Complication Of Kidney Transplantation Research Articles

#1849 Returning to dialysis after kidney transplant failure: preliminary findings of a multi-centre database

Abstract Background and Aims Kidney transplant failure contributes to a considerable proportion of new dialysis starters. In some centres there are dedicated clinics for patients with failing kidney transplants, however, the specific needs of patients with dialysis after graft loss (DAGL) may be lost in the non-specific clinical review practiced in the general dialysis community. This study examines the mortality and morbidity risk in patients returning with DAGL and compares it to transplant-naïve (T-N) dialysis starters, to determine if the former warrant a more specialised approach. Method This is a retrospective observational study of mortality in all adult patients who started dialysis treatments in Fresenius Medical Care (North America, Latin America, Europe, Middle East, Africa, and Asia Pacific) from 1st January 2018 to 31st March 2021, were identified in the Apollo Dial DB dataset. DAGL was identified from the ICD-10 codes ‘Kidney transplant failure’, ‘Unspecified complication of kidney transplant’ and ‘Other complication of kidney transplant’ at dialysis start. The T-N control group had not previously received a kidney transplant and had not received immunosuppressive medication during the first six months of dialysis start. The first six months on dialysis were defined as baseline, months 7 to the end of year 5 were defined as the follow-up period. All-cause mortality was recorded during follow-up. Cox proportional hazards models were applied to explore the association between DAGL and all-cause mortality. Results A total of 360 469 dialysis starter patients from 41 countries were included in the analysis. 10 010 patients had DAGL and were compared with 350 459 in the T-N control group. In univariate analysis, DAGL patients were significantly younger in all age categories and had a higher proportion of male sex. Serum creatinine, ferritin, phosphate and neutrophil-to-lymphocyte ratio were higher in the DAGL group. Haemoglobin was lower in the DAGL group (Table 1). In the Cox proportional model adjusted for age, gender, and other laboratory and clinical markers, patients with DAGL had an equivalent survival probability compared with T-N dialysis starters (HR: 0.93, 95% CI: 0.86, 1.02) (Table 2). Conclusion DAGL patients appeared to have an increased mortality compared to T-N dialysis starters historically in the literature. Our large and recent study is in line with other recent publications suggesting a more equivalent survival in the two groups. Our results are compatible with younger patients receiving kidney transplantation early in their renal replacement therapy journey, thus constituting a significant proportion of DAGL patients. We posit that DAGL patients may start dialysis at a lower level of renal function, with higher levels of inflammation. Our analysis is preliminary and limited, not fully accounting for confounding factors. Future analysis of this large and well recorded dataset will allow us to examine these interesting associations and design a more specialised management approach to DAGL more closely.

#2586 Time to event prediction of new-onset diabetes after transplantation in kidney transplant recipients using machine learning models

Abstract Background and Aims New-onset diabetes after transplantation (NODAT) is a common and serious complication of kidney transplantation that contributes to long-term morbidity and mortality after the transplant procedure. Conventional methods may predict the risk of, but not time to developing NODAT. We aimed to develop a machine learning model that predicts the time to NODAT in kidney transplant recipients (KTR). Method Two large prospective cohort studies of stable KTR (inclusion >1 year after transplantation) from the University Medical Center Groningen were combined. Data collection took place between 2001 and 2003 for cohort A, and between 2008 and 2011 for cohort B, resulting in the inclusion of 750 KTR free of NODAT at baseline. To predict absolute time to NODAT, a bootstrap aggregating (bagging) approach was utilized which consisted of several extreme gradient boosting (XGBoost) models with the accelerated failure time (AFT) objective. The performance of the resulting bagging model was internally evaluated by assessing the concordance index (c-index) in 20% of the dataset not used for training. Results From the 750 KTR included, 76 (10.1%) developed NODAT during a median (interquartile range [IQR]) follow-up of 5.8 (4.7 to 9.2) years. The median (IQR) age was 51.2 (40.5 to 60.7) years and 342 (45.6%) of the KTR were female. During feature engineering, 18 features from 53 were selected. After hyperparameter tuning, model performance during internal validation was 0.84. Furthermore, SHapley Additive exPlanations (SHAP) values were used to estimate feature importance, which revealed that glucose, HbA1c, mean arterial pressure, cyclosporine concentrations and daily vegetable intake were the most important features. Conclusion The developed machine learning model shows good discriminative ability of time to NODAT prediction. Due to the methodology used, the model allows for flexible incremental learning, meaning that the bagging model can be retrained with additional data without compromising on performance.

