Clinical Impact of Malnutrition According to the Global Leadership Initiative on Malnutrition Criteria Combined With Kidney Dysfunction to Determine Mortality in Inpatients

OBJECTIVE

The clinical impact of malnutrition based on the Global Leadership Initiative on Malnutrition (GLIM) criteria in patients with kidney dysfunction remains poorly understood. This study investigated the usefulness of GLIM criteria for malnutrition in predicting mortality in patients with kidney dysfunction and different clinical renal states, including no kidney disease (NKD), acute kidney injury (AKI), and chronic kidney disease (CKD).

METHODS

This single-center retrospective cohort study included 6,712 patients aged ≥18 admitted between 2018 and 2019. The relationship between the estimated glomerular filtration rate (eGFR) groups, nutritional status based on the GLIM criteria, and the incidence of all-cause mortality was evaluated using a multivariate Cox proportional hazards model. Malnutrition was defined as at least one phenotype (weight loss, low body mass index, or reduced muscle mass) and one etiological criterion (reduced intake/assimilation or disease burden/inflammation).

RESULTS

Multivariate Cox proportional hazards model showed that eGFR ≤29 (vs. eGFR: 60-89, adjusted hazard ratio [HR] = 1.84, 95% confidence interval [CI]: 1.52-2.22), 30-59 (vs. eGFR: 60-89, adjusted HR = 1.40, 95% CI: 1.20-1.64), and ≥90 (vs. eGFR: 60-89, adjusted HR = 1.40, 95% CI: 1.14-1.71), moderate and severe malnutrition (vs. without malnutrition, adjusted HR = 1.38 [1.18-1.62] and 2.18 [1.86-2.54], respectively) were independently associated with the incidence of death. The all-cause mortality rate was higher in patients with malnutrition or eGFR ≤29 (adjusted HR, 3.31; 95% CI: 2.51-4.35) than in patients without malnutrition or eGFR 60-89. Furthermore, moderate and severe malnutrition (vs. no malnutrition) was independently associated with death in patients with NKD, AKI, and CKD.

CONCLUSION

Malnutrition based on the GLIM criteria was associated with increased all-cause mortality in inpatients, and malnutrition combined with kidney dysfunction was associated with a higher risk of mortality. Furthermore, patients with NKD, AKI, and CKD showed an association between malnutrition based on GLIM criteria and mortality.

Role of endothelial hyaluronan in peritoneal membrane transport and disease conditions during peritoneal dialysis

Peritoneal membrane dysfunction in peritoneal dialysis (PD) is primarily attributed to angiogenesis; however, the integrity of vascular endothelial cells can affect peritoneal permeability. Hyaluronan, a component of the endothelial glycocalyx, is reportedly involved in preventing proteinuria in the normal glomerulus. One hypothesis suggests that development of encapsulating peritoneal sclerosis (EPS) is triggered by protein leakage due to vascular endothelial injury. We therefore investigated the effect of hyaluronan in the glycocalyx on peritoneal permeability and disease conditions. After hyaluronidase-mediated degradation of hyaluronan on the endothelial cells of mice, macromolecules, including albumin and β2 microglobulin, leaked into the dialysate. However, peritoneal transport of small solute molecules was not affected. Pathologically, hyaluronan expression was diminished; however, expression of vascular endothelial cadherin and heparan sulfate, a core protein of the glycocalyx, was preserved. Hyaluronan expression on endothelial cells was studied using 254 human peritoneal membrane samples. Hyaluronan expression decreased in patients undergoing long-term PD treatment and EPS patients treated with conventional solutions. Furthermore, the extent of hyaluronan loss correlated with the severity of vasculopathy. Hyaluronan on endothelial cells is involved in the peritoneal transport of macromolecules. Treatment strategies that preserve hyaluronan in the glycocalyx could prevent the leakage of macromolecules and subsequent related complications.

Effects of empagliflozin on progression of chronic kidney disease: a prespecified secondary analysis from the empa-kidney trial

BACKGROUND

Sodium-glucose co-transporter-2 (SGLT2) inhibitors reduce progression of chronic kidney disease and the risk of cardiovascular morbidity and mortality in a wide range of patients. However, their effects on kidney disease progression in some patients with chronic kidney disease are unclear because few clinical kidney outcomes occurred among such patients in the completed trials. In particular, some guidelines stratify their level of recommendation about who should be treated with SGLT2 inhibitors based on diabetes status and albuminuria. We aimed to assess the effects of empagliflozin on progression of chronic kidney disease both overall and among specific types of participants in the EMPA-KIDNEY trial.

METHODS

EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA), and included individuals aged 18 years or older with an estimated glomerular filtration rate (eGFR) of 20 to less than 45 mL/min per 1·73 m2, or with an eGFR of 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher. We explored the effects of 10 mg oral empagliflozin once daily versus placebo on the annualised rate of change in estimated glomerular filtration rate (eGFR slope), a tertiary outcome. We studied the acute slope (from randomisation to 2 months) and chronic slope (from 2 months onwards) separately, using shared parameter models to estimate the latter. Analyses were done in all randomly assigned participants by intention to treat. EMPA-KIDNEY is registered at ClinicalTrials.gov, NCT03594110.

FINDINGS

Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and then followed up for a median of 2·0 years (IQR 1·5-2·4). Prespecified subgroups of eGFR included 2282 (34·5%) participants with an eGFR of less than 30 mL/min per 1·73 m2, 2928 (44·3%) with an eGFR of 30 to less than 45 mL/min per 1·73 m2, and 1399 (21·2%) with an eGFR 45 mL/min per 1·73 m2 or higher. Prespecified subgroups of uACR included 1328 (20·1%) with a uACR of less than 30 mg/g, 1864 (28·2%) with a uACR of 30 to 300 mg/g, and 3417 (51·7%) with a uACR of more than 300 mg/g. Overall, allocation to empagliflozin caused an acute 2·12 mL/min per 1·73 m2 (95% CI 1·83-2·41) reduction in eGFR, equivalent to a 6% (5-6) dip in the first 2 months. After this, it halved the chronic slope from -2·75 to -1·37 mL/min per 1·73 m2 per year (relative difference 50%, 95% CI 42-58). The absolute and relative benefits of empagliflozin on the magnitude of the chronic slope varied significantly depending on diabetes status and baseline levels of eGFR and uACR. In particular, the absolute difference in chronic slopes was lower in patients with lower baseline uACR, but because this group progressed more slowly than those with higher uACR, this translated to a larger relative difference in chronic slopes in this group (86% [36-136] reduction in the chronic slope among those with baseline uACR <30 mg/g compared with a 29% [19-38] reduction for those with baseline uACR ≥2000 mg/g; ptrend<0·0001).

INTERPRETATION

Empagliflozin slowed the rate of progression of chronic kidney disease among all types of participant in the EMPA-KIDNEY trial, including those with little albuminuria. Albuminuria alone should not be used to determine whether to treat with an SGLT2 inhibitor.

FUNDING

Boehringer Ingelheim and Eli Lilly.

Impact of primary kidney disease on the effects of empagliflozin in patients with chronic kidney disease: secondary analyses of the EMPA-KIDNEY trial

BACKGROUND

The EMPA-KIDNEY trial showed that empagliflozin reduced the risk of the primary composite outcome of kidney disease progression or cardiovascular death in patients with chronic kidney disease mainly through slowing progression. We aimed to assess how effects of empagliflozin might differ by primary kidney disease across its broad population.

METHODS

EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA). Patients were eligible if their estimated glomerular filtration rate (eGFR) was 20 to less than 45 mL/min per 1·73 m2, or 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher at screening. They were randomly assigned (1:1) to 10 mg oral empagliflozin once daily or matching placebo. Effects on kidney disease progression (defined as a sustained ≥40% eGFR decline from randomisation, end-stage kidney disease, a sustained eGFR below 10 mL/min per 1·73 m2, or death from kidney failure) were assessed using prespecified Cox models, and eGFR slope analyses used shared parameter models. Subgroup comparisons were performed by including relevant interaction terms in models. EMPA-KIDNEY is registered with ClinicalTrials.gov, NCT03594110.

