Finite barrier bound state

A boundary mode localized on one side of a finite-size lattice can tunnel to the opposite side which results in unwanted couplings. Conventional wisdom tells that the tunneling probability decays exponentially with the size of the system which thus requires many lattice sites before eventually becoming negligibly small. Here we show that the tunneling probability for some boundary modes can apparently vanish at specific wavevectors. Thus, similar to bound states in the continuum, a boundary mode can be completely trapped within very few lattice sites where the bulk bandgap is not even well-defined. More intriguingly, the number of trapped states equals the number of lattice sites along the normal direction of the boundary. We provide two configurations and validate the existence of this peculiar finite barrier-bound state experimentally in a dielectric photonic crystal at microwave frequencies. Our work offers extreme flexibility in tuning the coupling between localized states and channels as well as a new mechanism that facilitates unprecedented manipulation of light.

Non-Abelian physics in light and sound

Non-Abelian phenomena arise when the sequence of operations on physical systems influences their behaviors. By possessing internal degrees of freedom such as polarization, light and sound can be subjected to various manipulations, including constituent materials, structured environments, and tailored source conditions. These manipulations enable the creation of a great variety of Hamiltonians, through which rich non-Abelian phenomena can be explored and observed. Recent developments have constituted a versatile testbed for exploring non-Abelian physics at the intersection of atomic, molecular, and optical physics; condensed matter physics; and mathematical physics. These fundamental endeavors could enable photonic and acoustic devices with multiplexing functionalities. Our review aims to provide a timely and comprehensive account of this emerging topic. Starting from the foundation of matrix-valued geometric phases, we address non-Abelian topological charges, non-Abelian gauge fields, non-Abelian braiding, non-Hermitian non-Abelian phenomena, and their realizations with photonics and acoustics and conclude with future prospects.

Generation of Spatiotemporal Vortex Pulses by Resonant Diffractive Grating

Spatiotemporal vortex pulses are wave packets that carry transverse orbital angular momentum, exhibiting exotic structured wave fronts that can twist through space and time. Existing methods to generate these pulses require complex setups like spatial light modulators or computer-optimized structures. Here, we demonstrate a new approach to generate spatiotemporal vortex pulses using just a simple diffractive grating. The key is constructing a phase vortex in frequency-momentum space by leveraging symmetry, resonance, and diffraction. Our approach is applicable to any wave system. We use a liquid surface wave (gravity wave) platform to directly demonstrate and observe the real-time generation and evolution of spatiotemporal vortex pulses. This straightforward technique provides opportunities to explore pulse dynamics and potential applications across different disciplines.

Outcomes of Integrated Home Dialysis Care: Results From the Canadian Organ Replacement Register

RATIONALE & OBJECTIVE

The integrated home dialysis model proposes the initiation of kidney replacement therapy (KRT) with peritoneal dialysis (PD) and a timely transition to home hemodialysis (HHD) after PD ends. We compared the outcomes of patients transitioning from PD to HHD with those initiating KRT with HHD.

STUDY DESIGN

Observational analysis of the Canadian Organ Replacement Register (CORR).

SETTINGS & PARTICIPANTS

All patients who initiated PD or HHD within the first 90 days of KRT between 2005 and 2018.

EXPOSURE

Patients transitioning from PD to HHD (PD+HHD group) versus patients initiating KRT with HHD (HHD group).

OUTCOME

(1) A composite of all-cause mortality and modality transfer (to in-center hemodialysis or PD for 90 days) and (2) all hospitalizations (considered as recurrent events).

ANALYTICAL APPROACH

A propensity score analysis for which PD+HHD patients were matched 1:1 to (1) incident HHD patients ("incident-match" analysis) or (2) HHD patients with a KRT vintage at least equivalent to the vintage of PD+HHD patients at the transition time ("vintage-matched" analysis). Cause-specific hazards models (composite outcome) and shared frailty models (hospitalization) were used to compare groups.

RESULTS

Among 63,327 individuals in the CORR, 163 PD+HHD patients (median of 1.9 years in PD) and 711 HHD patients were identified. In the incident-match analysis, compared to the HHD patients, the PD+HHD group had a similar risk of the composite outcome (HR, 0.88 [95% CI, 0.58-1.32]) and hospitalizations (HR, 1.04 [95% CI, 0.76-1.41]). In the vintage-match analysis, PD+HHD patients had a lower hazard for the composite outcome (HR, 0.61 [95% CI, 0.40-0.94]) but a similar hospitalization risk (HR, 0.85 [95% CI, 0.59-1.24]).

LIMITATIONS

Risk of survivor bias in the PD+HHD cohort and residual confounding.

CONCLUSIONS

Controlling for KRT vintage, the patients transitioning from PD to HHD had better clinical outcomes than the incident HHD patients. These data support the use of integrated home dialysis for patients initiating home-based KRT.

PLAIN-LANGUAGE SUMMARY

The integrated home dialysis model proposes the initiation of dialysis with peritoneal dialysis (PD) and subsequent transition to home hemodialysis (HHD) once PD is no longer feasible. It allows patients to benefit from initial lifestyle advantages of PD and to continue home-based treatments after its termination. However, some patients may prefer to initiate dialysis with HHD from the outset. In this study, we compared the long-term clinical outcomes of both approaches using a large Canadian dialysis register. We found that both options led to a similar risk of hospitalization. In contrast, the PD-to-HHD model led to improved survival when controlling for the duration of kidney failure.

Experimental Realization of Stable Exceptional Chains Protected by Non-Hermitian Latent Symmetries Unique to Mechanical Systems

Lines of exceptional points are robust in the three-dimensional non-Hermitian parameter space without requiring any symmetry. However, when more elaborate exceptional structures are considered, the role of symmetry becomes critical. One such case is the exceptional chain (EC), which is formed by the intersection or osculation of multiple exceptional lines (ELs). In this Letter, we investigate a non-Hermitian classical mechanical system and reveal that a symmetry intrinsic to second-order dynamical equations, in combination with the source-free principle of ELs, guarantees the emergence of ECs. This symmetry can be understood as a non-Hermitian generalized latent symmetry, which is absent in prevailing formalisms rooted in first-order Schrödinger-like equations and has largely been overlooked so far. We experimentally confirm and characterize the ECs using an active mechanical oscillator system. Moreover, by measuring eigenvalue braiding around the ELs meeting at a chain point, we demonstrate the source-free principle of directed ELs that underlies the mechanism for EC formation. Our Letter not only enriches the diversity of non-Hermitian exceptional point configurations, but also highlights the new potential for non-Hermitian physics in second-order dynamical systems.

Patient Survival With Extended Home Hemodialysis Compared to In-Center Conventional Hemodialysis

Introduction

More frequent and/or longer hemodialysis (HD) has been associated with improvements in numerous clinical outcomes in patients on dialysis. Home HD (HHD), which allows more frequent and/or longer dialysis with lower cost and flexibility in treatment planning, is not widely used worldwide. Although, retrospective studies have indicated better survival with HHD, this issue remains controversial. In this multicenter study, we compared thrice-weekly extended HHD with in-center conventional HD (ICHD) in a large patient population with a long-term follow-up.

