Significance of eGFR and proteinuria for cardiovascular disease in individuals beyond 85 years.

BACKGROUND: There are limited data on how advancing age influences prediction of CVD risk based on the estimated glomerular filtration rate (eGFR) and proteinuria, especially in older adults, including those aged ≥ 85 years. This study aimed to clarify the association of eGFR and proteinuria with CVD outcomes and the impact of age on this association. METHODS: The distribution of eGFR and urine protein in Japan was assessed retrospectively using real-world administrative claims and health checkup data collected between April 2014 and November 2022. We investigated the associations of these two parameters with the incidence of CVD, with an emphasis on the impact of aging. RESULTS: We assessed 1 829 020 individuals for distribution of eGFR and proteinuria; after excluding those with known CVD, their association with CVD risk was examined in 1 040 101 individuals aged ≥ 40 years. The prevalence of impaired kidney function (eGFR <60 mL/min/1.73 m2) increased with age, being 0.7%, 9.2%, 21.9%, 40.2%, and 60.2% at the ages of 18-39, 40-64, 65-74, 75-84, and ≥ 85 years (P for trend < 0.001); similarly, the proportion with positive proteinuria increased with age, being 2.7%, 4.3%, 5.6%, 9.2%, and 15.8%, respectively (P for trend < 0.001). Both eGFR and urine protein were identified to be independent risk factors for CVD. Hazard ratios for CVD increased significantly when eGFR was <45 mL/min/1.73 m2 at the ages of 40-64, 65-74, and 75-84 and <30 mL/min/1.73 m2 at ≥ 85 years, while proteinuria remained significantly associated with a high CVD risk regardless of age. These findings were consistent even when analyzed separately by sex. CONCLUSIONS: This study identified eGFR and urine dipstick proteinuria to be independent risk factors for CVD, even among individuals aged ≥ 85 years. However, the contribution of eGFR to the CVD risk was attenuated by aging, whereas proteinuria remained less affected by advancing age.

Efficacy of sucrose and povidone-iodine mixtures in peritoneal dialysis catheter exit-site care.

BACKGROUND: Exit-site infection (ESI) is a common recurring complication in patients undergoing peritoneal dialysis (PD). Sucrose and povidone-iodine (SPI) mixtures, antimicrobial ointments that promote wound healing, have been used for the treatment of ulcers and burns, but their efficacy in exit-site care is still unclear. METHODS: This single-center retrospective observational study included patients who underwent PD between May 2010 and June 2022 and presented with episodes of ESI. Patients were divided into SPI and non-SPI groups and followed up from initial ESI onset until PD cessation, death, transfer to another facility, or June 2023. RESULTS: Among the 82 patients (mean age 62, [54-72] years), 23 were treated with SPI. The median follow-up duration was 39 months (range, 14-64), with an overall ESI incidence of 0.70 episodes per patient-year. Additionally, 43.1% of second and 25.6% of third ESI were caused by the same pathogen as the first. The log-rank test demonstrated significantly better second and third ESI-free survival in the SPI group than that in the non-SPI group (p < 0.01 and p < 0.01, respectively). In a Cox regression analysis, adjusting for potential confounders, SPI use was a significant predictor of decreased second and third ESI episodes (hazard ratio [HR], 0.22; 95% confidence interval [CI], 0.10-0.52 and HR, 0.22; 95%CI, 0.07-0.73, respectively). CONCLUSIONS: Our results showed that the use of SPI may be a promising option for preventing the incidence of ESI in patients with PD. TRIAL REGISTRATION: This study was approved by the Keio University School of Medicine Ethics Committee (approval number 20231078) on August 28, 2023. Retrospectively registered.

Pediatric blood pressure category predicts longitudinal blood pressure change in adolescence and early adulthood.

