Characterization of a distinct population of circulating human non-adherent endothelial forming cells and their recruitment via intercellular adhesion molecule-3

Circulating vascular progenitor cells contribute to the pathological vasculogenesis of cancer whilst on the other hand offer much promise in therapeutic revascularization in post-occlusion intervention in cardiovascular disease. However, their characterization has been hampered by the many variables to produce them as well as their described phenotypic and functional heterogeneity. Herein we have isolated, enriched for and then characterized a human umbilical cord blood derived CD133+ population of non-adherent endothelial forming cells (naEFCs) which expressed the hematopoietic progenitor cell markers (CD133, CD34, CD117, CD90 and CD38) together with mature endothelial cell markers (VEGFR2, CD144 and CD31). These cells also expressed low levels of CD45 but did not express the lymphoid markers (CD3, CD4, CD8)or myeloid markers (CD11b and CD14) which distinguishes them from ‘early’ endothelial progenitor cells (EPCs). Functional studies demonstrated that these naEFCs (i) bound Ulex europaeus lectin, (ii)demonstrated acetylated-low density lipoprotein uptake, (iii) increased vascular cell adhesion molecule (VCAM-1) surface expression in response to tumor necrosis factor and (iv) in co-culture with mature endothelial cells increased the number of tubes, tubule branching and loops in a 3- dimensional in vitro matrix. More importantly, naEFCs placed in vivo generated new lumen containing vasculature lined by CD144 expressing human endothelial cells (ECs). Extensive genomic and proteomic analyses of the naEFCs showed that intercellular adhesion molecule (ICAM)-3 is expressed on their cell surface but not on mature endothelial cells. Furthermore, functional analysis demonstrated that ICAM-3 mediated the rolling and adhesive events of the naEFCs under shear stress. We suggest that the distinct population of naEFCs identified and characterized here represents a new valuable therapeutic target to control aberrant vasculogenesis.Sarah L. Appleby, Michaelia P. Cockshell, Jyotsna B. Pippal, Emma J. Thompson, Jeffrey M. Barrett, Katie Tooley, Shaundeep Sen, Wai Yan Sun, Randall Grose, Ian Nicholson, Vitalina Levina, Ira Cooke, Gert Talbo, Angel F. Lopez and Claudine S. Bonde

Endothelial progenitor cells, uraemic toxins, and the development of endothelial dysfunction in chronic kidney disease.

Morbidity and mortality rates for cardiovascular disease (CVD) are increased among end stage kidney disease (ESKD) patients receiving dialysis treatment, and not corrected with kidney transplantation (KTx). Classic CVD risk factors do not fully predict the increased risk, with novel factors causing endothelial dysfunction (ED), leading to arteriosclerosis, congestive heart failure (CHF) and sudden death, key to disease pathogenesis. These novel factors include bone marrow (BM) derived endothelial progenitor cells (EPCs), which have key roles in maintenance, repair and growth of the endothelium. There is limited data about the role of EPCs and CVD in the ESKD population. This uraemic milieu includes p-cresol (sulfate, PC/S) and indoxyl sulfate (IS), toxins associated with CVD in ESKD. In this thesis, the relationship between CVD and ESKD, and the potential role of EPCs and uraemic toxins was examined from epidemiological, clinical and laboratory perspectives. Data was obtained for the period between 2002-2007 for all hospital separations in Australia. Analysis was performed based on ICD-9/10 coding. This showed (for the first time in an Australian population): (i) an increase in risk for CVD hospital separations among dialysis and KTx, with higher rates for CHF than acute cardiac events (ACE); (ii) an advantage for KTx recipients in regards to ACE, but not CHF hospital separations, over dialysis recipients, and (iii) for CHF, no increase in in-hospital mortality, or length of stay per separation for any ESKD group compared to controls. At a clinical level, in groups of haemodialysis (HDx), KTx patients and controls, low peripheral blood (PB) EPC numbers were correlated with surrogate markers of CVD and ED. No clear relationship of IS and PC/S with ED was seen (although study power was limited). For in vitro studies, techniques were developed for isolation (Flow sort and AutoMACS), enumeration (FACS) and culture expansion of EPCs from BM and umbilical cord blood samples. The effects of uraemic serum and toxins PC and IS on cultured endothelial cells (ECs) and EPCs in vitro was examined, as a model of vascular pathology in ESKD. Greater HUVEC VCAM-1 expression and reduced tube formation in Matrigel were observed in response to increasing PC concentration than IS. The effect of IS (but not PC) at higher concentration in Matrigel was reduced by the addition of EPCs. Akt/ERK expression by western blot, cell migration to VEGF, and supernatant investigation by FlowCytoMix for soluble cell surface markers, were also performed. Testing of HUVEC function post-exposure to sera from control, transplant and HDx recipients did not replicate the above results on the basis of sera PC and IS levels. In summary, this thesis has explored the increased burden of CVD in ESKD patients in Australia, the relationship of EPCs, both in vivo and in vitro, to vascular disease in this setting, and the role of uraemic toxins as agents for CVD. These results underline why certain therapies may not be effective in the ESKD population for CVD prevention, and suggest novel approaches are needed.Thesis (Ph.D.) -- University of Adelaide, School of Medicine, 201

