Immunogenicity of High-Dose Versus MF59-Adjuvanted Versus Standard Influenza Vaccine in Solid Organ Transplant Recipients: The Swiss/Spanish Trial in Solid Organ Transplantation on Prevention of Influenza (STOP-FLU Trial).

BACKGROUND: The immunogenicity of the standard influenza vaccine is reduced in solid-organ transplant (SOT) recipients, so new vaccination strategies are needed in this population. METHODS: Adult SOT recipients from 9 transplant clinics in Switzerland and Spain were enrolled if they were >3 months after transplantation. Patients were randomized (1:1:1) to a MF59-adjuvanted or a high-dose vaccine (intervention), or a standard vaccine (control), with stratification by organ and time from transplant. The primary outcome was vaccine response rate, defined as a ≥4-fold increase of hemagglutination-inhibition titers to at least 1 vaccine strain at 28 days postvaccination. Secondary outcomes included polymerase chain reaction-confirmed influenza and vaccine reactogenicity. RESULTS: A total of 619 patients were randomized, 616 received the assigned vaccines, and 598 had serum available for analysis of the primary endpoint (standard, n = 198; MF59-adjuvanted, n = 205; high-dose, n = 195 patients). Vaccine response rates were 42% (84/198) in the standard vaccine group, 60% (122/205) in the MF59-adjuvanted vaccine group, and 66% (129/195) in the high-dose vaccine group (difference in intervention vaccines vs standard vaccine, 0.20; 97.5% confidence interval [CI], .12-1); P < .001; difference in high-dose vs standard vaccine, 0.24 [95% CI, .16-1]; P < .001; difference in MF59-adjuvanted vs standard vaccine, 0.17 [97.5% CI, .08-1]; P < .001). Influenza occurred in 6% of the standard, 5% in the MF59-adjuvanted, and 7% in the high-dose vaccine groups. Vaccine-related adverse events occurred more frequently in the intervention vaccine groups, but most of the events were mild. CONCLUSIONS: In SOT recipients, use of an MF59-adjuvanted or a high-dose influenza vaccine was safe and resulted in a higher vaccine response rate. CLINICAL TRIALS REGISTRATION: Clinicaltrials.gov NCT03699839.

Immune Monitoring-Guided Versus Fixed Duration of Antiviral Prophylaxis Against Cytomegalovirus in Solid-Organ Transplant Recipients: A Multicenter, Randomized Clinical Trial.

BACKGROUND: The use of assays detecting cytomegalovirus (CMV)-specific T cell-mediated immunity may individualize the duration of antiviral prophylaxis after transplantation. METHODS: In this randomized trial, kidney and liver transplant recipients from 6 centers in Switzerland were enrolled if they were CMV-seronegative with seropositive donors or CMV-seropositive receiving antithymocyte globulins. Patients were randomized to a duration of antiviral prophylaxis based on immune monitoring (intervention) or a fixed duration (control). Patients in the control group were planned to receive 180 days (CMV-seronegative) or 90 days (CMV-seropositive) of valganciclovir. Patients were assessed monthly with a CMV ELISpot assay (T-Track CMV); prophylaxis in the intervention group was stopped if the assay was positive. The co-primary outcomes were the proportion of patients with clinically significant CMV infection and reduction in days of prophylaxis. Between-group differences were adjusted for CMV serostatus. RESULTS: Overall, 193 patients were randomized (92 in the immune-monitoring group and 101 in the control group), of whom 185 had evaluation of the primary outcome (87 and 98 patients). CMV infection occurred in 26 of 87 (adjusted percentage, 30.9%) in the immune-monitoring group and in 32 of 98 (adjusted percentage, 31.1%) in the control group (adjusted risk difference, -0.1; 95% confidence interval [CI], -13.0% to 12.7%; P = .064). The duration of prophylaxis was shorter in the immune-monitoring group (adjusted difference, -26.0 days; 95%, CI, -41.1 to -10.8 days; P < .001). CONCLUSIONS: Immune monitoring resulted in a significant reduction of antiviral prophylaxis, but we were unable to establish noninferiority of this approach on the co-primary outcome of CMV infection. CLINICAL TRIALS REGISTRATION: NCT02538172.

Magnetic blood purification-based soluble fms-like tyrosine kinase-1 removal in comparison with dextran sulfate apheresis and therapeutic plasma exchange.

