Utilising organs from hepatitis C virus PCR-positive donors in Western Australia.

We transplanted six solid organs from three hepatitis C virus (HCV) polymerase chain reaction (PCR)-positive donors during 2018-2023. Recipients were treated with glecaprevir/pibrentasvir or sofosbuvir/velpatasvir for 4-12 weeks, with all six achieving sustained virological response without significant adverse events. As occurs in other jurisdictions, solid organ transplants from HCR PCR-positive donors can be safely utilised in Australia.

Markers of terminally differentiated T-cells as predictors of vascular health in renal transplant recipients and healthy adults.

Meta-analyses confirm a link between persistent human cytomegalovirus (HCMV) infections and cardiovascular disease, but the mechanisms are unclear. We assess whether proportions of T-cell populations are reliable predictors of subclinical atherosclerosis and/or reflect the burden of HCMV in healthy adults and renal transplant recipients (RTR). Samples were collected from healthy adults and RTR at baseline (T0) and after 32 (24-40) months (T1). Left carotid intima media thickness (cIMT) and proportions of T-cells expressing CD57, LIR-1 or the TEMRA phenotype increased in healthy adults and RTR. The T-cell populations correlated with levels of HCMV-reactive antibodies. Proportions of CD57+, LIR-1+ and TEMRA CD8+ T-cells correlated with left and right cIMT in healthy adults. Proportions of CD57+ and LIR-1+ CD8+ T-cells at T0 predicted left cIMT at T1 among healthy adults, but these associations disappeared after adjustment for covariates. We link LIR-1+ and CD57+CD8+ T-cells with the progression of cIMT in healthy adults.

A novel allocation strategy for the difficult-to-allocate donor: audit of deceased donor kidneys utilised for preemptive recipients within Western Australia.

Kidney donor allocation can occasionally be difficult in Australia given a small population spread over vast distances. Therefore, between 2017 and 2019 our service allowed transplantation from deceased donors into local (same-state) preemptive recipients, only if no well-matched dialysis-dependent transplant waitlist recipient was available. Transplantation using this novel allocation pathway was associated with good clinical and immunological outcomes.

Do variations in the HLA-E ligand encoded by UL40 distinguish individuals susceptible to HCMV disease?

Human cytomegalovirus (HCMV) is carried lifelong by ∼80 % of adults worldwide, generating distinct disease syndromes in transplant recipients, people with HIV (PWH) and neonates. Amino acids 15-23 encoded by the HCMV gene UL40 match positions 3-11 of HLA-A and HLA-C, and constitute a "signal peptide" able to stabilise cell surface HLA-E as a restriction element and a ligand of NKG2A and NKG2C. We present next generation sequencing of UL40 amplified from 15 Australian renal transplant recipients (RTR), six healthy adults and four neonates, and 21 Indonesian PWH. We found no groupwise associations between the presence of multiple sequences and HCMV burden (highest in PWH) or HCMV-associated symptoms in neonates. Homology between UL40 and corresponding HLA-C and HLA-A peptides in 11 RTR revealed perfect matches with HLA-C in three individuals, all carrying HCMV encoding only VMAPRTLIL - a peptide previously associated with viremia. However indices of the burden of HCMV did not segregate in our cohort.

Variants of HCMV UL18 Sequenced Directly from Clinical Specimens Associate with Antibody and T-Cell Responses to HCMV.

