BACKGROUND: The process of kidney transplantation remains the optimal treatment for end-stage renal disease, offering improved quality of life and increased survival rates compared to long-term dialysis. However, despite advances in surgical techniques, immunosuppression regimens, and post-operative care, there are still significant challenges in predicting the organ's status and long-term outcomes of transplantation. Among the many factors that influence graft survival, the quality of the donated organ plays a fundamental role. There is an ongoing need for accurate and reliable biomarkers. Syndecan-1 is found in the endothelial glycocalyx and shed at a higher rate into the blood during systemic pathological conditions. The aim of this study is to evaluate the potential of serum syndecan-1 levels as a biomarker for assessing donor kidney quality and to investigate its correlation with donor characteristics and short-term outcomes in kidney recipients. MATERIAL AND METHODS: We investigated serum syndecan-1 levels in 80 deceased donors and correlated them with donor characteristics and short-term outcomes (defined as delayed graft function - defined as the need for dialysis within the first week post-transplantation and renal function at 3 months post-transplantation - assessed using serum creatinine levels) in 104 corresponding kidney recipients. This single-center retrospective observational cohort study was conducted from April to December 2021. RESULTS: The donor pool consisted of 65% males with a median age of 53 years. Of these, 45 donors (56%) were classified as extended criteria donors. Higher syndecan-1 levels correlated with the last creatinine levels before organ procurement (R = 0.32, p = 0.01) and were marginally higher in donors with acute kidney injury (p = 0.07). However, syndecan-1 levels were not associated with short-term outcomes in kidney recipients (renal function at 3 months). CONCLUSIONS: The data suggests syndecan-1 could be a potential biomarker for assessing donor kidney quality, although its implications on recipient outcomes require further study. This pilot investigation underscores the importance of syndecan-1 in evaluating organ quality but highlights the necessity for more extensive research to validate these findings and explore their implications in transplant success.
- MeSH
- Biomarkers * blood MeSH
- Kidney Failure, Chronic surgery blood therapy MeSH
- Tissue Donors * MeSH
- Adult MeSH
- Kidney physiopathology MeSH
- Middle Aged MeSH
- Humans MeSH
- Delayed Graft Function blood MeSH
- Graft Survival MeSH
- Retrospective Studies MeSH
- Syndecan-1 * blood MeSH
- Kidney Transplantation * MeSH
- Check Tag
- Adult MeSH
- Middle Aged MeSH
- Humans MeSH
- Male MeSH
- Female MeSH
- Publication type
- Journal Article MeSH
- Observational Study MeSH
- Names of Substances
- Biomarkers * MeSH
- SDC1 protein, human MeSH Browser
- Syndecan-1 * MeSH
Most kidney transplant patients who undergo biopsies are classified as having no rejection based on consensus thresholds. However, we hypothesized that because these patients have normal adaptive immune systems, T cell-mediated rejection (TCMR) and antibody-mediated rejection (ABMR) may exist as subthreshold activity in some transplants currently classified as no rejection. To examine this question, we studied genome-wide microarray results from 5086 kidney transplant biopsies (from 4170 patients). An updated molecular archetypal analysis designated 56% of biopsies as no rejection. Subthreshold molecular TCMR and/or ABMR activity molecular activity was detectable as elevated classifier scores in many biopsies classified as no rejection, with ABMR activity in many TCMR biopsies and TCMR activity in many ABMR biopsies. In biopsies classified as no rejection histologically and molecularly, molecular TCMR classifier scores correlated with increases in histologic TCMR features and molecular injury, lower estimated glomerular filtration rate, and higher risk of graft loss, and molecular ABMR activity correlated with increased glomerulitis and donor-specific antibody. No rejection biopsies with high subthreshold TCMR or ABMR activity had a higher probability of having TCMR or ABMR, respectively, diagnosed in a future biopsy. We conclude that many kidney transplant recipients have unrecognized subthreshold TCMR or ABMR activity, with significant implications for future problems.