BACKGROUND: Preeclampsia remains one of the most serious complications of pregnancy. Effective therapies are yet to be developed. Recent research has identified an imbalance of angiogenic and antiangiogenic factors as a root cause of preeclampsia. In particular, soluble fms-like tyrosine kinase-1 (sFlt-1) has been shown to bind the angiogenic factors vascular endothelial growth factor (VEGF) and placental growth factor (PlGF), reducing blood vessel growth. Increasing preclinical and clinical evidence suggests that removal of the sFlt-1 protein may benefit patients with early onset preeclampsia. sFlt-1 may be removed by conventional blood purification techniques, such as therapeutic plasma exchange (TPE) and dextran sulfate apheresis (DSA), or emerging technologies, including extracorporeal magnetic blood purification (MBP). METHODS: We compare the performance and selectivity of TPE, DSA, and MBP for the therapeutic removal of sFlt-1. For MPB, we employ magnetic nanoparticles functionalized with either sFlt-1 antibodies or the sFlt-1-binding partner, vascular endothelial growth factor (VEGF). RESULTS: We demonstrate that sFlt-1 removal by MBP is feasible and significantly more selective than TPE and DSA at comparable sFlt-1 removal efficiencies (MBP 96%, TPE 92%, DSA 78%). During both TPE and DSA, complement factors (incl. C3c and C4) are depleted to a considerable extent (-90% for TPE, -55% for DSA), while in MBP, complement factor concentrations remain unaltered. We further demonstrate that the removal efficacy of sFlt-1 in the MBP approach is strongly dependent on the nanoparticle type and dose and can be optimized to reach clinically feasible throughputs. CONCLUSIONS: Taken together, the highly selective removal of sFlt-1 and potential other disease-causing factors by extracorporeal magnetic blood purification may offer new prospects for preeclamptic patients.

Relevance of deceased donor proteinuria for kidney transplantation: A comprehensive national cohort study.

PURPOSE: Proteinuria is frequent in patients with nephropathies and associated with progressive kidney disease and risk for end stage kidney disease. However, the relevance of deceased donor proteinuria on transplant outcome remains uncertain. In this nationwide cohort study, we evaluated the prevalence of proteinuria in deceased donor candidates and measured the impact on outcome after kidney transplantation. METHODS: Data from the Swiss Organ Allocation System and the Swiss Transplant Cohort Study were analyzed, comprising 1725 donors and 1516 recipients transplanted between 2008 and 2019. We correlated urine findings with donor characteristics and quantified the impact of proteinuria on allograft function at 12 months and survival. RESULTS: Proteinuria influenced allocation decisions in 4.5% of nonimmunological organ declines and was the leading cause for decline in 0.2% of cases. 74.1%, 51.4%, and 35.3% of donor candidates had a baseline proteinuria above 15, 30, and 50 mg protein/mmol urine creatinine, respectively. Proteinuria above 30 mg/mmol was associated with female donor sex, mechanical resuscitation, acute kidney injury, and time delay between ICU entry and urine sampling. Donor proteinuria was not associated with patient or allograft survival, nor allograft function at 12 months. CONCLUSION: We report a high prevalence of proteinuria in donor candidates, without evidence of a deleterious impact of proteinuria on graft function and/or survival. Therefore, low-level proteinuria should not be considered a limiting contraindication for kidney allocation in deceased donor transplant.

A National Survey Comparing Patients' and Transplant Professionals' Research Priorities in the Swiss Transplant Cohort Study.

We aimed to identify, assess, compare and map research priorities of patients and professionals in the Swiss Transplant Cohort Study. The project followed 3 steps. 1) Focus group interviews identified patients' (n = 22) research priorities. 2) A nationwide survey assessed and compared the priorities in 292 patients and 175 professionals. 3) Priorities were mapped to the 4 levels of Bronfenbrenner's ecological framework. The 13 research priorities (financial pressure, medication taking, continuity of care, emotional well-being, return to work, trustful relationships, person-centredness, organization of care, exercise and physical fitness, graft functioning, pregnancy, peer contact and public knowledge of transplantation), addressed all framework levels: patient (n = 7), micro (n = 3), meso (n = 2), and macro (n = 1). Comparing each group's top 10 priorities revealed that continuity of care received highest importance rating from both (92.2% patients, 92.5% professionals), with 3 more agreements between the groups. Otherwise, perspectives were more diverse than congruent: Patients emphasized patient level priorities (emotional well-being, graft functioning, return to work), professionals those on the meso level (continuity of care, organization of care). Patients' research priorities highlighted a need to expand research to the micro, meso and macro level. Discrepancies should be recognized to avoid understudying topics that are more important to professionals than to patients.

