Donor specific HLA antibodies and renal transplant outcomes

Despite the use of potent modern immunosuppressive agents chronic rejection remains the leading cause of allograft failure after renal transplant. Historically T cells were considered to be the main pivot of rejection mechanisms; however, over the past decade the key role of B cells in allograft rejection has been much more fully described. Antibody mediated rejection [AMR] was first classified as a distinct entity in the Banff histological classification of allograft pathology as late as 2001. This was a consequence of the demonstration of the complement split product C4d in renal allografts giving indirect evidence of humoral injury, along with the development of newer assays to detect circulating HLA donor specific antibodies [DSAs]; both of which were subsequently shown to be associated with reduced allograft survival. The development of solid phase technologies, in particular single antigen beads has introduced a readily available assay which can detect HLA DSA with high sensitivity and specificity. The benefit of routine application of such assays in renal transplantation is not known and is the principal question of this thesis; that is to establish if the detection of HLA DSAs will help in predicting rejection and allograft loss. Patients transplanted at Imperial College Renal and Transplant Centre were recruited into the studies. The underlying hypothesis is that donor specific antibodies identified by the more recently developed techniques are associated with inferior allograft survival, addressed in several related studies as follows: 1. Is C4d staining with no morphological features of rejection associated with risk of subsequent AMR and allograft loss? 2. Are preformed DSA detected by single antigen beads in the setting of a negative crossmatch associated with inferior allograft survival? 3. What is the relevance of de novo DSAs after renal transplantation? 4. What is the clinical significance of DQ DSA and should consideration be given to DQ mismatching in deceased organ allocation? 5. Do outcomes in patients with ACR with a humoral component differ when compared to those with pure ACR when treated in a uniform manner? A summary of the results is as follows: 1. C4d in the absence of histological features is not associated with AMR. However, patients with acute tubular injury who have DSA are at risk of subsequent AMR. 2. Patients with preformed DSA are at significant risk of AMR and allograft loss and as such antibodies detected by single antigen beads alone pre-transplant should be considered a relative contraindication to transplantation. 3. Patients who develop de novo DSA are at risk of AMR, transplant glomerulopathy [TG] and allograft failure. Routine testing for the detection of DSA may allow the potential to augment immunosuppression in order to improve outcomes. 4. DQ DSA are the most common DSA detected after transplant and are associated with inferior allograft outcomes. Patients mismatched at both DR and DQ alleles are at risk of developing DQ DSA. Algorithms incorporating the level of DQ mismatch might reduce DQ DSA formation and therefore improve long term allograft survival. 5. Patients with ACR with a humoral element are at risk of subsequent AMR, TG and graft failure. Such patients might benefit from more aggressive therapies than those targeted at ACR alone

Frailty and the psychosocial components of the edmonton frail scale are most associated with patient experience in older kidney transplant candidates – a secondary analysis within the kidney transplantation in older people (KTOP) study