FINDINGS

Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and followed up for a median of 2·0 years (IQR 1·5-2·4). Prespecified subgroupings by primary kidney disease included 2057 (31·1%) participants with diabetic kidney disease, 1669 (25·3%) with glomerular disease, 1445 (21·9%) with hypertensive or renovascular disease, and 1438 (21·8%) with other or unknown causes. Kidney disease progression occurred in 384 (11·6%) of 3304 patients in the empagliflozin group and 504 (15·2%) of 3305 patients in the placebo group (hazard ratio 0·71 [95% CI 0·62-0·81]), with no evidence that the relative effect size varied significantly by primary kidney disease (pheterogeneity=0·62). The between-group difference in chronic eGFR slopes (ie, from 2 months to final follow-up) was 1·37 mL/min per 1·73 m2 per year (95% CI 1·16-1·59), representing a 50% (42-58) reduction in the rate of chronic eGFR decline. This relative effect of empagliflozin on chronic eGFR slope was similar in analyses by different primary kidney diseases, including in explorations by type of glomerular disease and diabetes (p values for heterogeneity all >0·1).

INTERPRETATION

In a broad range of patients with chronic kidney disease at risk of progression, including a wide range of non-diabetic causes of chronic kidney disease, empagliflozin reduced risk of kidney disease progression. Relative effect sizes were broadly similar irrespective of the cause of primary kidney disease, suggesting that SGLT2 inhibitors should be part of a standard of care to minimise risk of kidney failure in chronic kidney disease.

FUNDING

Boehringer Ingelheim, Eli Lilly, and UK Medical Research Council.

Time to normalisation of C-reactive protein and incidence of relapse in microscopic polyangiitis: A medical records review study in Japan

OBJECTIVES

Despite the identification of risk factors for relapses in antineutrophil cytoplasmic antibody-associated vasculitis, the relationship between changes in C-reactive protein (CRP) levels after the initial treatment and the incidence of relapse remains unknown. This study aimed to assess the association between the time taken for normalisation of CRP levels and the incidence of relapse in Japanese adult patients with microscopic polyangiitis.

METHODS

This study included 85 consecutive patients with newly diagnosed microscopic polyangiitis who achieved remission after 6 months of immunosuppressive treatment at the Aichi Medical University Hospital between 2009 and 2017. The relationship between the time to normalisation of CRP after the initial immunosuppressive treatment and relapse incidences was evaluated using multivariable Cox proportional hazard models.

RESULTS

During the follow-up period, 13 (30.2%), 7 (41.2%), and 16 (64.0%) patients relapsed (P = .025) within 1-14, 15-28, and ≥29 days of normalisation, respectively. The hazard ratios [95% confidence intervals (CIs)] for the time to normalisation of CRP of 1-14, 15-28, and ≥29 days were 1.00 (reference), 2.42 (95% CI: 0.92-6.39), and 3.48 (95% CI: 1.56-7.76), respectively.

CONCLUSIONS

A significant association between the time to normalisation of CRP and the relapse incidence in Japanese patients with microscopic polyangiitis was observed.

Association between reduced left ventricular ejection fraction and peritoneal dialysis related peritonitis: a single center retrospective cohort study in Japan

We present a single-center retrospective analysis of 228 Japanese patients with peritoneal dialysis, in which we examined whether reduced left ventricular ejection fraction (LVEF) is a risk factor for peritonitis development. Time-dependent multivariable-adjusted Cox proportional hazards models revealed that reduced LVEF (LVEF < 50% vs. preserved LVEF ≥ 50%, hazard ratio (HR) 2.10; 95% confidence interval (CI) 1.16-3.82) was associated with peritonitis. Qualitatively, similar associations with reduced LVEF (< 50%) were observed for enteric peritonitis (adjusted HR 7.68; 95% CI 2.51-23.5) but not for non-enteric peritonitis (adjusted HR 1.15; 95% CI 0.54-2.44). Reduced LVEF is associated with a significantly higher risk of subsequent peritonitis, particularly enteric peritonitis. These results indicate that patients with reduced LVEF may be at risk of enteric peritonitis from bowel sources caused by intestinal involvement due to cardiac dysfunction.

Lymphopenia is a risk factor for severe infections in older patients with microscopic polyangiitis: a retrospective cohort study in Japan

Objective

Previous studies have identified the predictors of severe infections in ANCA-associated vasculitis. However, lymphopenia has not been fully evaluated as a predictor of subsequent severe infections in patients with microscopic polyangiitis (MPA). The aim of this study was to assess the association between lymphopenia and severe infections requiring hospitalization after receiving immunosuppressive therapy for MPA.

Methods

This single-centre retrospective cohort study included 130 consecutive patients with newly diagnosed MPA from Aichi Medical University Hospital, Japan, who received immunosuppressive therapy between March 2004 and December 2020. The relationship between lymphopenia and subsequent severe infections was assessed using time-dependent multivariate Cox proportional hazard models adjusted for clinically relevant factors.

Results

During the follow-up period (median: 38 months; interquartile range: 15-63 months), 56 severe infectious episodes occurred in 51 patients (39.2%). Time-dependent multivariate Cox proportional hazard analyses identified older age [adjusted hazard ratio (HR) = 1.74 per 10 years, 95% CI: 1.13, 2.67], methylprednisolone pulse therapy (adjusted HR = 2.04, 95% CI: 1.03, 4.02), moderate lymphopenia (vs normal, adjusted HR = 7.17, 95% CI: 3.10, 16.6) and severe lymphopenia (vs normal, adjusted HR = 36.1, 95% CI: 11.8, 110.9) as significant predictors of severe infection.

Conclusion

Lymphopenia is a predictor of subsequent severe infections in patients with MPA who receive immunosuppressive therapy. These results suggest the importance of sustained infection surveillance, particularly in older patients who develop lymphopenia during strong immunosuppressive therapy.

Peritoneal Expression of Membrane Complement Regulators Is Decreased in Peritoneal Dialysis Patients with Infected Peritonitis

In peritoneal dialysis (PD) patients, fungi and Pseudomonas aeruginosa are considered important causative microorganisms for peritonitis with poor prognosis. Our objective was to explore expressions of membrane complement (C) regulators (CRegs) and tissue injuries in the peritoneum of patients with PD-related peritonitis, including fungal and Pseudomonas aeruginosa peritonitis. In peritoneal biopsy tissues obtained at PD catheter removal, we investigated the severity of peritonitis-associated peritoneal injuries and the expression of CRegs, CD46, CD55, and CD59 against peritoneal tissues without any episode of peritonitis. In addition, we evaluated peritoneal injuries among fungal and Pseudomonas aeruginosa-peritonitis (P1) and Gram-positive bacterial peritonitis (P2). We also observed deposition of C activation products such as activated C and C5b-9 and measured sC5b-9 in the PD fluid of patients. As a result, the severity of peritoneal injuries correlated inversely with the expression of peritoneal CRegs. Peritoneal CReg expression in peritonitis was significantly reduced compared to no peritonitis. Peritoneal injuries were more severe in P1 than in P2. CReg expression was further decreased and C5b-9 further increased in P1 than in P2. In conclusion, severe peritoneal injuries due to fungal and Pseudomonas aeruginosa-peritonitis decreased CReg expression and increased deposition of activated C3 and C5b-9 in the peritoneum, suggesting that peritonitis, particularly fungal and Pseudomonas aeruginosa-peritonitis, might induce susceptibility to further peritoneal injuries due to excessive C activation.

Tissue Sodium Accumulation Induces Organ Inflammation and Injury in Chronic Kidney Disease

High salt intake is a primary cause of over-hydration in chronic kidney disease (CKD) patients. Inflammatory markers are predictors of CKD mortality; however, the pathogenesis of inflammation remains unclear. Sodium storage in tissues has recently emerged as an issue of concern. The binding of sodium to tissue glycosaminoglycans and its subsequent release regulates local tonicity. Many cell types express tonicity-responsive enhancer-binding protein (TonEBP), which is activated in a tonicity-dependent or tonicity-independent manner. Macrophage infiltration was observed in the heart, peritoneal wall, and para-aortic tissues in salt-loading subtotal nephrectomized mice, whereas macrophages were not prominent in tap water-loaded subtotal nephrectomized mice. TonEBP was increased in the heart and peritoneal wall, leading to the upregulation of inflammatory mediators associated with cardiac fibrosis and peritoneal membrane dysfunction, respectively. Reducing salt loading by a diuretic treatment or changing to tap water attenuated macrophage infiltration, TonEBP expression, and inflammatory marker expression. The role of TonEBP may be crucial during the cardiac fibrosis and peritoneal deterioration processes induced by sodium overload. Anti-interleukin-6 therapy improved cardiac inflammation and fibrosis and peritoneal membrane dysfunction. Further studies are necessary to establish a strategy to regulate organ dysfunction induced by TonEBP activation in CKD patients.

