Immune cell dysfunction and inflammation in end-stage renal disease. Nat Rev Nephrol. 2013;9:255-265. [PMID: 23507826 DOI: 10.1038/nrneph.2013.44]

Genome-wide transcriptome and DNA methylome profiling of acquired cystic disease-associated renal cell carcinoma

Acquired cystic disease (ACD)-associated renal cell carcinoma (RCC) develops uniquely and frequently in patients receiving long-term dialysis for end-stage renal disease (ESRD). In our previous study, the molecular alteration profiles of ACD-associated RCC were partially similar to those of papillary RCC (PRCC). However, the specific profiles of molecular alterations in ACD-associated RCC and their pathogenic mechanisms remain largely unknown. Therefore, we compared genome-wide transcription and DNA methylation profiles of 12 ACD-associated RCC and 26 PRCC samples, which comprised eight ESRD-induced and 18 sporadic (arising in non-dialysis kidney) PRCC samples. RNA-seq and Infinium Methylation EPIC were used to identify the unique genetic and epigenetic profiles in ACD-associated RCC. ACD-associated RCC harboured a unique expression profile from that of PRCC. Its profile was characterised by the upregulation of pathways related to amino acid metabolism. In addition, ACD-associated RCC exhibited a unique DNA methylation profile that was characterised by the hypomethylation of pathways related to amino acid metabolism. This reflected a significant difference between the expression profiles of ACD-associated RCC and PRCC. The present genome-wide transcriptome and DNA methylome profiling revealed that aberrant activation of amino acid metabolism-related pathways, potentially induced by DNA hypomethylation, may be involved in the pathogenesis of ACD-associated RCC.

A new era in the treatment of kidney diseases: NLRP3 inflammasome and cytokine-targeted therapies

The kidneys are crucial for filtering blood, managing overall body water, electrolyte, and acid-base balance, and regulating blood pressure. They remove metabolic waste products, toxins, and drugs. In addition, they limit inflammation by clearing cytokines and reduce immune cell activation by removing bacterial components. Dendritic cells (DCs) in the kidney maintain peripheral tolerance. About 85% of filtered water is reabsorbed by the proximal tubule, exposing distal nephron cells to high concentrations of low molecular weight antigens. These antigens are captured by DCs, helping to inactivate potentially autoreactive T cells and maintain tolerance to circulating antigens. In kidney failure, immune function is severely compromised due to the retention of toxins and cytokines, which activate immune cells and increase systemic inflammation. The kidneys are also vulnerable to immune-mediated diseases. Loss of immune homeostasis, characterized by over- or under-activity of the immune response, can adversely affect kidney function. With advances in immunology and cellular biology, biologic therapies targeting various pathways involved in the pathophysiology of kidney diseases are being developed. In this review, the immunologic aspects of kidney diseases and focus on cytokine-based therapies that may hold promise for the treatment of kidney diseases in the future will be presented.

A second act for spironolactone: cognitive benefits in renal dysfunction - a critical review

Renal dysfunction or Chronic kidney disease (CKD) are increasingly associated with cognitive deficit and memory impairment, suggesting a crucial kidney-brain axis. This review examines spironolactone's emerging role as a neuroprotective agent in the context of renal dysfunction-induced cognitive impairment. As a selective mineralocorticoid receptor (MR) antagonist, spironolactone demonstrates multifaceted protective mechanisms beyond its well established renoprotective effects. Evidences also suggests that spironolactone attenuates neuroinflammation, mitigates oxidative stress in brain, preserve blood-brain barrier (BBB) integrity and regulates hormonal imbalances associated with renal dysfunction. This review focuses on the reported beneficial effects of spironolactone in various neurodegenerative diseases (NDDs). These mechanisms collectively protect against the neurodegeneration in memory impairment induced by renal dysfunction. The dual action of spironolactone on both renal and cerebral tissues presents a novel therapeutic advantage in addressing this complex pathophysiology. This study elucidates multiple beneficial mechanisms by which spironolactone addresses cognitive impairment associated with renal dysfunction. Spironolactone enhances BBB protection and restores BBB integrity which is often compromised with renal dysfunction. It promotes neuroplasticity (allowing for improved neural adaptation and cognitive function), additionally mediates cerebral blood flow (CBF) ensuring adequate oxygen and nutrient delivery to brain. Spironolactone's anti-inflammatory effects by inhibiting the nuclear factor-kappa B (NF-κB) pathway and modulation of neuregulin1 (NRG1)/v-erb-b2 avian erythroblastic leukemia viral oncogene homolog 4 (ERBB4) signaling effectively reduce neuroinflammation that contributes to memory impairment. It also mitigates oxidative stress by targeting NADPH-oxidase (NOX), a major source of reactive oxygen species (ROS) in the central nervous system (CNS). Spironolactone also maintains hormonal balance, particularly regarding aldosterone levels, which become dysregulated in renal dysfunction and negatively impact brain function. These insights provide new possibilities for developing targeted therapies against renal dysfunction-induced memory impairment.

Drivers and mechanisms of cognitive decline in chronic kidney disease

Cognitive impairment is highly prevalent among individuals with chronic kidney disease (CKD). Despite its high prevalence, the contributing factors and mechanisms underlying brain-kidney dysfunction in CKD remain poorly understood. However, advances in neuroscience, including novel imaging techniques and cognitive assessment methods, have begun to clarify this complex relationship. Several factors contribute directly to cognitive decline in people with CKD, including accumulation of uraemic toxins, microvascular damage, malnutrition, chronic inflammation and disruptions in key neuroprotective pathways, such as those involving Klotho and the glymphatic system. These factors are also linked to the accelerated ageing observed in people with CKD, a key contributor to cognitive decline. However, most studies on cognition in people with CKD have been cross-sectional and associative, offering limited insight into causation. Research advances, such as studies on the effect of uraemic toxins on the blood-brain barrier and the role of the endothelial glycocalyx in vascular damage, offer promising new directions. Emerging data from longitudinal cohort studies are also enhancing our understanding of these processes, with potential implications for both the treatment of CKD-related cognitive decline and the broader issue of cognitive dysfunction in ageing populations. Here, we examine key mechanisms linking CKD to cognitive decline and consider potential therapeutic interventions.

Bidirectional Interaction Between Chronic Kidney Disease and Porphyromonas gingivalis Infection Drives Inflammation and Immune Dysfunction

Introduction: Chronic kidney disease (CKD) is characterized by a decline in renal function, increased mortality, and significant impairments in the immune system and function of immune cells. These alterations are often derived by uremic toxins, which, in turn, modify the immune system's response to infections. Our research investigates the progression of Porphyromonas gingivalis (P. gingivalis) infection during CKD and its subsequent impact on kidney failure. Methods: We utilized two infectious models, a chamber model representing short-term local inflammation and alveolar bone loss that mimic chronic infection of periodontium, both in conjunction with a CKD model. Additionally, our in vitro studies employed primary macrophages, osteoclasts, and lymphocytes to characterize the immune responses to P. gingivalis and pathogen-associated molecular patterns (PAMPs) in the presence of uremic toxins. Results and Conclusion: Our findings demonstrate that uremic toxins, such as indoxyl sulfate (IS), alter responses of macrophages and lymphocytes to P. gingivalis. In vivo, CKD significantly enhanced P. gingivalis survival and infection-induced alveolar bone loss. The increased distribution of pathogen within peripheral tissues was associated with altered inflammatory responses, indicating that CKD promotes infection. Moreover, P. gingivalis-infected mice exhibited a marked increase in renal inflammation, suggesting that the relationship between uremia and infection is bidirectional, with infection exacerbating kidney dysfunction. Furthermore, we observed that infected CKD mice exhibit decreased serum immunoglobulin G (IgG) levels compared to infected mice without CKD, implying that uremia is associated with immune dysfunction characterized by immunodepression and impaired B lymphocyte function.

Effectiveness of 2023-2024 COVID-19 vaccines against COVID-19-associated hospitalizations among adults aged ≥18 years with end stage kidney disease - United States, September 2023-April 2024

BACKGROUND

Persons with end stage kidney disease (ESKD) on dialysis are at high risk for severe COVID-19 disease. In September 2023, 2023-2024 COVID-19 vaccination was recommended in the United States for all persons aged ≥6 months. Due to possible immune dysfunction, advanced age, and high prevalence of additional underlying conditions, including immunocompromising conditions, among individuals with ESKD, reduced vaccine effectiveness (VE) is a concern. Understanding effectiveness of 2023-2024 COVID-19 vaccine among persons with ESKD can inform COVID-19 vaccine recommendations for this population.

METHODS

A retrospective cohort investigation was conducted among Medicare fee-for-service beneficiaries aged ≥18 years with ESKD receiving dialysis using Medicare enrollment and claims records. Follow-up began on September 17, 2023, and continued until the earliest occurrence of claim for a COVID-19-associated outcome, other censoring event, or end of follow-up. A marginal structural Cox model was used to estimate VE (calculated as [1 - hazard ratio]*100 %), interpreted as the benefit of 2023-2024 COVID-19 vaccination compared with no 2023-2024 vaccine dose. VE was estimated by presence of additional immunocompromising conditions, age group, and time since vaccination.

RESULTS

During September 17, 2023 - April 13, 2024, 17,749/112,250 (16 %) Medicare beneficiaries aged ≥18 years with ESKD without additional immunocompromising conditions received a 2023-2024 COVID-19 vaccine dose, with a maximum 209 days of follow-up since vaccination. During the follow-up period 6539 medically attended COVID-19 events, including 3605 COVID-19-associated hospitalizations, 789 COVID-19-associated deaths, and 896 COVID-19-associated thromboembolic events, were recorded. VE against COVID-19-associated hospitalization was 55 % (95 % confidence interval [CI]: 42 % - 65 %) at 7-59 days after vaccination and 47 % (95 % CI: 35 % - 57 %) at ≥60 days after vaccination. VE against COVID-19-associated death was 71 % (95 % CI: 46 % - 84 %) at 7-59 days after vaccination and 51 % (95 % CI: 24 % - 69 %) ≥60 days after vaccination. VE against COVID-19-associated thromboembolic events was 44 % (95 % CI, 24 %, 59 %).

CONCLUSIONS

The 2023-2024 COVID-19 vaccines provided protection against COVID-19-associated hospitalization, death, and thromboembolic events among adults with ESKD. These data support the recommendation that adults with ESKD receive the updated COVID-19 vaccine.