Around 80% of adults worldwide carry human cytomegaloviris (HCMV). The HCMV gene UL18 is a homolog of HLA class I genes and encodes a protein with high affinity for the NK and T-cell cytotoxicity inhibitor LIR-1. UL18 was deep sequenced from blood, saliva or urine from Indonesian people with HIV (PWH) (n = 28), Australian renal transplant recipients (RTR) (n = 21), healthy adults (n = 7) and neonates (n = 4). 95% of samples contained more than one variant of HCMV UL18, as defined by carriage of nonsynonymous variations. When aligned with immunological markers of the host's burden of HCMV, the S318N variation associated with high levels of antibody reactive with HCMV lysate in PWH over 12 months on antiretroviral therapy. The A107T variation associated with HCMV antibody levels and inflammatory biomarkers in PWH at early timepoints. Variants D32G, D248N, V250A and E252D aligned with elevated HCMV antibody levels in RTR, while M191K, E196Q and F165L were associated with HCMV-reactive T-cells and proportions of Vδ2- γδ T-cells-populations linked with high burdens of HCMV. We conclude that UL18 is a highly variable gene, where variation may alter the persistent burden of HCMV and/or the host response to that burden.

Prediction models used in the progression of chronic kidney disease: A scoping review.

OBJECTIVE: To provide a review of prediction models that have been used to measure clinical or pathological progression of chronic kidney disease (CKD). DESIGN: Scoping review. DATA SOURCES: Medline, EMBASE, CINAHL and Scopus from the year 2011 to 17th February 2022. STUDY SELECTION: All English written studies that are published in peer-reviewed journals in any country, that developed at least a statistical or computational model that predicted the risk of CKD progression. DATA EXTRACTION: Eligible studies for full text review were assessed on the methods that were used to predict the progression of CKD. The type of information extracted included: the author(s), title of article, year of publication, study dates, study location, number of participants, study design, predicted outcomes, type of prediction model, prediction variables used, validation assessment, limitations and implications. RESULTS: From 516 studies, 33 were included for full-text review. A qualitative analysis of the articles was compared following the extracted information. The study populations across the studies were heterogenous and data acquired by the studies were sourced from different levels and locations of healthcare systems. 31 studies implemented supervised models, and 2 studies included unsupervised models. Regardless of the model used, the predicted outcome included measurement of risk of progression towards end-stage kidney disease (ESKD) of related definitions, over given time intervals. However, there is a lack of reporting consistency on details of the development of their prediction models. CONCLUSIONS: Researchers are working towards producing an effective model to provide key insights into the progression of CKD. This review found that cox regression modelling was predominantly used among the small number of studies in the review. This made it difficult to perform a comparison between ML algorithms, more so when different validation methods were used in different cohort types. There needs to be increased investment in a more consistent and reproducible approach for future studies looking to develop risk prediction models for CKD progression.

A comparison of arteriovenous fistula failure between Malaysian and Australian and New Zealand participants enrolled in the FAVOURED trial.

AIM: To describe and compare de novo arteriovenous fistula (AVF) failure rates between Australia and New Zealand (ANZ), and Malaysia. BACKGROUND: AVFs are preferred for haemodialysis access but are limited by high rates of early failure. METHODS: A post hoc analysis of 353 participants from ANZ and Malaysia included in the FAVOURED randomised-controlled trial undergoing de novo AVF surgery was performed. Composite AVF failure (thrombosis, abandonment, cannulation failure) and its individual components were compared between ANZ (n = 209) and Malaysian (n = 144) participants using logistic regression adjusted for patient- and potentially modifiable clinical factors. RESULTS: Participants' mean age was 55 ± 14.3 years and 64% were male. Compared with ANZ participants, Malaysian participants were younger with lower body mass index, higher prevalence of diabetes mellitus and lower prevalence of cardiovascular disease. AVF failure was less frequent in the Malaysian cohort (38% vs 54%; adjusted odds ratio (OR) 0.53, 95% confidence interval (CI) 0.31-0.93). This difference was driven by lower odds of cannulation failure (29% vs 47%, OR 0.45, 95% CI 0.25-0.80), while the odds of AVF thrombosis (17% vs 20%, OR 1.24, 95% CI 0.62-2.48) and abandonment (25% vs 23%, OR 1.17, 95% CI 0.62-2.16) were similar. CONCLUSIONS: The risk of AVF failure was significantly lower in Malaysia compared to ANZ and driven by a lower risk of cannulation failure. Differences in practice patterns, including patient selection, surgical techniques, anaesthesia or cannulation techniques may account for regional outcome differences and warrant further investigation.