Systematic Review and Meta-Analysis Provide no Guidance on Management of Asymptomatic Bacteriuria within the First Year after Kidney Transplantation.

(1) Background: Urinary tract infections (UTIs) are among the most frequent complications in kidney transplant (KT) recipients. Asymptomatic bacteriuria (ASB) may be a risk factor for UTIs and graft rejection. We aimed to evaluate available evidence regarding the benefit of screening and treatment of ASB within the first year after KT. (2) Evidence acquisition: A systematic literature search was conducted in MEDLINE, the Cochrane Library CENTRAL and Embase. Inclusion criteria were manuscripts in English addressing the management of ASB after KT. The PICO questions concerned Patients (adults receiving a KT), Intervention (screening, diagnosis and treatment of ASB), Control (screening and no antibiotic treatment) and Outcome (UTIs, sepsis, kidney failure and death). (3) Evidence synthesis: The systematic review identified 151 studies, and 16 full-text articles were evaluated. Seven were excluded because they did not evaluate the effect of treatment of ASB. There was no evidence for a higher incidence of lower UTIs, acute pyelonephritis, graft loss, or mortality in patients not treated with antibiotics for ASB. Analysis of comparative non-randomized and observational studies did not provide supplementary evidence to guide clinical recommendations. We believe this lack of evidence is due to confounding risk factors that are not being considered in the stratification of study patients.

Incidence, Risk Factors, and Outcomes of Posttransplant Erythrocytosis Among Simultaneous Pancreas-Kidney Transplant Recipients.

Posttransplant erythrocytosis (PTE) is a well-known complication of kidney transplantation. However, the risk and outcomes of PTE among simultaneous pancreas-kidney transplant (SPKT) recipients are poorly described. We analyzed all SPKT recipients at our center between 1998 and 2021. PTE was defined as at least 2 consecutive hematocrit levels of >51% within the first 2 y of transplant. Controls were selected at a ratio of 3:1 at the time of PTE occurrence using event density sampling. Risk factors for PTE and post-PTE graft survival were identified. Of 887 SPKT recipients, 108 (12%) developed PTE at a median of 273 d (interquartile range, 160-393) after transplantation. The incidence rate of PTE was 7.5 per 100 person-years. Multivariate analysis found pretransplant dialysis (hazard ratio [HR]: 3.15; 95% confidence interval [CI], 1.67-5.92; P < 0.001), non-White donor (HR: 2.14; 95% CI, 1.25-3.66; P = 0.01), female donor (HR: 1.50; 95% CI, 1.0-2.26; P = 0.05), and male recipient (HR: 2.33; 95% CI, 1.43-3.70; P = 0.001) to be associated with increased risk. The 108 cases of PTE were compared with 324 controls. PTE was not associated with subsequent pancreas graft failure (HR: 1.36; 95% CI, 0.51-3.68; P = 0.53) or kidney graft failure (HR: 1.16; 95% CI, 0.40-3.42; P = 0.78). PTE is a common complication among SPKT recipients, even in the modern era of immunosuppression. PTE among SPKT recipients was not associated with adverse graft outcomes, likely due to appropriate management.

Interleukin-2/anti-interleukin-2 immune complex attenuates cold ischemia-reperfusion injury after kidney transplantation by increasing renal regulatory T cells.