- Keywords
- ABMR, TCMR, biopsy, gene expression, gradients, kidney transplant, microarray, transplant rejection,
- MeSH
- Biopsy MeSH
- Adult MeSH
- Glomerular Filtration Rate MeSH
- Isoantibodies immunology MeSH
- Middle Aged MeSH
- Humans MeSH
- Follow-Up Studies MeSH
- Graft Survival immunology MeSH
- Prognosis MeSH
- Graft Rejection * pathology immunology etiology MeSH
- Risk Factors MeSH
- T-Lymphocytes immunology MeSH
- Kidney Transplantation * adverse effects MeSH
- Kidney Function Tests MeSH
- Check Tag
- Adult MeSH
- Middle Aged MeSH
- Humans MeSH
- Male MeSH
- Female MeSH
- Publication type
- Journal Article MeSH
- Names of Substances
- Isoantibodies MeSH
BACKGROUND: Presensitized patients with circulating donor-specific antibodies (DSAs) before transplantation are at risk for antibody-mediated rejection (AMR). Peritransplant desensitization mitigates but does not eliminate the alloimmune response. We examined the possibility that subthreshold AMR activity undetected by histology could be operating in some early biopsies. METHODS: Transcriptome of kidney allograft biopsies performed within the first month in presensitized patients (DSA+) who had received desensitization and did not develop active/probable AMR by histology (R-) was compared with biopsies showing active/probable AMR (R+/DSA+). As negative controls, biopsies without rejection by histology in patients without DSA at transplantation were used (R-/DSA-). RNA sequencing from biopsies selected from the biobank was used in cohort 1 (n = 32) and microarray, including the molecular microscope (Molecular Microscope Diagnostic System [MMDx]) algorithm, in recent cohort 2 (n = 30). RESULTS: The transcriptome of R-/DSA+ was similar to R+/DSA+ as these groups differed in 14 transcripts only. Contrarily, large differences were found between both DSA+ groups and negative controls. Fast gene set enrichment analyses showed upregulation of the immune system in both DSA+ groups (gene ontology terms: adaptive immune response, humoral immune response, antigen receptor-mediated signaling, and B-cell receptor signaling or complement activation) when compared with negative controls. MMDx assessment in cohort 2 classified 50% of R-/DSA+ samples as AMR and found no differences in AMR molecular scores between R+ and R- DSA+ groups. In imlifidase desensitization, MMDx series showed a gradual increase in AMR scores over time. CONCLUSIONS: Presensitized kidney transplant recipients exhibited frequent molecular calls of AMR in biopsy-based transcript diagnostics despite desensitization therapy and negative histology.
- Publication type
- Journal Article MeSH
BACKGROUND: Acute kidney injury in deceased donors (D-AKI) is one of the common causes of donor kidney discard. The risk factors for D-AKI and its impact on kidney transplantation outcomes are not yet fully understood. METHODS: This single-center, retrospective cohort study included 388 donors referred between June 2021 and December 2022. D-AKI was defined and staged according to kidney disease: Improving global outcomes criteria, and donor clinical variables were analyzed to identify risk factors for D-AKI. Delayed graft function and estimated glomerular filtration rate (eGFR) at 6 mo were evaluated in 369 kidney grafts transplanted from donors with and without D-AKI. RESULTS: AKI was present in 171 deceased donors (44.1%), with 117 (30.2%) classified as AKI stage 1 and 54 (14%) as AKI stages 2 or 3. Donor history of hypertension (odds ratio [OR] 1.93; 95% confidence interval [CI], 1.21-3.10; P = 0.005), history of diabetes (OR 2.2; 95% CI, 1.21-3.98; P = 0.008), and anoxia as the cause of death (OR 2.61; 95% CI, 1.5-4.61; P < 0.001) were independently associated with an increased risk of D-AKI. Multivariable mixed models identified donor age (β -0.49; 95% CI, -0.71 to -0.28; P < 0.001) as the only independent risk factor for lower eGFR at 6 mo. D-AKI was not associated with delayed graft function or lower eGFR at 6 mo. CONCLUSIONS: Hypertension, diabetes, and anoxia as the cause of death were identified as risk factors for AKI in deceased donors. D-AKI should not be used as the sole criterion to assess the risk of poor graft outcomes. A broader range of donor variables should be considered when evaluating graft viability.
- Publication type
- Journal Article MeSH
- Publication type
- Journal Article MeSH
BACKGROUND: Booster doses of SARS-CoV-2 mRNA vaccines are commonly used in kidney transplant recipients (KTRs). However, there is uncertainty regarding the waning of vaccination responses and immunological safety in KTRs. METHODS: A total of 123 KTRs were included in the final analysis of this prospective observational cohort study. The aim was to evaluate the immunogenicity and immunological safety. SARS-CoV-2 antispike IgG antibodies and anti-HLA antibodies were measured at baseline and then at months 3, 6, and 12 after vaccination with the first booster dose (ie, the third vaccine dose). Antibodies against S1 and S2 subunits of SARS-CoV-2 were evaluated using an immunochemiluminescent assay (cutoff 9.5 AU/mL, sensitivity 91.2%, and specificity 90.2%). Anti-HLA antibodies were analyzed using single-antigen bead technology. RESULTS: Seroconversion was reached in 65% of KTRs previously nonresponding to 2-dose mRNA vaccination; the overall seroconversion rate 3 mo after the first booster dose was 83%. Vaccination induced a durable humoral response, and the antibody levels were stable during the 12-mo study follow-up. Higher age (exponentiated beta coefficient [eβ] 0.97; 95% confidence interval [CI], 0.943-0.997) and a full dose of mycophenolate (eβ 0.296; 95% CI, 0.089-0.984) were negatively associated with SARS-CoV-2 IgG antibody levels, whereas better graft function (eβ1.021; 95% CI, 1.005-1.037) was associated positively. There were no systematic signs of anti-HLA antibody development after vaccination. However, during the follow-up, there was a nonsignificant signal of an increase in anti-HLA antibodies in those who developed COVID-19. CONCLUSIONS: Additional booster doses of SARS-CoV-2 mRNA vaccines induce durable antibody response even in a large subset of previous nonresponders and are not associated with the risk of allosensitization. Furthermore, a signal linking COVID-19 to the development of anti-HLA antibodies was observed, and this should be confirmed and further examined (NCT05483725).