Sequencing of the Viral UL111a Gene Directly from Clinical Specimens Reveals Variants of HCMV-Encoded IL-10 That Are Associated with Altered Immune Responses to HCMV.

Human cytomegalovirus (HCMV) is a beta-herpesvirus carried by ~80% of adults worldwide. Acute infections are often asymptomatic in healthy individuals but generate diverse syndromes in neonates, renal transplant recipients (RTR), and people with HIV (PWH). The HCMV gene UL111a encodes a homolog of human interleukin-10 (IL-10) that interacts with the human IL-10 receptor. Deep sequencing technologies were used to sequence UL111a directly from 59 clinical samples from Indonesian PWH and Australian RTR, healthy adults, and neonates. Overall, 93% of samples contained more than one variant of HCMV, as defined by at least one nonsynonymous variation. Carriage of these variants differed between neonates and adults, Australians and Indonesians, and between saliva and blood leukocytes. The variant alleles of N41D and S71Y occurred together in Australian RTR and were associated with higher T-cell responses to HCMV pp65. The variant P122S was associated with lower levels of antibodies reactive with a lysate of HCMV-infected fibroblasts. L174F was associated with increased levels of antibodies reactive with HCMV lysate, immediate-early 1 (IE-1), and glycoprotein B (gB) in Australian RTR and Indonesians PWH, suggesting a higher viral burden. We conclude that variants of UL111a are common in all populations and may influence systemic responses to HCMV.

mTOR Inhibitors Induce Erythropoietin Resistance in Renal Transplant Recipients.

Aim: To elucidate the role of mTOR inhibitors on iron, hepcidin and erythropoietin-mediated regulation of hemopoiesis in stable renal transplant recipients (RTR). Background: Impaired hemopoiesis is common following renal transplantation managed using mTOR inhibitors. The mechanisms responsible are uncertain but include direct effects on iron, hepcidin or erythropoietin-mediated hemopoiesis. Methods: We conducted a single center prospective case-control study of 26 adult RTR with stable allograft function. RTR received stable mTOR dosing (cases, 11/26 [42%]) or stable tacrolimus dosing (controls, 15/26 [58%]). Baseline demographics, full blood count, renal function, iron studies, hepcidin-25, Interleukin-6 (IL-6) and erythropoietin (EPO) levels were determined. Results: There were no differences in age, gender or allograft function. Mean daily sirolimus dose for cases was 1.72 mg, with mean trough level of 8.46 ng/mL. Mean daily tacrolimus dose for controls was 4.3 mg, with mean trough level of 5.8 ng/mL. There were no differences in mean hemoglobin (143 vs. 147 g/L; p = 0.59), MCV (88 vs. 90 fL; p = 0.35), serum ferritin (150 vs. 85.7 µg/L; p = 0.06), transferrin saturation (26 vs. 23.3%; p = 0.46), IL-6 (11 vs. 7.02 pg/ml; p = 0.14) or hepcidin-25 (3.62 vs. 3.26 nM; p = 0.76) between the groups. EPO levels were significantly higher in the group receiving mTOR therapy (16.8 vs. 8.49 IU/L; p = 0.028). On logistic regression analysis EPO level was the only variable that had a significant impact providing an odds ratio of 0.84 (95%CI 0.66-0.98). The area under the receiver operator characteristic curve (ROC) for the analysis was 0.77 (95%CI 0.54-0.94) with p = 0.04.Conclusion: Higher levels of EPO in the absence of deranged iron biochemistry or hepcidin-25 levels suggest that EPO resistance rather than impaired iron metabolism may contribute to the impaired hemopoiesis previously demonstrated in RTR on mTOR therapy.

Dietary habits in Australian, New Zealand and Malaysian patients with end stage kidney failure: A pre-specified cross-sectional study of the FAVOURED trial participants.