Cold ischemia-reperfusion injury (IRI) is an unavoidable complication of kidney transplantation. We investigated the role of regulatory T cells (Treg) in cold IRI and whether the interleukin (IL)-2/anti-IL-2 antibody complex (IL-2C) can ameliorate cold IRI. We developed a cold IRI mouse model using kidney transplantation and analyzed the IL-2C impact on cold IRI in acute, subacute and chronic phases. Treg transfer attenuated cold IRI, while Treg depletion aggravated cold IRI. Next, IL-2C administration prior to IRI mitigated acute renal function decline, renal tissue damage and apoptosis and inhibited infiltration of effector cells into kidneys and pro-inflammatory cytokine expression on day 1 after IRI. On day 7 after IRI, IL-2C promoted renal regeneration and reduced subacute renal damage. Furthermore, on day 28 following IRI, IL-2C inhibited chronic fibrosis. IL-2C decreased reactive oxygen species-mediated injury and improved antioxidant function. When IL-2C was administered following IRI, it also increased renal regeneration with Treg infiltration and suppressed renal fibrosis. In contrast, Treg depletion in the presence of IL-2C eliminated the positive effects of IL-2C on IRI. Tregs protect kidneys from cold IRI and IL-2C inhibited cold IRI by increasing the renal Tregs, suggesting a potential of IL-2C in treating cold IRI. Interleukin (IL)-2/anti-IL-2 antibody complex attenuated acute renal injury, facilitated subacute renal regeneration and suppressed chronic renal fibrosis after cold ischemia-reperfusion injury (IRI) by increasing the renal Tregs. IL-2/anti-IL-2 antibody complex decreased reactive oxygen species-mediated injury and improved antioxidant function. This study suggests the therapeutic potential of the IL-2/anti-IL-2 antibody complex in kidney transplantation-associated cold IR.

Clinical characteristics and risk factors for late-onset pneumocystis jirovecii pneumonia in kidney transplantation recipients.

Pneumocystis jirovecii pneumonia (PJP) is a common and troublesome complication of kidney transplantation. In the era of prophylaxis, the peak incidence of PJP after kidney transplantation and specific characteristics of late-onset PJP have always been debated. We performed a retrospective study by analysing the data of post-transplantation pneumonia in adult kidney transplantation recipients between March 2014 and December 2021 in The Affiliated First Hospital of University of Science and Technology of China (USTC). A total of 361 patients were included and divided into early-onset PJP, late-onset PJP and non-PJP groups. The characteristics of each group and related risk factors for the late-onset patients were investigated. Some patients developed PJP 9 months later with a second higher occurrence between month 10 and 15 after transplantation. Compared with non-PJP, ABO-incompatible and cytomegalovirus (CMV) viremia were significantly associated with late onset of PJP in multivariate analysis. The use of tacrolimus, CMV viremia, elevated CD8(+) T cell percent and hypoalbuminemia were risk factors for late PJP. Receiver operating characteristic curve analysis demonstrated that a combination of those factors could increase the sensitivity of prediction remarkably, with an area under the curve of 0.82, a sensitivity of 80% and a specificity of 83%. PJP could occur months after kidney transplantation. ABO-incompatible transplant recipients are at high risk of PJP. In the later stages of transplantation, CMV viremia, T lymphocyte subsets percentage and serum albumin levels should be monitored in patients using tacrolimus.

Early surgical complications in kidney transplant recipients- A single center study

End-stage renal disease (ESRD) is becoming a significant global public health issue. The preferred course of treatment for people with ESRD is kidney transplantation, although its associated surgical complications raise serious doubts about the success rate of the procedure. Renal transplant surgical complications are frequently observed and can significantly affect graft performance, survival, and patient morbidity. This study aimed to analyze the frequency of early surgical complications, diagnoses, and treatment options in renal transplant patients. This retrospective cohort study included all transplanted patients with surgical complications from April 2017 to April 2022 at the Renal Transplant Unit of the Dow University of Health Sciences, Karachi, Pakistan. Out of 500 kidney transplant recipients, 86 patients (17.2%) experienced early post-transplant surgical complications. The most common complication was Lymphorrea (n=38, 7.6%) followed by wound infection (n=25 patients, 5%). The occurrence of these complications was associated with delayed graft function, indicating the need for careful monitoring and timely intervention in these cases. Future studies are needed to explore the predictors and risk factors of surgical complications in kidney transplantation and to identify strategies for reducing the incidence and improving the outcomes of these complications.

Preliminary Evaluation of 2 Patient-Centered Educational Animations About Kidney Transplant Complications.