Pre-transplant Social Adaptability Index and clinical outcomes in renal transplantation: The Swiss Transplant Cohort study.

BACKGROUND: The impact of pre-transplant social determinants of health on post-transplant outcomes remains understudied. In the United States, poor clinical outcomes are associated with underprivileged status, as assessed by the Social Adaptability Index (SAI), a composite score of education, employment status, marital status, household income, and substance abuse. Using data from the Swiss Transplant Cohort Study (STCS), we determined the SAI's predictive value regarding two post-transplant outcomes: all-cause mortality and return to dialysis. METHODS: Between 2012 and 2018, we included adult renal transplant patients (aged ≥ 18 years) with pre-transplant assessment SAI scores, calculated from a STCS Psychosocial Questionnaire. Time to all-cause mortality and return to dialysis were predicted using Cox regression. RESULTS: Of 1238 included patients (mean age: 53.8 ± 13.2 years; 37.9% female; median follow-up time: 4.4 years [IQR: 2.7]), 93 (7.5%) died and 57 (4.6%) returned to dialysis. The SAI's hazard ratio was 0.94 (95%CI: 0.88-1.01; p = .09) for mortality and 0.93 (95%CI: 0.85-1.02; p = .15) for return to dialysis. CONCLUSIONS: In contrast to most published studies on social deprivation, analysis of this Swiss sample detected no significant association between SAI score and mortality or return to dialysis.

Outcome of kidney transplantation from very senior donors in Switzerland - a national cohort study.

Kidney transplantation from older and marginal donors is effective to confront organ shortage. However, limitations after transplantation of kidneys from very marginal kidney donors remain unclear. We compared patient and graft outcome, achieved allograft function and quality of life of renal transplantations from Very Senior Donors (VSD, defined as donors aged 70 years and older) with Senior Donors (SD, aged 60-70 years) and Regular Donors (RD, aged younger than 60 years) in Switzerland. We evaluated the outcome of 1554 adult recipients of deceased donor kidney transplantations from 05/2008 to 12/2019; median follow-up was 4.7 years. Failure-free survival (freedom from graft loss or death), glomerular filtration rate (eGFR), and quality of life at 12 months were analyzed for RD (reference group, n = 940), SD (n = 404), and VSD (n = 210). Failure-free survival decreased with increasing donor age, mainly attributable to premature graft loss. Still, overall 5-year failure-free survival reached 83.1%, 81.0%, and 64.0% in the RD, SD, and VSD subgroups, respectively. eGFR 12 months post-transplantation was significantly higher in RD compared with SD and VSD. The acceptance rate of donor candidates for kidney TPL was 78% for the entire cohort (87% for RD, 79% for SD, and 56% for VSD). Deceased donor kidney transplantation from donors aged 70 years or older is associated with an inferior, yet acceptable failure-free outcome, with sustained quality of life.

Age at Time of Kidney Transplantation as a Predictor for Mortality, Graft Loss and Self-Rated Health Status: Results From the Swiss Transplant Cohort Study.

Introduction: The effect of age on health outcomes in kidney transplantation remains inconclusive. This study aimed to analyze the relationship between age at time of kidney transplantation with mortality, graft loss and self-rated health status in adult kidney transplant recipients. Methods: This study used data from the Swiss Transplant Cohort Study and included prospective data of kidney transplant recipients between 2008 and 2017. Time-to-event analysis was performed using Cox' regression analysis, and -in the case of graft loss- competing risk analysis. A random-intercept regression model was applied to analyse self-rated health status. Results: We included 2,366 kidney transplant recipients. Age at transplantation linearly predicted mortality. It was also predictive for graft loss, though nonlinearly, showing that recipients aged between 35 and 55 years presented with the lowest risk of experiencing graft loss. No relationship of age with self-rated health status was detected. Conclusion: Higher mortality in older recipients complies with data from the general population. The non-linear relationship between age and graft loss and the higher scored self-rated health status at all follow-up time-points compared to the pre-transplant status -regardless of age- highlight that age alone might not be an accurate measure for risk prediction and clinical decision making in kidney transplantation.