BACKGROUND: Dietary management plays an important role in patients with kidney failure. Current dietary habits of Australians and New Zealanders (ANZ) and Malaysians with chronic kidney disease (CKD Stage 4-5) have not been adequately investigated. We report the dietary habits of people with advanced CKD and their adherence to country-specific dietary guidelines. METHODS: Participants with CKD Stage 4-5, enrolled in the Omega-3 Fatty Acids (Fish oils) and Aspirin in Vascular access Outcomes in Renal Disease (FAVOURED) trial, completed a lifestyle questionnaire at baseline on their dietary intake. RESULTS: Of 567 participants, 538 (ANZ, n = 386; Malaysian, n = 152; mean ± SD age 54.8 ± 14.3 years, 64% male) completed the questionnaire. Dietary fruit and vegetable intakes were higher in ANZ participants; 49% (n = 189) consumed ≥2 serves day-1 of fruit and 61% (n = 235) ate ≥2 serves day-1 of vegetables compared to 24% (n = 36) and 34% (n = 52) of Malaysians, respectively (p < 0.0001). Only 4% (n = 15) of ANZ participants met Australian Dietary recommendations of two fruit and five vegetable serves day-1 . Fish consumption was higher in Malaysians with 83% (n = 126) consuming ≥2 serves week-1 compared to 21% (n = 81) of ANZ participants (p < 0.001). Red meat intake was higher in ANZ participants; however, chicken consumption was similar; 48% (n = 185) consumed >2 chicken serves week-1 and 65% (n = 251) ate >2 serves week-1 of red meat compared to 43% (n = 65) and 15% (n = 23) of Malaysians, respectively. CONCLUSIONS: Significant regional variation in dietary intake for fruit, vegetables and animal protein is described that likely reflects cultural and economic differences. Barriers to meeting recommended dietary intakes require further investigation.

Challenging the Conventional Interpretation of HCMV Seronegativity.

The majority of adults in the world (around 83%) carry antibodies reactive with HCMV and are thought to retain inactive or latent infections lifelong. The virus is transmitted via saliva, so infection events are likely to be common. Indeed, it is hard to imagine a life without exposure to HCMV. From 45 seronegative individuals (13 renal transplant recipients, 32 healthy adults), we present seven cases who had detectable HCMV DNA in their blood and/or saliva, or a CMV-encoded homologue of IL-10 (vIL-10) in their plasma. One case displayed NK cells characteristic of CMV infection before her HCMV DNA became undetectable. In other cases, the infection may persist with seroconversion blocked by vIL-10. Future research should seek mechanisms that can prevent an individual from seroconverting despite a persistent HCMV infection, as HCMV vaccines may not work well in such people.

Sequencing Directly from Clinical Specimens Reveals Genetic Variations in HCMV-Encoded Chemokine Receptor US28 That May Influence Antibody Levels and Interactions with Human Chemokines.

Human cytomegalovirus (HCMV) is a beta-herpesvirus carried by ∼80% of the world's population. Acute infections are asymptomatic in healthy individuals but generate diverse syndromes in neonates, solid organ transplant recipients, and HIV-infected individuals. The HCMV gene US28 encodes a homolog of a human chemokine receptor that is able to bind several chemokines and HIV gp120. Deep sequencing technologies were used to sequence US28 directly from 60 clinical samples from Indonesian HIV patients and Australian renal transplant recipients, healthy adults, and neonates. Molecular modeling approaches were used to predict whether nine nonsynonymous mutations in US28 may alter protein binding to a panel of six chemokines and two variants of HIV gp120. Ninety-two percent of samples contained more than one variant of HCMV, as defined by at least one nonsynonymous mutation. Carriage of these variants differed between neonates and adults, Australian and Indonesian samples, and saliva samples and blood leukocytes. Two nonsynonymous mutations (N170D and R267K) were associated with increased levels of immediate early protein 1 (IE-1) and glycoprotein B (gB) HCMV-reactive antibodies, suggesting a higher viral burden. Seven of the nine mutations were predicted to alter binding of at least one ligand. Overall, HCMV variants are common in all populations and have the potential to affect US28 interactions with human chemokines and/or gp120 and alter responses to the virus. The findings relied on deep sequencing technologies applied directly to clinical samples, so the variants exist in vivo. IMPORTANCE Human cytomegalovirus (HCMV) is a common viral pathogen of solid organ transplant recipients, neonates, and HIV-infected individuals. HCMV encodes homologs of several host genes with the potential to influence viral persistence and/or pathogenesis. Here, we present deep sequencing of an HCMV chemokine receptor homolog, US28, acquired directly from clinical specimens. Carriage of these variants differed between patient groups and was associated with different levels of circulating HCMV-reactive antibodies. These features are consistent with a role for US28 in HCMV persistence and pathogenesis. This was supported by in silico analyses of the variant sequences demonstrating altered ligand-binding profiles. The data delineate a novel approach to understanding the pathogenesis of HCMV and may impact the development of an effective vaccine.