BACKGROUND Fear of kidney transplant complications and incomplete information can lower transplant acceptance and preparedness. Our group developed 2 patient-centered educational animated videos on common kidney transplant complications to complement a previously developed video-based curriculum intended to promote kidney transplant access. MATERIAL AND METHODS We preliminarily evaluated the 2 animated educational videos at a single center using mixed methods. We conducted a before-and-after single group study with 22 patients after kidney transplantation to measure the videos' acceptability and feasibility to improve patient knowledge, understanding, and concerns of kidney transplant complications. Concurrently, we individually interviewed 12 patients before kidney transplantation about their perceptions of the 2 videos and analyzed the data thematically. RESULTS Knowledge of kidney transplant complications increased 10% (7.82 to 8.59, P=0.002) from before to after video viewing. Large effect size increases for knowledge were found for different strata of age, race, and health literacy. The mean total score for perceived understanding of kidney transplant complications increased after video exposure by 7% (mean 2.48 to 2.66, P=0.184). There was no change in kidney transplant concern scores from before to after video viewing (mean 1.70 to 1.70, P=1.00). After video viewing, all patients reported positive ratings on comfort watching, understanding, and engaging. Three themes of patient perceptions emerged: (1) messages received as intended, (2) felt informed, and (3) scared but not deterred. CONCLUSIONS Two animated educational videos about kidney transplant complications were well received and promise to positively impact individuals' knowledge and understanding, without raising excessive concerns.

Autophagy: A Silent Protagonist in Kidney Transplantation

Autophagy is a lysosome-dependent regulated mechanism that recycles unnecessary cytoplasmic components. It is now known that autophagy dysfunction may have a pathogenic role in several human diseases and conditions, including kidney transplantation. Both defective and excessive autophagy may induce or aggravate several complications of kidney transplantation, such as ischemia–reperfusion injury, alloimmune response, and immunosuppressive treatment and side effects. Although it is still complicated to measure autophagy levels in clinical practice, more attention should be paid to the factors that may influence autophagy. In kidney transplantation, the association of low doses of a mammalian target of rapamycin inhibitor with low doses of a calcineurin inhibitor may be of benefit for autophagy modulation. However, further studies are needed to explore the role of other autophagy regulators.

Anti-Thymocyte Globulin vs. Alemtuzumab Induction and Associated Complications in Kidney Transplantation: A 20-Year Multi-Center Experience

Anti-Thymocyte Globulin vs. Alemtuzumab Induction and Associated Complications in Kidney Transplantation: A 20-Year Multi-Center Experience

What Do Donor-Specific Antibody Changes Mean in Kidney Transplant Patients?

Objective: The role of immunological evaluation is significant in selecting a suitable donor to reduce post-transplant complications in kidney transplantation (KTx). It is unknown how often donor-specific antibody (DSA) positivity causes rejection or how often rejection will develop in patients who do not develop DSA positivity. We aimed to evaluate the relationship between the DSA changes and the KTx patients' biochemical parameters.&#x0D; Methods: The study was a cross-sectional study evaluating 45 KTx patients. Demographic and clinical characteristics of the patients, pre-transplant DSA values, post-transplant DSA values, and biochemical parameters were retrospectively scanned from the hospital system. The patients' data were divided into three groups according to DSA changes.&#x0D; Results: DSA was negative in 21 (46%) patients and positive in 24 (54%) before transplantation. In the post-transplant follow-up, it was observed that the DSA value became positive in 7 patients and turned negative in 9 patients. Rejection developed in 22% of 9 patients whose DSA was positive before transplantation and turned negative after transplantation, and in 28% of 7 patients turned positive from negative. Estimated glomerular filtration rate (e-GFR) and creatinine levels in the post-transplant period were associated with the change in DSA. Also, e-GFR and neutrophil values were independently associated with rejection.&#x0D; Conclusions: Although DSA change affects kidney functions, we found that DSA positivity alone cannot predict rejection, and rejection may occur in the DSA-negative group. Neutrophil count and e-GFR changes were closely related to rejection. Therefore, DSA levels should be monitored regularly, but DSA change alone is insufficient for rejection evaluation.

TMA in Kidney Transplantation.