© 2023 Thind, Levy, Wellsted, Willicombe and Brown. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). https://creativecommons.org/licenses/by/4.0/Background: Older people with end-stage kidney disease (ESKD) are vulnerable to frailty, which impacts on clinical and experiential outcomes. With kidney transplantation in older people increasing, a better understanding of patient experiences is necessary for guiding decision making. The Kidney Transplantation in Older People (KTOP):impact of frailty on outcomes study aims to explore this. We present a secondary analysis of the Edmonton Frail Scale (EFS) and its relationship with patient experience scores. Methods: The KTOP study is a single centre, prospective study, which began in October 2019. All ESKD patients aged ≥60 considered for transplantation at Imperial College Renal and Transplant Centre were eligible. Frailty was assessed using the EFS and 5 questionnaires assessed patient experience and quality of life (QoL) (Short Form-12(v2), Palliative Care Outcome Scale–Symptoms Renal, Depression Patient Health Questionnaire-9, Illness Intrusiveness Ratings Scale, Renal Treatment Satisfaction Questionnaire). The EFS was divided into 4 subdomains (psychosocial, physical function, medical status, and general health) and then compared with the questionnaire scores. Results: 210 patients have been recruited (aged 60-78), 186 of whom completed EFS assessments. 118 (63.4%) participants were not frail, 36 (19.4%) vulnerable, and 32 (17.2%) were frail. Worse frailty scores were associated with poorer patient experience and QoL scores across all questionnaires. Severe deficits in the EFS psychosocial subdomain showed a statistically significant association with higher depression screen scores (coefficient 4.9, 95% CI 3.22 to 6.59), lower physical (coefficient -4.35, 95% CI -7.59 to -1.12) and mental function scores (coefficient -8.33, 95% CI -11.77 to -4.88) from the Short Form-12(v2), and lower renal treatment satisfaction scores (coefficient -5.54, 95% CI -10.70 to -0.37). Deficits in the physical function and medical status EFS subdomians showed some association with patient experience scores. Conclusion: In the KTOP study cohort at recruitment vulnerable and frail candidates reported worse QoL and patient experiences. Severe deficits in the psychosocial subdomains of the EFS showed a strong association with patient experience and QoL, whilst physical function and medical status deficits showed a lesser association. This has highlighted specific EFS domains that may be suitable for targeted interventions to improve experiences and optimise outcomes.Peer reviewe

Frailty and the psychosocial components of the edmonton frail scale are most associated with patient experience in older kidney transplant candidates – a secondary analysis within the kidney transplantation in older people (KTOP) study

BackgroundOlder people with end-stage kidney disease (ESKD) are vulnerable to frailty, which impacts on clinical and experiential outcomes. With kidney transplantation in older people increasing, a better understanding of patient experiences is necessary for guiding decision making. The Kidney Transplantation in Older People (KTOP):impact of frailty on outcomes study aims to explore this. We present a secondary analysis of the Edmonton Frail Scale (EFS) and its relationship with patient experience scores.MethodsThe KTOP study is a single centre, prospective study, which began in October 2019. All ESKD patients aged ≥60 considered for transplantation at Imperial College Renal and Transplant Centre were eligible. Frailty was assessed using the EFS and 5 questionnaires assessed patient experience and quality of life (QoL) (Short Form-12(v2), Palliative Care Outcome Scale–Symptoms Renal, Depression Patient Health Questionnaire-9, Illness Intrusiveness Ratings Scale, Renal Treatment Satisfaction Questionnaire). The EFS was divided into 4 subdomains (psychosocial, physical function, medical status, and general health) and then compared with the questionnaire scores.Results210 patients have been recruited (aged 60-78), 186 of whom completed EFS assessments. 118 (63.4%) participants were not frail, 36 (19.4%) vulnerable, and 32 (17.2%) were frail. Worse frailty scores were associated with poorer patient experience and QoL scores across all questionnaires. Severe deficits in the EFS psychosocial subdomain showed a statistically significant association with higher depression screen scores (coefficient 4.9, 95% CI 3.22 to 6.59), lower physical (coefficient -4.35, 95% CI -7.59 to -1.12) and mental function scores (coefficient -8.33, 95% CI -11.77 to -4.88) from the Short Form-12(v2), and lower renal treatment satisfaction scores (coefficient -5.54, 95% CI -10.70 to -0.37). Deficits in the physical function and medical status EFS subdomians showed some association with patient experience scores.ConclusionIn the KTOP study cohort at recruitment vulnerable and frail candidates reported worse QoL and patient experiences. Severe deficits in the psychosocial subdomains of the EFS showed a strong association with patient experience and QoL, whilst physical function and medical status deficits showed a lesser association. This has highlighted specific EFS domains that may be suitable for targeted interventions to improve experiences and optimise outcomes

Blood transfusions post kidney transplantation are associated with inferior allograft and patient survival—it is time for rigorous patient blood management