Methods

We matched 349 patients starting HHD between 2010 and 2014 with 1047 concurrent patients on ICHD by using propensity scores. Patients were followed-up with from their respective baseline until September 30, 2018. The primary outcome was overall survival. Secondary outcomes were technique survival; hospitalization; and changes in clinical, laboratory, and medication parameters.

Results

The mean duration of dialysis session was 418 ± 54 minutes in HHD and 242 ± 10 minutes in patients on ICHD. All-cause mortality rate was 3.76 and 6.27 per 100 patient-years in the HHD and the ICHD groups, respectively. In the intention-to-treat analysis, HHD was associated with a 40% lower risk for all-cause mortality than ICHD (hazard ratio [HR] = 0.60; 95% confidence interval [CI] 0.45 to 0.80; P < 0.001). In HHD, the 5-year technical survival was 86.5%. HHD treatment provided better phosphate and blood pressure (BP) control, improvements in nutrition and inflammation, and reduction in hospitalization days and medication requirement.

Conclusion

These results indicate that extended HHD is associated with higher survival and better outcomes compared to ICHD.

Constrained tandem neural network assisted inverse design of metasurfaces for microwave absorption

Designing microwave absorbers with customized spectrums is an attractive topic in both scientific and engineering communities. However, due to the massive number of design parameters involved, the design process is typically time-consuming and computationally expensive. To address this challenge, machine learning has emerged as a powerful tool for optimizing design parameters. In this work, we present an analytical model for an absorber composed of a multi-layered metasurface and propose a novel inverse design method based on a constrained tandem neural network. The network can provide structural and material parameters optimized for a given absorption spectrum, without requiring professional knowledge. Furthermore, additional physical attributes, such as absorber thickness, can be optimized when soft constraints are applied. As an illustrative example, we use the neural network to design broadband microwave absorbers with a thickness close to the causality limit imposed by the Kramers-Kronig relation. Our approach provides new insights into the reverse engineering of physical devices.

BNT162b2 versus mRNA-1273 Third Dose COVID-19 Vaccine in Patients with CKD and Maintenance Dialysis Patients

BACKGROUND

There is a lack of randomized controlled trial data regarding differences in immunogenicity of varying coronavirus disease 2019 (COVID-19) mRNA vaccine regimens in CKD populations.

METHODS

We conducted a randomized controlled trial at three kidney centers in Toronto, Ontario, Canada, evaluating the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibody response after third dose vaccination. Participants ( n =273) with CKD not on dialysis or receiving dialysis were randomized 1:1 to third dose 30- µ g BNT162b2 (Pfizer-BioNTech) or 100- µ g mRNA-1273 (Moderna). The primary outcome of this study was SARS-CoV-2 IgG-binding antibodies to the receptor-binding domain (anti-RBD). Spike protein (antispike), nucleocapsid protein, and vaccine reactogenicity were also evaluated. Serology was measured before third dose and 1, 3, and 6 months after third dose. A subset of participants ( n =100) were randomly selected to assess viral pseudovirus neutralization against wild-type D614G, B.1.617.2 (Delta), and B.1.1.529 (Omicron BA.1).

RESULTS

Among 273 participants randomized, 94% were receiving maintenance dialysis and 59% received BNT162b2 for initial two dose COVID-19 vaccination. Third dose of mRNA-1273 was associated with higher mean anti-RBD levels (1871 binding antibody units [BAU]/ml; 95% confidence interval [CI], 829 to 2988) over a 6-month period in comparison with third dose BNT162b2 (1332 BAU/ml; 95% CI, 367 to 2402) with a difference of 539 BAU/ml (95% CI, 139 to 910; P = 0.009). Neither antispike levels nor neutralizing antibodies to wild-type, Delta, and Omicron BA.1 pseudoviruses were statistically different. COVID-19 infection occurred in 10% of participants: 15 (11%) receiving mRNA-1273 and 11 (8%) receiving BNT162b2. Third dose BNT162b2 was not associated with a significant different risk for COVID-19 in comparison with mRNA-1273 (hazard ratio, 0.78; 95% CI, 0.27 to 2.2; P = 0.63).

CONCLUSIONS

In patients with CKD, third dose COVID-19 mRNA vaccination with mRNA-1273 elicited higher SARS-CoV-2 anti-RBD levels in comparison with BNT162b2 over a 6-month period.

CLINICAL TRIAL REGISTRY NAME AND REGISTRATION NUMBER

COVID-19 Vaccine Boosters in Patients With CKD (BOOST KIDNEY), NCT05022329 .

Integrated Care: A Person-Centered and Population Health Strategy for the COVID-19 Pandemic Recovery and Beyond

The COVID-19 pandemic has mandated a re-imagination of how healthcare is administered and delivered, with a view towards focusing on person-centred care and advancing population health while increasing capacity, access and equity in the healthcare system. These goals can be achieved through healthcare integration. In 2019, the University Health Network (UHN), a consortium of four quaternary care hospitals in Ontario, Canada, established the first stage of a pilot program to increase healthcare integration at the institutional level and vertically with other primary, secondary and tertiary institutions in the Ontario healthcare system. Implementation of the program was accelerated during the COVID-19 pandemic and demonstrated how healthcare integration improves person-centred care and population health; therefore serving as the foundation for a health system response for the COVID-19 pandemic recovery and beyond.

Scalar topological photonic nested meta-crystals and skyrmion surface states in the light cone continuum

Topological photonics is rapidly expanding. However, discovering three-dimensional topological electromagnetic systems can be more challenging than electronic systems for two reasons. First, the vectorial nature of electromagnetic waves results in complicated band dispersions, and simple tight-binding-type predictions usually fail. Second, topological electromagnetic surface modes inside the light cone have very low quality factors (Q factors). Here, we propose the concept of scalar topological photonics to address these challenges. Our approach is experimentally validated by employing a nested meta-crystal configuration using connected coaxial waveguides. They exhibit scalar-wave-like band dispersions, making the search for photonic topological phases an easier task. Their surface states have skyrmion-like electric field distributions, resulting in a whole, bright surface state band inside the light cone continuum. As such, the topological surface states in our three-dimensional nested crystals can be exposed to air, making such systems well-suited for practical applications.

Automated Digital Counseling Program (ODYSSEE-Kidney Health): A Pilot Study on Health-Related Quality of Life

Key Points

Feasibility of implementing an automated, scalable, digital self-care program for patients with CKD was established. The primary outcome of improvement in health-related quality of life improved with the ODYSSEE-Kidney Health program. A dose relationship was shown between program engagement tertile and improvement in 4-month outcomes.

Background

In-person counseling programs promote self-care behavior and health-related quality of life (HRQoL). ODYSSEE-Kidney Health (prO moting health with D igitallY based counS eling for S elf-care bE havior and quality of lifE ; ODYSSEE-KH) is an automated, scalable, digital counseling program for patients with CKD. This open-label, single-arm pilot study tested the efficacy potential of the ODYSSEE-KH program to improve HRQoL in patients with CKD.

Methods

Adults with categories G3b to 5d CKD were recruited from nephrology clinics in Toronto, Canada. Patients (N =29) received access to the ODYSSEE-KH program in conjunction with usual care. Generalized linear models and pairwise comparisons of mean change scores were conducted to assess the primary outcome: Mental Component Score (MCS) of the Kidney Disease Quality of Life–Short Form instrument. Secondary outcomes included the MCS Mental Health Scale, 36-Item Kidney Disease Quality of Life–Short Form, Generalized Anxiety Disorder Scale, Patient Health Questionnaire for depression, Enhancing Recovery in Coronary Heart Disease Social Support Instrument, and 3-Item Revised University of California, Los Angeles (UCLA) Loneliness Scale.