Thrombotic microangiopathy (TMA) is a rare and devastating complication of kidney transplantation, which often leads to graft failure. Posttransplant TMA (PT-TMA) may occur either de novo or as a recurrence of the disease. De novo TMA can be triggered by immunosuppressant drugs, antibody-mediated rejection, viral infections, and ischemia/reperfusion injury in patients with no evidence of the disease before transplantation. Recurrent TMA may occur in the kidney grafts of patients with a history of atypical hemolytic uremic syndrome (aHUS) in the native kidneys. Studies have shown that some patients with aHUS carry genetic abnormalities that affect genes that code for complement regulators (CFH, MCP, CFI) and components (C3 and CFB), whereas in 10% of patients (mostly children), anti-FH autoantibodies have been reported. The incidence of aHUS recurrence is determined by the underlying genetic or acquired complement abnormality. Although treatment of the causative agents is usually the first line of treatment for de novo PT-TMA, this approach might be insufficient. Plasma exchange typically resolves hematologic abnormalities but does not improve kidney function. Targeted complement inhibition is an effective treatment for recurrent TMA and may be effective in de novo PT-TMA as well, but it is necessary to establish which patients can benefit from different therapeutic options and when and how these can be applied.

Risk Factors and Causality of Early Graft Loss in Kidney Transplanted Patients in Northwestern Iran: A 10-Year Retrospective Study

Background: Early graft loss (EGL) is one of the rare complications of kidney transplantation. Several factors play a role in the occurrence of EGL in kidney transplant recipients, which must be identified and limited. Objectives: This ten-year retrospective study was conducted in a single center on 32 kidney transplant recipients with EGL to determine the reasons for and risk factors of kidney transplant rejection in Iran. Methods: This descriptive-analytical study’s population included 605 kidney transplant recipients receiving kidneys during the last ten years in our center. The diagnosis of EGL was based on renal allograft biopsy examination and primary clinical complications, including a rapid increase in serum creatinine. The age, gender, blood group, and rhesus (Rh) of both donors and recipients, as well as the kinship between the donor and recipient (relative and non-relative), right/left-sided living donor/recipient kidneys, primary kidney disease, the presence of underlying disease in the recipient, dialysis duration, the year of kidney transplantation, transplant survival time, patient survival time, and complications (surgery and others) were gathered. The data were analyzed using SPSS version 18. Results: In this study, 32 out of 605 kidney transplant recipients (5.28%) experienced EGL (53.1% male and 46.9% female, average age of 41.12 years). The duration of kidney function after transplantation was 5.56 ± 0.13 days. The transplanted kidneys were functional between 72 hours and one week after transplantation in 34.4% of the patients. The causes of EGL were found to be tissue rejection in 31.3% of the patients and vascular thrombosis and hyperacute rejection in 21.8%. Nephrectomy occurred in 41% of the patients, and 43.75% died because of a heart attack. Conclusions: Our findings supported previous studies' results, suggesting that EGL is associated with receiving an incompatible kidney transplant and surgery-related complications, including bleeding and thrombosis.

BK polyomavirus DNAemia in pancreas transplant recipients compared to pancreas-kidney recipients.

BK polyomavirus (BKV) infection is a common complication of kidney transplantation. While BKV has been described in non-kidney transplant recipients, data are limited regarding its epidemiology and outcomes in pancreas transplant recipients. We conducted a retrospective cohort study of adults who underwent pancreas transplantation from 2010-2020. The primary outcome was BKV DNAemia. Secondary outcomes were estimated glomerular filtration rate (eGFR) reduction by 30%, eGFR<30mL/min/1.73m2 , endstage kidney disease, and pancreas allograft failure. Cox regression with time-dependent variables was utilized. Four hundred and sixty-six patients were analyzed, including 74, 46, and 346 with pancreas transplant alone (PTA), pancreas-after-kidney, or simultaneous pancreas-kidney transplants, respectively. PTA recipients experienced a lower incidence of BKV DNAemia (8.8% vs. 32.9%; p<.001) and shorter duration of DNAemia (median 28.0 vs. 84.5 days). No PTA recipients with BKV DNAemia underwent kidney biopsy or developed endstage kidney disease. Lymphopenia, non-PTA transplantation, and older age were associated with BKV DNAemia, which itself was associated with pancreas allograft failure (adjusted hazard ratio 2.14, 95% confidence interval 1.27-3.60; p=.004). Among PTA recipients, BKV DNAemia was not associated with eGFR reduction or eGFR<30mL/min/1.73m2 . BKV DNAemia was common among PTA recipients, though lower than a comparable group of pancreas-kidney recipients. However, BKV DNAemia was not associated with adverse native kidney outcomes and no PTA recipients developed endstage kidney disease. Conversely, BKV DNAemia was associated with pancreas allograft failure. Further studies are needed to estimate the rate of BKV nephropathy in this population, and further evaluate long-term kidney outcomes.