BackgroundPatient Blood Management (PBM), endorsed by the World Health Organisation is an evidence-based, multi-disciplinary approach to minimise inappropriate blood product transfusions. Kidney transplantation presents a particular challenge to PBM, as comprehensive evidence of the risk of transfusion is lacking. The aim of this study is to investigate the prevalence of post-transplant blood transfusions across multiple centres, to analyse risk factors for transfusion and to compare transplant outcomes by transfusion status.MethodsThis analysis was co-ordinated via the UK Transplant Registry within NHS Blood and Transplant (NHSBT), and was performed across 4 centres. Patients who had received a kidney transplant over a 1-year period, had their transfusion status identified and linked to data held within the national registry.ResultsOf 720 patients, 221(30.7%) were transfused, with 214(29.7%) receiving a red blood cell (RBC) transfusion. The proportion of patients transfused at each centre ranged from 20% to 35%, with a median time to transfusion of 4 (IQR:0-12) days post-transplant. On multivariate analysis, age [OR: 1.02(1.01-1.03), p=0.001], gender [OR: 2.11(1.50-2.98), p<0.0001], ethnicity [OR: 1.28(1.28-2.60), p=0.0008], and dialysis dependence pre-transplant [OR: 1.67(1.08-2.68), p=0.02], were associated with transfusion. A risk-adjusted Cox proportional hazards model showed transfusion was associated with inferior 1-year patient survival [HR 7.94(2.08-30.27), p=0.002] and allograft survival [HR: 3.33(1.65-6.71), p=0.0008], and inferior allograft function.ConclusionRBC transfusions are common and are independently associated with inferior transplant outcomes. We urge that further research is needed to understand the mechanisms behind the outcomes, to support the urgent development of transplant-specific anaemia guidelines

Prevalence of frailty and cognitive impairment in older transplant candidates - a preview to the Kidney Transplantation in Older People (KTOP): impact of frailty on outcomes study

© The Author(s) 2022. This article is licensed under a Creative Commons Attribution 4.0 International License. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.Abstract: Background: Kidney transplantation in older people has increased, however older transplant recipients experience mixed outcomes that invariably impacts on their quality of life. The increased vulnerability of older end stage kidney disease patients to frailty and cognitive impairment, may partially explain the differences in outcomes observed. The Kidney Transplantation in Older People (KTOP): impact of frailty on clinical outcomes study is an active clinical study aiming to explore the experience of older people waiting for and undergoing transplantation. In this manuscript we present the study protocol, the study cohort, and the prevalence of frailty and cognitive impairment identified at recruitment. Methods: The KTOP study is a single centre, prospective, mixed methods, observational study. Recruitment began in October 2019. All patients aged 60 or above either active on the deceased donor waitlist or undergoing live donor transplantation were eligible for recruitment. Recruited participants completed a series of questionnaires assessing frailty, cognition, and quality of life, which are repeated at defined time points whilst on the waitlist and post-transplant. Clinical data was concurrently collected. Any participants identified as frail or vulnerable were also eligible for enrolment into the qualitative sub-study. Results: Two hundred eight participants have been recruited (age 60–78). Baseline Montreal Cognitive Assessments were available for 173 participants, with 63 (36.4%) participants identified as having scores below normal (score < 26). Edmonton Frail Scale assessments were available for 184 participants, with 29 participants (15.8%) identified as frail (score ≥ 8), and a further 37 participants (20.1%) identified as being vulnerable (score 6–7). Conclusion: In the KTOP study cohort we have identified a prevalence of 36.4% of participants with MoCA scores suggestive of cognitive impairment, and a prevalence of frailty of 15.8% at recruitment. A further 20.1% were vulnerable. As formal testing for cognition and frailty is not routinely incorporated into the work up of older people across many units, the presence and significance of these conditions is likely not known. Ultimately the KTOP study will report on how these parameters evolve over time and following a transplant, and describe their impact on quality of life and clinical outcomes.Peer reviewe

Lack of seroresponse to SARS-CoV-2 booster vaccines given early post-transplant in patients primed pre-transplantation