Population pharmacokinetics and limited sampling strategy for therapeutic drug monitoring of mycophenolate mofetil in Japanese patients with lupus nephritis

BACKGROUND

Mycophenolate mofetil (MMF), a prodrug of the immunosuppressive agent mycophenolic acid (MPA), is difficult to administer because of the pharmacokinetic complexity of MPA. Although dosage adjustment according to the 12-h area under the concentration-time curve (AUC_0-12) is thought to be desirable, multiple blood samplings for AUC calculation may pose a clinical challenge. A limited sampling strategy (LSS) would provide a solution; however, little is known about MPA pharmacokinetics in lupus nephritis patients, especially in those with Asian backgrounds, or few, if any, LSSs are reported for them.

METHODS

Thirty-four adult Japanese patients receiving MMF for lupus nephritis were examined retrospectively. MPA pharmacokinetics were investigated, and a PPK model was developed using Phoenix® NLME™ software. Single and double blood sampling strategies from Bayesian estimation using the PPK model and from multiple linear regression were compared. Tolerability was also evaluated.

RESULTS

In the pharmacokinetic analysis, renal function and serum albumin had significant effects on dose-normalized AUC_0-12; and serum albumin, concomitant proton pump inhibitor (PPI) and iron/magnesium oxide did on dose-normalized maximum concentration. As a PPK model, a two-compartment model was developed with a transit absorption model and first-order elimination, in which creatinine clearance and serum albumin were covariates for MPA clearance. The double sampling strategy at 1 and 4 h by multiple linear regression showed the best agreement with the observed AUC_0-12 (r² = 0.885). Of the single sampling strategies, the one at 6 h by Bayesian estimation performed best (r² = 0.769). The tolerability evaluation showed that correlations were suggested for gastrointestinal involvement.

CONCLUSIONS

The present study developed the first PPK model of MPA for Japanese lupus nephritis patients. As for LSSs, a double sampling strategy at 1 and 4 h by multiple linear regression would work best; when only a single blood sampling is allowed, a strategy at 6 h by Bayesian estimation using the PPK model developed in this study would be best. The LSSs good enough for clinical use may facilitate safer, more effective, and individualized therapy.

Case report: Thrombotic microangiopathy concomitant with macrophage activation syndrome in systemic lupus erythematosus refractory to conventional treatment successfully treated with eculizumab

Thrombotic microangiopathy (TMA) is a rare but life-threatening complication of systemic lupus erythematosus (SLE). Macrophage activation syndrome (MAS) is also a rare, life-threatening hyperinflammatory condition that is comorbid with SLE. However, the association between TMA and MAS in patients with SLE has rarely been assessed, and the difficulty of diagnosing these conditions remains prevalent. The efficacy of eculizumab has been reported for SLE patients whose conditions are complicated with TMA. However, no study has investigated the therapeutic efficacy of eculizumab for TMA concomitant with SLE-associated MAS. Herein, we report the first case of TMA concomitant with SLE-associated MAS that was initially refractory to conventional immunosuppressive therapy but showed remarkable recovery after eculizumab treatment. Furthermore, we evaluated serum syndecan-1 and hyaluronan levels, which are biomarkers of endothelial damage. We found that these levels decreased after the administration of eculizumab, suggesting that TMA was the main pathology of the patient. This case illustrates that it is important to appropriately assess the possibility of TMA during the course of SLE-associated MAS and consider the use of eculizumab as necessary.

Mepolizumab administration for eosinophilic granulomatosis with polyangiitis in an elderly patient with an abrupt onset of limb ischaemia and peripheral neuropathy: A case-based literature review

Eosinophilic granulomatosis with polyangiitis (EGPA) is a type of anti-neutrophil cytoplasmic antibody-associated vasculitis characterised by small- to medium-sized vessel vasculitis and is typically associated with eosinophilic granulomatous inflammation. EGPA can affect any organ system, most commonly the lungs, skin, and the nervous system. However, limb ulcers are rare complications and have only been described in few case reports. Furthermore, no documented cases of EGPA have been treated with mepolizumab. Herein, we report a case of an 86-year-old Japanese woman with anti-neutrophil cytoplasmic antibody-negative EGPA, who had an abrupt onset of upper limb ulcers and bilateral foot drop due to multiple mononeuropathy. Clinicopathological sural nerve biopsy showed eosinophil-associated vascular damage. The patient was administered steroids, intravenous immunoglobulin, vasodilators, and mepolizumab; this resulted in clinical improvement of her finger ulcers and peripheral neuropathy without any adverse effects. In cases of an abrupt onset of limb ischaemia and peripheral neuropathy, physicians should consider the possibility of EGPA as a differential diagnosis. Furthermore, the early administration of mepolizumab might yield better outcomes in terms of improving limb ischaemia and peripheral neuropathy.

Interleukin-6 blockade reduces salt-induced cardiac inflammation and fibrosis in subtotal nephrectomized mice

Cardiovascular disease is the most common comorbidity in patients with chronic kidney disease (CKD), affecting both their prognosis and quality of life. Cardiac fibrosis is common in patients with CKD with left ventricular diastolic dysfunction, and it is associated with increased risk of heart failure and mortality. Recent evidence suggests that high salt intake activates immune responses associated with local accumulation of sodium. We reported that high salt intake promotes cardiac inflammation in subtotal nephrectomized (Nx) mice. We investigated the effects of administration of MR16-1, a rat anti-mouse monoclonal interleukin (IL)-6 receptor antibody, in Nx mice with salt loading (Nx-salt). Expression of monocyte chemoattractant protein-1, tumor necrosis factor-α, IL-1β, and IL-6 mRNAs and macrophage infiltration was significantly reduced in the heart of Nx-salt mice treated with MR16-1 (Nx-salt-MR16-1) compared with Nx-salt mice treated with control rat rat IgG1 (Nx-salt-rat IgG1). Correspondingly, cardiac fibrosis was significantly attenuated in Nx-salt-MR16-1 mice compared with Nx-salt-rat IgG1 mice. Furthermore, in the heart of Nx-salt-MR16-1 mice, expression of mRNA for nicotinamide adenine dinucleotide phosphate oxidase-2, an oxidative stress marker, was significantly downregulated compared with Nx-salt-rat IgG1 mice. Increases in cardiac metabolites, including histidine and γ-butyrobetaine, were also reversed by IL-6 blockade treatment. In conclusion, IL-6 blockade exerts anti-inflammatory, antifibrotic, and partial antioxidative effects in the heart of Nx-salt mice.NEW & NOTEWORTHY In the present study, IL-6 blockade exerted anti-inflammatory, antifibrotic, and partial antioxidative effects on the hearts of mice with CKD on a high-salt diet. Therefore, IL-6 potentially mediates cardiac fibrosis induced by high salt intake in patients with CKD, a finding with therapeutic implications. Of note, the next therapeutic implication may simply be the reinforcement of low-salt diets or diuretics and further research on the anti-inflammatory effects of these measures rather than IL-6 blockade with high-salt diet.