Neutrophils and NETs in kidney disease

Neutrophils, conventionally regarded as a homogeneous immune cell population, have emerged as a heterogeneous group of cells with distinct gene profiles and immune properties. Activated neutrophils release a spectrum of bioactive substances, including cytokines, chemokines, proteolytic enzymes, reactive oxygen species and neutrophil extracellular traps (NETs), which are composed of decondensed DNA and antimicrobial proteins. NETs have a pivotal role in innate immunity, including in preventing the ascent of uropathogenic bacteria into the kidneys, as they efficiently trap pathogenic microorganisms. However, although indispensable for defence against pathogens, NETs also pose risks of self-damage owing to their cytotoxicity, thrombogenicity and autoantigenicity. Accordingly, neutrophils and NETs have been implicated in the pathogenesis of various disorders that affect the kidneys, including acute kidney injury, vasculitis, systemic lupus erythematosus, thrombotic microangiopathy and in various aetiologies of chronic kidney disease. Pathological alterations in the glomerular vascular wall can promote the infiltration of neutrophils, which can cause tissue damage and inflammation through their interactions with kidney-resident cells, including mesangial cells and podocytes, leading to local cell death. Targeting neutrophil activation and NET formation might therefore represent a new therapeutic strategy for these conditions.

LILRB3 genetic variation is associated with kidney transplant failure in African American recipients

African American (AA) kidney transplant recipients exhibit a higher rate of graft loss compared with other racial and ethnic populations, highlighting the need to identify causative factors. Here, in the Genomics of Chronic Allograft Rejection cohort, pretransplant blood RNA sequencing revealed a cluster of four consecutive missense single-nucelotide polymorphisms (SNPs), within the leukocyte immunoglobulin-like receptor B3 (LILRB3) gene, strongly associated with death-censored graft loss. This SNP cluster (named LILRB3-4SNPs) encodes missense mutations at amino acids 617-618 proximal to a SHP1/2 phosphatase-binding immunoreceptor tyrosine-based inhibitory motif. The LILRB3-4SNPs cluster is specifically enriched within AA individuals and exhibited a strong association with death-censored graft loss and estimated glomerular filtration rate decline in the AA participants from multiple transplant cohorts. In two large Biobanks (BioMe and All-of-Us), the LILRB3-4SNPs cluster was associated with the early onset of end-stage renal disease and acted synergistically with the apolipoprotein L1 (APOL1) G1/G2 allele to accelerate disease progression. The SNPs were also linked to multiple immune-related diseases in AA individuals. Last, on multiomics analysis of blood and biopsies, recipients with LILRB3-4SNPs showed enhanced inflammation and monocyte ferroptosis. While larger and prospective studies are needed, our data provide insights on the genetic variation underlying kidney transplant outcomes.

Autologous cord blood vs individualized supplements in autistic spectrum disorder: CORDUS study results

BACKGROUND

Cellular therapies have started an important new therapeutic direction in autistic spectrum disorder (ASD), and the ample diversity of ASD pathophysiology and the different types of cell therapies prompt an equally ample effort to employ clinical studies for studying the ASD causes and cell therapies. Stem cells have yielded so far mixed results in clinical trials, and at patient level the results varied from impressive to no improvement. In this context we have administered autologous cord blood (ACB) and a non-placebo, material intervention represented by an individualized combination of supplements (ICS) to ASD children.

AIM

To compare the efficacy of ACB vs ICS and find markers correlated with the child's progress in order to better predict ACB efficacy.

METHODS

CORDUS clinical study is a crossover study in which both oral ICS and intravenous ACB were sequentially administered to 56 children; ACB was infused as an inpatient procedure. Treatment efficacy was evaluated pre-treatment and post-treatment at 6 months by an independent psychotherapist with Autism Treatment Evaluation Checklist, Quantitative Checklist for Autism in Toddlers and a 16-item comparative table score, after interviewing the children’s parents and therapists. Before and after each intervention participants had a set of blood tests including inflammatory, metabolic and oxidative markers, and the neuronal specific enolase.

RESULTS

No serious adverse reactions were noted during and after cord blood or supplement administration. ACB improved evaluation scores in 78% of children with age 3–7-years (n = 28), but was much less effective in kids older than 8 years or with body weight of more than 35 kg (n = 28; only 11% of children improved scores). ICS yielded better results than ACB in 5 cases out of 28, while in 23 kids ACB brought more improvement than ICS (P < 0.05); high initial levels of inflammation and ferritin were associated with no improvement. Ample individual differences were noted in children's progress, and statistically significant improvements were seen after ACB on areas such as verbalization and social interaction, but not on irritability or aggressive behavior.

CONCLUSION

ACB has superior efficacy to ICS in ASD; high inflammation, ferritin, age and body weight predict less improvement; more clinical studies are needed for studying ACB efficacy in ASD.

Increased risk of genitourinary cancer in kidney transplant recipients: a large-scale national cohort study and its clinical implications

PURPOSE

To investigate the risk of genitourinary (GU) cancer in kidney transplant recipients (KTRs) compared to that in the general population, focusing on potential risk factors and clinical implications.

METHODS

Using a national cohort of approximately 360,000 individuals, including 31,542 KTRs, we conducted a retrospective analysis of the data from 2007 to 2018. Propensity score matching was used to compare KTRs with a healthy population, adjusting for age, sex, diabetes, hypertension, and hypercholesterolemia.

RESULTS

We identified a significantly increased risk of GU cancers, particularly bladder and kidney cancers, in KTRs. Multivariate analysis revealed a higher risk of GU cancer associated with kidney transplantation [hazard ratio (HR) 2.133, 95% confidence interval (CI) 1.641-2.772] and hypercholesterolemia (HR 1.725, 95% CI 1.227-2.425), with older age and male sex also being significant risk factors. Conversely, no significant increase in prostate cancer risk was observed in KTRs compared to the general population.

CONCLUSION

This national cohort-based study indicated an increased risk of GU cancer in KTRs, underscoring the need for targeted cancer surveillance and pre- and post-transplant counseling. These findings provide valuable insights for the development of cancer surveillance programs for KTRs and highlight the necessity for further research in this field.

D 4 -CHIP REVEALS IMPAIRED T-CELL FUNCTION IN SEPSIS: INSIGHTS FROM PLASMA MICROENVIRONMENT ANALYSIS AND MITOCHONDRIAL-TARGETED THERAPY

ABSTRACT

Background: Sepsis, a systemic inflammation syndrome initiated by infection, poses significant challenges due to its intricate pathophysiology. T cells play a crucial role in combating infections during sepsis. Despite previous observations indicating T-cell dysfunction in sepsis, reliable in vitro detection methods were lacking, and the factors influencing these impairments remained unclear. Methods: We developed a novel method using the D 4 -Chip to assess sepsis T-cell migration function. This microfluidic platform enabled precise analysis of migration function under controlled conditions. Additionally, We explored the impact of the plasma microenvironment on T-cell behavior, along with the redox environment in sepsis, and assessed the potential efficacy of Mitoquinone mesylate (MitoQ), a mitochondrial-targeted drug. Results: Our findings revealed impaired migration function in sepsis T cells compared to healthy controls. Interestingly, sepsis plasma enhanced the migration of healthy T cells, yet incubation with healthy plasma did not fully restore migration impairments in sepsis T cells. Subsequent investigations uncovered a significant increase in NADH/NAD+ levels in sepsis T cells, with healthy T cells exposed to various sepsis plasma conditions also showing elevated NADH/NAD+ levels. Importantly, MitoQ normalized abnormal intracellular NADH/NAD+ levels and enhanced the migration ability of T cells. Conclusions: Short-term incubation with sepsis plasma does not directly inhibit T-cell migration but instead affects T-cell function by disrupting the intracellular redox environment. Improving the intracellular redox environment of sepsis patients contributes to restoring impaired migration and proliferation, with MitoQ demonstrating therapeutic potential.

IL-2Rα is a potential biomarker for heart failure diagnosis of patients with end-stage renal disease and haemodialysis

AIMS

Heart failure (HF) is a leading cause of mortality in patients with end-stage renal disease (ESRD) undergoing haemodialysis. Identifying novel predictors of HF is essential for improving diagnostic precision and enhancing patient outcomes.

METHODS

This study included 68 participants from the Haemodialysis Centre at the Second Hospital of Tianjin Medical University. Clinical characteristics and echocardiographic data were collected and analysed. We measured the plasma of 44 cytokines to investigate their correlation with cardiac function and their potential as HF biomarkers.

RESULTS

In the HF with reduced ejection fraction (HFrEF) group, the levels of several cytokines, including stem cell growth factor-β (SCGF-β), C-X-C motif chemokine 10 (CXCL10), interleukin-1α (IL-1α), interleukin-6 (IL-6), interleukin-8 (IL-8), interleukin-16 (IL-16), interleukin-1 receptor antagonist protein (IL-1Ra), interferon-γ (IFN-γ), tumour necrosis factor-α (TNF-α), leukaemia inhibitory factor (LIF), C-C motif chemokine 3 (CCL3), interleukin-10 (IL-10), interleukin-2 receptor subunit alpha (IL-2Rα), tumour necrosis factor ligand superfamily member 10 (TNFSF10), macrophage colony-stimulating factor (M-CSF), granulocyte colony-stimulating factor (G-CSF) and stem cell factor (SCF), were significantly increased, while C-C motif chemokine 11 (CCL11)/eotaxin levels were decreased compared with those in the control group (P < 0.05). Receiver operating characteristic (ROC) curve analysis highlighted TNF-α [area under the ROC curve (AUC) = 0.85, odds ratio (OR) = 1.080, 95% confidence interval (CI): 1.033-1.128, P = 0.001], IFN-γ (AUC = 0.84, OR = 1.836, 95% CI: 1.289-2.615, P = 0.003) and IL-2Rα (AUC = 0.82, OR = 1.022, 95% CI: 1.009-1.035, P = 0.001) as excellent predictors for HFrEF in haemodialysis patients with ESRD, and they outperformed soluble suppression of tumourigenicity-2 (sST2) but slightly underperformed N-terminal pro-brain natriuretic peptide (NT-proBNP). IL-2Rα (AUC = 0.77, OR = 1.018, 95% CI: 1.007-1.030, P = 0.001) demonstrated superior diagnostic capabilities when distinguishing patients with HF with left ventricular ejection fraction (LVEF) <50% from controls. IL-2Rα emerged as a robust biomarker for left ventricular HF, while TNF-α (AUC = 0.89, OR = 1.140, 95% CI: 1.039-1.250, P = 0.005) showed promise in assessing HF severity in patients with ESRD. IL-2Rα (AUC = 0.80, OR = 1.017, 95% CI: 1.007-1.027, P = 0.001) also significantly predicted right ventricular systolic dysfunction. During a median follow-up of 14 months, 10 patients (14.7%) experienced all-cause mortality. Multivariate Cox regression analysis confirmed that plasma IL-2Rα was an independent predictor of all-cause death [hazard ratio (HR): 1.010, 95% CI: 1.001-1.020, P = 0.039] after adjusting for other variables.