SARS-CoV-2 vaccines are recommended pre-transplantation, however, waning immunity and evolving variants mandate booster doses. Currently there no data to inform the optimal timing of booster doses post-transplant, in patients primed pre-transplant. We investigated serial serological samples in 204 transplant recipients who received 2 or 3 SARS-CoV-2 vaccines pre-transplant. Spike protein antibody concentrations, [anti-S], were measured on the day of transplantation and following booster doses post-transplant. In infection-naïve patients, post-booster [anti-S] did not change when V3 (1st booster) was given at 116(78-150) days post-transplant, falling from 122(32-574) to 111(34-682) BAU/ml, p=0.78. Similarly, in infection-experienced patients, [anti-S] on Day-0 and post-V3 were 1090(133-3667) and 2207(650-5618) BAU/ml respectively, p=0.26. In patients remaining infection-naïve, [anti-S] increased post-V4 (as 2nd booster) when given at 226(208-295) days post-transplant, rising from 97(34-1074) to 5134(229-5680) BAU/ml, p=0.0016. Whilst in patients who had 3 vaccines pre-transplant, who received V4 (as 1st booster) at 82(49-101) days post-transplant, [anti-S] did not change, falling from 981(396-2666) to 871(242-2092) BAU/ml, p=0.62. Overall, infection pre-transplant and [anti-S] at the time of transplantation predicted post-transplant infection risk. As [Anti-S] fail to respond to SARS-CoV-2 booster vaccines given early post-transplant, passive immunity may be beneficial to protect patients during this period

Omicron neutralising antibodies after COVID-19 vaccination in haemodialysis patients.

Funder: Kidney Research U

Antibody prevalence after three or more COVID-19 vaccine doses in individuals who are immunosuppressed in the UK: a cross-sectional study from MELODY

SummaryBackground In the UK, additional COVID-19 vaccine booster doses and treatments are offered to people who are immunosuppressed to protect against severe COVID-19, but how best to choose the individuals that receive these vaccine booster doses and treatments is unclear. We investigated the association between seropositivity to SARSCoV-2 spike protein with demographic, disease, and treatment- related characteristics after at least three COVID-19 vaccines in three cohorts of people who are immunosuppressed.Methods In a cross-sectional study using UK national disease registries, we identified, contacted, and recruited recipients of solid organ transplants, participants with rare autoimmune rheumatic diseases, and participants with lymphoid malignancies who were 18 years or older, resident in the UK, and who had received at least three doses of a COVID-19 vaccine. The study was open to recruitment from Dec 7, 2021, to June 26, 2022. Participants received a lateral flow immunoassay test for SARS-CoV-2 spike antibodies to complete at home, and an online questionnaire. Multivariable logistic regression was used to estimate the mutually adjusted odds of seropositivity against each characteristic.FindingsBetween Feb 14 and June 26, 2022, we screened 101 972 people (98 725 invited, 3247 self-enrolled) and recruited 28 411 (27·9%) to the study. 23 036 (81·1%) recruited individuals provided serological data. Of these, 9927 (43·1%) were recipients of solid organ transplants, 6516 (28·3%) had rare autoimmune rheumatic diseases, and 6593 (28·6%) had lymphoid malignancies. 10 485 (45·5%) participants were men and 12 535 (54·4%) were women (gender was not reported for 16 [<0·1%] participants), and 21661 (94·0%) participants were of White ethnicity. The median age of participants with solid organ transplants was 60 years (SD 50–67), with rare autoimmune rheumatic diseases was 65 years (54–73), and with lymphoid malignancy was 69 years (61–75). Of the 23 036 participants with serological data, 6583 (28·6%) had received three vaccine doses, 14 234 (61·8%) had received four vaccine doses, and 2219 (9·6%) had received five or more vaccine doses. IgG anti-spike antibodies were undetectable in 2310 (23·3%) of 9927 patients with solid organ transplants, 922 (14·1%) of 6516 patients with rare autoimmune rheumatic diseases, and 1366 (20·7%) of 6593 patients with lymphoid malignancies. In all groups, seropositivity was associated with younger age, higher number of vaccine doses (ie, five vs three), and previous COVID-19. Immunosuppressive medication reduced the likelihood of seropositivity: the lowest odds of seropositivity were found in recipients of solid organ transplants receiving a combination of an anti-proliferative agent, a calcineurin inhibitor, and steroids, and those with rare autoimmune rheumatic diseases or lymphoid malignancies treated with anti-CD20 therapies. InterpretationApproximately one in five recipients of solid organ transplants, individuals with rare autoimmune rheumatic diseases, and individuals with lymphoid malignancies have no detectable IgG anti-spike antibodies despite three or more vaccine doses, but this proportion decreases with sequential booster doses. Choice of immunosuppressant and disease type is strongly associated with serological response. Antibody testing using lateral flow immunoassay tests could enable rapid identification of individuals who are most likely to benefit from additional COVID-19 interventions