- Publication type
- Journal Article MeSH
INTRODUCTION: Cardiovascular disease (CVD) is the leading cause of morbidity and mortality in kidney transplant recipient (KTR). There is a dearth of standardized guidelines on optimal cardiovascular evaluation of transplant candidates. METHODS: This single-center cohort study aims to determine the effectiveness of our standardized risk-stratified pretransplant cardiovascular screening protocol, which includes coronary angiography (CAG), in identifying advanced CVD, the proper pretransplant management of which could lead to a reduction in the incidence of major cardiac events (MACE) in the early posttransplant period. RESULTS: Out of the total 776 KTR transplanted between 2017 and 2019, CAG was performed on 541 patients (69.7%), of whom 22.4% were found to have obstructive coronary artery disease (CAD). Asymptomatic obstructive CAD was observed in 70.2% of cases. In 73.6% of cases, CAG findings resulted in myocardial revascularization. MACE occurred in 5.6% (N = 44) of the 23 KTR with pretransplant CVD and 21 without pretransplant CVD. KTR with posttransplant MACE occurrence had significantly worse kidney graft function at the first year posttransplant (p = 0.00048) and worse patient survival rates (p = 0.0063) during the 3-year follow-up period compared with KTR without MACE. After adjustment, the independent significant factors for MACE were arrhythmia (HR 2.511, p = 0.02, 95% CI 1.158-5.444), pretransplant history of acute myocardial infarction (HR 0.201, p = 0.046, 95% CI 0.042-0.970), and pretransplant myocardial revascularization (HR 0.225, p = 0.045, 95% CI 0.052-0.939). CONCLUSION: Asymptomatic CVD is largely prevalent in KTR. Posttransplant MACE has a negative effect on grafts and patient outcomes. Further research is needed to assess the benefits of pretransplant myocardial revascularization in asymptomatic kidney transplant candidates.
BACKGROUND: Infliximab selectively targets recently activated effector cells and, as an induction agent, might enable the safe elimination of mycophenolate from maintenance immunosuppression in kidney transplantation. METHODS: This is a phase II international multicenter open-label single-arm confidence interval (CI)-based clinical trial of the BIO-DrIM EU consortium aimed at assessing the efficacy and safety of rabbit antithymocyte globulin and infliximab induction in kidney transplantation. Sixty-seven primary kidney transplant recipients at low risk (panel-reactive antibodies <20%, no donor-specific antibodies [DSA]) received rabbit antithymocyte globulin (2 × 1.5 mg/kg, postoperative days 0 and 1) and infliximab (5 mg/kg, postoperative day 2), followed by mycophenolate-free tacrolimus-based immunosuppression for 12 mo. The primary endpoint was efficacy failure, defined as a composite of acute rejection, graft loss, or poor graft function (estimated glomerular filtration rate <40 mL/min) at 12 mo and was based on the endpoint of the comparator study. Additionally, a historical propensity-matched control cohort was established. RESULTS: Primary endpoint occurred in 22 of 67 patients (32.84%), with upper bound of an exact 1-sided 95% CI of 43.47%, which met the predefined criteria (efficacy failure of <40% and upper-bound 95% CI of <50%) and was similar in the historical matched cohort. By 12 mo, 79.1% of patients remained on the study protocol. Lower rates of BK replication (6% versus 22.4%; P = 0.013) but higher rates of de novo DSAs (11.9% versus 1.5%; P = 0.039) were observed in the study cohort. CONCLUSIONS: A similar efficacy of the study immunosuppression regimen to the comparator study and the historical matched cohort was found. However, a higher de novo DSA emergence points to an increased risk of antibody-mediated rejection (NCT04114188).