Post-COVID-19 complications in kidney transplant recipients

Background. Although most people recover from acute COVID-19 within a few weeks, some have long-lasting clinical problems. The prevalence of these prolonged complications in kidney transplant (KT) recipients has not been determined.&#x0D; Materials and methods. Six months following of 148 patients with post-COVID-19 syndrome admitted to three centers in Iran (Tehran, Shiraz and Babol) that underwent KT were included in this study. Also, one-hundred COVID-19 patients without KT were included as the control group. The demographic data, medications, and disease course were recorded. The baseline and demographic characteristics were analyzed using the Chi-square test. Moreover, students t-test were utilized to compare case and control groups.&#x0D; Results. The total number of patients was 248, of which 148 were in the case groups. Hospitalization associated with COVID-19 was for all patients; besides, there were 18 patients in control and 24 case groups admitted to an intensive care unit (ICU). The most commonly reported symptom was fever. Multivariate analysis identified the history of chronic kidney disease, hypertension, cerebral vascular accident, and diabetes mellites as predictors for developing post-COVID clinical complications.&#x0D; Conclusion. Evidence shows the high commonness of post-COVID-19 syndrome among kidney transplant patients after COVID-19, and the most common symptoms were fever, chills, and myalgia. So, all patients recovered from acute COVID-19 should undergo long-term monitoring to evaluate and treat possible complications.

Contemporary and Emerging MRI Strategies for Assessing Kidney Allograft Complications: Arterial Stenosis and Parenchymal Injury, From the AJR Special Series on Imaging of Fibrosis.

MRI plays an important role in the evaluation of kidney allografts for vascular complications as well as parenchymal insults. Transplant renal artery stenosis, the most common vascular complication of kidney transplant, can be evaluated by MRA using gadolinium and nongadolinium contrast agents as well as by unenhanced MRA techniques. Parenchymal injury occurs through a variety of pathways, including graft rejection, acute tubular injury, BK polyomavirus infection, drug-induced interstitial nephritis, and pyelonephritis. Investigational MRI techniques have sought to differentiate among these causes of dysfunction as well as to assess the degree of interstitial fibrosis or tubular atrophy (IFTA)-the common end pathway for all of these processes-which is currently evaluated by invasively obtained core biopsies. Some of these MRI sequences have shown promise in not only assessing the cause of parenchymal injury but also assessing IFTA noninvasively. This review describes current clinically used MRI techniques and previews promising investigational MRI techniques for assessing complications of kidney grafts.

The Impact and Effectiveness of Weight Loss on Kidney Transplant Outcomes: A Narrative Review.

Obesity is a worldwide epidemic that leads to several non-communicable illnesses, including chronic kidney disease (CKD). Diet and lifestyle modifications have shown a limited impact in the treatment of obesity. Because the group of end-stage renal disease (ESRD) patients examined in this study had limited access to kidney transplantation (KT), patients with obesity were thought to be at an increased risk of intraoperative and postoperative KT complications. Although bariatric surgery (BS) is now recognized as the gold standard treatment for morbid obesity, its role in ESRD or kidney transplant patients remains unknown. It is critical to know the correlation between weight loss and complications before and after KT, the impact of the overall graft, and patients' survival. Hence, this narrative review aims to present updated reports addressing when to perform surgery (before or after a KT), which surgical procedure to perform, and again, if strategies to avoid weight regain must be specific for these patients. It also analyzes the metabolic alterations produced by BS and studies its cost-effectiveness pre- and post-transplantation. Due to the better outcomes found in KT recipients, the authors consider it more convenient to perform BS before KT. However, more multicenter trials are required to provide a solid foundation for these recommendations in ERSD patients with obesity.