Center-Effect of Incident Hemodialysis Vascular Access Use: Analysis of a Bi-national Registry.

Background: Commencing hemodialysis (HD) with an arteriovenous access is associated with superior patient outcomes compared with a catheter, but the majority of patients in Australia and New Zealand initiate HD with a central venous catheter. This study examined patient and center factors associated with arteriovenous fistula/graft access use at HD commencement. Methods: We included all adult patients starting chronic HD in Australia and New Zealand between 2004 and 2015. Access type at HD initiation was analyzed using logistic regression. Patient-level factors included sex, age, race, body mass index (BMI), smoking status, primary kidney disease, late nephrologist referral, comorbidities, and prior RRT. Center-level factors included size; transplant capability; home HD proportion; incident peritoneal dialysis (average number of patients commencing RRT with peritoneal dialysis per year); mean weekly HD hours; average blood flow; and achievement of phosphate, hemoglobin, and weekly Kt/V targets. The study included 27,123 patients from 61 centers. Results: Arteriovenous access use at HD commencement varied four-fold from 15% to 62% (median 39%) across centers. Incident arteriovenous access use was more likely in patients aged 51-72 years, males, and patients with a BMI of >25 kg/m2 and polycystic kidney disease; but use was less likely in patients with a BMI of <18.5 kg/m2, late nephrologist referral, diabetes mellitus, cardiovascular disease, chronic lung disease, and prior RRT. Starting HD with an arteriovenous access was less likely in centers with the highest proportion of home HD, and no center factor was associated with higher arteriovenous access use. Adjustment for center-level characteristics resulted in a 25% reduction in observed intercenter variability of arteriovenous access use at HD initiation compared with the model adjusted for only patient-level characteristics. Conclusions: This study identified several patient and center factors associated with incident HD access use, yet these factors did not fully explain the substantial variability in arteriovenous access use across centers.

Human Cytomegalovirus-Encoded microRNAs Can Be Found in Saliva Samples from Renal Transplant Recipients.

Human cytomegalovirus (HCMV) infections are common following renal transplantation and may have long-lasting effects. HCMV can be measured directly by viral DNA or indirectly via host immune responses. HCMV-encoded microRNA (miRNA) may alter the pathobiology of HCMV infections and contribute to the progression of HCMV disease. HCMV-encoded miRNAs can be detected in blood but have not been sought in saliva. We investigated saliva samples from 32 renal transplant recipients (RTR) and 12 seropositive healthy controls for whom immunological data was available. Five HCMV-encoded miRNAs (miR-UL112-5p, miR-US5-2-3p, miR-UL36, miR-US25-2-3p and miR-UL22A) were sought using primer probe assays. HCMV miRNA species were detected in saliva from 15 RTR and 3 healthy controls, with miR-US5-2-3p most commonly detected. The presence of HCMV miRNAs associated with increased T-cell responses to HCMV IE-1 in RTR, suggesting a link with frequent reactivations of HCMV.