Dialysis after graft loss: a Swiss experience.

BACKGROUND: Patients returning to dialysis after graft loss have high early morbidity and mortality. METHODS: We used data from the Swiss Transplant Cohort Study to describe the current practice and outcomes in Switzerland. All patients who received a renal allograft between May 2008 and December 2014 were included. The patients with graft loss were divided into two groups depending on whether the graft loss occurred within 1 year after transplantation (early graft loss group) or later (late graft loss group). Patients with primary non-function who never gained graft function were excluded. RESULTS: Seventy-seven out of 1502 patients lost their graft during follow-up, 40 within 1 year after transplantation. Eleven patients died within 30 days after allograft loss. Patient survival was 86, 81 and 74% at 30, 90 and 365 days after graft loss, respectively. About 92% started haemodialysis, 62% with definitive vascular access, which was associated with decreased mortality (hazard ratio = 0.28). At the time of graft loss, most patients were on triple immunosuppressive therapy with significant reduction after nephrectomy. One year after graft loss, 77.5% (31 of 40) of patients in the early and 43.2% (16 out of 37) in the late-loss group had undergone nephrectomy. Three years after graft loss, 36% of the patients with early and 12% with late graft loss received another allograft. CONCLUSION: In summary, our data illustrate high mortality, and a high number of allograft nephrectomies and re-transplantations. Patients commencing haemodialysis with a catheter had significantly higher mortality than patients with definitive access. The role of immunosuppression reduction and allograft nephrectomy as interdependent factors for mortality and re-transplantation needs further evaluation.

Genetic immune and inflammatory markers associated with diabetes in solid organ transplant recipients.

New-onset diabetes mellitus after transplantation (NODAT) is a complication following solid organ transplantation (SOT) and may be related to immune or inflammatory responses. We investigated whether single nucleotide polymorphisms (SNPs) within 158 immune- or inflammation-related genes contribute to NODAT in SOT recipients. The association between 263 SNPs and NODAT was investigated in a discovery sample of SOT recipients from the Swiss Transplant Cohort Study (STCS, n1  = 696). Positive results were tested in a first STCS replication sample (n2  = 489) and SNPs remaining significant after multiple test corrections were tested in a second SOT replication sample (n3  = 156). Associations with diabetic traits were further tested in several large general population-based samples (n > 480 000). Only SP110 rs2114592C>T remained associated with NODAT in the STCS replication sample. Carriers of rs2114592-TT had 9.9 times (95% confidence interval [CI]: 3.22-30.5, P = .00006) higher risk for NODAT in the combined STCS samples (n = 1184). rs2114592C>T was further associated with NODAT in the second SOT sample (odds ratio: 4.8, 95% CI: 1.55-14.6, P = .006). On the other hand, SP110 rs2114592C>T was not associated with diabetic traits in population-based samples, suggesting a specific gene-environment interaction, possibly due to the use of specific medications (ie, immunosuppressants) in transplant patients and/or to the illness that may unmask the gene effect.

Genetic and clinic predictors of new onset diabetes mellitus after transplantation.

New Onset Diabetes after Transplantation (NODAT) is a frequent complication after solid organ transplantation, with higher incidence during the first year. Several clinical and genetic factors have been described as risk factors of Type 2 Diabetes (T2DM). Additionally, T2DM shares some genetic factors with NODAT. We investigated if three genetic risk scores (w-GRS) and clinical factors were associated with NODAT and how they predicted NODAT development 1 year after transplantation. In both main (n = 725) and replication (n = 156) samples the clinical risk score was significantly associated with NODAT (ORmain: 1.60 [1.36-1.90], p = 3.72*10-8 and ORreplication: 2.14 [1.39-3.41], p = 0.0008, respectively). Two w-GRS were significantly associated with NODAT in the main sample (ORw-GRS 2:1.09 [1.04-1.15], p = 0.001 and ORw-GRS 3:1.14 [1.01-1.29], p = 0.03) and a similar ORw-GRS 2 was found in the replication sample, although it did not reach significance probably due to a power issue. Despite the low OR of w-GRS on NODAT compared to clinical covariates, when integrating w-GRS 2 and w-GRS 3 in the clinical model, the Area under the Receiver Operating Characteristics curve (AUROC), specificity, sensitivity and accuracy were 0.69, 0.71, 0.58 and 0.68, respectively, with significant Likelihood Ratio test discrimination index (p-value 0.0004), performing better in NODAT discrimination than the clinical model alone. Twenty-five patients needed to be genotyped in order to detect one misclassified case that would have developed NODAT 1 year after transplantation if using only clinical covariates. To our knowledge, this is the first study extensively examining genetic risk scores contributing to NODAT development.