SO017EFFECT OF HIGH-CUTOFF DIALYSIS FOR ACUTE KIDNEY INJURY SECONDARY TO CAST NEPHROPATHY IN PATIENTS WITH MULTIPLE MYELOMA: A SYSTEMATIC REVIEW AND META-ANALYSIS

Abstract Background and Aims The incidence of multiple myeloma (MM) is increasing. Abnormal secretion of serum free light chains (sFLC) can lead to cast nephropathy and severe acute kidney injury (AKI) requiring haemodialysis (HD), which is associated with increased morbidity and mortality. High cut-off (HCO) HD membranes demonstrate better sFLC clearance. However, their role in all-cause mortality and renal recovery remains uncertain. Method A systematic review and meta-analysis was performed examining all randomized controlled trials (RCTs) and observational studies assessing the effect of high cut-off HD compared to conventional HD on clinical outcomes of patients with MM complicated by cast nephropathy induced-severe AKI. Medline, EMBASE, and the Cochrane Central Register of Controlled Trials were searched until September 2019. The primary outcome was all-cause mortality at the end of the study. The secondary outcomes included all-cause mortality at 12 months, haemodialysis independence at 3, 6 and 12 months, biopsy-proven haematologic responses at 90 days and sFLC (kappa and lambda) reduction. Random effect models were used to pool relative risks (RR) with 95% confidence intervals (CIs) for individual studies. Results The search identified 5 studies including 276 patients with a mean follow-up of 18.7 months. There were 2 RCTs and 3 retrospective cohort studies. Compared with patients treated with conventional HD, patients on HCO dialysis did not show survival benefits at 12 months (4 studies, 186 patients, RR 0.79; 95% CI 0.46-1.36), or at the end of the study (5 studies, 276 patients, RR 0.86; 95% CI 0.60-1.25). Although survival benefits at the end of study (3 studies, 88 patients, RR 0.64; 95% CI 0.45-0.90) were seen in observational studies, no differences in all-cause mortality was seen in RCTs (2 studies, 188 patients, RR 1.31; 95% CI 0.50-3.46). Likewise, although the pooled data from the observational studies demonstrated significantly higher rates of HD independence at 90 days (2 trials, 78 patients, RR 2.23; 95% CI 1.09-4.55), this difference disappeared when the data from RCTs were included to the analysis (4 studies, 266 patients, RR 1.28; 95% CI 0.95-1.73).  There was no difference in HD Independence at 6 months (2 studies, 188 patients, RR 1.19; 95% CI 0.68-2.06), and 12 months (2 studies, 188 patients, RR 1.14; 95% CI 0.58-2.26) between these two therapies. Patients receiving HCO dialysis, however, had significantly better biopsy-proven haematologic response at 90 days by 40% (3 studies, 176 patients, RR 1,40; 95% CI 1.13-1.74) and a significantly higher kappa light chain reduction (2 studies, 188 patients, standardized mean difference (SMD) 2.37; 95% CI 1.99-2.75; I2 = 0%). Overall, the majority of the studies were of suboptimal quality and underpowered. Conclusion Current evidence from RCTs and observational studies suggest HCO dialysis provides haematological benefits but makes no significant improvement in all-cause mortality and renal outcomes, compared to conventional HD for patients with multiple myeloma associated cast nephropathy. However, there is a trend towards better renal outcomes, therefore further large-scale RCTs are needed to assess the effect of HCO dialysis on clinical outcomes in patients with multiple myeloma complicated by cast-nephropathy. </jats:sec