CONCLUSIONS

This study underscores the potential of IL-2Rα as a valuable biomarker for HF diagnosis and management in haemodialysis patients with ESRD and contributes to our understanding of this high-risk population.

Serosurvey For Measles, Mumps and Rubella in Children and Adolescents with Chronic Kidney Disease

OBJECTIVE

Children with Chronic Kidney Disease (CKD) are at increased risk for vaccine-preventable diseases. The primary objective of the study was to estimate IgG antibody titers against measles, mumps, and rubella (MMR) in children with CKD and healthy controls who were previously immunized with measles/ MMR vaccine.

METHODS

This case control study was conducted between January 2019 and January 2020. Children aged 2-18 years with CKD and healthy controls who had received at least one dose of measles/MMR were included. Children on dialysis were excluded. Clinical details of immunization were recorded, and antibody titers measured by ELISA based kits.

RESULTS

120 children (60 cases and 60 controls) were enrolled; seroprotection rates for measles, mumps and rubella in the CKD group and control group were 90% vs 86.7%, P = 0.01; 71.7% vs 77.7%, P = 0.77; and 86.7% vs 88.3%; P = 0.05, respectively, with lower antibody titers for mumps and measles in late-stages (stage 4 or 5) CKD.

CONCLUSION

Seroprotection amongst children with CKD for measles, rubella and mumps is not inferior to that in controls. However, children with late-stage CKD (stages 4 and 5) have lower seroprotection especially for mumps and measles compared to those with early-stage (1-3) CKD.

Association of Nutritional Risk Index With Infection-Related Hospitalization and Death After Hospitalization in Patients Undergoing Maintenance Hemodialysis

OBJECTIVE

Patients undergoing dialysis frequently experience hospitalization due to cardiovascular disease (CVD) and infection. This population is also at high risk of rehospitalization and subsequent death. In addition to serious outcomes, hospitalization incurs substantial medical cost. Prevention of hospitalization is accordingly an urgent matter. Here, we examined whether nutritional disorder was associated with hospitalization and subsequent death.

METHODS

The study was conducted under a prospective design using data from the Japanese Dialysis Outcomes and Practice Pattern Study. The exposure was the Nutritional Risk Index for Japanese Hemodialysis (NRI-JH), through which patients were divided into low-, medium-, and high-risk groups, with the low-risk group as referent. The primary outcome was CVD-related or infection-related hospitalization. Secondary outcome was all-cause mortality. For exploratory analyses, the associations of baseline or latest NRI-JH just before hospitalization, with death after hospitalizations, were examined.

RESULTS

Of 4021 patients, 566 patients had CVD-related hospitalization and 375 had infection-related hospitalization during a median follow-up of 2.6 years. NRI-JH at baseline was significantly associated with infection-related hospitalization but not with CVD-related hospitalization, in multivariable Cox models (hazard ratio [HR] 1.46, 95% confidential interval [CI]: 1.09 to 1.97, P = .012 for medium-risk vs. low-risk group) (HR 2.46, 95% CI: 1.81 to 3.35, P < .001 for high-risk vs. low-risk group). NRI-JH was also associated with all-cause mortality. In addition, the baseline and latest high-risk NRI-JH groups were significantly associated with death after both CVD-related and infection-related hospitalizations.

CONCLUSIONS

A higher nutritional risk as evaluated by NRI-JH was associated with infection-related hospitalization but not with CVD-related hospitalization. However, NRI-JH was significantly associated with death after both CVD-related and infection-related hospitalizations, suggesting that nutritional risk may be separately involved in hospitalization or subsequent death. NRI-JH may be useful in the planning of individual care to improve outcomes.

Mortality associated with the COVID-19 pandemic in the Swiss dialysis population beyond SARS-CoV-2 infection

Background

While SARS-CoV-2 infection has direct obvious consequences on patients undergoing dialysis, the COVID-19 pandemic also had an indirect impact on health systems. Therefore, we aimed to determine whether the COVID-19 era itself was associated with adverse consequences in the Swiss dialysis population as compared to the pre-COVID-19 era, while accounting for direct impact of SARS-CoV-2 infection.

Methods

We retrospectively included all patients recorded in the Swiss dialysis registry from January 2014 to December 2022. The pre-COVID-19 era and the COVID-19 era were defined based on the cut-off date of January 2020. Cox proportional hazard model was used with all-cause mortality as the primary outcome.

Results

The cohort consisted of 7837 patients from 97 dialysis centres. Median age was 68.6 years with 66.1% men. Crude mortality rates were 11.6% (11.0% to 12.2%) and 14.2% (13.4% to 14.9%) person-years for the pre-COVID-19 era and the COVID-19 era, respectively. In multivariable analysis, SARS-CoV-2 infection was associated with an increased risk of mortality (HR 4.26, 95% CI 3.65 to 4.97, P < .001) while the COVID-19 era itself was not (HR 0.98, 95% CI 0.88 to 1.08, P = .687).

Conclusions

The COVID-19 era was not associated with an excess of mortality in the Swiss dialysis population as compared to the pre-COVID-19 era when accounting for the direct effect of SARS-CoV-2 infection. This suggests that control measures established during the pandemic did not have a negative impact on dialysis patients at the national level. These results could inform health policy makers in the eventuality of future pandemics.

Unique Pathological Findings of Polarized Calcium Oxalate Crystals in Spondylodiscitis of an ESRD Hemodialysis Patient: A Case Report

Patients with end-stage renal disease (ESRD) undergoing chronic hemodialysis are at an increased risk of developing spondylodiscitis, an infectious condition affecting the vertebral column. In this case report, we present a 22-year-old male with ESRD, a history of hyperoxaluria, nephrolithiasis, and anemia, who developed spondylodiscitis. Notably, pathological examination of tissue samples obtained during surgical intervention revealed the presence of polarized calcium oxalate crystals within the lumbar laminae and spinal discs, a rare finding in this clinical context. The deposition of these crystals may have contributed to the development and progression of spondylodiscitis by creating an environment conducive to bacterial growth and infection. This case highlights the importance of comprehensive pathological assessment in ESRD patients with spondylodiscitis, as it may uncover uncommon manifestations that could have implications for disease management. Further research is necessary to elucidate the underlying mechanisms of this rare presentation and its impact on the clinical course and treatment of spondylodiscitis in ESRD patients undergoing hemodialysis.

Terbinafine in acrylic polymer for the treatment of onychomycosis in hemodialysis patients: a phase II clinical trial

Introduction

Onychomycosis is a nail infection caused by dermatophyte fungi, non-dermatophyte fungi, and yeast. Patients with chronic kidney disease on dialysis are part of the population that presents higher rates of this disease, mainly due to immunosuppression. Among patients with chronic kidney disease on dialysis, the treatment of onychomycosis is complex, mainly due to the limitations imposed by comorbidities. In this context, the study evaluated the safety and potential efficacy of a treatment that combines nail debridement with the use of acrylic gel nails carrying terbinafine at a concentration of 2%.

Methods

Patients from the Hemodialysis Center of the São Francisco de Assis University Hospital in Bragança Paulista, São Paulo, Brazil were included. Those had hallux onychomycosis with clinical forms whose treatment involved the need for nail debridement. After the debridement procedure, a nail prosthesis made with acrylic reconstruction gel and 2% terbinafine was applied. The procedure was renewed every 2 weeks (~14 days) for 11 months. The evolution was monitored with measurements of the normal-appearing nail plate and photographs. Direct mycological examination and fungal culture were performed at the beginning of the study and 30 days after applications were interrupted. Assessment of clinical response, clinical cure, mycological cure, and complete cure was performed at the end of the study. All participants answered a questionnaire about their perception of the treatment.

Results

Out of the 155 patients on hemodialysis, 64/155 (41.3%) individuals were identified with symptoms suggestive of onychomycosis in the halluces after clinical analysis. Among them, 35/64 (54.7%) individuals presented a positive direct mycological examination and underwent fungal culture to identify the etiological agent. In this group of patients, 24/35 (68.6%) individuals who presented clinical forms whose treatment involved the need for nail debridement were selected. Only 15/24 (62.5%) individuals completed the study. Among the study participants, 5/15 (33.3%) still presented positive fungal culture in the presence of a negative direct mycological examination and 1/15 (6.7%) presented a positive direct mycological examination, but with a negative culture. Among those with a positive fungal culture, 3/15 (20.0%) participants presented microorganisms different from those isolated in the initial exams. Regarding cure, 5/15 (33.3%) participants showed a clinical response, 4/15 (26.7%) clinical cure, and 3/15 (20.0%) complete cure. No patient presented an allergic reaction or local irritation caused by the material used in the treatment. There were accidental superficial ulcerations caused by the electric sandpaper; however, no wound developed secondary infection. No participant reported discomfort due to the nail prosthesis use, 3/15 (20.0%) reported a feeling of discomfort caused by the vibration of the electric file and 12/15 (80.0%) reported the perception that their nails had a better appearance during treatment with nail prosthesis made with acrylic reconstruction gel and 2% terbinafine.

Conclusion

The application of 2% terbinafine in acrylic reconstruction gel for the manufacture of nail prostheses applied after debridement of moderate and severe forms of onychomycosis showed low efficacy as an isolated treatment in patients on dialysis due to chronic kidney disease. On the other hand, most patients had a good perception of the appearance of their nails during treatment, even when it did not result in apparent clinical improvement or complete cure.

The American Association of Tissue Banks tissue donor screening for Mycobacterium tuberculosis-Recommended criteria and literature review

After two multistate outbreaks of allograft tissue-transmitted tuberculosis (TB) due to viable bone, evidence-based donor screening criteria were developed to decrease the risk of transmission to recipients. Exclusionary criteria, commentary, and references supporting the criteria are provided, based on literature search and expert opinion. Both exposure and reactivation risk factors were considered, either for absolute exclusion or for exclusion in combination with multiple risk factors. A criteria subset was devised for tissues containing viable cells. Risk factors for consideration included exposure (e.g., geographic birth and residence, travel, homelessness, incarceration, healthcare, and workplace) and reactivation (e.g., kidney disease, liver disease, history of transplantation, immunosuppressive medications, and age). Additional donor considerations include the possibility of sepsis and chronic illness. Donor screening criteria represent minimal criteria for exclusion and do not completely exclude all possible donor TB risks. Additional measures to reduce transmission risk, such as donor and product testing, are discussed but not included in the recommendations. Careful donor evaluation is critical to tissue safety.