Results

The mean age of the patients was 53.5 years (SD=18.3); 35% were women; 56% were White; 93% had completed ≥postsecondary education; patients came from the Multi-Care Kidney Clinic (n =9), Home Peritoneal Dialysis Unit (n =12), and Home Hemodialysis Unit (n =8); and 24 participants completed the 4-month end-of-study questionnaires. Outcomes were assessed according to tertiles of program log-on minutes: median (range)=67 (62–108), 212 (119–355), and 500 (359–1573) minutes, respectively. Patients in the highest tertile of engagement showed significant improvements on the MCS versus the moderate tertile group (P = 0.01). Significant dose-response associations were observed for the MCS Mental Health Scale (P < 0.05), KDQoL Burden on Kidney Disease (P < 0.01), KDQoL Effect of Kidney Disease on Everyday Life (P < 0.01), aggregated KDQoL Summary Scale (P < 0.05), Generalized Anxiety Disorder Scale (P < 0.01), Patient Health Questionnaire for Depression (P < 0.05), Enhancing Recovery in Coronary Heart Disease Social Support Instrument (P < 0.01), and 3-Item Revised UCLA Loneliness Scale (P < 0.01).

Conclusion

The ODYSSEE-KH program demonstrated feasibility as an automated, scalable, digital self-care program for patients with CKD. There is evidence of its efficacy potential to improve HRQoL. Further evaluation with a larger sample is warranted.

Omicron variant neutralizing antibodies following BNT162b2 BA.4/5 versus mRNA-1273 BA.1 bivalent vaccination in patients with end-stage kidney disease

Neutralization of Omicron subvariants by different bivalent vaccines has not been well evaluated. This study characterizes neutralization against Omicron subvariants in 98 individuals on dialysis or with a kidney transplant receiving the BNT162b2 (BA.4/BA.5) or mRNA-1273 (BA.1) bivalent COVID-19 vaccine. Neutralization against Omicron BA.1, BA.5, BQ.1.1, and XBB.1.5 increased by 8-fold one month following bivalent vaccination. In comparison to wild-type (D614G), neutralizing antibodies against Omicron-specific variants were 7.3-fold lower against BA.1, 8.3-fold lower against BA.5, 45.8-fold lower against BQ.1.1, and 48.2-fold lower against XBB.1.5. Viral neutralization was not significantly different by bivalent vaccine type for wild-type (D614G) (P = 0.48), BA.1 (P = 0.21), BA.5 (P = 0.07), BQ.1.1 (P = 0.10), nor XBB.1.5 (P = 0.10). Hybrid immunity conferred higher neutralizing antibodies against all Omicron subvariants. This study provides evidence that BNT162b2 (BA.4/BA.5) and mRNA-1273 (BA.1) induce similar neutralization against Omicron subvariants, even when antigenically divergent from the circulating variant.

Kidney and Cancer Outcomes with Standard Versus Alternative Chemotherapy Regimens for First-Line Treatment of Metastatic Urothelial Carcinoma

Key Points

Many patients with metastatic urothelial carcinoma are deemed cisplatin-ineligible because of reduced kidney function. Options include split-dose cisplatin or carboplatin. There was no significant association between regimen type and AKI. Alternative regimens were associated with higher risk of progressive disease. There is a need to revisit cisplatin eligibility criteria and develop strategies to optimize cancer treatment for patients with CKD.

Background

Cisplatin-based chemotherapy regimens remain the optimal first-line treatment for patients with metastatic urothelial carcinoma (mUC). However, many patients are deemed cisplatin-ineligible, predominantly because of reduced kidney function. Other treatment options include split-dose cisplatin, carboplatin, and non–platinum-based regimens. We compared the incidence of AKI and cancer outcomes within three chemotherapy regimens.

Methods

We conducted a single-center retrospective study of patients with mUC who received first-line chemotherapy from 2005 to 2019. We compared standard gemcitabine–cisplatin (gem-cis) with two alternative regimens: (1 ) gem-cis split-dose regimen (split) with cisplatin divided over days 1 and 8 and (2 ) combination of gemcitabine–carboplatin or single-agent gemcitabine (gem/gem-carbo). The primary outcome was Kidney Disease Improving Global Outcomes–defined AKI. Secondary outcomes included overall survival and progression-free survival.

Results

We identified 183 patients (98 gem-cis, 32 split, and 53 gem/gem-carbo). Median baseline eGFR in the gem/cis group was 78 ml/min per 1.73 m2 (interquartile range, 66–91), in the split group 64 (48–77), and in the gem/gem-carbo 45 (33–57). There was no significant association between regimen type and incidence of AKI when adjusted for age, Eastern Cooperative Oncology Group, baseline eGFR, hypertension, diabetes, and visceral disease. The adjusted hazard ratios were 1.31 (95% confidence interval [CI], 0.61 to 2.78; P = 0.49) and 0.98 (95% CI, 0.46 to 2.07; P = 0.95) for split and gem/gem-carbo groups, respectively, versus gem-cis. Split and gem/gem-carbo regimens were associated with higher mortality and progressive disease relative to gem-cis with an adjusted hazard ratio of 1.54 (95% CI, 1.02 to 2.33; P = 0.04) and 1.96 (95% CI, 1.31 to 2.95; P < 0.01), respectively. Median progression free survival was 8.1 (interquartile range, 4.6–14.8), 6.1 (4.1–9.3), and 4.4 (2.3–8.6) months in the gem-cis, split, and gem/gem-carbo groups.

Conclusions

There was no significant difference in the incidence of AKI between the three regimens studied. However, standard gem-cis was associated with improved cancer outcomes. Novel regimens and kidney protective strategies are needed for patients with mUC with kidney disease.

Systems Innovations to Increase Home Dialysis Utilization

Globally, there is an interest to increase home dialysis utilization. The most recent United States Renal Data System (USRDS) data report that 13.3% of incident dialysis patients in the United States are started on home dialysis, while most patients continue to initiate KRT with in-center hemodialysis. To effect meaningful change, a multifaceted innovative approach will be needed to substantially increase the use of home dialysis. Patient and provider education is the first step to enhance home dialysis knowledge awareness. Ideally, one should maximize the number of patients with CKD stage 5 transitioning to home therapies. If this is not possible, infrastructures including transitional dialysis units and community dialysis houses may help patients increase self-care efficacy and eventually transition care to home. From a policy perspective, adopting a home dialysis preference mandate and providing financial support to recuperate increased costs for patients and providers have led to higher uptake in home dialysis. Finally, respite care and planned home-to-home transitions can reduce the incidence of transitioning to in-center hemodialysis. We speculate that an ecosystem of complementary system innovations is needed to cause a sufficient change in patient and provider behavior, which will ultimately modify overall home dialysis utilization.