The Impact of Clinical Presentation on Survival in Patients Requiring Hemodialysis Catheters for Acute and Unplanned Dialysis: A Prospective Observational Study

Background: Most studies addressing hemodialysis initiation with a dialysis catheter focus on patients entering maintenance dialysis programs and exclude other patients, such as those with acute kidney injury (AKI), making interpretation and application of the results difficult for clinicians managing patients at the time of dialysis commencement. Objective: To compare the survival of all patients requiring a catheter for hemodialysis access according to the nature of clinical presentation. Design: Prospective observational. Setting: An Australian tertiary renal unit. Patients: All patients requiring a central venous catheter (CVC) for hemodialysis access between 2005 and 2015. Measurements: Baseline comorbidities, demographics, and nature of clinical presentation. Data regarding each episode of dialysis access insufficiency and each CVC were collected. The primary outcome was all-cause mortality. Methods: Patients were classified into 1 of 3 groups based on physician assessment at the time of presentation: patients believed to have AKI with expected renal recovery (AKI), patients considered to be entering the maintenance dialysis program without a functioning dialysis access (Maintenance Dialysis), patients unable to perform peritoneal dialysis, or use their existing hemodialysis access (Access Failure). Time-split multivariable Cox regression analyses were used to compare survival between groups. Results: A total of 557 eligible patients had complete prospective data regarding CVC use and were included in the analyses. The majority of patients were in the AKI (246/557, 44%) and Maintenance Dialysis groups (182/557, 33%) compared with the Access Failure group (129/557, 23%). During a median follow-up of 3 years, 302 (54%) of the 557 patients died. Following adjustment, risk of all-cause mortality was higher in the AKI group (hazard ratio [HR]: 2.01, 95% confidence interval [CI]: 1.31-3.60, P = .001) during the first 2 years after catheter insertion and lower in years 2 to 4 (HR: 0.42, 95% CI: 0.20-0.88, P = .02) than in the reference Maintenance Dialysis group. No difference in mortality risk between the Access Failure and reference group was found. Limitations: Single-center study. Possible residual confounding owing to the observational study design. Conclusions: Patients requiring acute or unplanned hemodialysis experience high mortality, and the nature of clinical presentation does influence outcomes. Most notable is the greater early mortality experienced by patients with AKI compared to other patient groups. Prospective definition of the nature of unplanned dialysis initiation is important to accurately measure and improve outcomes in this high-risk patient population. Human Research Ethics Committee Approval Number CH62/6/2017-042. </jats:sec

Effect of high cut-off dialysis for acute kidney injury secondary to cast nephropathy in patients with multiple myeloma: a systematic review and meta-analysis