Thoracoscopic minimally invasive surgical treatment with the same incisions in a patient with uremia complicated with large thymoma and right upper lobe lung cancer: a case report

A 41 year old female with stage 5 chronic kidney disease undergoing hemodialysis was admitted to the hospital. Chest CT scan revealed a large mass lesion of approximately 6.0 × 3.5x4.9 cm in size in the anterior superior mediastinum and a ground glass nodule in the upper lobe of the right lung, which increased in size from 9 × 7 mm 1 year and 9 months ago to 11mmx9mm before surgery. We designed a localization method to accurately locate the pulmonary nodule and successfully performed thoracoscopic minimally invasive resection of both thymoma and lung cancer through a subxiphoid approach with the same incision for this patient. With the support of perioperative hemodialysis, the patient's outcome is good. The pathological diagnosis of the anterior mediastinal mass is thymoma (b1 type), and the pathological diagnosis of the right upper lobe nodule is invasive lung adenocarcinoma (acinar type). This report describes the diagnosis and treatment process of the case.

Decoding the Immune Response and Its Biomarker B2M for High Altitude Pulmonary Edema in Rat: Implications for Diagnosis and Prognosis

Purpose

We aimed to investigate whether peripheral blood biomarkers B2M related to immune response can serve as indicators of HAPE pathophysiological characteristics or disease progression.

Patients and Methods

Bioinformatics technology was used to explore the peripheral blood pathophysiological mechanisms and immune hub genes related to the occurrence of HAPE. The hub gene was verified through animal experiments, and its function and correlation between its expression level and the diagnosis, treatment effect and prognosis of HAPE were explored.

Results

The GSVA results showed that the occurrence of HAPE was related to the down-regulation of immune response pathways by RUNX3 and STING. WGCNA results showed that the peripheral blood immune gene module related to the development of HAPE was related to the decrease of immune function and the increase of immune checkpoint molecule PD-L1 gene expression, and the expression of immune checkpoint genes LILRB2 and SIGLEC15 increased. Cytoscape software, RT-qPCR and WB confirmed that the hub gene B2M is a specific peripheral blood biomarker of HAPE. ROC, DCA, RT-qPCR, HE and Masson results showed that the expression of peripheral blood B2M has the ability to indicate the diagnosis, treatment effect and prognosis of HAPE. The decreased expression of B2M protein in peripheral blood leukocytes may be a marker of HAPE. Single-gene GSEA confirmed that the reduced expression of B2M in peripheral blood may be involved in the down-regulation of the antigen presentation pathway mediated by MHC class I molecules, was positively correlated with the down-regulation of the TNF signaling pathway, and was negatively correlated with the expression of LILRB2 and SIGLEC15.

Conclusion

The occurrence of HAPE may be related to decreased immune function and immune tolerance. Peripheral blood B2M may be involved in the related pathways, its expression level can prompt the diagnosis, treatment and prognosis of HAPE.

Network Analysis of Dysregulated Immune Response to COVID-19 mRNA Vaccination in Hemodialysis Patients

INTRODUCTION

End-stage renal disease (ESRD) results in immune dysfunction that is characterized by both systemic inflammation and immune incompetence, leading to impaired responses to vaccination.

METHODS

To unravel the complex regulatory immune interplay in ESRD, we performed the network-based transcriptomic profiling of ESRD patients on maintenance hemodialysis (HD) and matched healthy controls (HCs) who received the two-dose regimen of the COVID-19 mRNA vaccine BNT162b2.

RESULTS

Co-expression networks based on blood transcription modules (BTMs) of genes differentially expressed between the HD and HC groups revealed co-expression patterns that were highly similar between the two groups but weaker in magnitude in the HD compared to HC subjects. These networks also showed weakened coregulation between BTMs within the dendritic cell (DC) family as well as with other BTM families involved with innate immunity. The gene regulatory networks of the most enriched BTMs, likewise, highlighted weakened targeting by transcription factors of key genes implicated in DC, natural killer (NK) cell, and T cell activation and function. The computational deconvolution of immune cell populations further bolstered these findings with discrepant proportions of conventional DC subtypes, NK T cells, and CD8+ T cells in HD subjects relative to HCs.

CONCLUSION

Altogether, our results indicate that constitutive inflammation in ESRD compromises the activation of DCs and NK cells, and, ultimately, their mediation of downstream lymphocytes, leading to a delayed but intact immune response to mRNA vaccination.

Cluster of differentiation-44 as a novel biomarker of lupus nephritis and its role in kidney inflammation and fibrosis

Introduction

CD44 is a transmembrane glycoprotein implicated in tissue inflammation and fibrosis. We investigated its role in kidney inflammation and fibrosis in a murine model of lupus nephritis (LN), and the clinico-pathological association of serum CD44 level in patients with biopsy-proven Class III/IV ± V LN.

Methods

NZB/W F1 mice were treated with control IgG or anti-CD44 monoclonal antibody for 4 weeks and disease parameters assessed. Serum CD44 level in LN patients was determined by ELISA. Control groups included healthy subjects and patients with non-renal SLE or non-lupus renal disease.

Results

CD44 expression was absent in the normal kidney, but it was expressed in proximal and distal tubular epithelial cells and infiltrating cells in renal biopsies from patients with active proliferative LN. ScRNA-Seq datasets confirmed that CD44 was predominantly expressed in tubular cells and all immune cells identified in LN patients including tissue resident, inflammatory and phagocytic macrophages, Treg cells, effector and central memory CD4+ T cells, resident memory CD8+ T cells and naïve and activated B cells. Treatment of NZB/W F1 mice with anti-CD44 antibody preserved kidney histology and reduced proteinuria, tubulo-interstitial infiltration of CD3+, CD4+ and CD19+ immune cells, and mediators of kidney fibrosis compared to Control mice. Longitudinal studies showed that serum CD44 level increased prior to clinical renal flare by 4.5 months and the level decreased after treatment. ROC curve analysis showed that CD44 level distinguished patients with active LN from healthy subjects and patients with quiescent LN, active non-renal lupus, and non-lupus CKD (ROC AUC of 0.99, 0.96, 0.99 and 0.99 respectively). CD44 level correlated with leukocyte infiltration and interstitial inflammation scores in active LN kidney biopsies.

Discussion

Our findings suggest that CD44 plays a pathogenic role in renal parenchymal inflammation and fibrosis in active LN and monitoring CD44 may facilitate early diagnosis of flare.

Cutaneous adaptive immunity and uraemia: a narrative review

Chronic kidney disease affects 1 in 10 people globally, with a prevalence twenty times that of cancer. A subset of individuals will progress to end-stage renal disease (ESRD) where renal replacement therapy is required to maintain health. Cutaneous disease, including xerosis and pruritus, are endemic amongst patients with ESRD. In the uraemia-associated immune deficiency of ESRD, impaired circulating immune responses contribute to increased infection risk and poorer vaccination response. Clinical manifestations of dysregulated adaptive immunity within the skin have been well-described and have been posited to play a role in cutaneous features of ESRD. However, our understanding of the mechanisms by which adaptive immunity within the skin is affected by uraemia is relatively limited. We provide an overview of how the cutaneous adaptive immune system is impacted both directly and indirectly by uraemia, highlighting that much work has been extrapolated from the circulating immune system and often has not been directly evaluated in the skin compartment. We identify knowledge gaps which may be addressed by future research. Ultimately, greater understanding of these pathways may facilitate novel therapeutic approaches to ameliorate widespread cutaneous symptomatology in ESRD.

Metabolic Pathways Affected in Patients Undergoing Hemodialysis and Their Relationship with Inflammation

Worldwide, 3.9 million individuals rely on kidney replacement therapy. They experience heightened susceptibility to cardiovascular diseases and mortality, alongside an increased risk of infections and malignancies, with inflammation being key to explaining this intensified risk. This study utilized semi-targeted metabolomics to explore novel metabolic pathways related to inflammation in this population. We collected pre- and post-session blood samples of patients who had already undergone one year of chronic hemodialysis and used liquid chromatography and high-resolution mass spectrometry to perform a metabolomic analysis. Afterwards, we employed both univariate (Mann-Whitney test) and multivariate (logistic regression with LASSO regularization) to identify metabolites associated with inflammation. In the univariate analysis, indole-3-acetaldehyde, 2-ketobutyric acid, and urocanic acid showed statistically significant decreases in median concentrations in the presence of inflammation. In the multivariate analysis, metabolites positively associated with inflammation included allantoin, taurodeoxycholic acid, norepinephrine, pyroglutamic acid, and L-hydroorotic acid. Conversely, metabolites showing negative associations with inflammation included benzoic acid, indole-3-acetaldehyde, methionine, citrulline, alphaketoglutarate, n-acetyl-ornithine, and 3-4-dihydroxibenzeneacetic acid. Non-inflamed patients exhibit preserved autophagy and reduced mitochondrial dysfunction. Understanding inflammation in this group hinges on the metabolism of arginine and the urea cycle. Additionally, the microbiota, particularly uricase-producing bacteria and those metabolizing tryptophan, play critical roles.

Severe COVID-19 infection: An institutional review and literature overview

BACKGROUND

Our study aimed to describe the group of severe COVID-19 patients at an institutional level, and determine factors associated with different outcomes.

METHODS

A retrospective chart review of patients admitted with severe acute hypoxic respiratory failure due to COVID-19 infection. Based on outcomes, we categorized 3 groups of severe COVID-19: (1) Favorable outcome: progressive care unit admission and discharge (2) Intermediate outcome: ICU care (3) Poor outcome: in-hospital mortality.