BACKGROUND: Patterns of blood pressure (BP) change from early adolescence to young adulthood have not been well-described. The objective of this study was to examine the predictive value of pediatric BP classification on BP change and identify subpopulations with large BP increases during adolescence and early adulthood. METHODS: Baseline data were obtained from medical checkups of Japanese adolescents aged 12-13 years in 2009 or 2010 and subsequent BP values were followed for a 9-year period. Mixed-effects models were used to estimate the effects of baseline factors on subsequent BP changes. RESULTS: Hypertensive and elevated BP group consistently had higher BP values than normal BP group throughout the observation period. Multivariate mixed-effects model analyses revealed group-by-time interactions between systolic BP change and BP category in males and uric acid category in females, and between diastolic BP change and white blood cell count in males and obesity and high-density lipoprotein cholesterol in females; however, these factors had limited effects on the rate of BP increase, indicating that they are not suitable as clinical predictors of BP increase. CONCLUSIONS: Pediatric BP category predicted BP values, but there was no factor that identified subpopulations with large BP increases in adolescence and early adulthood. IMPACT: Blood pressure category in the American Academy of Pediatrics clinical practice guideline at age 12-13 years predicted subsequent blood pressure values during adolescence and early adulthood. No baseline factor that identified a subpopulation with large increase in blood pressure during adolescence and early adulthood in clinical practice was found. Our study contributes to the existing literature by demonstrating the usefulness of the American Academy of Pediatrics clinical practice guideline for blood pressure classification in a Japanese population.

Efficacy of pre-emptive kidney transplantation for adults with end-stage kidney disease: a systematic review and meta-analysis.

BACKGROUND: Pre-emptive kidney transplantation (PEKT), i.e., transplantation performed before initiation of maintenance dialysis, is considered an ideal renal replacement therapy because there is no exposure to long-term dialysis therapy. Therefore, we summarized advantages/disadvantages of PEKT to assist in deciding whether kidney transplantation should be performed pre-emptively. METHODS: This study was registered with PROSPERO, CRD42021269163. Observational studies comparing clinical outcomes between PEKT and non-PEKT were included; those involving only pediatric recipients or simultaneous multi-organ transplantations were excluded. The PubMed/MEDLINE, Cochrane Library, and Ichushi-Web databases were searched on 1 August 2021. Studies were pooled using the generic inverse-variance method with random effects model, and risk of bias was assessed using ROBINS-I. RESULTS: Seventy-six studies were included in the systematic review (sample size, 23-121,853; enrollment year, 1968-2019). PEKT patients had lower all-cause mortality (adjusted HR: 0.78 [95% CI 0.66-0.92]), and lower death-censored graft failure (0.81 [0.67-0.98]). Unadjusted RRs for the following outcomes were comparable between the two patient groups: cardiovascular disease, 0.90 (0.58-1.40); biopsy-proven acute rejection, 0.75 (0.55-1.03); cytomegalovirus infection, 1.04 (0.85-1.29); and urinary tract infection, 0.89 (0.61-1.29). Mean differences in post-transplant QOL score were comparable in both groups. The certainty of evidence for mortality and graft failure was moderate and that for other outcomes was very low following the GRADE classification. CONCLUSIONS: The present meta-analysis shows the potential benefits of PEKT, especially regarding patient and graft survival, and therefore PEKT is recommended for adults with end-stage kidney disease.

Low birth weight is associated with decline in renal function in Japanese male and female adolescents.

BACKGROUND: Low birth weight (LBW) is a risk factor for chronic kidney disease (CKD) in later life and is becoming increasingly common in developed countries, including Japan. Furthermore, a serial decrease in birth weight has been associated with an increasing prevalence of CKD stage 2 in male Japanese adolescents. Sex-specific differences affect CKD susceptibility, and the association between birth weight and CKD in women, has not been elucidated. In this study, we investigated the sex-specific effect of LBW on renal function. METHODS: Annual cross-sectional data of 2417 Japanese adolescents (males 1736; females 681), aged 15-16 years, were evaluated over 8 years (2007-2014). RESULTS: Over the study period, mean birth weights decreased significantly in males (p < 0.01) and females (p < 0.05). Furthermore, both sexes showed significant decrease in estimated glomerular filtration rates corresponding to the birth weight reduction. The prevalence of CKD stage 2 also increased in males (from 26.0 to 32.4%, p < 0.01) and females (from 6.3 to 18.5%, p < 0.05). The incidence of CKD stage 2 was significantly related to history of LBW (males: odds ratio 1.73; 95% confidence interval 1.06-2.80; p < 0.05; females: odds ratio 3.29; 95% confidence interval 1.25-8.02; p < 0.05). CONCLUSIONS: Our data revealed that renal function and birth weight have decreased over time, in healthy Japanese adolescents. In view of the recent declining trend demonstrated by birth weight in Japan, we speculate that the prevalence of CKD might increase in the future.