Andreas Pierratos Tribute: Personal Reflections

Since the passing of Andreas Pierratos on November 15, 2022, we have had many occasions to reflect on what our relationship with a friend and colleague has meant. We have done this in solitude, with colleagues while at work and more recently, in a tribute organized at Humber River Hospital on March 26, 2023. We also had the opportunity to expand, in the February 2023 issue of the Nephrology News & Issues, on his many contributions to nephrology and to the betterment of patients' lives. For this collaboration, we thought we would share our personal reflections of this unique individual, with the hope that this effort would provide a deeper appreciation of his unique humanity.

Second Chern crystals with inherently non-trivial topology

Chern insulators have been generalized to many classical wave systems and thereby lead to many potential applications such as robust waveguides, quantum computation and high-performance lasers. However, the band structure of a material can be either topologically trivial or non-trivial, depending on how the crystal structure is designed. Here, we propose a second Chern crystal in a four-dimensional parameter space by introducing two extra synthetic translation dimensions. Since the topology of the bulk bands in the synthetic translation space is intrinsically non-trivial, our proposed four-dimensional crystal is guaranteed to be topologically non-trivial regardless of the crystal's detailed configuration. We derive the topologically protected modes on the lower dimensional boundaries of such a crystal via dimension reduction. Remarkably, we observe the one-dimensional gapless dislocation modes and confirm their robustness in experiments. Our findings provide novel perspectives on topologically non-trivial crystals and may inspire designs of classical wave devices.

Frailty and Clinical Outcomes in Patients Treated With Hemodialysis: A Prospective Cohort Study

Rationale and Objective

Frailty is common among people with kidney failure treated with hemodialysis (HD). The objective was to describe how frailty evolves over time in people treated by HD, how improvements in frailty and frailty markers are associate with clinical outcomes, and the characteristics that are associated with improvement in frailty.

Study Design

Prospective cohort study.

Setting and Participants

Adults initiating thrice weekly in-center HD in Canada.

Exposure

We classified frailty using a 5-point score (3 or more indicates frailty) based on physical inactivity, slowness or weakness, poor endurance or exhaustion, and malnutrition. We categorized the frailty trajectory as never present, improving, deteriorating, and always present.

Outcomes

All-cause death, hospitalizations, and placement into long-term care.

Analytical Approach

We examined the association between time-varying frailty measures and these outcomes using Cox and negative binomial models, after adjustment for potential confounders.

Results

985 participants were included and followed up for a median of 33 months; 507 (51%) died, 761 (77%) experienced ≥1 hospitalization and 115 (12%) entered long-term care. Overall, 760 (77%) reported frailty during follow-up. Three-quarters (78%) of those with frailty at baseline remained frail throughout the follow-up, 46% without baseline frailty became frail, and 23% with baseline frailty became nonfrail. Higher frailty scores were associated with an increased risk of mortality (fully adjusted HR, 1.58 per unit; 95% CI, 1.39-1.80) and an increased rate of hospitalization (RR, 1.16 per unit; 95% CI, 1.09-1.23). Compared with those who were frail throughout the follow-up, participants with frailty at baseline but improving during follow-up showed a lower mortality (HR, 0.59; 95% CI, 0.42-0.81), and a lower rate of hospitalization (RR, 0.70; 95% CI, 0.56-0.87).

Limitations

There was missing data on frailty at baseline and during follow-up.

Conclusions

Frailty was associated with a higher risk of poor outcomes compared with those without frailty, and participants whose status improved from frail to nonfrail showed better clinical outcomes than those who remained frail. These findings emphasize the importance of identifying and implementing effective treatments for frailty in patients receiving maintenance HD.

Interleukin-3 coordinates glial-peripheral immune crosstalk to incite multiple sclerosis

Glial cells and central nervous system (CNS)-infiltrating leukocytes contribute to multiple sclerosis (MS). However, the networks that govern crosstalk among these ontologically distinct populations remain unclear. Here, we show that, in mice and humans, CNS-resident astrocytes and infiltrating CD44hiCD4+ T cells generated interleukin-3 (IL-3), while microglia and recruited myeloid cells expressed interleukin-3 receptor-ɑ (IL-3Rɑ). Astrocytic and T cell IL-3 elicited an immune migratory and chemotactic program by IL-3Rɑ+ myeloid cells that enhanced CNS immune cell infiltration, exacerbating MS and its preclinical model. Multiregional snRNA-seq of human CNS tissue revealed the appearance of IL3RA-expressing myeloid cells with chemotactic programming in MS plaques. IL3RA expression by plaque myeloid cells and IL-3 amount in the cerebrospinal fluid predicted myeloid and T cell abundance in the CNS and correlated with MS severity. Our findings establish IL-3:IL-3RA as a glial-peripheral immune network that prompts immune cell recruitment to the CNS and worsens MS.

Home hemodialysis technique survival: insights and challenges

Home hemodialysis (HHD) offers several clinical, quality of life and cost-saving benefits for patients with end-stage kidney disease. While uptake of this modality has increased in recent years, its prevalence remains low and high rates of discontinuation remain a challenge. This comprehensive narrative review aims to better understand what is currently known about technique survival in HHD patients, elucidate the clinical factors that contribute to attrition and expand on possible strategies to prevent discontinuation. With increasing efforts to encourage home modalities, it is imperative to better understand technique survival and find strategies to help maintain patients on the home therapy of their choosing. It is crucial to better target high-risk patients, examine ideal training practices and identify practices that are potentially modifiable to improve technique survival.

Intrinsic Triple Degeneracy Point Bounded by Nodal Surfaces in Chiral Photonic Crystal

In periodic systems, band degeneracies are typically protected and classified by spatial symmetries. However, in photonic systems, the Γ point at zero frequency is an intrinsic degeneracy due to the polarization degree of freedom of electromagnetic waves. For chiral photonic crystals, such an intrinsic degeneracy carries ±2 chiral topological charge while having linear band dispersions, different from the general perception of charge-2 nodes being associated with quadratic dispersions. Here, we show that these topological characters originate from the spin-1 Weyl point at zero frequency node of triple degeneracy, due to the existence of an electrostatic flat band. Such a topological charge at zero frequency is usually buried in bulk band projections and has never been experimentally observed. To address this challenge, we introduce space-group screw symmetries in the design of chiral photonic crystal, which makes the Brillouin zone boundary an oppositely charged nodal surface enclosing the Γ point. As a result, the emergent Fermi arcs are forced to connect the projections of these topological singularities, enabling their experimental observation. The number of Fermi arcs then directly reveals the embedded topological charge at zero frequency.

Home dialysis: conclusions from a Kidney Disease: Improving Global Outcomes (KDIGO) Controversies Conference

Home dialysis modalities (home hemodialysis [HD] and peritoneal dialysis [PD]) are associated with greater patient autonomy and treatment satisfaction compared with in-center modalities, yet the level of home-dialysis use worldwide is low. Reasons for limited utilization are context-dependent, informed by local resources, dialysis costs, access to healthcare, health system policies, provider bias or preferences, cultural beliefs, individual lifestyle concerns, potential care-partner time, and financial burdens. In May 2021, KDIGO (Kidney Disease: Improving Global Outcomes) convened a controversies conference on home dialysis, focusing on how modality choice and distribution are determined and strategies to expand home-dialysis use. Participants recognized that expanding use of home dialysis within a given health system requires alignment of policy, fiscal resources, organizational structure, provider incentives, and accountability. Clinical outcomes across all dialysis modalities are largely similar, but for specific clinical measures, one modality may have advantages over another. Therefore, choice among available modalities is preference-sensitive, with consideration of quality of life, life goals, clinical characteristics, family or care-partner support, and living environment. Ideally, individuals, their care-partners, and their healthcare teams will employ shared decision-making in assessing initial and subsequent kidney failure treatment options. To meet this goal, iterative, high-quality education and support for healthcare professionals, patients, and care-partners are priorities. Everyone who faces dialysis should have access to home therapy. Facilitating universal access to home dialysis and expanding utilization requires alignment of policy considerations and resources at the dialysis-center level, with clear leadership from informed and motivated clinical teams.