New-onset obesity after liver transplantation-outcomes and risk factors: the Swiss Transplant Cohort Study.

Weight gain after liver transplantation (LTx) facilitates development of new-onset obesity; however, its risk factors and outcomes are poorly understood. We identified the impact of new-onset obesity on cardiovascular events (CVEs) and patient survival, and risk factors for new-onset obesity. Multiple Cox regression models examined risk factors for CVEs, patient survival, and new-onset obesity in 253 adults (mean age 52.2 ± 11.6 years, male gender 63.6%, mean follow up 5.7 ± 2.1 years). Cumulative incidence of post-LTx CVE was 28.1%; that of new-onset obesity was 21.3%. Regardless of CVE at LTx, post-LTx CVEs were predicted by new-onset obesity [Hazard Ratio (HR), 2.95; P = 0.002] and higher age at LTx (HR, 1.05; P < 0.001). In patients without known pre-LTx CVEs (n = 214), risk factors for post-LTx CVEs were new-onset obesity (HR, 2.59; P = 0.014) and higher age (HR, 1.04; P = 0.001). Survival was not associated with new-onset obesity (P = 0.696). Alcoholic liver disease predicted new-onset obesity (HR, 3.37; P = 0.025), female gender was protective (HR, 0.39; P = 0.034). In 114 patients with available genetic data, alcoholic liver disease (HR, 12.82; P = 0.014) and hepatocellular carcinoma (HR, 10.02; P = 0.048) predicted new-onset obesity, and genetics remained borderline significant (HR, 1.07; P = 0.071). Early introduction of post-LTx weight management programs may suggest a potential pathway to reduce CVE risk.

Evolution of body weight parameters up to 3 years after solid organ transplantation: The prospective Swiss Transplant Cohort Study.

Obesity and weight gain are serious concerns after solid organ transplantation (Tx); however, no unbiased comparison regarding body weight parameter evolution across organ groups has yet been performed. Using data from the prospective nationwide Swiss Transplant Cohort Study, we compared the evolution of weight parameters up to 3 years post-Tx in 1359 adult kidney (58.3%), liver (21.7%), lung (11.6%), and heart (8.4%) recipients transplanted between May 2008 and May 2012. Changes in mean weight and body mass index (BMI) category were compared to reference values from 6 months post-Tx. At 3 years post-Tx, compared to other organ groups, liver Tx recipients showed the greatest weight gain (mean 4.8±10.4 kg), 57.4% gained >5% body weight, and they had the highest incidence of obesity (38.1%). After 3 years, based on their BMI categories at 6 months, normal weight and obese liver Tx patients, as well as underweight kidney, lung and heart Tx patients had the highest weight gains. Judged against international Tx patient data, the majority of our Swiss Tx recipients' experienced lower post-Tx weight gain. However, our findings show weight gain pattern differences, both within and across organ Tx groups that call for preventive measures.

ExplorinG frailty and mild cognitive impairmEnt in kidney tRansplantation to predict biomedicAl, psychosocial and health cost outcomeS (GERAS): protocol of a nationwide prospective cohort study.

AIM: To present the rationale, design and methodology of the GERAS project, which examines whether assessment of frailty and mild cognitive impairment could enhance risk prediction for biomedical, psychosocial outcomes and foster efficient resource allocation in kidney transplantation. BACKGROUND: For the burgeoning cohort of older patients considered for kidney transplantation, evidence gaps regarding frailty and mild cognitive impairment limit clinical decision-making and medical management. As known risk factors for 'hard' clinical outcomes in chronic illness, both require further study in transplantation. Integrating these and other bio-psychosocial factors into a comprehensive pre-transplant patient assessment will provide insights regarding economic implications and may improve risk prediction. DESIGN: A nation-wide multi-centre prospective cohort study nested in the Swiss Transplant Cohort Study. METHODS: Our nationally representative convenience sample includes 250 adult kidney transplant recipients. Data sources include the Swiss Transplant Cohort Study and primary data collected at time of transplantation, 6 months, 1 and 2 years post-transplant via established measures (the Montreal Cognitive Assessment, Psychosocial Questionnaire, Fried Frailty Instrument and a blood analysis), investigator-developed instruments and datasets compiled by hospitals' management control units, sickness funds, the Swiss Federal Statistical Office and the European Renal Association. Descriptive, competing risk survival and mixed effects analyses will be performed. Research Ethics Committee approval was obtained in January 2016. DISCUSSION: This pioneering project jointly examines frailty and mild cognitive impairment from bio-psychosocial and health economic perspectives. Results may significantly inform risk prediction, care tailoring and resource optimization to improve health outcomes in the ageing kidney transplant cohort.