Galactose-deficient IgA1 is Involved in IgA Deposition in Renal Grafts Biopsied One Hour after Kidney Transplantation

Objective Asymptomatic renal immunoglobulin A (IgA) deposition occurs in healthy subjects, but its etiologic role in disease is unclear. Galactose-deficient IgA1 (Gd-IgA1) is involved in the pathogenesis of IgA nephropathy. We investigated Gd-IgA1 deposition in transplanted kidneys that were considered healthy showing subclinical latent IgA deposition one hour after transplantation. Methods A total of 723 transplanted kidney specimens biopsied 1 h after kidney transplantation from 2009 to 2016 at Nagoya Red Cross Hospital were examined. A total of 81 cases of IgA deposition were extracted, and 41 were ultimately studied. Double immunofluorescence staining for Gd-IgA1 and IgA was conducted to investigate the role of Gd-IgA1 in subclinical IgA deposition. Results Light microscopy findings for the 41 cases indicated only minor glomerular abnormalities. Immunofluorescence analyses revealed that all cases were positive for IgA. C3, IgG, and IgM positivity rates were 78.0%, 7.3%, and 60.9%, respectively. All 41 cases were positive for Gd-IgA1, which merged with IgA deposition in immunofluorescence double staining. IgA disappeared in 26 of 40 cases (65.0%) 1 year after kidney transplantation. In contrast, IgA redeposition was observed in three cases. Conclusion Gd-IgA1 was demonstrated in all transplanted kidneys, with latent IgA deposition noted in otherwise healthy kidneys. Deposition of Gd-IgA1 might indicate the initial stage of IgA nephropathy; however, additional factors, such as IgG deposition, are required for the ultimate development of IgA nephropathy.

Association of alcohol consumption with the incidence of proteinuria and chronic kidney disease: a retrospective cohort study in Japan

BACKGROUND

The difference in the clinical impact of alcohol consumption on kidney function based on sex remains to be elucidated. This study aimed to assess the association between the dose of alcohol consumption and the incidence of proteinuria and chronic kidney disease stratified by sex.

METHODS

This retrospective cohort study included 26,788 workers (19,702 men and 7086 women) with normal renal function (estimated glomerular filtration rate ≥ 60 mL/min/1.73 m²) at annual health examinations between January 2010 and March 2015 in Japan. The main exposure was alcohol consumption. The primary outcomes were the incidence of proteinuria (dipstick urinary protein ≥ 1) and incidence of low estimated glomerular filtration rate (eGFR; rate < 60 mL/min per 1.73 m²; decreased from the baseline eGFR by 25%).

RESULTS

During a median observational period of 4 years (interquartile range: 2-6), 1993 (10.1%) men and 462 (6.5%) women developed proteinuria, whereas 667 (3.4%) men and 255 (3.6%) women developed low eGFR. After adjustment for clinically relevant factors using a Cox proportional hazards model, alcohol consumption of ≥ 46 g/day in females was significantly associated with the incidence of proteinuria (hazard ratio, 1.57; 95% confidence interval, 1.10-2.26) and low eGFR (hazard ratio, 1.62; 95% confidence interval, 1.04-2.53). However, no significant association between alcohol consumption and primary outcomes was observed in men.

CONCLUSIONS

In conclusion, daily higher alcohol consumption was significantly associated with a higher incidence of proteinuria and low eGFR among women. Women might be prone to high alcohol consumption with kidney dysfunction.

Anti-Neutrophil Cytoplasmic Antibody-Associated Vasculitis Complicated by Thrombotic Microangiopathy with Posterior Reversible Encephalopathy Syndrome Successfully Treated with Eculizumab: A Case Report

Thrombotic microangiopathy is characterised by endothelial cell injury, intravascular platelet-fibrin thrombi, and vascular damage, leading to acute kidney injury, thrombocytopenia, and microangiopathic haemolytic anaemia. Among the autoimmune diseases related to thrombotic microangiopathy, anti-neutrophil cytoplasmic antibody-associated vasculitis-related thrombotic microangiopathy cases have been rarely reported; therefore, the optimal treatment for associated vasculitis-related thrombotic microangiopathy remains unknown. An 84-year-old woman without significant medical history presented with a 1-month history of general fatigue, fever, and deteriorating bilateral leg numbness and was admitted to our hospital. She had elevated myeloperoxidase anti-neutrophil cytoplasmic antibody levels, polyneuropathy, and rapid progressive glomerulonephritis because of pauci-immune crescentic glomerulonephritis, as revealed by a kidney biopsy. Accordingly, we diagnosed her with microscopic polyangiitis. After administering methylprednisolone pulse therapy, rituximab, and intravenous immunoglobulin, the patient's mental state deteriorated, presenting signs of thrombotic microangiopathy with posterior reversible encephalopathy syndrome. Intermittent haemodialysis and plasma exchange were initiated; however, her condition was not improved, and eculizumab administration was initiated thereafter. The patient's symptoms showed a remarkable response to eculizumab; thrombotic microangiopathy findings, kidney function, and neurological symptoms improved after only two doses of eculizumab, and she achieved sustained remission. The extremely effective course of eculizumab treatment indicated that overt complement activation affected the development of thrombotic microangiopathy. Anti-neutrophil cytoplasmic antibody-associated vasculitis-related thrombotic microangiopathy may be mediated by complement activation, and prompt induction of eculizumab therapy may be a superior strategy to prevent organ damage. Further studies should elucidate the role of complement activation in associated vasculitis-related thrombotic microangiopathy and the efficacy of eculizumab treatment.

Long-term good outcome of the fibrocavitary form of pulmonary Mycobacterium avium complex disease with concomitant abatacept monotherapy in a patient with rheumatoid arthritis

A 53-year-old woman diagnosed with rheumatoid arthritis (RA) demonstrated thick-walled large cavities with consolidation in the left upper lobe on chest computed tomography (CT). Mycobacterium avium was isolated from sputum cultures, and she was diagnosed as having the fibrocavitary (FC) form of pulmonary Mycobacterium avium complex (MAC) disease. Clarithromycin-containing, multidrug, anti-MAC chemotherapy was started immediately. After 7 months, the cavitary lesions improved, and sputum cultures showed negative conversion. Thereafter, abatacept monotherapy was started due to high RA disease activity. Clinical remission of RA has been sustained and cavitary lesions disappeared by concomitant abatacept and anti-MAC therapy for more than 5 years. Immediate initiation of anti-MAC therapy and prior confirmed efficacy are needed for the treatment of the FC form. Abatacept and anti-MAC therapy could be continued, leading to the withdrawal of prednisolone, along with careful observation by strict chest CT evaluation and repeated sputum cultures. Biologics are generally contraindicated for pulmonary MAC disease, particularly the FC form. When there is a pre-existing lung lesion apparently of FC type, abatacept cannot be started without prior anti-MAC chemotherapy. This case suggests that abatacept may be carefully used to avoid progressive joint destruction after FC lesions of pulmonary MAC disease are resolved.

Relationship between doses of antihypertensive drugs and left ventricular mass index changes in hemodialysis patients in a Japanese cohort

Left ventricular hypertrophy commonly occurs in dialysis patients and is associated with a risk of developing cardiovascular disease events and all-cause mortality. Although hypertension treatment reduces left ventricular mass index (LVMI) in hemodialysis patients, the relationships of prescription pattern, dose, and changes in the dose of antihypertensive drugs with LVMI have not been completely elucidated. Here, we hypothesized that volume reduction would lead to a decrease in the antihypertensive drug dose and subsequently to a reduction in LVMI; conversely, fluid retention would lead to an increase in the antihypertensive drug use and, subsequently, to LVMI progression. To assess this hypothesis, we investigated the relationship between changes in the dose of antihypertensive drugs and subsequent changes in LVMI in 240 patients who had just started hemodialysis using a retrospective hemodialysis cohort in Japan. Using multiple linear regression analysis, we assessed the association between changes in the antihypertensive drug dose over 1 year after hemodialysis initiation and changes in LVMI during this period. A decrease and an increase in the antihypertensive drug dose were significantly associated with a reduction in LVMI (vs. no change; β  = – 17.386, p < .001) and LVMI progression (vs. no change; β  = 16.192, p < .001), respectively. In conclusion, our findings suggested that volume reduction, leading to a decrease in the use of antihypertensive drugs, is a therapeutic strategy in patients undergoing hemodialysis to prevent LVMI progression.