- MeSH
- Antilymphocyte Serum * MeSH
- Immunosuppressive Agents adverse effects MeSH
- Immunosuppression Therapy MeSH
- Infliximab adverse effects MeSH
- Enzyme Inhibitors MeSH
- Humans MeSH
- Graft Survival MeSH
- Antibodies MeSH
- Graft Rejection prevention & control MeSH
- Tacrolimus * adverse effects MeSH
- Treatment Outcome MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
- Clinical Trial MeSH
- Multicenter Study MeSH
- Names of Substances
- Antilymphocyte Serum * MeSH
- Immunosuppressive Agents MeSH
- Infliximab MeSH
- Enzyme Inhibitors MeSH
- Antibodies MeSH
- Tacrolimus * MeSH
- thymoglobulin MeSH Browser
PURPOSE: Advanced age is associated with an impaired humoral immune response to SARS-CoV-2 mRNA vaccination in kidney transplant recipients (KTR). The mechanisms are, however, poorly understood. Frailty syndrome assessment may determine the most vulnerable population. METHODS: This study is a secondary analysis of a prospective study (NCT04832841) regarding seroconversion after BNT162b2 vaccination, including 101 SARS-CoV-2 naïve KTR 70 years and older. The Fried frailty components were evaluated, and antibodies against S1 and S2 subunits of SARS-CoV-2 were examined > 14 days after the second dose of BNT162b2 vaccine. RESULTS: Seroconversion was observed in 33 KTR. Male gender, eGFR, MMF-free immunosuppression, and a lower frailty score were associated with higher seroconversion rates in univariable regression. Concerning frailty components, physical inactivity had the most negative effect on seroconversion (OR = 0.36, 95% CI 0.14-0.95, p = 0.039). In a multivariable regression adjusted for eGFR, MMF-free immunosuppression, time from transplant and gender, pre-frail (OR = 0.27, 95% CI 0.07-1.00, p = 0.050), and frail status (OR = 0.14, 95% CI 0.03-0.73, p = 0.019) were associated with an increased risk of unresponsiveness to SARS-CoV-2 vaccines. CONCLUSION: Frailty was associated with an impaired humoral response to SARS-CoV-2 mRNA vaccination in older SARS-CoV-2 naïve KTR. TRAIL REGISTRATION: This study is registered under the identifier NCT04832841 on ClinicalTrials.gov.
- Keywords
- Frailty, Kidney transplantation, SARS-CoV-2 infection, Vaccination,
- MeSH
- COVID-19 * prevention & control MeSH
- Frailty * MeSH
- Frail Elderly MeSH
- Humans MeSH
- RNA, Messenger MeSH
- Transplant Recipients MeSH
- Prospective Studies MeSH
- Antibodies, Viral MeSH
- SARS-CoV-2 MeSH
- Aged MeSH
- Kidney Transplantation * MeSH
- BNT162 Vaccine MeSH
- COVID-19 Vaccines MeSH
- Check Tag
- Humans MeSH
- Male MeSH
- Aged MeSH
- Publication type
- Journal Article MeSH
- Names of Substances
- RNA, Messenger MeSH
- Antibodies, Viral MeSH
- BNT162 Vaccine MeSH
- COVID-19 Vaccines MeSH
BACKGROUND: Recurrence of immunoglobulin A nephropathy (IgAN) limits graft survival in kidney transplantation. However, predictors of a worse outcome are poorly understood. METHODS: Among 442 kidney transplant recipients (KTRs) with IgAN, 83 (18.8%) KTRs exhibited biopsy-proven IgAN recurrence between 1994 and 2020 and were enrolled in the derivation cohort. A multivariable Cox model predicting allograft loss based on clinical data at the biopsy and a web-based nomogram were developed. The nomogram was externally validated using an independent cohort (n = 67). RESULTS: Patient age <43 years {hazard ratio [HR] 2.20 [95% confidence interval (CI) 1.41-3.43], P < .001}, female gender [HR 1.72 (95% CI 1.07-2.76), P = .026] and retransplantation status [HR 1.98 (95% CI 1.13-3.36), P = .016] were identified as independent risk factors for IgAN recurrence. Patient age <43 years [HR 2.77 (95% CI 1.17-6.56), P = .02], proteinuria >1 g/24 hours [HR 3.12 (95% CI 1.40-6.91), P = .005] and C4d positivity [HR 2.93 (95% CI 1.26-6.83), P = .013] were found to be associated with graft loss in patients with IgAN recurrence. A nomogram predicting graft loss was constructed based on clinical and histological variables, with a C statistic of 0.736 for the derivation cohort and 0.807 for the external validation cohort. CONCLUSIONS: The established nomogram identified patients with recurrent IgAN at risk for premature graft loss with good predictive performance.
- Keywords
- IgA nephropathy, glomerulonephritis, kidney transplantation, nomogram, recurrence,
- MeSH
- Allografts pathology MeSH
- Adult MeSH
- Glomerulonephritis, IGA * complications surgery MeSH
- Kidney pathology MeSH
- Humans MeSH
- Nomograms MeSH
- Graft Survival MeSH
- Prognosis MeSH
- Recurrence MeSH
- Retrospective Studies MeSH
- Check Tag
- Adult MeSH
- Humans MeSH
- Female MeSH
- Publication type
- Journal Article MeSH