Good manufacturing practices production of a purification-free oral cholera vaccine expressed in transgenic rice plants.

KEY MESSAGE: The first Good Manufacturing Practices production of a purification-free rice-based oral cholera vaccine (MucoRice-CTB) from transgenic plants in a closed cultivation system yielded a product meeting regulatory requirements. Despite our knowledge of their advantages, plant-based vaccines remain unavailable for human use in both developing and industrialized countries. A leading, practical obstacle to their widespread use is producing plant-based vaccines that meet governmental regulatory requirements. Here, we report the first production according to current Good Manufacturing Practices of a rice-based vaccine, the cholera vaccine MucoRice-CTB, at an academic institution. To this end, we established specifications and methods for the master seed bank (MSB) of MucoRice-CTB, which was previously generated as a selection-marker-free line, evaluated its propagation, and given that the stored seeds must be renewed periodically. The production of MucoRice-CTB incorporated a closed hydroponic system for cultivating the transgenic plants, to minimize variations in expression and quality during vaccine manufacture. This type of molecular farming factory can be operated year-round, generating three harvests annually, and is cost- and production-effective. Rice was polished to a ratio of 95 % and then powdered to produce the MucoRice-CTB drug substance, and the identity, potency, and safety of the MucoRice-CTB product met pre-established release requirements. The formulation of MucoRice-CTB made by fine-powdering of drug substance and packaged in an aluminum pouch is being evaluated in a physician-initiated phase I study.

Renin-angiotensin blockade resets podocyte epigenome through Kruppel-like Factor 4 and attenuates proteinuria.

Proteinuria is a central component of chronic kidney disease and an independent risk factor for cardiovascular disease. Kidney podocytes have an essential role as a filtration barrier against proteinuria. Kruppel-like Factor 4 (KLF4) is expressed in podocytes and decreased in glomerular diseases leading to methylation of the nephrin promoter, decreased nephrin expression and proteinuria. Treatment with an angiotensin receptor blocker (ARB) reduced methylation of the nephrin promoter in murine glomeruli of an adriamycin nephropathy model with recovery of KLF4 expression and a decrease in albuminuria. In podocyte-specific KLF4 knockout mice, the effect of ARB on albuminuria and the nephrin promoter methylation was attenuated. In cultured human podocytes, angiotensin II reduced KLF4 expression and caused methylation of the nephrin promoter with decreased nephrin expression. In patients, nephrin promoter methylation was increased in proteinuric kidney diseases with decreased KLF4 and nephrin expression. KLF4 expression in ARB-treated patients was higher in patients with than without ARB treatment. Thus, angiotensin II can modulate epigenetic regulation in podocytes and ARB inhibits these actions in part via KLF4 in proteinuric kidney diseases. This study provides a new concept that renin-angiotensin system blockade can exert therapeutic effects through epigenetic modulation of the kidney gene expression.

Challenges in mucosal vaccines for the control of infectious diseases.

The mucosal surface is the largest route through which pathogens enter the human body. To control the outbreak of mucosal infectious diseases, we must use our knowledge of the mucosal immune system to create vaccines that elicit protective mucosal and systemic immunity. Mucosal vaccines have advantages over traditional injectable vaccines in that they not only induce effective mucosal immune responses, but they also do not cause physical or psychological discomfort. Mucosal vaccines currently licensed for human use include oral vaccines against Vibrio cholerae, Salmonella typhi, poliovirus and rotavirus, and nasal vaccines against influenza virus. To further improve the existing vaccines, it will be necessary to develop novel vaccine production, storage and delivery systems through innovative strategies derived from interdisciplinary scientific research. Our accumulated knowledge of the innate and acquired arms of the mucosal immune system and the recent scientific and technical advancements in the fields of molecular biology, plant biology, bio-engineering and chemical engineering, genome biology and systems biology have created a unique research and development platform for the development of the next generation of mucosal vaccines. This review summarizes the current perspectives and future directions of mucosal vaccine development with emphasis on oral and nasal vaccines for the control of infectious diseases.