Roles of glomerular endothelial hyaluronan in the development of proteinuria

Vascular endothelial cells are covered with glycocalyx comprising heparan sulfate, hyaluronan, chondroitin sulfate, and associated proteins. Glomerular endothelial glycocalyx is involved in protecting against induction of proteinuria and structural damage, but the specific components in glycocalyx that represent therapeutic targets remain unclear. Anti-vascular endothelial growth factor (VEGF) therapy is associated with an increased risk of glomerular endothelial injury. This study investigated whether hyaluronan could provide a therapeutic target to protect against proteinuria. We conducted ex vivo and in vivo experiments to explore the effects of degrading glomerular hyaluronan by administering hyaluronidase and of supplementation with hyaluronan. We investigated hyaluronan expression using biotin-labeled hyaluronan-binding protein (HABP) in human kidney specimens or serum hyaluronan in endothelial injuries under inhibition of VEGF signaling. We directly demonstrated hyaluronan in glomerular endothelial layers using HABP staining. Ex vivo and in vivo experiments showed the development of proteinuria after digestion of hyaluronan in glomerular capillaries. Supplementation with hyaluronan after hyaluronidase treatment suppressed proteinuria. Mice in the in vivo study developed albuminuria after intraperitoneal injection of hyaluronidase with decreased glomerular hyaluronan and increased serum hyaluronan. In human kidneys with endothelial cell dysfunction and proteinuria due to inhibition of VEGF, glomerular expression of hyaluronan was reduced even in normal-appearing glomeruli. Serum hyaluronan levels were elevated in patients with pre-eclampsia with VEGF signaling inhibition. Our data suggest that hyaluronan itself plays crucial roles in preventing proteinuria and preserving the integrity of endothelial cells. Hyaluronan could provide a therapeutic target for preventing glomerular endothelial glycocalyx damage, including VEGF signaling inhibition.

Association between serum magnesium levels and abdominal aorta calcification in patients with pre-dialysis chronic kidney disease stage 5

BACKGROUND

Several studies have revealed the relationship between serum magnesium levels and vascular calcification in chronic kidney disease patients. Despite excellent predictability of abdominal aorta calcification for cardiovascular disease events, the relationship between serum magnesium levels and abdominal aorta calcification, as evaluated by quantitative methods, in pre-dialysis patients remains unclear. This study aimed to determine the abdominal aorta calcification volume using computerized tomography and its association with serum magnesium levels in pre-dialysis chronic kidney disease stage 5 patients.

METHODS

This single-center cross-sectional study included 100 consecutive patients with pre-dialysis chronic kidney disease stage 5 between January 2016 and May 2020 at Aichi Medical University Hospital, Japan. The relationships between serum magnesium levels and the abdominal aorta calcification volume were assessed using multiple linear regression models after adjusting for clinically relevant factors. We also assessed clinical factors that affect serum magnesium levels.

RESULTS

The mean serum magnesium level was 2.0 mg/dL (interquartile range, 1.8 to 2.3). Multivariate analyses revealed that a higher serum magnesium level (stand. β = -0.245, p = 0.010) was significantly associated with a reduced abdominal aorta calcification volume, and that a history of cardiovascular disease (stand. β = 0.3792, p < 0.001) and older age (stand. β = 0.278, p = 0.007) were significantly associated with an increased abdominal aorta calcification volume. Moreover, multivariate analysis showed that the use of proton pump inhibitor or potassium-competitive acid blocker was significantly associated with lower serum magnesium levels (stand. β = -0.246, p = 0.019).

CONCLUSIONS

The present study revealed that the higher Mg level was significantly associated with lower volume of abdominal aorta calcification in pre-dialysis chronic kidney disease stage 5 patients. Further studies should be undertaken to determine the appropriate magnesium level to suppress vascular calcification.

Low-GDP, pH-neutral solutions preserve peritoneal endothelial glycocalyx during long-term peritoneal dialysis

BACKGROUND

During peritoneal dialysis (PD), solute transport and ultrafiltration are mainly achieved by the peritoneal blood vasculature. Glycocalyx lies on the surface of endothelial cells and plays a role in vascular permeability. Low-glucose degradation product (GDP), pH-neutral PD solutions reportedly offer higher biocompatibility and lead to less peritoneal injury. However, the effects on the vasculature have not been clarified.

METHODS

Peritoneal tissues from 11 patients treated with conventional acidic solutions (acidic group) and 11 patients treated with low-GDP, pH-neutral solutions (neutral group) were examined. Control tissues were acquired from 5 healthy donors of kidney transplants (control group). CD31 and ratio of luminal diameter to vessel diameter (L/V ratio) were evaluated to identify endothelial cells and vasculopathy, respectively. Immunostaining for heparan sulfate (HS) domains and Ulex europaeus agglutinin-1 (UEA-1) binding was performed to assess sulfated glycosaminoglycans and the fucose-containing sugar chain of glycocalyx.

RESULTS

Compared with the acidic group, the neutral group showed higher CD31 positivity. L/V ratio was significantly higher in the neutral group, suggesting less progression of vasculopathy. Both HS expression and UEA-1 binding were higher in the neutral group, whereas HS expression was markedly more preserved than UEA-1 binding in the acidic group. In vessels with low L/V ratio, which were found only in the acidic group, HS expression and UEA-1 binding were diminished, suggesting a loss of glycocalyx.

CONCLUSION

Peritoneal endothelial glycocalyx was more preserved in patients treated with low-GDP, pH-neutral solution. The use of low-GDP, pH-neutral solutions could help to protect peritoneal vascular structures and functions.

C1 inhibitor mitigates peritoneal injury in zymosan-induced peritonitis

Peritonitis, due to a fungal or bacterial infection, leads to injury of the peritoneal lining and thereby forms a hazard for the long-term success of peritoneal dialysis (PD) and remains a lethal complication in patients with PD. This study investigated whether C1 inhibitor (C1-INH) could protect against the progression of peritoneal injuries with five daily administrations of zymosan after mechanical scraping of the rat peritoneum to mimic fungal peritonitis. Severe peritoneal injuries were seen in this model, accompanied by fibrinogen/fibrin exudation and peritoneal deposition of complement activation products such as activated C3 and C5b-9. However, intraperitoneal injection of C1-INH decreased peritoneal depositions of activated C3 and C5b-9, ameliorated peritoneal thickening, reduced the influx of inflammatory cells, and prevented the production of peritoneal fibrous layers with both one and two doses of C1-INH each day. Our results suggest that C1-INH might be useful to protect against peritoneal injuries after causes of peritonitis such as fungal infection. This clinically available agent may thus help extend the duration of PD.NEW & NOTEWORTHY Peritoneal injuries associated with peritonitis comprise an important issue to prevent long-term peritoneal dialysis (PD) therapy. Here, we showed that C1 inhibitor (C1-INH), as an anticomplement agent, protected against peritoneal injuries in a peritonitis animal model related to fungal infection. Therefore, C1-INH might be useful to protect against peritoneal injuries after peritonitis due to fungal infection. This clinically available agent may thus help extend the duration of PD.

Association between body mass index and severe infection in older adults with microscopic polyangiitis: a retrospective cohort in Japan

BACKGROUND

Although previous studies have evaluated risk factors for the incidence of severe infection in patients with antineutrophil cytoplasmic antibody-associated vasculitis (AAV), the relationship between body mass index (BMI) and severe infection in AAV has not been elucidated. We hypothesized that older adults with AAV and a low BMI would be at a higher risk of infection. We therefore investigated the association between underweight status at AAV diagnosis and subsequent occurrence of severe infection in older adults with AAV.

METHODS

This single-center retrospective cohort study included 93 consecutive older adults with microscopic polyangiitis (MPA) treated at the Aichi Medical University Hospital in Japan between 2004 and 2018. The relationships between BMI at diagnosis and subsequent first severe infection were assessed using multivariate Cox proportional hazards models. The cumulative probability of the development of the first severe infection was calculated using the Kaplan-Meier method and the log-rank test. The level of statistical significance was set at P <  0.05.

RESULTS

During the median follow-up period of 19 (6-53) months, 29 (31.2%) patients developed at least one severe infection. Older age (adjusted hazard ratio [HR] = 2.02, 95% confidence interval [CI]: 1.14-3.52, per 10 years; P =  0.016), low BMI (< 18.5 kg/m² compared with normal BMI [18.5-23.0 kg/m²], adjusted HR =  2.63, 95% CI: 1.11-6.19; P =  0.027), and use of methylprednisolone pulse therapy (adjusted HR = 2.48, 95% CI: 1.07-5.76; P =  0.034) were found to be significant predictors of severe infection.