Allograft and Patient Outcomes Between Indigenous and Nonindigenous Kidney Transplant Recipients.

BACKGROUND: Kidney transplant outcomes of indigenous Australians are poorer compared with nonindigenous Australians, but it is unknown whether the type of acute rejection differs between these patient groups or whether rejection mediates the effect between ethnicity, death-censored graft failure (DCGF), and death with a functioning graft (DWFG). METHODS: Biopsy-proven acute rejection (BPAR) rates and types were compared between indigenous and nonindigenous recipients. The associations between ethnicity, BPAR, DCGF, and DWFG were examined using adjusted competing risk analyses, and mediation analysis was conducted to determine whether BPAR mediated the adverse effects between ethnicity and outcomes. RESULTS: Fifty-seven (9.3%) of 616 patients who have received kidney-only transplants between 2000 and 2010 in Western Australia were indigenous. Compared with nonindigenous recipients, BPAR rates were higher in indigenous recipients (42 versus 74 episodes/100 recipients, P < 0.01), with an excess of antibody-mediated rejections. During a median follow-up of 8 years, indigenous recipients were more likely to experience BPAR, DCGF, and DWFG compared with nonindigenous recipients, with adjusted subdistribution hazard ratio of 1.94 (1.39-2.70), 1.53 (0.85-2.76; P = 0.159), and 2.14 (1.13-4.06; P = 0.020), respectively. Although 70% of the effect between ethnicity and DCGF was mediated by BPAR, no similar association was found for DWFG. CONCLUSIONS: Indigenous recipients experienced poorer allograft and patient outcomes compared with nonindigenous recipients, with BPAR an important determinant for DCGF. Future research identifying other risk factors and mediators associated with patient survival in indigenous recipients should be considered a priority.

Cytomegalovirus burden improves a predictive model identifying measures of vascular risk in renal transplant recipients and healthy adults.

Cytomegalovirus (CMV) has been implicated in vascular pathologies and may warrant inclusion in cardiovascular predictive algorithms. We addressed this in healthy older adults and renal transplant recipients (RTR) as they retain a high burden of CMV. RTR (n = 45) stable more than 2 years after transplantation and 58 age-matched healthy adults were assessed. Plasma inflammatory biomarkers (soluble isoform of the interferon-ß receptor [sIFNAR2], soluble tumour necrosis factorreceptor-1 [sTNFR1], soluble cluster of differentiation 14 [sCD14], C reactive protein, P-selectin, intracellular cell adhesion molecule-1, vascular cell adhesion molecule-1), and measures of CMV burden (antibodies, saliva CMV DNA, and interferon γ responses to CMV) were assessed in 2014 and evaluated in 2017 as predictors of vascular health-defined using flow-mediated dilatation (FMD), pulse wave velocity (PWV), and augmentation indices (Aix@ 75). Linear regression models adjusted for age, sex, and body mass index (BMI) were optimized to identify risk factors. In 2017, RTR had inferior vascular health marked by impaired FMD and PWV. Detectable CMV DNA (P = .02) was associated with impaired FMD, whilst CMV glycoprotein B (gB) antibody attenuated this effect (P = .03) (adjusted R2 = .42). In healthy adults, the optimal model for predicting FMD (R2 =.22) incorporated high P-selectin (P = .03) and low ICAM-1 (P = .03) levels with no significant impact of CMV. Elevated sIFNAR2 (P = .04) and gB antibody (P = .06) levels predicted increasing Aix@ 75 (poor vascular health) in healthy adults (R2 = .4), whilst optimal models for RTR (R2 = .37) linked low sIFNAR2 and CMV IE-1 antibody levels with lower Aix@ 75 (better vascular health). CMV IE-1 antibody was also protective in relation to PWV in healthy adults (R2 = .55). Overall, measures of active CMV replication were more predictive of impaired FMD in RTR than standard biomarkers, but increased CMV gB antibodies may be protective.