Evaluation of NAG, NGAL, and KIM-1 as Prognostic Markers of the Initial Evolution of Kidney Transplantation.

Kidney transplantation is the best option for end-stage chronic kidney disease. Transplant viability is conditioned by drugs' nephrotoxicity, ischemia-reperfusion damage, or acute rejection. An approach to improve graft survival is the identification of post-transplant renal function prognostic biomarkers. Our objective was to study three early kidney damage biomarkers (N-acetyl-d-glucosaminidase, NAG; neutrophil gelatinase-associated lipocalin, NGAL; and kidney injury molecule-1, KIM-1) in the initial period after transplantation and to identify possible correlations with main complications. We analysed those biomarkers in urine samples from 70 kidney transplant patients. Samples were taken on days 1, 3, 5, and 7 after intervention, as well as on the day that renal function stabilised (based on serum creatinine). During the first week after transplant, renal function improved based on serum creatinine evolution. However, increasing levels of biomarkers at different times during that first week could indicate tubular damage or other renal pathology. A relationship was found between NGAL values in the first week after transplantation and delayed graft function. In addition, higher NAG and NGAL, and lower KIM-1 values predicted a longer renal function stabilisation time. Therefore, urinary NAG, NGAL, and KIM-1 could constitute a predictive tool for kidney transplant complications, contributing to improve graft survival rates.

Evaluation of technical urinary tract complications in kidney transplantation recipients with a prolonged dialysis history

BackgroundThe kidney transplant waiting list continues to expand, resulting in prolonged dialysis times exceeding 8 years before transplantation in some regions. The relationship between long-term dialysis and urinary tract complications after kidney transplant remains largely unexplored. This study aims to evaluate post–kidney transplant complications in patients with a history of prolonged dialysis. MethodsA single-center, retrospective cohort study of patients maintained on dialysis ≥8 years before kidney transplant between January 2000 and July 2020 was conducted. Clinical variables, including demographics and comorbidities, were reviewed. The primary objective was the development of a technical urinary tract complication. Secondary outcomes included any postoperative complication by type, stratified by medical and surgical complications. ResultsOverall, 376 patients met the inclusion criteria. The mean pre–kidney transplant dialysis time was 10.2 ± 2.6 years. The majority (65.7%) of the study participants were anuric. Four patients (1.1%) experienced a urine leak, and 8 patients (2.1%) had a ureteral stricture. Any complication was observed in 111 (29.5%) patients, with urinary tract infections being the most common. Urinary catheters remained in place for a median of 4 (3, 5) days. Drains were commonly used (62.8%) for a median of 5 (4, 6) days. ConclusionIn our large, single-center experience with kidney transplants in high-risk patients with prolonged dialysis and anuria, the technical urinary tract complications rate remained low. With the current literature consisting of small cohorts and having relatively short pre–kidney transplant dialysis periods, our analysis addresses the shortcomings of the literature while suggesting that this patient population may not truly be “high risk.”

Characteristics and management of thrombotic microangiopathy in kidney transplantation.

Thrombotic microangiopathy is not a rare complication of kidney transplantation and is characterized by microangiopathic hemolytic anemia, thrombocytopenia, and acute kidney injury with extensive thrombosis of the arterioles and capillaries. Various factors can cause thrombotic microangiopathy after kidney transplantation, including surgery, warm and cold ischemia-reperfusion injury, exposure to immunosuppressants, infection, and rejection. Many recent studies on atypical hemolytic uremic syndrome have described genetic abnormalities related to excessive activation of the alternative complement pathway. The affected patients' genetic backgrounds revealed significant genetic heterogeneity in several genes involved in complement regulation, including the complement factor H, complement factor H-related proteins, complement factor I, complement factor B, complement component 3, and CD46 genes in the alternative complement pathway. Although clinical studies have provided a better understanding of the pathogenesis of diseases, the diverse triggers present in the transplant environment can lead to thrombotic microangiopathy, along with various genetic predispositions, and it is difficult to identify the genetic background in various clinical conditions. Given the poor prognosis of posttransplant thrombotic microangiopathy, further research is necessary to improve the diagnosis and treatment protocols based on risk factors or genetic predisposition, and to develop new therapeutic agents.