RESULTS

Eighty-nine patients met our inclusion criteria; 42.7% were female. The average age was 59.7 (standard deviation (SD):13.7). Most of the population were Caucasian (95.5%) and non-Hispanic (91.0%). Age, sex, race, and ethnicity were similar between outcome groups. Medicare and Medicaid patients accounted for 62.9%. The average BMI was 33.5 (SD:8.2). Moderate comorbidity was observed, with an average Charlson Comorbidity index (CCI) of 3.8 (SD:2.6). There were no differences in the average CCI between groups(p = 0.291). Many patients (67.4%) had hypertension, diabetes (42.7%) and chronic lung disease (32.6%). A statistical difference was found when chronic lung disease was evaluated; p = 0.002. The prevalence of chronic lung disease was 19.6%, 27.8%, and 40% in the favorable, intermediate, and poor outcome groups, respectively. Smoking history was associated with poor outcomes (p = 0.04). Only 7.9% were fully vaccinated. Almost half (46.1%) were intubated and mechanically ventilated. Patients spent an average of 12.1 days ventilated (SD:8.5), with an average of 6.0 days from admission to ventilation (SD:5.1). The intermediate group had a shorter average interval from admission to ventilator (77.2 hours, SD:67.6), than the poor group (212.8 hours, SD:126.8); (p = 0.001). The presence of bacterial pneumonia was greatest in the intermediate group (72.2%), compared to the favorable group (17.4%), and the poor group (56%); this was significant (p<0.0001). In-hospital mortality was seen in 28.1%.

CONCLUSION

Most patients were male, obese, had moderate-level comorbidity, a history of tobacco abuse, and government-funded insurance. Nearly 50% required mechanical ventilation, and about 28% died during hospitalization. Bacterial pneumonia was most prevalent in intubated groups. Patients who were intubated with a good outcome were intubated earlier during their hospital course, with an average difference of 135.6 hours. A history of cigarette smoking and chronic lung disease were associated with poor outcomes.

Impact of COVID-19 Vaccination on Mortality and Clinical Outcomes in Hemodialysis Patients

This study analyzed 550 hemodialysis patients, 469 unvaccinated and 81 vaccinated against COVID-19, to assess the impact on infection rates, mortality, and clinical/laboratory parameters. Gender distribution was similar (p = 0.209), but the vaccinated group's median age was significantly lower (p = 0.005). Hospitalization rates showed no significant difference (p = 0.987), while mortality was lower in the vaccinated group (p = 0.041). Only uric acid levels were significantly higher in the vaccinated group (p = 0.009); other parameters, including creatinine and B-type natriuretic peptide, showed no significant differences. Age was an independent predictor of mortality (HR = 1.07, p < 0.001). Peak mortality occurred in December 2022 and January 2023, predominantly among unvaccinated patients. Although vaccination lowered mortality, it did not significantly affect long-term survival rates (p = 0.308). Logistic regression identified age and dialysis duration as significant mortality factors. Monthly death counts indicated higher mortality among unvaccinated patients during peak pandemic months, suggesting that vaccination provides some protection, though no significant long-term survival benefit was found.

Invasive Listeriosis in End-Stage Kidney Disease (ESKD) Patients Receiving Long-Term Dialysis: A 21-Year Case Series

Background

Listeriosis is caused by the facultative anaerobic bacterium Listeria monocytogenes. Infection from Listeria-contaminated food or water is the main etiology. If Listeria travels outside the intestines, it can cause invasive listeriosis, such as sepsis, meningitis, and meningoencephalitis. Invasive illness is especially dangerous for pregnant women and their newborns, elderly people, and people with compromised immune systems or medical conditions such as end-stage kidney disease (ESKD) patients receiving long-term dialysis.

Purpose

Describe the manifestations and hospital outcomes of invasive listeriosis and identify the risk factors for in-hospital and one-year mortality in ESKD patients receiving long-term dialysis.

Patients and Methods

This retrospective observational study examined hospitalized patient records at a Taiwanese tertiary medical center from August 1, 2000, to August 31, 2021. ESKD patients on chronic dialysis were identified with invasive listeriosis by blood culture and discharge diagnosis. Over 21 years, we accurately recorded 26 cases.

Results

ESKD patients on chronic dialysis with invasive listeriosis have a poor prognosis. Only 53.8% of chronic dialysis patients with invasive listeriosis survived their first hospital episode. 42.3% of hospitalized ESKD patients with invasive listeriosis survived one year later. In univariate analysis, shock, tachypnea (RR ≥ 22), respiratory failure, qSOFA score ≥ 2, and lower initial platelet count were linked to greater in-hospital mortality rates.

Conclusion

ESKD patients with invasive listeriosis have a grave prognosis. Our research reveals that an early blood sample for a bacterial culture may identify invasive listeriosis in chronic dialysis patients with fever, nausea or vomiting, confusion, and respiratory distress. This study is the first to identify a lower platelet count and qSOFA score ≥ 2 as markers of high-risk invasive listeriosis in ESKD patients.

Uremic toxin indoxyl sulfate induces trained immunity via the AhR-dependent arachidonic acid pathway in end-stage renal disease (ESRD)

Trained immunity is the long-term functional reprogramming of innate immune cells, which results in altered responses toward a secondary challenge. Despite indoxyl sulfate (IS) being a potent stimulus associated with chronic kidney disease (CKD)-related inflammation, its impact on trained immunity has not been explored. Here, we demonstrate that IS induces trained immunity in monocytes via epigenetic and metabolic reprogramming, resulting in augmented cytokine production. Mechanistically, the aryl hydrocarbon receptor (AhR) contributes to IS-trained immunity by enhancing the expression of arachidonic acid (AA) metabolism-related genes such as arachidonate 5-lipoxygenase (ALOX5) and ALOX5 activating protein (ALOX5AP). Inhibition of AhR during IS training suppresses the induction of IS-trained immunity. Monocytes from end-stage renal disease (ESRD) patients have increased ALOX5 expression and after 6 days training, they exhibit enhanced TNF-α and IL-6 production to lipopolysaccharide (LPS). Furthermore, healthy control-derived monocytes trained with uremic sera from ESRD patients exhibit increased production of TNF-α and IL-6. Consistently, IS-trained mice and their splenic myeloid cells had increased production of TNF-α after in vivo and ex vivo LPS stimulation compared to that of control mice. These results provide insight into the role of IS in the induction of trained immunity, which is critical during inflammatory immune responses in CKD patients.

New insights into the pathogenesis of SARS-CoV-2 during and after the COVID-19 pandemic

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is responsible for the respiratory distress condition known as COVID-19. This disease broadly affects several physiological systems, including the gastrointestinal, renal, and central nervous (CNS) systems, significantly influencing the patient's overall quality of life. Additionally, numerous risk factors have been suggested, including gender, body weight, age, metabolic status, renal health, preexisting cardiomyopathies, and inflammatory conditions. Despite advances in understanding the genome and pathophysiological ramifications of COVID-19, its precise origins remain elusive. SARS-CoV-2 interacts with a receptor-binding domain within angiotensin-converting enzyme 2 (ACE2). This receptor is expressed in various organs of different species, including humans, with different abundance. Although COVID-19 has multiorgan manifestations, the main pathologies occur in the lung, including pulmonary fibrosis, respiratory failure, pulmonary embolism, and secondary bacterial pneumonia. In the post-COVID-19 period, different sequelae may occur, which may have various causes, including the direct action of the virus, alteration of the immune response, and metabolic alterations during infection, among others. Recognizing the serious adverse health effects associated with COVID-19, it becomes imperative to comprehensively elucidate and discuss the existing evidence surrounding this viral infection, including those related to the pathophysiological effects of the disease and the subsequent consequences. This review aims to contribute to a comprehensive understanding of the impact of COVID-19 and its long-term effects on human health.

PMMA dialyzers modulate both humoral and cell-mediate immune response to anti-COVID-19 vaccine (BNT162b2) in a cohort of chronic hemodialyzed patients

Patients on hemodialysis (HD) have a high risk of death from COVID-19. We evaluated the humoral and cell-mediated immune response to BNT162b2 (Pfizer-BioNTech) vaccine in HD patients, comparing HD with Poly-methyl-methacrylate (PMMA) and HD with Polysulphone (PS). Samples were collected before vaccination (T0) and 14-days after the 2ndvaccine (T2) in a TG (TG, n = 16-Foggia) and in a VG (CG, n = 36-Novara). Anti-SARS-CoV-2-Ig were titrated in the cohort 2-weeks after the 2nddose of vaccine. In the Testing-Group, serum neutralizing antibodies (NAb) were assayed and PBMCs isolated from patients were thawed, counted and stimulated with SARS-CoV-2 IGRA stimulation tube set. All patients had a positive ab-response, except in a case. PMMA-patients had higher levels of anti-SARS-CoV-2 IgG (p = 0.031); VG data confirmed these findings (p < 0.05). NAb evaluation: PMMA patients passed the positive cut-off value, while in PS group only only 1/8 patient did not respond. PMMA patients showed higher percentages of anti-SARS-CoV-2 S1/RBD-Ig after a complete vaccine schedule (p = 0.028). Interferon-gamma release: PMMA patients showed significantly higher release of IFNγ (p = 0.014). The full vaccination course provided sufficient protection against SARS-CoV-2 across the entire cohort, regardless of dialyzer type. After vaccination, PMMA patients show a better immune response, both humoral and cellular, at the end of the vaccination course than PS patients.

SGLT2 inhibition to target kidney aging

Anti-aging therapy is the latest frontier in the world of medical science, especially for widespread diseases such as chronic kidney disease (CKD). Both renal aging and CKD are characterized by increased cellular senescence, inflammation and oxidative stress. A variety of cellular signalling mechanisms are involved in these processes, which provide new potential targets for therapeutic strategies aimed at counteracting the onset and progression of CKD. At the same time, sodium-glucose co-transporter 2 inhibitors (SGLT2is) continuously demonstrate large beneficial effects at all stages of the cardiorenal metabolic continuum. The broad-spectrum benefits of SGLT2is have led to changes in several treatment guidelines and to growing scientific interest in the underlying working principles. Multiple mechanisms have been studied to explain these great renal benefits, but many things remain to be solved. With this in mind, we provide an overview of the experimental evidence for the effects of SGLT2is on the molecular pathway's ability to modulate senescence, aging and parenchymal damage, especially at the kidney level. We propose to shed some light on the role of SGLT2is in kidney care by focusing on their potential to reduce the progression of kidney disease across the spectrum of aging and dysregulation of senescence.

Acute and Chronic Kidney Disease Worsen Outcomes in Experimental Sepsis

Key Points

Acute kidney disease (AKD) and CKD are common conditions associated with high rates of incident infection, and poor outcomes once infection have been established. We successfully modeled AKD and CKD in rodents and then administered a cecal slurry solution to create peritonitis and tracked sepsis severity, end organ injury, and inflammatory changes. Our results indicate that AKD mice are more susceptible to infection than CKD mice, developing an aggravated inflammatory response and suggests that this condition predisposes to disparate infection risk.