Longitudinal proteomic profiling of dialysis patients with COVID-19 reveals markers of severity and predictors of death

Funder: The Sidharth Burman endowmentEnd-stage kidney disease (ESKD) patients are at high risk of severe COVID-19. We measured 436 circulating proteins in serial blood samples from hospitalised and non-hospitalised ESKD patients with COVID-19 (n = 256 samples from 55 patients). Comparison to 51 non-infected patients revealed 221 differentially expressed proteins, with consistent results in a separate subcohort of 46 COVID-19 patients. Two hundred and three proteins were associated with clinical severity, including IL6, markers of monocyte recruitment (e.g. CCL2, CCL7), neutrophil activation (e.g. proteinase-3), and epithelial injury (e.g. KRT19). Machine-learning identified predictors of severity including IL18BP, CTSD, GDF15, and KRT19. Survival analysis with joint models revealed 69 predictors of death. Longitudinal modelling with linear mixed models uncovered 32 proteins displaying different temporal profiles in severe versus non-severe disease, including integrins and adhesion molecules. These data implicate epithelial damage, innate immune activation, and leucocyte–endothelial interactions in the pathology of severe COVID-19 and provide a resource for identifying drug targets

Factors associated with COVID-19 vaccine uptake in people with kidney disease: an OpenSAFELY cohort study.

OBJECTIVE: To characterise factors associated with COVID-19 vaccine uptake among people with kidney disease in England. DESIGN: Retrospective cohort study using the OpenSAFELY-TPP platform, performed with the approval of NHS England. SETTING: Individual-level routine clinical data from 24 million people across GPs in England using TPP software. Primary care data were linked directly with COVID-19 vaccine records up to 31 August 2022 and with renal replacement therapy (RRT) status via the UK Renal Registry (UKRR). PARTICIPANTS: A cohort of adults with stage 3-5 chronic kidney disease (CKD) or receiving RRT at the start of the COVID-19 vaccine roll-out was identified based on evidence of reduced estimated glomerular filtration rate (eGFR) or inclusion in the UKRR. MAIN OUTCOME MEASURES: Dose-specific vaccine coverage over time was determined from 1 December 2020 to 31 August 2022. Individual-level factors associated with receipt of a 3-dose or 4-dose vaccine series were explored via Cox proportional hazards models. RESULTS: 992 205 people with stage 3-5 CKD or receiving RRT were included. Cumulative vaccine coverage as of 31 August 2022 was 97.5%, 97.0% and 93.9% for doses 1, 2 and 3, respectively, and 81.9% for dose 4 among individuals with one or more indications for eligibility. Delayed 3-dose vaccine uptake was associated with younger age, minority ethnicity, social deprivation and severe mental illness-associations that were consistent across CKD severity subgroups, dialysis patients and kidney transplant recipients. Similar associations were observed for 4-dose uptake. CONCLUSION: Although high primary vaccine and booster dose coverage has been achieved among people with kidney disease in England, key disparities in vaccine uptake remain across clinical and demographic groups and 4-dose coverage is suboptimal. Targeted interventions are needed to identify barriers to vaccine uptake among under-vaccinated subgroups identified in the present study