Polymorphisms in the lectin pathway of complement activation influence the incidence of acute rejection and graft outcome after kidney transplantation.

There are conflicting data on the role of the lectin pathway of complement activation and its recognition molecules in acute rejection and outcome after transplantation. To help resolve this we analyzed polymorphisms and serum levels of lectin pathway components in 710 consecutive kidney transplant recipients enrolled in the nationwide Swiss Transplant Cohort Study, together with all biopsy-proven rejection episodes and 1-year graft and patient survival. Functional mannose-binding lectin (MBL) levels were determined in serum samples, and previously described MBL2, ficolin 2, and MBL-associated serine protease 2 polymorphisms were genotyped. Low MBL serum levels and deficient MBL2 diplotypes were associated with a higher incidence of acute cellular rejection during the first year, in particular in recipients of deceased-donor kidneys. This association remained significant (hazard ratio 1.75, 95% confidence interval 1.18-2.60) in a Cox regression model after adjustment for relevant covariates. In contrast, there was no significant association with rates of antibody-mediated rejection, patient death, early graft dysfunction or loss. Thus, results in a prospective multicenter contemporary cohort suggest that MBL2 polymorphisms result in low MBL serum levels and are associated with acute cellular rejection after kidney transplantation. Since MBL deficiency is a relatively frequent trait in the normal population, our findings may lead to individual risk stratification and customized immunosuppression.

Influence of IFNL3/4 polymorphisms on the incidence of cytomegalovirus infection after solid-organ transplantation.

BACKGROUND: Polymorphisms in IFNL3 and IFNL4, the genes encoding interferon λ3 and interferon λ4, respectively, have been associated with reduced hepatitis C virus clearance. We explored the role of such polymorphisms on the incidence of cytomegalovirus (CMV) infection in solid-organ transplant recipients. METHODS: White patients participating in the Swiss Transplant Cohort Study in 2008-2011 were included. A novel functional TT/-G polymorphism (rs368234815) in the CpG region upstream of IFNL3 was investigated. RESULTS: A total of 840 solid-organ transplant recipients at risk for CMV infection were included, among whom 373 (44%) received antiviral prophylaxis. The 12-month cumulative incidence of CMV replication and disease were 0.44 and 0.08 cases, respectively. Patient homozygous for the minor rs368234815 allele (-G/-G) tended to have a higher cumulative incidence of CMV replication (subdistribution hazard ratio [SHR], 1.30 [95% confidence interval {CI}, .97-1.74]; P = .07), compared with other patients (TT/TT or TT/-G). The association was significant among patients followed by a preemptive approach (SHR, 1.46 [95% CI, 1.01-2.12]; P = .047), especially in patients receiving an organ from a seropositive donor (SHR, 1.92 [95% CI, 1.30-2.85]; P = .001), but not among those who received antiviral prophylaxis (SHR, 1.13 [95% CI, .70-1.83]; P = .6). These associations remained significant in multivariate competing risk regression models. CONCLUSIONS: Polymorphisms in the IFNL3/4 region influence susceptibility to CMV replication in solid-organ transplant recipients, particularly in patients not receiving antiviral prophylaxis.

Pre-transplant donor specific antibodies in ABO incompatible kidney transplantation - data from the Swiss transplant cohort study.