CONCLUSIONS

Low BMI was associated with a higher risk of severe infection in older adults with MPA, suggesting that careful management may be required to prevent this complication in this vulnerable group. Further studies are needed to elucidate the optimal treatment strategy for these patients.

Oral Antibiotics are Effective for Preventing Colonoscopy-associated Peritonitis as a Preemptive Therapy in Patients on Peritoneal Dialysis

Objective In patients on peritoneal dialysis (PD), it was reported that colonoscopy, but not upper gastrointestinal endoscopy, could cause peritonitis as a complication. A guideline of the International Society for Peritoneal Dialysis recommends preemptive intravenous antibiotics administration of ampicillin and aminoglycoside with or without metronidazole, to prevent colonoscopy-associated peritonitis. In this study, we retrospectively evaluated the effects of preemptive antibiotics therapy by oral administration instead of intravenous administration. Methods We investigated the incidence of colonoscopy-associated peritonitis in a single center. In 170 patients undergoing PD between January 2010 and December 2019, 50 colonoscopies were performed, including 49 with oral administration of amoxicillin and ciprofloxacin and/or metronidazole as preemptive therapy 1 hour before the colonoscopy procedure, and 1 without. Results We observed no incidence of colonoscopy-associated peritonitis. Conclusion Generally, oral administration of preemptive antibiotics is less painful and more convenient than intravenous administration, especially in outpatient procedures, such as a colonoscopy. Our results suggest that oral antibiotic administration might be effective for preventing colonoscopy-associated peritonitis in PD patients.

Association between sinusitis and relapse and changes in the myeloperoxidase-antineutrophil cytoplasmic antibody in microscopic polyangiitis

Previous studies have evaluated the risk factors for relapse of antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) and the biomarkers of AAV for predicting relapse. However, little is known about the association between the presence of sinusitis and relapse and changes in the ANCA levels in AAV. This single-center, retrospective cohort study included 104 consecutive patients who were newly diagnosed with myeloperoxidase (MPO)-ANCA-positive microscopic polyangiitis (MPA) between 2006 and 2018 and were treated at the Aichi Medical University Hospital in Japan. The relationships between sinusitis and relapse of vasculitis and elevated MPO-ANCA levels were assessed using multivariate Cox proportional hazards models that were adjusted for clinically relevant factors. During the entire follow-up period (median, 24 months; interquartile range, 7-54 months), 93 (89.4%) patients achieved remission. After achieving remission, 38 (40.9%) patients experienced at least one relapse (13 [65.0%] in the sinusitis group; 25 [34.3%] in the non-sinusitis group). Sinusitis was identified as a significant predictor of relapse (adjusted hazard ratio: 2.41, 95% confidence interval [CI]: 1.19-4.88; P = 0.015). Furthermore, sinusitis was more likely to be associated with elevated MPO-ANCA levels (adjusted hazard ratio: 2.59, 95% CI: 1.14-5.92; P = 0.024). In conclusion, sinusitis was associated with a higher risk of relapse and elevated MPO-ANCA levels in MPA patients, suggesting that careful management may be required to reduce the risk of relapse in patients with sinusitis. Further studies are needed to elucidate the optimal treatment strategy for these patients.

The effectiveness and safety of computed tomographic peritoneography and video-assisted thoracic surgery for hydrothorax in peritoneal dialysis patients: A retrospective cohort study in Japan

Introduction

Albeit uncommon, hydrothorax is an important complication of peritoneal dialysis (PD). Due to paucity of evidence for optimal treatment, this study aimed to evaluate the effectiveness and safety of computed tomographic (CT) peritoneography and surgical intervention involving video-assisted thoracic surgery (VATS) for hydrothorax in a retrospective cohort of patients who underwent PD in Japan.

Methods

Of the 982 patients who underwent PD from six centers in Japan between 2007 and 2019, 25 (2.5%) with diagnosed hydrothorax were enrolled in this study. PD withdrawal rates were compared between patients who underwent VATS for diaphragm repair (surgical group) and those who did not (non-surgical group) using the Kaplan-Meier method and log-rank test.

Results

The surgical and non-surgical groups comprised a total of 11 (44%) and 14 (56%) patients, respectively. Following hydrothorax diagnosis by thoracentesis and detection of penetrated sites on the diaphragm using CT peritoneography, VATS was performed at a median time of 31 days (interquartile range [IQR], 20–96 days). During follow-up (median, 26 months; IQR, 10–51 months), 9 (64.3%) and 2 (18.2%) patients in the non-surgical and surgical groups, respectively, withdrew from PD (P = 0.021). There were no surgery-related complications or hydrothorax relapse in the surgical group.

Conclusions

This study demonstrated the effectiveness and safety of CT peritoneography and VATS for hydrothorax. This approach may be useful in hydrothorax cases to avoid early drop out of PD and continue PD in the long term. Further studies are warranted to confirm these results.

Vasculopathy plays an important role during the development and relapse of encapsulating peritoneal sclerosis with conventional peritoneal dialysis solutions

Background

Encapsulating peritoneal sclerosis (EPS) is an uncommon but life-threatening complication of peritoneal dialysis (PD) therapy. The causative factors of EPS remain unclear. Pathological studies of the peritoneum affected by EPS and relationships with clinical factors including PD solutions remain lacking. The objective of this study was to examine peritoneal samples from EPS patients and to identify the associations of peritoneal pathology with different clinical factors.

Methods

Peritoneal specimens were obtained at the time of surgical enterolysis in Tsuchiya General Hospital from 1993 to 2016. A total of 223 PD patients were enrolled and analyzed. Tissues were fixed with formalin and processed with hematoxylin and eosin and Masson’s trichrome staining, as well as immunohistochemical staining for CD31 and CD68.

Results

Evaluations could be made in 174 patients who received surgical enterolysis. Conventional or pH-neutral low-glucose degradation product PD solutions were utilized during PD treatment. The conventional PD solution group showed less angiogenesis (P = 0.013) but more severe vasculopathy, in the form of a lower ratio of luminal diameter to vessel diameter (L/V ratio) (P &lt; 0.001) in association with longer PD treatment. Multivariate Cox proportional hazard models revealed that L/V ratio (per 0.1 increase, hazard ratio = 0.88, 95% confidence interval 0.77–0.99, P = 0.047) was significantly associated with a lower incidence of EPS relapse. In contrast, most of the cases in the pH-neutral solution group showed milder vasculopathy.

Conclusions

The pathology of EPS differed between conventional and pH-neutral solution groups. Vasculopathy was related to the development and relapse of EPS in the conventional solution group.

Excessive salt intake increases peritoneal solute transport rate via local tonicity-responsive enhancer binding protein in subtotal nephrectomized mice

BACKGROUND

High peritoneal transport is associated with high mortality and technical failure in peritoneal dialysis (PD). Baseline peritoneal solute transport rate (PSTR) as measured by the peritoneal equilibration test (PET) within 6 months after PD initiation varies between patients. Sodium is reported to be stored in the skin or muscle of dialysis patients. This study investigated whether excessive salt intake in uremic mice caused peritoneal alterations without exposure to PD fluid.

METHODS

Sham-operated (Sham) and subtotal nephrectomized (Nx) mice were randomly given tap water or 1% sodium chloride (NaCl)-containing water for 8 weeks. PET was then performed to evaluate peritoneal function. Human mesothelial cell line Met-5A was used for in vitro studies.

RESULTS

We observed higher PSTR in Nx mice with 1% NaCl-containing drinking water (Nx + salt) compared with those with tap water (Nx + water), along with enhanced angiogenesis and inflammation in the peritoneum. Blockade of interleukin (IL)-6 signaling rescued peritoneal transport function in Nx + salt mice. In cultured Met-5A, additional NaCl in the medium upregulated IL-6 as well as vascular endothelial growth factor-A, associated with increased expression and nuclear translocation of tonicity-responsive enhancer binding protein (TonEBP). Knockdown of TonEBP lowered the induction caused by high tonicity. Peritoneal TonEBP expression was higher in Nx + salt mice, while removal of high-salt diet lowered TonEBP level and improved peritoneal transport function.