The mucosal immune system: From dentistry to vaccine development.

The oral cavity is the beginning of the aero-digestive tract, which is covered by mucosal epithelium continuously under the threat of invasion of pathogens, it is thus protected by the mucosal immune system. In the early phase of our scientific efforts for the demonstration of mucosal immune system, dental science was one of major driving forces due to their foreseeability to use oral immunity for the control of oral diseases. The mucosal immune system is divided functionally into, but interconnected inductive and effector sites. Intestinal Peyer's patches (PPs) are an inductive site containing antigen-sampling M cells and immunocompetent cells required to initiate antigen-specific immune responses. At effector sites, PP-originated antigen-specific IgA B cells become plasma cells to produce polymeric IgA and form secretory IgA by binding to poly-Ig receptor expressed on epithelial cells for protective immunity. The development of new-generation mucosal vaccines, including the rice-based oral vaccine MucoRice, on the basis of the coordinated mucosal immune system is a promising strategy for the control of mucosal infectious diseases.

Secular trends and age-specific distribution of blood pressure in Japanese adolescents aged 12-18 years in 2000-2019.

Adolescent blood pressure is a predictor of future risk for hypertension and cardiovascular diseases, and therefore its status needs to be accurately determined. However, limited evidence is available regarding the secular trends and distribution of adolescent blood pressure. In the present study, we assessed the secular trends and age-specific distributions of blood pressure in Japanese adolescents aged 12-18 years by using data drawn from 20 years of annual health checkups conducted between 2000 and 2019. Participants underwent health checkups every year for three years at the same school and the data were divided into four 5-year cycles: 2000-2004, 2005-2009, 2010-2014, and 2015-2019. From a total of 124,460 records (33,496 individuals) retrieved, 3000 records (3000 individuals) from each year-cycle were randomly selected to avoid duplicating data from the same individuals. In the study period, in males systolic blood pressure showed a decreasing trend over time, whereas in females diastolic blood pressure showed an increasing trend. Subgroup analyses by school category (junior/senior high school) and by obesity category showed similar blood pressure trends as in the overall analysis. Age-specific blood pressure values in Japanese adolescents increased with age in males but not in females. Thus, different patterns of change in blood pressure values over the past 20 years were observed between males and females. Age-specific blood pressure distributions are also presented. Together, these findings will be useful for understanding blood pressure trends among adolescents.

Combining hemodialysis with peritoneal dialysis improves cognitive function: a three-case report.

Chronic kidney disease (CKD) is associated with multiple complications, with recent scholarly attention underscoring cognitive impairment as a salient manifestation. Considering societal aging, preserving cognitive function has emerged as an urgent medical concern. Prolonged dialysis, encompassing hemodialysis (HD) and peritoneal dialysis (PD), has been associated with a decline in cognitive function. Here, we present the cases of three patients undergoing PD who exhibited a noticeable improvement in cognitive function upon the initiation of HD. One patient had exhibited mild cognitive decline, whereas the remaining two presented more severe impairment. Apart from a mild tendency for fluid retention, none of the three patients exhibited abnormalities in physical or imaging examinations. Evaluation using the Japanese version of the Montreal Cognitive Assessment (MoCA-J) yielded decreased scores across multiple domains, notably in executive and attention functions. However, after HD initiation, all patients demonstrated a marked enhancement in multiple MoCA-J parameters, accompanied by a significant improvement in subjective symptoms. Moreover, improvements in anemia and hypoalbuminemia were observed in all three patients, whereas consistent trends in other parameters were absent. These clinical observations suggest that the integration of HD into the therapeutic regimen of patients undergoing PD may enhance cognitive function, highlighting the contributory roles of hemoglobin and albumin in CKD-associated cognitive impairment.

Renal sinus fat is associated with intrarenal hemodynamic abnormalities independent of visceral fat in patients with chronic kidney disease.