Background: Living donor (LD) kidney transplantation in the setting of ABO blood group incompatibility (ABOi) has been previously reported to be associated with increased risk for antibody-mediated rejection (ABMR). It is however unclear if the presence of pre-transplant donor specific antibodies (DSA) works as an additive risk factor in the setting of ABOi and if DSA positive ABOi transplants have a significantly worse long-term outcome as compared with ABO compatible (ABOc) DSA positive transplants. Methods: We investigated the effect of pre-transplant DSA in the ABOi and ABOc setting on the risk of antibody-mediated rejection (ABMR) and graft loss in a cohort of 952 LD kidney transplants. Results: We found a higher incidence of ABMR in ABOi transplants as compared to ABOc transplants but this did not significantly affect graft survival or overall survival which was similar in both groups. The presence of pre-transplant DSA was associated with a significantly increased risk of ABMR and graft loss both in the ABOi and ABOc setting. We could not detect an additional risk of DSA in the ABOi setting and outcomes were comparable between DSA positive ABOi and ABOc recipients. Furthermore, a combination of DSA directed at both Class I and Class II, as well as DSA with a high mean fluorescence intensity (MFI) showed the strongest relation to ABMR development and graft loss. Conclusion: The presence of pre-transplant DSA was associated with a significantly worse long-term outcome in both ABOi and ABOc LD kidney transplants and our results suggests that the risk associated with pre-transplant DSA is perhaps not augmented in the ABOi setting. Our study is the first to investigate the long-term effects of DSA in the ABOi setting and argues that pre-transplant DSA risk could potentially be evaluated similarly regardless of ABO compatibility status.

Design and methodology of the Swiss Transplant Cohort Study (STCS): a comprehensive prospective nationwide long-term follow-up cohort.

In Switzerland, organ procurement is well organized at the national-level but transplant outcomes have not been systematically monitored so far. Therefore, a novel project, the Swiss Transplant Cohort Study (STCS), was established. The STCS is a prospective multicentre study, designed as a dynamic cohort, which enrolls all solid organ recipients at the national level. The features of the STCS are a flexible patient-case system that allows capturing all transplant scenarios and collection of patient-specific and allograft-specific data. Beyond comprehensive clinical data, specific focus is directed at psychosocial and behavioral factors, infectious disease development, and bio-banking. Between May 2008 and end of 2011, the six Swiss transplant centers recruited 1,677 patients involving 1,721 transplantations, and a total of 1,800 organs implanted in 15 different transplantation scenarios. 10 % of all patients underwent re-transplantation and 3% had a second transplantation, either in the past or during follow-up. 34% of all kidney allografts originated from living donation. Until the end of 2011 we observed 4,385 infection episodes in our patient population. The STCS showed operative capabilities to collect high-quality data and to adequately reflect the complexity of the post-transplantation process. The STCS represents a promising novel project for comparative effectiveness research in transplantation medicine.

Clinical prediction model for prognosis in kidney transplant recipients (KIDMO): study protocol.

BACKGROUND: Many potential prognostic factors for predicting kidney transplantation outcomes have been identified. However, in Switzerland, no widely accepted prognostic model or risk score for transplantation outcomes is being routinely used in clinical practice yet. We aim to develop three prediction models for the prognosis of graft survival, quality of life, and graft function following transplantation in Switzerland. METHODS: The clinical kidney prediction models (KIDMO) are developed with data from a national multi-center cohort study (Swiss Transplant Cohort Study; STCS) and the Swiss Organ Allocation System (SOAS). The primary outcome is the kidney graft survival (with death of recipient as competing risk); the secondary outcomes are the quality of life (patient-reported health status) at 12 months and estimated glomerular filtration rate (eGFR) slope. Organ donor, transplantation, and recipient-related clinical information will be used as predictors at the time of organ allocation. We will use a Fine & Gray subdistribution model and linear mixed-effects models for the primary and the two secondary outcomes, respectively. Model optimism, calibration, discrimination, and heterogeneity between transplant centres will be assessed using bootstrapping, internal-external cross-validation, and methods from meta-analysis. DISCUSSION: Thorough evaluation of the existing risk scores for the kidney graft survival or patient-reported outcomes has been lacking in the Swiss transplant setting. In order to be useful in clinical practice, a prognostic score needs to be valid, reliable, clinically relevant, and preferably integrated into the decision-making process to improve long-term patient outcomes and support informed decisions for clinicians and their patients. The state-of-the-art methodology by taking into account competing risks and variable selection using expert knowledge is applied to data from a nationwide prospective multi-center cohort study. Ideally, healthcare providers together with patients can predetermine the risk they are willing to accept from a deceased-donor kidney, with graft survival, quality of life, and graft function estimates available for their consideration. STUDY REGISTRATION: Open Science Framework ID: z6mvj.