Background

Infection is a leading cause of morbidity in individuals with acute kidney disease (AKD) and CKD. However, there is significant difficulty in modeling infection into an animal host with preexisting kidney disease. We report a novel method of peritoneal infection induced via cecal slurry (CS) inoculation deployed into mice with experimental aristolochic acid–induced AKD and CKD.

Methods

AKD, CKD, and paired control mice were injected with sham, low, or higher doses of donor–recipient matched CS solution. Animal survival, sepsis severity, and change in GFR were tracked longitudinally throughout the study. Histology for kidney injury, flow cytometry, plasma cytokines, and evidence of indirect organ injury from sepsis were also assessed.

Results

Infected AKD mice experienced significantly heightened sepsis severity, with 100% mortality by 24 hours after high CS doses versus no mortality in control mice. In addition, AKD mice receiving lower CS doses developed dramatically increased proinflammatory cytokines and persistent cytopenias. Infected CKD mice also had worse outcomes than paired CKD controls, although less severe than in AKD mice. Interestingly, animals with AKD had worse outcomes than mice with CKD after any CS dose or time point after inoculation, despite higher baseline kidney function and less uremic sequela.

Conclusions

These data confirm that acute bacterial infection can be modeled in animals with established kidney disease and suggest that the clinical state of kidney disease (AKD versus CKD) may influence host susceptibility to infection more than the degree of kidney failure alone.

Characteristics of Patients With Initial Clostridioides difficile Infection (CDI) That Are Associated With Increased Risk of Multiple CDI Recurrences

Background

Because interventions are available to prevent further recurrence in patients with recurrent Clostridioides difficile infection (rCDI), we identified predictors of multiple rCDI (mrCDI) in adults at the time of presentation with initial CDI (iCDI).

Methods

iCDI was defined as a positive C difficile test in any clinical setting during January 2018-August 2019 in a person aged ≥18 years with no known prior positive test. rCDI was defined as a positive test ≥14 days from the previous positive test within 180 days after iCDI; mrCDI was defined as ≥2 rCDI. We performed multivariable logistic regression analysis.

Results

Of 18 829 patients with iCDI, 882 (4.7%) had mrCDI; 437 with mrCDI and 7484 without mrCDI had full chart reviews. A higher proportion of patients with mrCDI than without mrCDI were aged ≥65 years (57.2% vs 40.7%; P < .0001) and had healthcare (59.1% vs 46.9%; P < .0001) and antibiotic (77.3% vs 67.3%; P < .0001) exposures in the 12 weeks preceding iCDI. In multivariable analysis, age ≥65 years (adjusted odds ratio [aOR], 1.91; 95% confidence interval [CI], 1.55-2.35), chronic hemodialysis (aOR, 2.28; 95% CI, 1.48-3.51), hospitalization (aOR, 1.64; 95% CI, 1.33-2.01), and nitrofurantoin use (aOR, 1.95; 95% CI, 1.18-3.23) in the 12 weeks preceding iCDI were associated with mrCDI.

Conclusions

Patients with iCDI who are older, on hemodialysis, or had recent hospitalization or nitrofurantoin use had increased risk of mrCDI and may benefit from early use of adjunctive therapy to prevent mrCDI. If confirmed, these findings could aid in clinical decision making and interventional study designs.

Antimicrobial Treatment Challenges in the Management of Infective Spondylodiscitis Associated with Hemodialysis: A Comprehensive Review of Literature and Case Series Analysis

Infective spondylodiscitis (ISD), the infection of vertebral bodies and surrounding tissues, is a rare complication with major impact on the long-term survival of hemodialysis (HD) patients. Although the most frequent etiology is staphylococcal, identifying these pathogens in blood cultures and biopsy cultures is often difficult. This paper aims to present suitable antibiotic combinations for the treatment of these patients, which is usually challenging in the case of an unidentified pathogen. We presented the therapies applied for 13 HD patients and 19 patients without chronic kidney disease (CKD), diagnosed with ISD between 2013 and 2023 in Bihor County. The percentage of positive blood cultures was low in both groups (30.78% HD vs. 15.78% non-HD). The average length of antibiotic therapy was 5.15 weeks in HD patients and 6.29 weeks in non-HD patients. The use of Carbapenem alone (e.g., Meropenem) for an average of 19.6 days for patients in HD when the pathogen was not identified has proven to be efficient in most cases, similarly to using Vancomycin and Fluoroquinolone/Cephalosporines in combination. Regarding the non-CKD patients, the use of Clindamycin in various combinations for an average of 30.3 days has proven to be efficient in more than 90% of cases of ISD with a nonidentified pathogen. Within 2 years after ISD was diagnosed, 12 of the 13 HD patients passed away, mainly due to cardiovascular causes. Unfortunately, there are no guidelines in the literature concerning the empiric treatment of ISD in the particular case of HD patients. Upon checking the literature on PubMed and Google Scholar, only 10 studies provided relevant data regarding ISD treatment for HD patients. More data about the treatment and evolution of these patients is needed in order to elaborate a truly relevant metanalysis.

Adequacy to immunosuppression management guidelines in kidney transplant recipients with severe COVID-19 pneumonia: a practice survey

Introduction

Coronavirus disease 2019 (COVID-19) poses an important risk of morbidity and of mortality, in patients after solid organ transplantation. Recommendations have been issued by various transplantation societies at the national and European level to manage the immunosuppressive (IS) regimen upon admission to intensive care unit (ICU).

Method

The aim of this study was to evaluate the adequacy of IS regimen minimization strategy in kidney transplant recipients hospitalized in an ICU for severe COVID-19, in relation to the issued recommendations.

Results

The immunosuppressive therapy was minimized in all patients, with respectively 63% and 59% of the patients meeting the local and european recommendations upon admission. During ICU stay, IS was further tapered leading to 85% (local) and 78% (european) adequacy, relative to the guidelines. The most frequent deviation was the lack of complete withdrawal of mycophenolic acid (22%). Nevertheless, the adequacy/inadequacy status was not associated to the ICU- or one-year-mortality.

Discussion

In this single-center cohort, the only variable associated with a reduction in mortality was vaccination, emphasizing that the key issue is immunization prior to infection, not restoration of immunity during ICU stay.

Vaccination and Nutritional Outcomes of Hemodialysis Patients Infected With SARS-CoV-2

BACKGROUND

Patients on hemodialysis are particularly vulnerable to COVID-19 and may have a reduced response to vaccination because of a decreased immune response. The nutritional status before or during the infection could also impact on the clinical effectiveness of vaccination.

OBJECTIVES

We aim to describe the evolution of clinical and nutritional biomarkers of hemodialysis patients infected with SARS-CoV-2 and to assess their association with vaccination status.

METHODS

An observational, analytic, longitudinal, retrospective multicenter study was carried out in 82 patients on hemodialysis with SARS-CoV-2 infection. Nutritional status was assessed using the Geriatric Nutritional Risk Index (GNRI), anthropometry, and biochemical parameters. The association of the vaccine doses with clinical- and nutritional-related variables was also evaluated.

RESULTS

The percentage of vaccinated patients was similar to that of nonvaccinated patients. Before infection, most of the patients were malnourished. They presented lower albumin, creatinine, and urea levels than the well-nourished patients. Significant deterioration of nutritional status after infection was evidenced considering GNRI score, dry weight, and body mass index. Albumin and creatinine also decreased significantly after infection, whereas C-reactive protein increased in the acute phase. Significant inverse correlation was found between the variation of post-pre GNRI scores and basal albumin and C-reactive protein at 7 days. In addition, we observed the opposite trend between albumin at 30 days and basal cholesterol. A negative value in the GNRI variation was associated with bilateral pneumonia, need for hospitalization, and nutritional support. Vaccinated patients presented substantially less bilateral pneumonia and hospitalization. No significant effects were observed between vaccine doses and the variation in nutritional status, although a positive correlation was detected with the albumin at 7 days and C-reactive protein before infection and the number of vaccine doses received.

DISCUSSION

COVID-19 is associated with affectations in the nutritional status and biomarkers in hemodialysis patients. In this study, vaccines have shown a protective effect against the clinical consequences of COVID. However, they have shown limitations in preventing the deterioration of nutritional status after infection. The results highlight the importance of promoting the vaccination in these patients as well as incorporating nutritional assessment before, during, and after the infection.

Lack of Association Between Immunotherapy and Improvement of Survival for Non-small Cell Lung Cancer Patients With Hemodialysis: A Nationwide Retrospective Cohort Study

BACKGROUND

The number of patients undergoing hemodialysis continues to increase globally, and the incidence of cancer is high among these patients. Immune checkpoint inhibitors are widely used in patients with advanced cancer, especially non-small cell lung cancer (NSCLC); however, their effectiveness in hemodialysis patients is poorly documented.

METHODS

This retrospective cohort study used data from a nationwide database. Patients diagnosed with NSCLC, undergoing hemodialysis, and who started chemotherapy between September 2008 and January 2023 were included. In the intention to treat (ITT) analysis, patients were divided into immune checkpoint inhibitor (ICI) and conventional chemotherapy group, and in the chronological analysis, patients were divided into 2 groups before and after ICI approval. Overall survival (OS) was analyzed using the Kaplan-Meier method with log-rank tests and Cox proportional hazards analyses. A propensity score approach was applied to address confounding factors, and analyses were performed by weighting each patient with the inverse of the estimated propensity score.

RESULTS

We identified 322 and 389 patients in the ITT and chronological analyses respectively. In both analyses, there were no notable difference of OS between 2 groups (P values by log-rank test 0.933 and 0.248, respectively). The hazard ratios for OS were 0.980 (95% confidence interval [CI]: 0.678-1.415) in the ITT analysis and 0.805 (95% CI: 0.531-1.219) in the chronological analysis.

CONCLUSION

The ICI treatment and approval were not significantly associated with improvement of survival in patients with NSCLC undergoing hemodialysis.