CONCLUSIONS

Excessive dietary salt intake caused peritoneal membrane functional and structural changes under uremic status. TonEBP regulated hypertonicity-related inflammatory changes and might play a crucial role in high baseline peritoneal transport.

Association between statin use and incidence of relapse in anti-neutrophil cytoplasmic antibody-associated vasculitis: a single-center retrospective cohort study

Several studies have shown the efficacy of statins for some autoimmune disorders caused by anti-inflammatory and immunomodulatory reactions. However, little information is available about the impact of statins on relapse in antineutrophil cytoplasmic antibody-associated vasculitis (AAV). We performed the first investigation examining whether statin use has an effect on suppressing the first relapse of AAV in Japanese patients with AAV. This single-center retrospective cohort study included 98 consecutive patients with newly diagnosed AAV from Aichi Medical University Hospital, Japan between March 2009 and December 2017. Time to first relapse from the first remission was compared between 36 patients in the statin group and 62 patients in the non-statin group using multivariate Cox proportional hazard models, which were adjusted for clinically relevant factors. During the follow-up period (median, 24 months; interquartile range, 9-50 months), 35 (97.2%) patients in the statin group achieved remission, whereas 56 (90.3%) patients achieved remission in the non-statin group (P = 0.201). After achieving the first remission, 9 (25.7%) patients in the statin group and 29 (51.8%) patients in the non-statin group had at least one relapse. Multivariate Cox proportional hazard models revealed that statin use was significantly associated with a lower incidence of relapse compared with non-statin use (multivariate-adjusted hazard ratio = 0.41, 95% confidence interval: 0.18-0.92; P = 0.031). Patients with statin use were associated with a lower incidence of relapse in AAV. Our results should be assessed in well-designed randomized controlled trials.

Successful Introduction of Peritoneal Dialysis in an End-stage Renal Failure Patient with Idiopathic Aplastic Anemia

A 45-year-old man with idiopathic aplastic anemia required renal replacement therapy (RRT) due to end-stage renal disease (ESRD). We succeeded in inserting the peritoneal dialysis (PD) catheter under cover of frequent red blood cell and platelet infusions because of severe pancytopenia. During the one-year period after starting PD using an ultraviolet-ray sterilization device, he developed severe leukopenia but no PD-related peritonitis or exit site/tunnel infection until he died of pneumonia. This case suggests that PD might be a suitable choice as RRT in ESRD patients with aplastic anemia, even in those with severe pancytopenia.

Carboplatin-related acute interstitial nephritis in a patient with pancreatic neuroendocrine tumor

Carboplatin is characterized by low nephrotoxicity, including acute tubular necrosis (ATN), compared to a conventional platinum complex due to its low accumulative property in the renal tubules. Therefore, there are extremely few reports of carboplatin-induced kidney injury and only one case has been histologically examined. Herein, we describe the case of a 53-year-old man who presented with acute kidney injury (AKI) that occurred after carboplatin administration and was diagnosed with biopsy-proven acute interstitial nephritis (AIN). To our knowledge, this is the second case report of carboplatin-related AIN. The patient was diagnosed with a pancreatic neuroendocrine tumor, and chemotherapy consisting of cisplatin and irinotecan was initiated. However, 1 week later, he was admitted to our institution with fever, fatigue and an increase in C-reactive protein (CRP) level. The chemotherapy regimen was altered to carboplatin and etoposide, but high fever occurred on the first day, and CRP re-elevation and AKI became apparent 9 days later. Renal biopsy revealed prominent inflammatory cell infiltration into the interstitium, which lead to the pathological diagnosis of AIN. On immunostaining for surface markers, CD3- and CD68-positive cells were found to be predominant, and CD20-positive cells were relatively few. Although the serum creatinine level increased to 6.81 mg/dL, it decreased to 1.43 mg/dL 15 days after steroid therapy. This case demonstrated that carboplatin-related kidney injury includes not only ATN but also AIN. Appropriate pathological diagnosis including renal biopsy and indications for steroid treatment should be carefully considered.

Connective tissue growth factor is correlated with peritoneal lymphangiogenesis

Lymphatic absorption in the peritoneal cavity may contribute to ultrafiltration failure in peritoneal dialysis (PD). Lymphatic vessels develop during PD-related peritoneal fibrosis. Connective tissue growth factor (CTGF, also called CCN2) is an important determinant of fibrotic tissue remodeling, but little is known about its possible involvement in lymphangiogenesis. In this study, we investigated the relationship between CTGF and peritoneal lymphangiogenesis. A positive correlation was observed between vascular endothelial growth factor-C (VEGF-C), a major lymphangiogenic growth factor, and the CTGF concentration in human PD effluents. CTGF expression was positively correlated with expression of lymphatic markers and VEGF-C in human peritoneal biopsies. We found a positive correlation between the increase in CTGF and the increase in VEGF-C in cultured human peritoneal mesothelial cells (HPMCs) treated with transforming growth factor-β1 (TGF-β1). The diaphragm is a central player in peritoneal lymphatic absorption. CTGF expression was also correlated with expression of VEGF-C and lymphatics in a rat diaphragmatic fibrosis model induced by chlorhexidine gluconate (CG). Furthermore, CTGF gene deletion reduced VEGF-C expression and peritoneal lymphangiogenesis in the mouse CG model. Inhibition of CTGF also reduced VEGF-C upregulation in HPMCs treated with TGF-β1. Our results suggest a close relationship between CTGF and PD-associated lymphangiogenesis.

Oral candidiasis is a significant predictor of subsequent severe infections during immunosuppressive therapy in anti-neutrophil cytoplasmic antibody-associated vasculitis

BACKGROUND

Several studies have identified predictors of severe infections in antineutrophil cytoplasmic antibody-associated vasculitis (AAV). However, the development of oral candidiasis (OC) as a predictor of subsequent severe infections has not been evaluated. The aim of this study was to assess the association between OC and subsequent severe infection requiring hospitalization during immunosuppressive therapy in AAV.

METHODS

This single-center retrospective cohort study included 71 consecutive patients with newly diagnosed AAV from Aichi Medical University Hospital, Japan, starting immunosuppressive therapy between March 2013 and December 2018. The relationships between OC and subsequent severe infections were assessed using multivariate Cox proportional hazards models, adjusted for clinically relevant factors.

RESULTS

During the follow-up period (median, 23 months; interquartile range, 11-51 months), 25 severe infectious episodes occurred in 19 patients (26.8%) and OC occurred in 17 patients (23.9%). A log-rank test showed that the OC group was significantly associated with severe infection (P <  0.001). Multivariate Cox proportional hazards models identified lower serum albumin (per 1 g/dl adjusted hazard ratio (HR)  = 0.38, 95% confidence interval (CI): 0.15-0.85; P  =  0.018), use of methylprednisolone pulse (adjusted HR  =  5.44, 95% CI: 1.54-20.0; P  =  0.010), and OC (adjusted HR  = 5.31, 95% CI: 1.86-15.8; P  =  0.002) as significant predictors of severe infection. Furthermore, a significant effect modification of the use of methylprednisolone pulse on OC was observed (P <  0.001).

CONCLUSIONS

OC is one of the predictors of subsequent severe infections. The results suggest the importance of prolonging infection surveillance, especially for patients who developed OC under strong immunosuppressive therapy.