OBJECTIVE: Obesity is a risk factor of chronic kidney disease (CKD), contributing to the rising incidence of cardiometabolic diseases. Renal sinus fat (RSF) is an ectopic fat depot located at the renal cavity that could impair renal function and hemodynamic through compression of renal structures. The major purpose of this study was to explore the relationship between RSF accumulation and renal dysfunction in CKD patients. METHODS: We evaluated the associations between computed tomography measured RSF volume and key clinical and histologic parameters involved in renal function and hemodynamics in 132 well-characterized CKD patients who underwent renal biopsy (median age: 62 years; 63.6% men). RESULTS: RSF volume normalized by renal volume (RSF%) positively correlated with obesity-related traits such body mass index and visceral fat volume (VFV) (all P < 0.001) whereas it negatively correlated with estimated glomerular filtration rate (eGFR) (ρ = -0.42, P < 0.001) and 24-h urinary creatinine clearance (CCr) (ρ = -0.34, P < 0.001). Notably, we found robust positive correlations between RSF% and renal resistive index (RRI) measured by the Doppler ultrasound (ρ = 0.40, P < 0.001), and the histological severity of global glomerular sclerosis (ρ = 0.48, P < 0.001) and interstitial fibrosis and tubular atrophy (IFTA) (ρ = 0.35, P < 0.001). In the multivariate linear regression models, after accounting for potential confounders including VFV, RSF% remained significantly associated with CCr (ß = -0.26, P < 0.001), RRI (ß = 0.17, P = 0.022), global glomerular sclerosis (ß = 0.21, P = 0.002), and IFTA (ß = 0.17, P = 0.012). CONCLUSION: RSF accumulation is associated with renal dysfunction and hemodynamic abnormalities independent of visceral adiposity. Our results suggest that RSF may have a potential unique role in the pathogenesis of CKD.

A systematic review and meta-analysis of the clinical impact of stopping renin-angiotensin system inhibitor in patients with chronic kidney disease.

Although renin-angiotensin system (RAS) inhibitors reduce the risk of cardiovascular diseases and end-stage kidney disease (ESKD) in chronic kidney disease (CKD) patients, they are often discontinued in clinical practice due to drug-related adverse events. However, limited evidence is available about the clinical impact of RAS inhibitor discontinuation in CKD patients. A comprehensive search of publications investigating the effect of discontinuing RAS inhibitors on clinical outcomes in CKD patients in PubMed, the Cochrane Library, and Web of Science was conducted (inception to November 7, 2022), and potentially relevant studies were searched by hand (through November 30, 2022). Two reviewers independently extracted data according to the PRISMA and MOOSE guidelines and assessed the quality of each study with risk-of-bias tools, RoB2 and ROBINS-I. The pooled hazard ratio (HR) for each outcome was integrated with a random-effect model. A total of 1 randomized clinical trial and 6 observational studies involving 248,963 patients were included in the systematic review. The meta-analysis of observational studies showed that discontinuation of RAS inhibitors was associated with a higher risk of all-cause mortality (HR, 1.41 [95% CI, 1.23-1.62]; I2 = 97%), ESKD (1.32 [95% CI, 1.10-1.57]; I2 = 94%) and MACE (1.20 [95% CI 1.15-1.25]; I2 = 38%), but not with hyperkalemia (0.79 [95% CI 0.55-1.15]; I2 = 90%). Overall risk of bias was moderate-to-serious, and quality of evidence (GRADE system) was low-to-very low. The present study suggests that CKD patients would benefit from continuing RAS inhibitors.

Significance of podocyte DNA damage and glomerular DNA methylation in CKD patients with proteinuria.

The number of chronic kidney disease (CKD) patients is increasing worldwide, and it is necessary to diagnose CKD patients in earlier stages to improve their prognosis. Previously, in a study using human samples, we reported that DNA methylation and DNA damage in podocytes are potential markers for kidney function decline in IgA nephropathy; however, these candidate markers have not been adequately investigated in other glomerular diseases. Here, we report that the association of podocyte DNA damage and DNA methylation with eGFR decline and proteinuria differs depending on the type of glomerular disease. Patients diagnosed with minor glomerular abnormality (MGA, n = 33), membranous nephropathy (MN, n = 9) or diabetic nephropathy (DN, n = 10) following kidney biopsy at Keio University Hospital from 2015 to 2017 were included. In MGA patients, both podocyte DNA damage and glomerular DNA methylation were associated with the severity of proteinuria. In DN patients, podocyte DNA double-strand breaks (DSBs) and glomerular DNA methylation were associated with an eGFR decline. When patients with urinary protein levels of more than 1 g/gCr were examined, fewer podocyte DNA DSBs were detected in MN patients than in MGA patients, and the level of glomerular DNA methylation was lower in MN patients than in MGA or DN patients. These results indicate that investigating podocyte DNA DSBs and DNA methylation changes may be useful for understanding the pathogenesis of CKD with proteinuria in humans. This study suggested the association of podocyte DNA damage and subsequent DNA methylation with proteinuria in minor glomerular abnormalities (MGA) patients and those with eGFR declines in diabetic nephropathy (DN) patients, respectively.