Adaptation of home nocturnal hemodialysis for a patient with epidermolysis bullosa: A call to personalized care!

Epidermolysis bullosa (EB) is a genetic disease characterized by skin fragility presenting with blistering and skin erosions. Recurrent skin infections are noted to be associated with the pathogenesis of IgA nephropathy. End stage kidney disease (ESKD) is a rare complication in patients with EB (Ducret F., et al., Nephrol Ther, 2008). Kidney replacement therapy is very challenging in this vulnerable patient population (Fine JD. et al., Am J Kidney Dis, 2004). Herein, we describe the adaptations to our home nocturnal hemodialysis training and operations to facilitate a patient with EB and ESKD to undergo personalized home nocturnal hemodialysis therapy.

Monocytes re-enter the bone marrow during fasting and alter the host response to infection

Diet profoundly influences physiology. Whereas over-nutrition elevates risk for disease via its influence on immunity and metabolism, caloric restriction and fasting appear to be salutogenic. Despite multiple correlations observed between diet and health, the underlying biology remains unclear. Here, we identified a fasting-induced switch in leukocyte migration that prolongs monocyte lifespan and alters susceptibility to disease in mice. We show that fasting during the active phase induced the rapid return of monocytes from the blood to the bone marrow. Monocyte re-entry was orchestrated by hypothalamic-pituitary-adrenal (HPA) axis-dependent release of corticosterone, which augmented the CXCR4 chemokine receptor. Although the marrow is a safe haven for monocytes during nutrient scarcity, re-feeding prompted mobilization culminating in monocytosis of chronologically older and transcriptionally distinct monocytes. These shifts altered response to infection. Our study shows that diet-in particular, a diet's temporal dynamic balance-modulates monocyte lifespan with consequences for adaptation to external stressors.

Case Studies of Intradialytic Total Parenteral Nutrition in Nocturnal Home Hemodialysis

The standard use of intradialytic parenteral nutrition has yielded heterogeneous clinical results. Confounders include patient selection, limited dialysis sessional duration, and frequency. Nocturnal home hemodialysis provides an intensive form of kidney replacement therapy (5 sessions per week and 8 hours per treatment). We present a series of 4 nocturnal home hemodialysis patients who required intradialytic total parenteral nutrition (IDTPN) as their primary source of caloric intake. We describe the context, effectiveness, and complications of IDTPN in these patients. Our patients received a range of 1200 to 1590 kCal (including 60 to 70 g of amino acids) with each IDTPN session for up to 27 months. As the availability of home hemodialysis continues to grow, the role of supplemental or primary IDTPN will require further research for this vulnerable patient population.

Determining the Longitudinal Serologic Response to COVID-19 Vaccination in the Chronic Kidney Disease Population: A Clinical Research Protocol

Background

People living with chronic kidney disease (CKD) have been disproportionately affected by the coronavirus disease 2019 (COVID-19) pandemic, including higher rates of infection, hospitalization, and death. Data on responsiveness to COVID-19 vaccination strategies and immunogenicity are limited, yet required to inform vaccination strategies in this at-risk population.

Objective

The objective of this study is to characterize the longitudinal serologic response to COVID-19 vaccination.

Design

This is a prospective observational cohort study.

Setting

Participating outpatient kidney programs within Ontario and British Columbia.

Patients

Up to 2500 participants with CKD G3b-5D receiving COVID-19 vaccination, including participants receiving dialysis and kidney transplant recipients (CKD G1T-5T).

Measurements

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) IgG antibodies (anti-spike, anti-receptor binding domain, anti-nucleocapsid) will be detected by ELISA (enzyme-linked immunosorbent assay) from serum or dried blood spot testing. In a subset of participants, neutralizing antibodies against novel variants of concern will be evaluated. Peripheral blood mononuclear cells will be collected for exploratory immune profiling of SARS-CoV-2 specific cellular immunity.

Methods

Participants will be recruited prior to or following any COVID-19 vaccine dose and have blood sampled for serological testing at multiple timepoints: 1, 3, 6, 9, and 12 months post vaccination. When possible, samples will be collected prior to a dose or booster. Participants will remain in the study for at least 1 year following their last COVID-19 vaccine dose.

Strengths and limitations

The adaptive design of this study allows for planned modification based on emerging evidence or rapid changes in public health policy surrounding vaccination. Limitations include incomplete earlier timepoints for blood collection due to rapid vaccination of the population.

Conclusions

This large multicenter serologic study of participants living with kidney disease will generate data on the kinetics of SARS-CoV-2 immune response to vaccination across the spectrum of CKD, providing insights into the amplitude and duration of immunity conferred by COVID-19 vaccination and allowing for characterization of factors associated with immune response. The results of this study may be used to inform immunization guidelines and public health recommendations for the 4 million Canadians living with CKD.

Amyloidoses in Onco-Nephrology Practice: A Multidisciplinary Case-Based Conference Report

Introduction and Objective

Amyloidoses are a heterogeneous group of disorders resulting from deposition of amyloid fibrils into extracellular tissues. While the kidneys are one of the most frequent sites of amyloid deposition, amyloid deposits can also affect a wide range of organ systems, including the heart, liver, gastrointestinal tract, and peripheral nerves. The prognosis of amyloidosis, especially with cardiac involvement, remains poor; however, a collaborative approach applying new tools for diagnosis and management may improve outcomes. In September 2021, the Canadian Onco-Nephrology Interest Group hosted a symposium to discuss diagnostic challenges and recent advances in the management of amyloidosis from the perspectives of the nephrologist, cardiologist, and onco-hematologist.

Methods and Sources of Information

Through structured presentations, the group discussed a series of cases highlighting the varied clinical presentations of amyloidoses affecting the kidney and heart. Expert opinions, clinical trial findings, and publication summaries were used to illustrate patient-related and treatment-related considerations in the diagnosis and management of amyloidoses.

Key findings

(1) Overview of the clinical presentation of amyloidoses and the role of specialists in performing timely and accurate diagnostic workup; (2) review of best practices for multidisciplinary management of amyloidosis, including prognostic variables and determinants of treatment response; and (3) update on new and emerging treatments in the management of light chain and amyloid transthyretin amyloidoses.

Limitations

This conference featured multidisciplinary discussion of cases, and learning points reflect the assessments by the involved experts/authors.

Implications

Identification and management of amyloidoses can be facilitated with a multidisciplinary approach and higher index of suspicion from cardiologists, nephrologists, and hemato-oncologists. Increased awareness of clinical presentations and diagnostic algorithms for amyloidosis subtyping will lead to more timely interventions and improved clinical outcomes.