ABSTRACT Background Acute kidney injury (AKI) caused by cast nephropathy is associated with increased morbidity and mortality among patients with multiple myeloma (MM). High cut-off haemodialysis (HCO-HD) has proven to be effective in the removal of serum light chains but the effect on clinical outcomes, especially renal recovery, remains uncertain. Methods A systematic review and meta-analysis were performed examining all randomized controlled trials (RCTs) and observational studies (OBSs) assessing the effect of HCO-HD on clinical outcomes of patients with MM complicated by cast nephropathy–induced severe AKI. The primary outcome was all-cause mortality at the end of the study. The secondary outcomes included all-cause mortality at 12 months, HD independence and serum kappa and lambda light chain reduction. Pooled analysis was performed using random effects models. Results We identified five studies, comprising two RCTs and three retrospective cohort studies, including 276 patients with a mean follow-up of 18.7 months. The majority of the studies were of suboptimal quality and underpowered. Compared with patients treated with conventional HD, HCO-HD was not associated with a survival benefit at 12 months {five studies, 276 patients, relative risk [RR] 1.02 [95% confidence interval (CI) 0.76–1.35], I2 = 33.9%} or at the end of the studies at an average of 34 months [five studies, 276 patients, RR 1.32 (95% CI 0.71–2.45), I2 = 62.0%]. There was no difference in HD independence at 90 days [two trials, 78 patients, RR 2.23 (95% CI 1.09–4.55)], 6 months [two studies, 188 patients, RR 1.19 (95% CI 0.68–2.06)] or 12 months [two studies, 188 patients, RR 1.14 (95% CI 0.58–2.26)]. Patients receiving HCO dialysis, however, had a greater reduction in serum kappa [two studies, 188 patients, weighted mean difference (WMD) 46.7 (95% CI 38.6–54.7), I2 =  52.0%] and lambda [two studies, 188 patients, WMD 50.3 (95% CI 21.4–79.3), I2 = 95.1%] light chain levels. Conclusion Current evidence from RCTs and OBSs suggests HCO dialysis is able to reduce serum free light chains but makes no significant improvement in all-cause mortality and renal outcomes compared with conventional HD for patients with myeloma cast nephropathy. However, there is a trend towards better renal outcomes with the use of HCO dialysis. The lack of long-term data and the small sample sizes of the included studies limit this analysis. Therefore further large-scale RCTs with longer follow-up are needed to assess the effect of HCO dialysis on clinical outcomes in patients with myeloma cast nephropathy. </jats:sec

Patient and Clinician Perspectives on the use of Remote Patient Monitoring in Peritoneal Dialysis

Background: Numerous factors influence patient recruitment to, and retention on, peritoneal dialysis (PD), but a major challenge is a perceived “inaccessibility” to treating clinicians. It has been suggested that remote patient monitoring (RPM) could be a means of improving such oversight and, thereby, uptake of PD. Objective: To describe patient and clinician perspectives toward RPM and the use of applications (Apps) suitable for mobiles, tablets, or computers to support the provision of PD care. Design: Qualitative design using semi-structured interviews. Setting: All patient participants perform PD treatment at home under the oversight of an urban PD unit in Sydney, Australia. Patient and clinician interviews were conducted within the PD unit. Participants: 14 participants (5 clinicians [2 nephrologists, 3 PD nurses] and 9 patients treated with PD). Methods: Semi-structured interviews were conducted using interview guides tailored for clinician and patient participants. Transcripts were coded and analyzed by a single researcher using thematic analysis. Results: Six themes were identified: perceived benefits of RPM implementation (offering convenience and efficiency, patient assurance through increased surveillance, more complete data and monitoring adherence), uncertainty regarding data governance (protection of personal data, data reliability), reduced patient engagement (transfer of responsibility leading to complacency), changing patient-clinician relationships (reduced patient-initiated communication, the need to maintain patient independence), increased patient and clinician burden (inadequate technological literacy, overmanagement leading to frequent treatment changes), and clinician preference influencing patient behavior. Limitations: The interviews were conducted in English only and with participants from a single urban dialysis unit, which may limit generalizability. Conclusions: For patients and clinicians, advantages from the use of RPM in PD may include increased patient confidence and assurance, improved treatment oversight, more complete data capture, and overcoming barriers to data documentation. Careful patient selection and patient and clinician education may help to optimize the benefits of RPM, maintain patient independence, and reduce the risks of patient disengagement. The use of an App may support RPM; however, participants expressed concerns about increasing the burden on some patients through the use of unfamiliar technology. Human Research Ethics Committee Approval Number: CH62/6/2019-028 </jats:sec

Digital health interventions for physical activity in chronic kidney disease: Systematic review