Compared effectiveness of sodium zirconium cyclosilicate and calcium polystyrene sulfonate on hyperkalemia in patients with chronic kidney disease.

Hyperkalemia is a well-recognized electrolyte abnormality in patients with chronic kidney disease (CKD). Potassium binders are often used to prevent and treat hyperkalemia. However, few studies have evaluated the difference in serum potassium (K+) level-lowering effect during the post-acute phase between the novel potassium binder, sodium zirconium cyclosilicate (ZSC), and conventional agents. This retrospective study included patients who received potassium binders (either ZSC or calcium polystyrene sulfonate [CPS]) in our hospital between May 2020 and July 2022. The patients were divided into the ZSC and CPS groups. After propensity score matching, we compared changes from baseline to the first follow-up point, at least 4 weeks after initiating potassium binders, in electrolytes including K+ level between the two groups. Of the 132 patients, ZSC and CPS were administered in 48 and 84 patients, respectively. After matching, 38 patients were allocated to each group. The ZSC group showed greater reduction in K+ levels than did the CPS group (P < 0.05). Moreover, a significant increase in serum sodium minus chloride levels, a surrogate marker for metabolic acidosis, was observed in the ZSC group (P < 0.05). Our results demonstrated that ZSC could potentially improve hyperkalemia and metabolic acidosis in patients with CKD.

Association Between Renal Sinus Fat and Cardiometabolic and Renin-Angiotensin System Parameters in Primary Aldosteronism.

Context: Renal sinus fat (RSF) accumulation is associated with cardiometabolic diseases, such as obesity, diabetes, hypertension, and chronic kidney disease. However, clinical implications of RSF in primary aldosteronism (PA) remain unclear. Objective: We aimed to investigate relationships between RSF volume and key cardiometabolic and renin-angiotensin system (RAS) parameters in PA patients and clarify the differences in these relationships between unilateral and bilateral subtypes. Methods: We analyzed data obtained from well-characterized PA patients that involved 45 unilateral (median age: 52 years; 42.2% men) and 92 bilateral patients (51 years; 42.4% men). Results: RSF volume normalized by renal volume (RSF%) was greater in the unilateral group than in the bilateral group (P < .05). RSF% was greater in men than in women (P < .05). RSF% positively correlated with parameters related to cardiometabolic risk, including age, body mass index, visceral fat volume, creatinine, triglycerides/high-density lipoprotein cholesterol ratio, uric acid, fasting glucose, and C-reactive protein regardless of PA subtypes (all P < .05). Intriguingly, RSF% positively correlated with plasma aldosterone concentration (PAC), aldosterone-to-renin ratio, and intact parathyroid hormone (iPTH) (all P < .05) in bilateral patients but did not correlate with RAS parameters and even showed an opposite trend in unilateral patients. In subgroup analyses by sex, these distinctions became more evident in women. After adjustment for potential confounders, RSF% remained positively correlated with PAC and iPTH in bilateral patients. Conclusion: Our results indicate that RSF accumulation is involved in cardiometabolic dysfunction associated with PA. However, there were distinct correlations between RSF volume and RAS parameters according to sex and PA subtypes.

Plasminogen activator inhibitor 1 is not a major causative factor for exacerbation in a mouse model of SARS-CoV-2 infection.