Observation of Non-Abelian Charged Nodes Linking Nonadjacent Gaps

Nodal links are special configurations of band degeneracies in the momentum space, where nodal line branches encircle each other. In PT symmetric systems, nodal lines can be topologically characterized using the eigenvector frame rotations along an encircling loop and the linking structure can be described with non-Abelian frame charges involving adjacent bands. While the commutation rules between the frame charges are well established, the underlying relationship between distant band gap closing nodes remains to be explored. In this Letter, we present a photonic multiple nodal links system, where the nodal lines of nonadjacent bands are investigated with symmetry constraints on frame charges. Through an orthogonal nodal chain, the nodal line from the lower two bands predicts the existence of nodal lines formed between the higher bands. We designed and fabricated a metamaterial, with which the multiple nodal links and the topological connection between nonadjacent nodal lines are experimentally demonstrated.

Sleep exerts lasting effects on hematopoietic stem cell function and diversity

A sleepless night may feel awful in its aftermath, but sleep's revitalizing powers are substantial, perpetuating the idea that convalescent sleep is a consequence-free physiological reset. Although recent studies have shown that catch-up sleep insufficiently neutralizes the negative effects of sleep debt, the mechanisms that control prolonged effects of sleep disruption are not understood. Here, we show that sleep interruption restructures the epigenome of hematopoietic stem and progenitor cells (HSPCs) and increases their proliferation, thus reducing hematopoietic clonal diversity through accelerated genetic drift. Sleep fragmentation exerts a lasting influence on the HSPC epigenome, skewing commitment toward a myeloid fate and priming cells for exaggerated inflammatory bursts. Combining hematopoietic clonal tracking with mathematical modeling, we infer that sleep preserves clonal diversity by limiting neutral drift. In humans, sleep restriction alters the HSPC epigenome and activates hematopoiesis. These findings show that sleep slows decay of the hematopoietic system by calibrating the hematopoietic epigenome, constraining inflammatory output, and maintaining clonal diversity.

Observation of boundary induced chiral anomaly bulk states and their transport properties

The most useful property of topological materials is perhaps the robust transport of topological edge modes, whose existence depends on bulk topological invariants. This means that we need to make volumetric changes to many atoms in the bulk to control the transport properties of the edges in a sample. We suggest here that we can do the reverse in some cases: the properties of the edge can be used to induce chiral transport phenomena in some bulk modes. Specifically, we show that a topologically trivial 2D hexagonal phononic crystal slab (waveguide) bounded by hard-wall boundaries guarantees the existence of bulk modes with chiral anomaly inside a pseudogap due to finite size effect. We experimentally observed robust valley-selected transport, complete valley state conversion, and valley focusing of the chiral anomaly bulk states (CABSs) in such phononic crystal waveguides. The same concept also applies to electromagnetics.

Peritoneal dialysis first policy in Hong Kong for 35 years: Global impact

Peritoneal dialysis (PD) first policy has been established in Hong Kong since 1985. After 35 years of practice, the PD first policy in Hong Kong has influenced many countries around the world including governments, health ministries, nephrologists and renal nurses on the overall health policy structure and clinical practice in treating kidney failure patients using PD as an important dialysis modality. In 2021, the International Association of Chinese Nephrologists and the Hong Kong Society of Nephrology jointly held a symposium celebrating the 35 years of PD first policy in Hong Kong. In that symposium, experts and opinion leaders from around the world have shared their perspectives on how the PD first policy has grown and how it has affected PD and home dialysis practice globally. The advantages of PD during COVID-19 pandemic were highlighted and the use of telemedicine as an important adjunct was discussed in treating kidney failure patients to improve the overall quality of care. Barriers to PD and the need for sustainability of PD first policy were also emphasized. Overall, the knowledge awareness of PD as a home dialysis for patients, families, care providers and learners is a prerequisite for the success of PD first. A critical mass of PD regional hubs is needed for training and mentorship. Importantly, the alignment of policy and clinical goals are enablers of PD first program.

Cardiovascular Effects of Home Dialysis Therapies: A Scientific Statement From the American Heart Association

Cardiovascular disease is the leading cause of morbidity and mortality in patients with end-stage kidney disease. Currently, thrice-weekly in-center hemodialysis for 3 to 5 hours per session is the most common therapy worldwide for patients with treated kidney failure. Outcomes with thrice-weekly in-center hemodialysis are poor. Emerging evidence supports the overarching hypothesis that a more physiological approach to administering dialysis therapy, including in the home through home hemodialysis or peritoneal dialysis, may lead to improvement in several cardiovascular risk factors and cardiovascular outcomes compared with thrice-weekly in-center hemodialysis. The Advancing American Kidney Health Initiative, which has a goal of increasing the use of home dialysis, is aligned with the American Heart Association's 2024 mission to champion a full and healthy life and health equity. We conclude that incorporation of interdisciplinary care models to increase the use of home dialysis therapies in an equitable manner will contribute to the ultimate goal of improving outcomes for patients with kidney failure and cardiovascular disease.

Automated digital counselling with social network support as a novel intervention for patients with heart failure: protocol for randomised controlled trial

INTRODUCTION

Heart failure (HF) symptoms improve through self-care, for which adherence remains low among patients despite the provision of education for these behaviours by clinical teams. Open Access Digital Community Promoting Self-Care, Peer Support and Health Literacy (ODYSSEE-vCHAT) combines automated digital counselling with social network support to improve mortality and morbidity, engagement with self-care materials, and health-related quality of life.

METHODS AND ANALYSIS

Use of ODYSSEE-vCHAT via Internet-connected personal computer by 162 HF patients will be compared with a control condition over 22 months. The primary outcome is a composite index score of all-cause mortality, all-cause emergency department visits, and HF-related hospitalisation at trial completion. Secondary outcomes include individual components of the composite index, engagement with self-care materials, and patient-reported measures of physical and psychosocial well-being, disease management, health literacy, and substance use. Patients are recruited from tertiary care hospitals in Toronto, Canada and randomised on a 1:1 ratio to both arms of the trial. Online assessments occur at baseline (t=0), months 4, 8 and 12, and trial completion. Ordinal logistic regression analyses and generalised linear models will evaluate primary and secondary outcomes.

ETHICS AND DISSEMINATION

The trial has been approved by the research ethics boards at the University Health Network (20-5960), Sunnybrook Hospital (5117), and Mount Sinai Hospital (21-022-E). Informed consent of eligible patients occurs in person or online. Findings will be shared with key stakeholders and the public. Results will allow for the preparation of a Canada-wide phase III trial to evaluate the efficacy of ODYSSEE-vCHAT in improving clinical outcomes and raising the standard of outpatient care.

TRIAL REGISTRATION NUMBER

NCT04966104.

Effective Hamiltonian for Photonic Topological Insulator with Non-Hermitian Domain Walls

The gain and loss in photonic lattices provide possibilities for many functional phenomena. In this Letter, we consider photonic topological insulators with different types of gain-loss domain walls, which will break the translational symmetry of the lattices. A method is proposed to construct effective Hamiltonians, which accurately describe states and the corresponding energies at the domain walls for different types of photonic topological insulators and domain walls with arbitrary shapes. We also consider domain-induced higher-order topological states in two-dimensional non-Hermitian Aubry-André-Harper lattices and use our method to explain such phenomena successfully. Our results reveal the physics in photonic topological insulators with gain-loss domain walls, which provides advanced pathways for manipulation of non-Hermitian topological states in photonic systems.