Background Patients (pts) with rheumatoid arthritis (RA) often experience substantial pain despite treatment, and pain control is considered an important treatment outcome. The FINCH 1–3 studies demonstrated the efficacy and acceptable safety of the preferential Janus kinase (JAK) 1 inhibitor filgotinib (FIL) in pts living with RA. Objectives This post-hoc analysis of the FINCH studies assessed specific effects of FIL on pain. Methods FINCH 1–3 (NCT02889796, NCT02873936, NCT02886728) were Phase 3, randomized, double-blind trials of FIL 100 mg and 200 mg (FIL100/200). In FINCH 1, pts with an inadequate response (IR) to methotrexate (MTX) received FIL, adalimumab (ADA) or placebo (PBO) + MTX for 52 weeks. In FINCH 2, pts with an IR to biologic disease-modifying anti-rheumatic drugs (DMARDs) received FIL or PBO + conventional synthetic DMARDs for 24 weeks. In FINCH 3, MTX-naïve pts received FIL ± MTX or MTX for 52 weeks. For each treatment group, pts reported pain on a 100-mm visual analog scale (VAS). Scores of ≤10 mm reflected limited to no pain; scores of ≤20 mm indicated health status was not negatively affected by pain.[1] Time to first VAS score of ≤10 mm was assessed. The proportion of pts who achieved remission (as per Disease Activity Score 28 with C-reactive protein [DAS28-CRP] <2.6 or Clinical Disease Activity Index [CDAI] ≤2.8) at Week 24 was evaluated. Of pts who achieved DAS28-CRP or CDAI remission, the proportion who also reported VAS pain scores of ≤10 mm or ≤20 mm was determined. Results In FINCH 1, there was a higher probability of achieving a VAS pain score of ≤10 mm with FIL200, vs ADA + MTX or PBO + MTX; responses were better or comparable with FIL100 vs other treatment arms (Figure 1). Similar findings were observed in FINCH 2 and 3 for FIL vs PBO and MTX, respectively. In FINCH 1, the proportion of pts achieving DAS28-CRP remission was greater with FIL200 + MTX (48.4%) and comparable for the FIL100 + MTX (35.2%) vs ADA + MTX arms (35.7%; Table 1). Further, the proportion of pts who achieved VAS pain scores of ≤10 mm and ≤20 mm in addition to DAS28-CRP remission was 26.3% and 35.8%, respectively, in the FIL200 + MTX group, compared with 17.2% and 24.6% in the ADA + MTX group (Table 1). In FINCH 2 and 3, a greater proportion of pts in the FIL groups achieved remission vs the PBO or MTX arms, respectively. A greater proportion of pts achieved pain responses in addition to DAS28-CRP remission in the FIL groups of FINCH 2 and FINCH 3 compared with PBO or MTX, respectively. Findings were similar when CDAI remission was assessed. Conclusion FIL positively affected pain parameters across the FINCH studies as early as Week 2, with responses sustained over time (up to Week 52 [FINCH 1 and 3] and Week 24 [FINCH 2]). In FINCH 1, FIL200 had a particularly favorable impact when pain response and remission were assessed together. Similar findings were seen with FIL compared with PBO and MTX in FINCH 2 and 3, respectively. These findings suggest that JAK inhibition may offer potential added value with respect to patient-reported pain outcomes when treat-to-target goals are met. Reference [1] Taylor PC, et al. J Clin Med 2019;8:831No Full Tex

Digital Physical Activity and Exercise Interventions for People Living with Chronic Kidney Disease: A Systematic Review of Health Outcomes and Feasibility

Physical activity is essential to interrupt the cycle of deconditioning associated with chronic kidney disease (CKD). However, access to targeted physical activity interventions remain under-supported due to limited funding and specialised staff. Digital interventions may address some of these factors. This systematic review sought to examine the evidence base of digital interventions focused on promoting physical activity or exercise and their effect on health outcomes for people living with CKD. Electronic databases (PubMed, CINAHL, Embase, Cochrane) were searched from 1 January 2000 to 1 December 2023. Interventions (smartphone applications, activity trackers, websites) for adults with CKD (any stage, including transplant) which promoted physical activity or exercise were included. Study quality was assessed, and a narrative synthesis was conducted. Of the 4057 records identified, eight studies (five randomised controlled trials, three single-arm studies) were included, comprising 550 participants. Duration ranged from 12-weeks to 1-year. The findings indicated acceptability and feasibility were high, with small cohort numbers and high risk of bias. There were inconsistent measures of physical activity levels, self-efficacy, body composition, physical function, and psychological outcomes which resulted in no apparent effects of digital interventions on these domains. Data were insufficient for meta-analysis. The evidence for digital interventions to promote physical activity and exercise for people living with CKD is limited. Despite popularity, there is little evidence that current digital interventions yield the effects expected from traditional face-to-face interventions. However, 14 registered trials were identified which may strengthen the evidence-base