Cytomegalovirus Diseases of the Gastrointestinal Tract in Immunocompetent Patients: A Narrative Review

Cytomegalovirus (CMV) is a potential pathogen that causes gastrointestinal (GI) tract diseases regardless of host immunity. In contrast to immunocompromised individuals, immunocompetent patients lack a comprehensive overview of the gastrointestinal manifestations. This study aims to provide a comprehensive summary of the current evidence regarding presentations, diagnostics, management, risk assessment, and outcomes in immunocompetent patients with CMV GI disease. A thorough literature search of English publications up to April 2022 was conducted across electronic databases to identify relevant articles, with eligible case series selected for detailed analysis. The majority of immunocompetent patients affected by CMV GI disease are typically elderly, critically ill, or burdened with comorbidities that compromise immunity. Clinical presentations range from subtle symptoms to severe surgical conditions, including instances of mortality. Specific clinical presentations, blood test results, or endoscopic features are lacking, necessitating reliance on histopathological tests such as immunohistochemistry staining for diagnosis. While antiviral therapy may offer benefits in improving outcomes, careful individual assessment is warranted due to diverse comorbidities and potential side effects. Mortality rates vary considerably based on underlying medical conditions and therapeutic approaches. It is imperative for clinicians to maintain vigilance for CMV GI disease among high-risk groups, despite their baseline immunocompetence, in order to enhance clinical outcomes.

Development of a Prediction Model to Identify the Risk of Clostridioides difficile Infection in Hospitalized Patients Receiving at Least One Dose of Antibiotics

OBJECTIVE

This study's objective was to develop a risk-prediction model to identify hospitalized patients at risk of Clostridioides difficile infection (CDI) who had received at least one dose of systemic antibiotics in a large tertiary hospital.

PATIENTS AND METHODS

This was a retrospective case-control study that included patients hospitalized for more than 2 days who received antibiotic therapy during hospitalization. The study included two groups: patients diagnosed with hospital CDI and controls without hospital CDI. Cases were matched 1:3 with assigned controls by age and sex. Descriptive statistics were used to identify the study population by comparing cases with controls. Continuous variables were stated as the means and standard deviations. A multivariate analysis was built to identify the significantly associated covariates between cases and controls for CDI.

RESULTS

A total of 364 patients were included and distributed between the two groups. The control group included 273 patients, and the case group included 91 patients. The risk factors for CDI were investigated, with only significant risks identified and included in the risk assessment model: age older than 70 years (p = 0.034), chronic kidney disease (p = 0.043), solid organ transplantation (p = 0.021), and lymphoma or leukemia (p = 0.019). A risk score of ≥2 showed the best sensitivity, specificity, and accuracy of 78.02%, 45.42%, and 78.02, respectively, with an area under the curve of 0.6172.

CONCLUSION

We identified four associated risk factors in the risk-prediction model. The tool showed good discrimination that might help predict, identify, and evaluate hospitalized patients at risk of developing CDI.

Chronic kidney disease in the shadow of COVID-19: insights from the bibliometric analysis

OBJECTIVE

This study aims to present the current status and frontiers of research on COVID-19 in relation to chronic kidney disease through bibliometric analysis and visualization.

METHODS

Access to information through the Web of Science Core Collection, retrieved from December 2019 to May 2023. The bibliometric visualization of countries, institutions, and keywords was analyzed using VOSviewer.

RESULTS

A total of 1038 publications are included. The global scientific community showed a high level of collaborative consensus. The three countries with the most publications are the USA, China, and the UK. The institution with the most publications is Harvard Medical School. The research frontier for 2020 is thrombosis, for 2021 is telemedicine, for 2022 is depression, and for 2019-2023 is the COVID-19 vaccines.

CONCLUSIONS

This is the first bibliometric report to establish a link between COVID-19 and CKD. The USA, China, and some European countries and their institutions are major contributors to these publications. Thrombosis, telemedicine, depression, and COVID-19 vaccines are current hot topics in the field and have the potential to shape future research trends.

Safety and efficacy of kidney transplantation in patients with aortoiliac stenosis: a retrospective cohort study

BACKGROUND

The impact of aortoiliac occlusive disease on kidney transplantation remains unclear. This study aims to investigate the clinical outcomes of kidney transplant patients with aortoiliac atherosclerotic stenosis.

METHODS

Retrospective data from our transplant center were used to identify patients undergoing kidney transplantation between January 2010 and December 2020. Aortoiliac atherosclerotic stenosis was screened and stratified by the Trans-Atlantic Inter-Society Consensus (TASC) II classification. The primary outcome was patient survival. Secondary outcomes were 90-day mortality, death-censored graft survival, graft function, and arterial complications. Propensity score matching was used to match all patients in the stenosis group with patients without stenosis sharing similar characteristics.

RESULTS

The analysis included 655 patients, 524 without stenosis and 131 with aortoiliac stenosis (95 with TASC A/B stenosis and 36 with TASC C/D stenosis). Recipient age [median (IQR), 66 (60-70) vs. 66 (59-71) years; P =0.47], sex [male: 87 (66%) vs. 355 (68%), P =0.85], and comorbidities were comparable between the stenosis and no-stenosis groups. Forty-six (35%) patients with stenosis were symptomatic. Patient survival was significantly lower in the stenosis group compared with the no-stenosis group (TASC A/B: 30.6% vs. no-stenosis: 44.1%, P =0.013; TASC C/D: 11.4% vs. no-stenosis: 44.1%, P <0.001). The incidence rates of artery dissection, lower extremity ischemia, and acute thrombosis were significantly higher in the stenosis group ( P <0.001). However, death-censored graft survival (TASC A/B: 73.6% vs. no-stenosis: 72.9%, P =0.62; TASC C/D: 58.1% vs. no-stenosis: 72.9%, P =0.16) and graft function were comparable between the groups.

CONCLUSIONS

Aortoiliac atherosclerotic stenosis significantly impacts patient survival but not graft survival. Our analyses suggest that patients with TASC A/B stenosis have prolonged survival and enhanced quality of life through kidney transplantation. However, for patients with TASC C/D stenosis, kidney transplantation improves quality of life without bringing survival benefits.

Investigation of COVID-19 vaccination among maintenance hemodialysis patients in Sichuan, China

AIM

To investigate the current status of COVID-19 vaccination in maintenance hemodialysis (MHD) patients and its influencing factors.

METHODS

In total, 585 patients undergoing regular hemodialysis in Sichuan Province of China from January to March 2022 were selected to complete a questionnaire survey on their knowledge, attitudes and practices regarding COVID-19 vaccination. Independent t tests and logistic multivariate analysis were used to analyze the influencing factors of COVID-19 vaccination in hemodialysis patients.

RESULTS

The survey showed that 37.44% of MHD patients had been vaccinated with the COVID-19 vaccine. Being married was associated with COVID-19 vaccination in patients with MHD (odds ratio [OR] = 1.969 95% CI 0 .870 ~ 4.453). MHD patients living in county areas have higher rates of COVID-19 vaccination (OR = 0.572 95% CI 0.301 ~ 1.087). Family /relatives/friends who are healthcare workers are associated with COVID-19 vaccination for MHD patients (OR = 1.840 95% CI 1.140 ~ 2.970). Other vaccination history within 5 years was a factor in COVID-19 vaccination for MHD patients (OR = 5.592 95% CI 2.997 ~ 10.434). Attitude (OR = 0.885 95% CI 0.808 ~ 0.905), and practice (OR = 0.756 95% CI 0.697 ~ 0.819) scores on the COVID-19 vaccination knowledge and practice questionnaire were related to the vaccination status of MHD patients.

CONCLUSIONS

MHD patients had lower rates of COVID-19 vaccination. Marital status, living environment, whether family/relatives/friends were medical workers, and the score of the COVID-19 vaccine knowledge and practice questionnaire were the factors influencing their vaccination status. Clinical attention should be given to the adverse reactions of COVID-19 vaccination in MHD patients to improve the awareness of primary medical staff on hemodialysis, and families and society should pay more attention to COVID-19 vaccination in MHD patients.

Renal cell carcinoma outcomes in end-stage renal disease: A 40-year study from two Japanese institutions

OBJECTIVES

The objective of the study was to analyze the outcomes of patients with renal cell carcinoma (RCC) arising in end-stage renal disease (ESRD) over a 40-year span.

METHODS

We retrospectively evaluated data of patients with ESRD-RCC diagnosed between 1979 and 2020 at two institutions. We assessed changes in stage, surgical approaches, and cancer-specific survival (CSS) following nephrectomy according to era between ESRD-RCC and sporadic RCC. Furthermore, perioperative outcomes in patients with ESRD-RCC were compared between laparoscopic and open surgery.

RESULTS

Patients with ESRD-RCC (n = 549) were diagnosed at an earlier stage (p = 0.0276), and the ratio of laparoscopic nephrectomy was increased (p < 0.0001) according to eras. Since 2000 (i.e., after implementation of laparoscopic nephrectomy), patients with ESRD-RCC (n = 305) had significantly shorter CSS (p = 0.0063) after nephrectomy than sporadic RCC (n = 2732). After adjustment by multivariate analysis and propensity score matching, ESRD status was independently associated with shorter CSS (p = 0.0055 and p = 0.0473, respectively). Improved CSS in sporadic RCC (p < 0.0001), but not ESRD-RCC (p = 0.904), according to era contributed to this difference. Laparoscopic nephrectomy showed favorable outcomes, including shorter surgery time, lower estimated bleeding volumes, transfusion rates, and readmission rates, and shorter postoperative hospitalization than open nephrectomy (p < 0.05).

CONCLUSIONS

Advances in diagnostic and treatment modalities potentially enable early diagnosis and minimally invasive surgery for patients with ESRD-RCC. As ESRD-RCC may not present indolently, careful post-operative monitoring is needed.

Tixagevimab and Cilgavimab (Evusheld) Boosts Antibody Levels to SARS-CoV-2 in End-Stage Renal Disease Patients on Chronic Hemodialysis: A Single-Center Study

Background and Objectives: In addition to a suboptimal and rapidly diminishing response to the coronavirus disease 2019 (COVID-19) vaccine, hemodialysis (HD) patients are at risk for developing a severe COVID-19 infection. In 2022, the combination of cilgavimab and tixagevimab (Evusheld, AstraZeneca) was approved for COVID-19 preexposure prophylaxis in high-risk groups. The purpose of this study was to evaluate the humoral response and short-term safety of this antibody combination in a group of HD patients. Materials and Methods: Seventy-three adult maintenance hemodialysis patients were recruited from a tertiary-care hospital for this double-blinded, non-randomized, placebo-controlled study. Patients were placed into two groups: the intervention group (n = 43) received a single 300 mg dosage of cilgavimab and tixagevimab, while the control group (n = 30) received a saline placebo. The titer of COVID-19-neutralizing antibodies was measured at baseline and after 1 and 6 months. The patients were evaluated for any drug-related adverse effects and monitored for six months for the emergence of any COVID-19-related events. Results: Patients in the intervention group were substantially older and had been on HD for longer (p = 0.002 and 0.006, respectively). The baseline antibody levels were higher in the Evusheld group. The antibody level in the intervention group increased significantly after 1 month and remained consistent for 6 months, whereas the antibody level in the control group fell significantly after 6 months during the study period (Wald χ2 = 30.620, p < 0.001). The drug-related adverse effects were modest and well-tolerated, and only seven patients experienced them. Six months after study enrollment, 10 patients in the intervention group and 6 patients in the control group had been infected with COVID-19, respectively. In the control group, ICU admission and mortality were observed, but in the intervention group, the infection was milder with no aggressive consequences. Conclusions: This study demonstrated the short-term safety and efficacy of tixagevimab-cilgavimab for COVID-19 preexposure prophylaxis in HD patients. These findings require more studies with more HD patients and longer follow-up periods.