Photonic Z_{2} Topological Anderson Insulators

That disorder can induce nontrivial topology is a surprising discovery in topological physics. As a typical example, Chern topological Anderson insulators (TAIs) have been realized in photonic systems, where the topological phases exist without symmetry protection. In this Letter, by taking transverse magnetic and transverse electric polarizations as pseudospin degrees of freedom, we theoretically propose a scheme to realize disorder-induced symmetry-protected topological phase transitions in two-dimensional photonic crystals with a combined time-reversal, mirror, and duality symmetry T_{f}=TM_{z}D. In particular, we demonstrate that the disorder-induced symmetry-protected topological phase persists even without pseudospin conservation, thereby realizing a photonic Z_{2} TAI, in contrast to a Z-classified quantum spin Hall (QSH) TAI with decoupled spins. By formulating a new scattering approach, we show that the topology of both the QSH and Z_{2} TAIs can be manifested by the accumulated spin rotations of the reflected waves from the photonic crystals. Using a transmission structure, we also illustrate the trivialization of a disordered QSH phase with an even integer topological index caused by spin coupling.

Straight Photonic Nodal Lines with Quadrupole Berry Curvature Distribution and Superimaging "Fermi Arcs"

In periodic systems, nodal lines are loops in the three-dimensional momentum space with each point on them representing a band degeneracy. Nodal lines exhibit rich topological features, as they can take various configurations such as rings, links, chains, and knots. These line nodes are generally protected by mirror or PT symmetry and frequently accompanied by drumhead surface states. Here, we propose and demonstrate a novel type of photonic straight nodal lines in a D_{2D} metacrystal, which are protected by an unusual rotoinversion time (roto-PT) symmetry. These nodal lines are located at the central axis and hinges of the Brillouin zone. They appear as quadrupole sources of Berry curvature flux in contrast to the Weyl points, which are monopoles. Interestingly, topological surface states exist at all three cutting surfaces, as guaranteed by π-quantized Zak phases along all three directions. As frequency changes, the surface state equifrequency contours evolve from closed to open and become straight lines at a critical transition frequency, at which diffractionless surface wave propagations are experimentally demonstrated, paving the way toward development of superimaging topological devices.

Brain motor and fear circuits regulate leukocytes during acute stress

The nervous and immune systems are intricately linked¹. Although psychological stress is known to modulate immune function, mechanistic pathways linking stress networks in the brain to peripheral leukocytes remain poorly understood². Here we show that distinct brain regions shape leukocyte distribution and function throughout the body during acute stress in mice. Using optogenetics and chemogenetics, we demonstrate that motor circuits induce rapid neutrophil mobilization from the bone marrow to peripheral tissues through skeletal-muscle-derived neutrophil-attracting chemokines. Conversely, the paraventricular hypothalamus controls monocyte and lymphocyte egress from secondary lymphoid organs and blood to the bone marrow through direct, cell-intrinsic glucocorticoid signalling. These stress-induced, counter-directional, population-wide leukocyte shifts are associated with altered disease susceptibility. On the one hand, acute stress changes innate immunity by reprogramming neutrophils and directing their recruitment to sites of injury. On the other hand, corticotropin-releasing hormone neuron-mediated leukocyte shifts protect against the acquisition of autoimmunity, but impair immunity to SARS-CoV-2 and influenza infection. Collectively, these data show that distinct brain regions differentially and rapidly tailor the leukocyte landscape during psychological stress, therefore calibrating the ability of the immune system to respond to physical threats.

Design and Development of a Digital Counseling Program for Chronic Kidney Disease

Background:

Self-management has shown to improve the quality of life in patients with chronic kidney disease (CKD). Readily accessible self-management tools are essential in promoting adherence to self-care behaviors. In recognizing that digital health facilitates efficient access to self-management programs, we developed a digital counseling program, ODYSSEE Kidney Health, to promote self-care behaviors while supporting health-related quality of life.

Objective:

To present the design and development of ODYSSEE Kidney Health for digital counseling for patients with CKD.

Design:

The study involved an iterative design process based on user-centered design principles to develop the digital counseling program, ODYSSEE Kidney Health.

Setting:

A sample of 10 to 15 participants were purposively sampled from nephrology clinics at the University Health Network, Toronto, Canada.

Methods:

Participants underwent 2 phases in the development process. In each phase, participants were presented with a component of the program, asked to perform goal-oriented tasks, and participate in the “think-aloud” process. Semi-structured interviews followed the first phase to identify feedback about the overall program. Thematic analysis of the interviews identified themes from the usability testing. Descriptive statistics were used to summarize patient demographic data.

Results:

We enrolled 11 participants (n = 7 males, n = 4 females, ages 30-82). The main themes generated anchored on (1) impact on nephrology care, (2) technical features, and (3) CKD content. Overall, participants reported positive satisfaction toward the navigation, layout, and content of the program. They cited the value of the program in their daily CKD care.

Limitations:

Study limitations included using a single center to recruit participants, most of the participants having prior technology use, and using one module as a representative of the entire digital platform.

Conclusion:

The acceptability of a digital counseling program for patients with CKD relies on taking the patients’ perspective using a user-centered design process. It is vital in ensuring adoption and adherence to self-management interventions aimed at sustaining behavioral change.

Experimental Observation of Non-Abelian Earring Nodal Links in Phononic Crystals

Nodal lines are symmetry-protected one-dimensional band degeneracies in momentum space, which can appear in numerous topological configurations such as nodal rings, chains, links, and knots. Very recently, non-Abelian topological physics have been proposed in space-time inversion (PT) symmetric systems. One of the most special configurations in such systems is the earring nodal link, composing of a nodal chain linking with an isolated nodal line. Such earring nodal links have not been observed in real systems. We designed phononic crystals with earring nodal links, and experimentally observed two different kinds of earring nodal links by measuring the band structures. We found that the order of the nodal chain and line can be switched after band inversion but their link cannot be severed. Our Letter provides experimental evidence for phenomena unique to non-Abelian band topology and our acoustic system provides a convenient platform for studying the new materials carrying non-Abelian charges.

The Implementation of a Virtual Home Dialysis Mentoring Program for Nephrologists

Virtual home dialysis physician mentorship is feasible.In total, 53% of participants perceived the program would change the perspective of participants on prescribing home dialysis.More research is needed to ascertain the effect of virtual mentorship on home dialysis incidence and attrition rates in a wider audience.

Chronic kidney disease, survival and graft-versus-host-disease/relapse-free survival in recipients of allogeneic hematopoietic stem cell transplant

Background

Advances in allogeneic hematopoietic stem cell transplant (HSCT) have increased patient survival, although substantial treatment-related toxicity remains, including chronic kidney disease (CKD). We assessed the association between CKD and survival and transplant-specific outcomes in HSCT recipients.