Coronavirus disease (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) remains a global pandemic. Although several vaccines targeting SARS-CoV-2 spike proteins protect against COVID-19 infection, mutations affecting virus transmissibility and immune evasion potential have reduced their efficacy, leading to the need for a more efficient strategy. Available clinical evidence regarding COVID-19 suggests that endothelial dysfunction with thrombosis is a central pathogenesis of progression to systemic disease, in which overexpression of plasminogen activator inhibitor-1 (PAI-1) may be important. Here we developed a novel peptide vaccine against PAI-1 and evaluated its effect on lipopolysaccharide (LPS)-induced sepsis and SARS-CoV-2 infection in mice. Administration of LPS and mouse-adapted SARS-CoV-2 increased serum PAI-1 levels, although the latter showed smaller levels. In an LPS-induced sepsis model, mice immunized with PAI-1 vaccine showed reduced organ damage and microvascular thrombosis and improved survival compared with vehicle-treated mice. In plasma clot lysis assays, vaccination-induced serum IgG antibodies were fibrinolytic. However, in a SARS-CoV-2 infection model, survival and symptom severity (i.e., body weight reduction) did not differ between vaccine- and vehicle-treated groups. These results indicate that although PAI-1 may promote the severity of sepsis by increasing thrombus formation, it might not be a major contributor to COVID-19 exacerbation.

DNA-damaged podocyte-CD8 T cell crosstalk exacerbates kidney injury by altering DNA methylation.

Recent epigenome-wide studies suggest an association between blood DNA methylation and kidney function. However, the pathological importance remains unclear. Here, we show that the homing endonuclease I-PpoI-induced DNA double-strand breaks in kidney glomerular podocytes cause proteinuria, glomerulosclerosis, and tubulointerstitial fibrosis with DNA methylation changes in blood cells as well as in podocytes. Single-cell RNA-sequencing analysis reveals an increase in cytotoxic CD8+ T cells with the activating/costimulatory receptor NKG2D in the kidneys, which exhibit a memory precursor effector cell phenotype, and the CD44high memory CD8+ T cells are also increased in the peripheral circulation. NKG2D blockade attenuates the renal phenotype caused by podocyte DNA damage. Blood methylome shows increased DNA methylation in binding sites for STAT1, a transcription factor contributing to CD8+ T cell homeostasis. Collectively, podocyte DNA damage alters the blood methylome, leading to changes in CD8+ T cells, which contribute to sustained renal injury in chronic kidney disease.

[Current status of vaccination therapy for hypertension].

The renin-angiotensin system (RAS) plays a central role in the control of systemic blood pressure. Since the 1950s, both laboratory and clinical studies have been performed to test the efficacy of vaccines against the RAS for the management of hypertension. Although initial studies using renin vaccines and angiotensin I vaccines were unsuccessful, a recent phase IIa study has shown that vaccination against angiotensin II is effective for the treatment of patients with essential hypertension. Results from animal studies have also suggested that vaccination against the AT1 receptor may be effective not only for lowering blood pressure, but also for the prevention of hypertensive end-organ damage. In the future, the RAS may be an important target for the development of vaccines not only for the treatment, but also for the prevention of hypertension and hypertensive complications.

Vaccination against connective tissue growth factor attenuates the development of renal fibrosis.

There is a critical need for efficient treatment of chronic kidney disease (CKD). Renal fibrosis is a final common pathway to end-stage renal disease independent of the underlying etiology, and connective tissue growth factor (CTGF) is a well-recognized profibrotic factor in fibrosis of various organ systems. Here, we developed a novel peptide vaccine against CTGF to attenuate the development of renal fibrosis. Three inoculations with this CTGF vaccine at 2-week intervals elicited antibodies specifically binding to human full-length CTGF, and the antigen-specific serum IgG antibody titers were maintained for > 30 weeks. The efficacy of the CTGF vaccine on renal fibrosis was evaluated in adenine-induced CKD and unilateral ureteral obstruction (UUO) murine models. In adenine-induced CKD model, immunization with the CTGF vaccine attenuated renal interstitial fibrosis. Vaccinated mice showed low levels of serum creatinine and urea nitrogen and low urine albumin-creatinine ratio compared with vehicle-treated mice. In UUO model, the CTGF vaccination also suppressed the onset of renal fibrosis. In an in vitro study, CTGF vaccine-elicited IgG antibodies efficiently suppressed CTGF-induced- and transforming growth factor-ß-induced α-smooth muscle actin expression in kidney fibroblasts. These results demonstrate that the CTGF vaccine is a promising strategy to attenuate the development of renal fibrosis.