Pan-immune-inflammation value is associated with poor prognosis in patients undergoing peritoneal dialysis

BACKGROUND

Immune-inflammatory biomarkers (IIBs) have been shown to be correlated with prognosis in patients undergoing peritoneal dialysis (PD). In this study, we aimed to evaluate the relationship between a novel comprehensive biomarker, the pan-immune-inflammation value (PIV), and the prognosis of patients undergoing PD.

METHODS

We retrospectively analyzed data from a multicenter, large-sample PD database. PIV was calculated as (neutrophil count × platelet count × monocyte count)/lymphocyte count. The prognostic endpoints in this study were all-cause death all-cause, cardiovascular disease (CVD) and infection-related death. The Kaplan-Meier method, a Cox proportional hazards regression, Fine-Gray competing risk model, smooth curve, and subgroup analysis were used to analyze the independent relationship between PIV and the prognosis of patients undergoing PD.

RESULTS

A total of 2796 cases of PD were included, and the study population was divided into Tertiles 1, 2, and 3, according to the tertiles of baseline PIVs. After adjusting for multiple model factors, patients in the Tertile 3 group had a significantly higher risk of all-cause death, CVD death and infection-related death compared with patients with PIV in the Tertile 1 group. Interaction tests showed no positive correlations for subgroup parameters. Regarding all-cause death, compared with the lowest tertile, the multivariable-adjusted hazard ratios (95% confidence intervals) of the highest and middle tertiles were 1.55 (1.25-1.94) and 1.77 (1.43-2.19), respectively; PIV (log2 processing) was associated with 17% excess of mortality in the continuous model.

CONCLUSIONS

A high PIV at baseline was significantly associated with an increased risk of deaths due to all-causes, CVD and infection in patients undergoing PD.

A novel multiplex biomarker panel for profiling human acute and chronic kidney disease

Acute and chronic kidney disease continues to confer significant morbidity and mortality in the clinical setting. Despite high prevalence of these conditions, few validated biomarkers exist to predict kidney dysfunction. In this study, we utilized a novel kidney multiplex panel to measure 21 proteins in plasma and urine to characterize the spectrum of biomarker profiles in kidney disease. Blood and urine samples were obtained from age-/sex-matched healthy control subjects (HC), critically-ill COVID-19 patients with acute kidney injury (AKI), and patients with chronic or end-stage kidney disease (CKD/ESKD). Biomarkers were measured with a kidney multiplex panel, and results analyzed with conventional statistics and machine learning. Correlations were examined between biomarkers and patient clinical and laboratory variables. Median AKI subject age was 65.5 (IQR 58.5-73.0) and median CKD/ESKD age was 65.0 (IQR 50.0-71.5). Of the CKD/ESKD patients, 76.1% were on hemodialysis, 14.3% of patients had kidney transplant, and 9.5% had CKD without kidney replacement therapy. In plasma, 19 proteins were significantly different in titer between the HC versus AKI versus CKD/ESKD groups, while NAG and RBP4 were unchanged. TIMP-1 (PPV 1.0, NPV 1.0), best distinguished AKI from HC, and TFF3 (PPV 0.99, NPV 0.89) best distinguished CKD/ESKD from HC. In urine, 18 proteins were significantly different between groups except Calbindin, Osteopontin and TIMP-1. Osteoactivin (PPV 0.95, NPV 0.95) best distinguished AKI from HC, and β2-microglobulin (PPV 0.96, NPV 0.78) best distinguished CKD/ESKD from HC. A variety of correlations were noted between patient variables and either plasma or urine biomarkers. Using a novel kidney multiplex biomarker panel, together with conventional statistics and machine learning, we identified unique biomarker profiles in the plasma and urine of patients with AKI and CKD/ESKD. We demonstrated correlations between biomarker profiles and patient clinical variables. Our exploratory study provides biomarker data for future hypothesis driven research on kidney disease.

Farnesoid X receptor prevents neutrophil extracellular traps via reduced sphingosine-1-phosphate in chronic kidney disease

Farnesoid X receptor (FXR) activation reduces renal inflammation, but the underlying mechanisms remain elusive. Neutrophil extracellular traps (NETs) are webs of DNA formed when neutrophils undergo specialized programmed cell death (NETosis). The signaling lipid sphingosine-1-phosphate (S1P) stimulates NETosis via its receptor on neutrophils. Here, we identify FXR as a negative regulator of NETosis via repressing S1P signaling. We determined the effects of the FXR agonist obeticholic acid (OCA) in mouse models of adenosine phosphoribosyltransferase (APRT) deficiency and Alport syndrome, both genetic disorders that cause chronic kidney disease. Renal FXR activity is greatly reduced in both models, and FXR agonism reduces disease severity. Renal NETosis and sphingosine kinase 1 (Sphk1) expression are increased in diseased mice, and they are reduced by OCA in both models. Genetic deletion of FXR increases Sphk1 expression, and Sphk1 expression correlates with NETosis. Importantly, kidney S1P levels in Alport mice are two-fold higher than controls, and FXR agonism restores them back to baseline. Short-term inhibition of sphingosine synthesis in Alport mice with severe kidney disease reverses NETosis, establishing a causal relationship between S1P signaling and renal NETosis. Finally, extensive NETosis is present in human Alport kidney biopsies (six male, nine female), and NETosis severity correlates with clinical markers of kidney disease. This suggests the potential clinical relevance of the newly identified FXR-S1P-NETosis pathway. In summary, FXR agonism represses kidney Sphk1 expression. This inhibits renal S1P signaling, thereby reducing neutrophilic inflammation and NETosis.NEW & NOTEWORTHY Many preclinical studies have shown that the farnesoid X receptor (FXR) reduces renal inflammation, but the mechanism is poorly understood. This report identifies FXR as a novel regulator of neutrophilic inflammation and NETosis via the inhibition of sphingosine-1-phosphate signaling. Additionally, NETosis severity in human Alport kidney biopsies correlates with clinical markers of kidney disease. A better understanding of this signaling axis may lead to novel treatments that prevent renal inflammation and chronic kidney disease.

Calprotectin blockade inhibits long-term vascular pathology following peritoneal dialysis-associated bacterial infection

Bacterial infections and the concurrent inflammation have been associated with increased long-term cardiovascular (CV) risk. In patients receiving peritoneal dialysis (PD), bacterial peritonitis is a common occurrence, and each episode further increases late CV mortality risk. However, the underlying mechanism(s) remains to be elucidated before safe and efficient anti-inflammatory interventions can be developed. Damage-Associated Molecular Patterns (DAMPs) have been shown to contribute to the acute inflammatory response to infections, but a potential role for DAMPs in mediating long-term vascular inflammation and CV risk following infection resolution in PD, has not been investigated. We found that bacterial peritonitis in mice that resolved within 24h led to CV disease-promoting systemic and vascular immune-mediated inflammatory responses that were maintained up to 28 days. These included higher blood proportions of inflammatory leukocytes displaying increased adhesion molecule expression, higher plasma cytokines levels, and increased aortic inflammatory and atherosclerosis-associated gene expression. These effects were also observed in infected nephropathic mice and amplified in mice routinely exposed to PD fluids. A peritonitis episode resulted in elevated plasma levels of the DAMP Calprotectin, both in PD patients and mice, here the increase was maintained up to 28 days. In vitro, the ability of culture supernatants from infected cells to promote key inflammatory and atherosclerosis-associated cellular responses, such as monocyte chemotaxis, and foam cell formation, was Calprotectin-dependent. In vivo, Calprotectin blockade robustly inhibited the short and long-term peripheral and vascular consequences of peritonitis, thereby demonstrating that targeting of the DAMP Calprotectin is a promising therapeutic strategy to reduce the long-lasting vascular inflammatory aftermath of an infection, notably PD-associated peritonitis, ultimately lowering CV risk.

Antibody response to ChAdOx1 nCoV-19 (Covishield®) vaccine in people on maintenance hemodialysis

INTRODUCTION

People on renal replacement therapy (RRT) have a high risk of COVID-19 infection and subsequent death. COVID-19 vaccination is strongly recommended for those on RRT. Data are limited on the immune response of the ChAdOx1 nCoV-19/AZD1222 (Covishield®) vaccine in patients on RRT.

METHODS

A prospective cohort of adult (age > 18 years), on RRT in the form of hemodialysis were included and received two intramuscular doses of Covishield®. A blood specimen of 5.0 mL was collected at two time points, within a few days before administering the first dose of the vaccine and at 4-16 weeks after the second dose. According to their prior COVID-19 infection status, the participants were grouped as (i) prior symptomatic COVID-19 infection, (ii) prior asymptomatic COVID-19 infection, and (iii) no prior COVID-19 infection.

RESULTS

A large proportion (81%) of participants had anti-spike antibodies (ASAb) before vaccination, and a reasonable proportion (30%) also had neutralizing antibodies (NAb). The titer of ASAb was relatively low (207 U/mL) before vaccination. The ASAb titer (9405 [1635-25,000] U/mL) and percentage of NAb (96.4% [59.6-98.1%]) were markedly increased following the administration of two doses of the vaccine. The participants' prior COVID-19 exposure status did not influence the rise in ASAb titer and NAb percentage. Further, administering two doses of the Covishield vaccine helps them achieve a high ASAb titer.

CONCLUSION

Two doses of ChAdOx1 nCoV-19/AZD1222 (Covishield®) vaccine, given 12 weeks apart, achieve a high titer of ASAb and a high percentage of NAb in people on hemodialysis.