Methods

We conducted a retrospective study of all 408 adult patients with allogenic HSCT at Princess Margaret Cancer Centre (Toronto, Canada, 2015–18). We used logistic regression to identify risk factors for CKD at 1 year post-transplant. Associations between CKD at 1 year and overall survival, relapse-free survival, graft-versus-host-disease (GVHD)-free/relapse-free survival, relapse and transplant-related mortality were examined using extended time-varying Cox models. In a sensitivity analysis, we restricted the cohort to survivors at 1 year, using standard Cox proportional hazard models to examine associations between CKD and overall survival, relapse-free survival and GVHD-free/relapse-free survival, and Fine and Gray's competing risk models to determine associations between CKD and relapse/transplant-related mortality.

Results

The prevalence of CKD at 1 year was 19% (46 patients) with median follow-up of 23 months. Multivariable regression identified age at transplant [adjusted OR (aOR) 1.09, 95% confidence interval (95% CI) = 1.05–1.14; P < 0.0001), female gender (aOR 2.83, 95% CI = 1.34–5.97; P = 0.006) and acute kidney injury during the first 100 days (aOR 3.86, 95% CI = 1.70–8.73; P = 0.001) as risk factors for CKD at 1 year. Patients with CKD at 1 year had significantly poorer overall survival than those without CKD, when adjusted for relevant covariates [adjusted HR (aHR) 1.93, 95% CI = 1.02–3.66; P = 0.04 in the time-varying Cox model, and aHR 2.06, 95% CI = 1.04–4.07; P = 0.04 using the standard Cox model]. CKD at 1 year was also associated with worse GVHD-free/relapse-free survival (aHR 1.65, 95% CI = 1.04–2.61; P = 0.03).

Conclusions

CKD adversely affects the long-term prognosis for allogeneic HSCT recipients, with increased mortality risk and worse GVHD-free/relapse-free survival.

The need for individualizing teaching and assurance of knowledge transmission to patients training for home dialysis

Patients have varied learning styles and this has implications for home haemodialysis (HHD). Assessment tools directed toward understanding these styles remains understudied. As a consequence, this may lead to substandard retention rates or adverse events in HHD programs. As part of a continuous quality improvement initiative we have aimed to improve our understanding of patient learning styles and consequently tailor home dialysis training to individuals. To objectively determine knowledge translation and comprehension, irrespective of learning styles, we have introduced an objective structured clinical examination (OSCE). This assessment tool allows for further refinement of educational priorities by highlighting both deficiencies and strengths. Thereafter, an exit OSCE ensures patients attain an acceptable standard to complete home haemodialysis independently. We hope this tool will help shape future training criteria for HHD programs and consequently reduce adverse event rates.

Mortality Trends after Transfer from Peritoneal Dialysis to Hemodialysis

Introduction

Transition to hemodialysis (HD) is a common outcome in peritoneal dialysis (PD), but the associated mortality risk is poorly understood. This study sought to identify rates of and risk factors for mortality after transitioning from PD to HD.

Methods

Patients with incident PD (between 2000 and 2014) who transferred to HD for ≥1 day were identified, using data from Australia and New Zealand Dialysis and Transplantation registry (ANZDATA), Canadian Organ Replacement Register (CORR), Europe Renal Association (ERA) Registry, and the United States Renal Dialysis System (USRDS). Crude mortality rates were calculated for the first 180 days after transfer. Separate multivariable Cox models were built for early (<90 days), medium (90–180 days), and late (>180 days) periods after transfer.

Results

Overall, 6683, 5847, 21,574, and 80,459 patients were included from ANZDATA, CORR, ERA Registry, and USRDS, respectively. In all registries, crude mortality rate was highest during the first 30 days after a transfer to HD declining thereafter to nadir at 4 to 6 months. Crude mortality rates were lower for patients transferring in the most recent years (than earlier). Older age, PD initiation in earlier cohorts, and longer PD vintage were associated with increased risk of death, with the strongest associations during the first 90 days after transfer and attenuating thereafter. Mortality risk was lower for men than women <90 days after transfer, but higher after 180 days.

Conclusion

In this multinational study, mortality was highest in the first month after a transfer from PD to HD and risk factors varied by time period after transfer. This study highlights the vulnerability of patients at the time of modality transfer and the need to improve transitions.

Differences in mRNA-1273 (Moderna) and BNT162b2 (Pfizer-BioNTech) SARS-CoV-2 vaccine immunogenicity among patients undergoing dialysis

BACKGROUND

Differences in immunogenicity between mRNA SARS-CoV-2 vaccines have not been well characterized in patients undergoing dialysis. We compared the serologic response in patients undergoing maintenance hemodialysis after vaccination against SARS-CoV-2 with BNT162b2 (Pfizer-BioNTech) and mRNA-1273 (Moderna).

METHODS

We conducted a prospective observational cohort study at 2 academic centres in Toronto, Canada, from Feb. 2, 2021, to July 20, 2021, which included 129 and 95 patients who received the BNT162b2 and mRNA-1273 SARS-CoV-2 vaccines, respectively. We measured SARS-CoV-2 immunoglobulin G antibodies to the spike protein (anti-spike), receptor binding domain (anti-RBD) and nucleocapsid protein (anti-NP) at 6-7 and 12 weeks after the second dose of vaccine and compared those levels with the median convalescent serum antibody levels from 211 controls who were previously infected with SARS-CoV-2.

RESULTS

At 6-7 weeks after 2-dose vaccination, we found that 51 of 70 patients (73%) who received BNT162b2 and 83 of 87 (95%) who received mRNA-1273 attained convalescent levels of anti-spike antibody (p < 0.001). In those who received BNT162b2, 35 of 70 (50%) reached the convalescent level for anti-RBD compared with 69 of 87 (79%) who received mRNA-1273 (p < 0.001). At 12 weeks after the second dose, anti-spike and anti-RBD levels were significantly lower in patients who received BNT162b2 than in those who received mRNA-1273. For anti-spike, 70 of 122 patients (57.4%) who received BNT162b2 maintained the convalescent level versus 68 of 71 (96%) of those who received mRNA-1273 (p < 0.001). For anti-RBD, 47 of 122 patients (38.5%) who received BNT162b2 maintained the anti-RBD convalescent level versus 45 of 71 (63%) of those who received mRNA-1273 (p = 0.002).

INTERPRETATION

In patients undergoing hemodialysis, mRNA-1273 elicited a stronger humoral response than BNT162b2. Given the rapid decline in immunogenicity at 12 weeks in patients who received BNT162b2, a third dose is recommended in patients undergoing dialysis as a primary series, similar to recommendations for other vulnerable populations.

Superhybrid Mode-Enhanced Optical Torques on Mie-Resonant Particles

Circularly polarized light carries spin angular momentum, so it can exert an optical torque on the polarization-anisotropic particle by the spin momentum transfer. Here, we show that giant positive and negative optical torques on Mie-resonant (gain) particles arise from the emergence of superhybrid modes with magnetic multipoles and electric toroidal moments, excited by linearly polarized beams. Anomalous positive and negative torques on particles (doped with judicious amount of dye molecules) are over 800 and 200 times larger than the ordinary lossy counterparts, respectively. Meanwhile, a rotational motor can be configured by switching the s- and p-polarized beams, exhibiting opposite optical torques. These giant and reversed optical torques are unveiled for the first time in the scattering spectrum, paving another avenue toward exploring unprecedented physics of hybrid and superhybrid multipoles in metaoptics and optical manipulations.