for the competing risk of mortality or KRT were used to estimate the 2-year probability of clinical outcomes and planning events. Results 2,645 patients were included – 51% from France, 36% from the US, and 14% from Brazil. Overall, 56% of patients were male, the mean age was 66 ± 14 years, approximately 50% had diabetes, 27% had coronary artery disease, and 16% had heart failure. Patients in Brazil tended to be younger (63 years) than those in France (67) and the US (67); patients in the US had the greatest burden of cardiovascular comorbidities. The mean eGFR at the study baseline was 16.6 mL/min/1.73m² (15.4 in Brazil, 15.9 in the US, and 17.3 in France). Over a median follow-up of 15.7 [7.2–24] months, 1140 patients (43.1%) started KRT, whereas 377 (14.3%) died before KRT. The 2-year cumulative incidence of KRT was 32% in Brazil, 33% in France, and 44% in the US (Figure 1). The median eGFR at KRT initiation was 11.7 in Brazil, 9.0 in France, and 10.3 in the US. Pre-KRT death risk in two years was 7.3% in Brazil, 10.9% in France, and 16.4% in the US. In two years, approximately one-third of patients had a VA created across countries (Table 1). The probability of transplant waitlisting was higher in France and the US, while patient-reported KRT education was more common in Brazil (Table 1). Conclusion In this international analysis of advanced CKD patients, we found important variations in nephrology practice and outcomes across countries. Patients in the US have a higher risk of both pre-KRT death and KRT. Patient-reported education was far more common in Brazil than in the US and France. Although patients in Brazil are referred for VA creation earlier in the course of advanced CKD, 2-year cumulative incidences for such are similar across countries. The 2-year probability of pre-emptive kidney transplant listing was higher in France and the US. Further international studies evaluating risk factors for adverse outcomes and barriers to KRT planning among advanced CKD patients are warranted.