Tubulointerstitial expression and urinary excretion of connective tissue growth factor 3 months after renal transplantation predict interstitial fibrosis and tubular atrophy at 5 years in a retrospective cohort analysis

Connective tissue growth factor (CTGF) is an important mediator of renal allograft fibrosis, and urinary CTGF (CTGFu) levels correlate with the development of human allograft interstitial fibrosis. We evaluated the predictive value of CTGF protein expression in 160 kidney transplant recipients with paired protocol biopsies at 3 months and 5 years after transplantation. At month 3 and year 1, CTGFu was measured using ELISA, and biopsies were immunohistochemically stained for CTGF, with semiquantitative scoring of tubulointerstitial CTGF-positive area (CTGFti). Predictors of interstitial fibrosis and tubular atrophy (IF/TA) severity at 5 years were donor age [OR 1.05 (1.02-1.08), P = 0.001], female donor [OR 0.40 (0.18-0.90), P = 0.026], induction therapy [OR 2.76 (1.10-6.89), P = 0.030], and CTGFti >10% at month 3 [OR 2.72 (1.20-6.15), P = 0.016]. In subgroups of patients with little histologic damage at 3 months [either ci score 0 (n = 119), IF/TA score ≤1 (n = 123), or absence of IF/TA, interstitial inflammation, and tubulitis (n = 45)], consistent predictors of progression of chronic histologic damage by 5 years were donor age, induction therapy, CTGFti >10%, and CTGFu. These results suggest that, even in patients with favorable histology at 3 months, significant CTGF expression is often present which may predict accelerated accumulation of histologic damage.

Age-dependent shifts in renal response to injury relate to altered BMP6/CTGF expression and signaling

Age is associated with an increased prevalence of chronic kidney disease (CKD), which, through progressive tissue damage and fibrosis, ultimately leads to loss of kidney function. Although much effort is put into studying CKD development experimentally, age has rarely been taken into account. Therefore, we investigated the effect of age on the development of renal tissue damage and fibrosis in a mouse model of obstructive nephropathy (i.e., unilateral ureter obstruction; UUO). We observed that after 14 days, obstructed kidneys of old mice had more tubulointerstitial atrophic damage but less fibrosis than those of young mice. This was associated with reduced connective tissue growth factor (CTGF), and higher bone morphogenetic protein 6 (BMP6) expression and pSMAD1/5/8 signaling, while transforming growth factor-β expression and transcriptional activity were no different in obstructed kidneys of old and young mice. In vitro, CTGF bound to and inhibited BMP6 activity. In summary, our data suggest that in obstructive nephropathy atrophy increases and fibrosis decreases with age and that this relates to increased BMP signaling, most likely due to higher BMP6 and lower CTGF expression.

TGF-β1 promotes lymphangiogenesis during peritoneal fibrosis

Peritoneal fibrosis (PF) causes ultrafiltration failure (UFF) and is a complicating factor in long-term peritoneal dialysis. Lymphatic reabsorption also may contribute to UFF, but little is known about lymphangiogenesis in patients with UFF and peritonitis. We studied the role of the lymphangiogenesis mediator vascular endothelial growth factor-C (VEGF-C) in human dialysate effluents, peritoneal tissues, and peritoneal mesothelial cells (HPMCs). Dialysate VEGF-C concentration correlated positively with the dialysate-to-plasma ratio of creatinine (D/P Cr) and the dialysate TGF-β1 concentration. Peritoneal tissue from patients with UFF expressed higher levels of VEGF-C, lymphatic endothelial hyaluronan receptor-1 (LYVE-1), and podoplanin mRNA and contained more lymphatic vessels than tissue from patients without UFF. Furthermore, mesothelial cell and macrophage expression of VEGF-C increased in the peritoneal membranes of patients with UFF and peritonitis. In cultured mesothelial cells, TGF-β1 upregulated the expression of VEGF-C mRNA and protein, and this upregulation was suppressed by a TGF-β type I receptor (TGFβR-I) inhibitor. TGF-β1-induced upregulation of VEGF-C mRNA expression in cultured HPMCs correlated with the D/P Cr of the patient from whom the HPMCs were derived (P<0.001). Moreover, treatment with a TGFβR-I inhibitor suppressed the enhanced lymphangiogenesis and VEGF-C expression associated with fibrosis in a rat model of PF. These results suggest that lymphangiogenesis associates with fibrosis through the TGF-β-VEGF-C pathway.

A large inversion in the linear chromosome of Streptomyces griseus caused by replicative transposition of a new Tn3 family transposon

We have comprehensively analyzed the linear chromosomes of Streptomyces griseus mutants constructed and kept in our laboratory. During this study, macrorestriction analysis of AseI and DraI fragments of mutant 402-2 suggested a large chromosomal inversion. The junctions of chromosomal inversion were cloned and sequenced and compared with the corresponding target sequences in the parent strain 2247. Consequently, a transposon-involved mechanism was revealed. Namely, a transposon originally located at the left target site was replicatively transposed to the right target site in an inverted direction, which generated a second copy and at the same time caused a 2.5-Mb chromosomal inversion. The involved transposon named TnSGR was grouped into a new subfamily of the resolvase-encoding Tn3 family transposons based on its gene organization. At the end, terminal diversity of S. griseus chromosomes is discussed by comparing the sequences of strains 2247 and IFO13350.

SCP1, a 356 023 bp linear plasmid adapted to the ecology and developmental biology of its host, Streptomyces coelicolor A3(2)

The sequencing of the entire genetic complement of Streptomyces coelicolor A3(2) has been completed with the determination of the 365,023 bp sequence of the linear plasmid SCP1. Remarkably, the functional distribution of SCP1 genes somewhat resembles that of the chromosome: predicted gene products/functions include ECF sigma factors, antibiotic biosynthesis, a gamma-butyrolactone signalling system, members of the actinomycete-specific Wbl class of regulatory proteins and 14 secreted proteins. Some of these genes are among the 18 that contain a TTA codon, making them targets for the developmentally important tRNA encoded by the bldA gene. RNA analysis and gene fusions showed that one of the TTA-containing genes is part of a large bldA-dependent operon, the gene products of which include three proteins isolated from the spore surface by detergent washing (SapC, D and E), and several probable metabolic enzymes. SCP1 shows much evidence of recombinational interactions with other replicons and transposable elements during its history. For example, it has two sets of partitioning genes (which may explain why an integrated copy of SCP1 partially suppressed the defective partitioning of a parAB-deleted chromosome during sporulation). SCP1 carries a cluster of probable transfer determinants and genes encoding likely DNA polymerase III subunits, but it lacks an obvious candidate gene for the terminal protein associated with its ends. This may be related to atypical features of its end sequences.

Integrated structures of the linear plasmid SCP1 in two bidirectional donor strains of Streptomyces coelicolor A3(2)

The linear plasmid SCP1 is integrated into the central region of the chromosome of Streptomyces coelicolor A3(2). The integrated structures of SCP1 in two bidirectional donor strains, 2612 and A634, were analyzed by cloning and sequencing of the junctions between the SCP1 DNA and the chromosomal DNA. In the NF (normal fertility) strain 2612, SCP1 is integrated in a right-handed direction into ORF-X at the left end of the IS cluster in AseI fragment E. An almost intact left end of SCP1 is retained, while the right terminal inverted repeat (TIR-R) of SCP1 and a 33-kb chromosomal DNA segment including the IS cluster are deleted. In the NF-like strain A634, SCPI is also integrated into AseI fragment E in a left-handed direction. The left junction is composed of IS466 with complete deletion of TIR-R of SCP1, and the right junction is located at the left end of IS468A* with half of TIR-L being deleted. During the integration event, a 5.4-kb chromosomal DNA segment including IS468A, IS468B, IS469 and IS466A was duplicated so that this sequence is now present on both sides of SCP1. Since 2612 and A634 exhibit a similar bidirectional gradient of gene transfer, it is surprising that their chromosomal structures are so different.

Cloning and analysis of the replication origin and the telomeres of the large linear plasmid pSLA2-L in Streptomyces rochei

The replication origin and both terminal segments were cloned from the large linear plasmid pSLA2-L in Streptomyces rochei 7434AN4. The basic replicon consists of a 1.9-kb DNA fragment, which contains the genetic information required for autonomous replication in circular form. Sequence analysis revealed two ORFs, RepL1 and RepL2, with no similarity to any of the replication initiator proteins in the database. Deletion and mutational analysis showed that RepL1 is essential for replication and RepL2 has a subsidiary function. The origin of replication may be located 800 bp upstream of repL1. Sequencing of the left and right terminal segments revealed the presence of 12 palindromes. The sequence of the first 90 bp, including palindromes I-IV, shows great similarity to that of other Streptomyces linear chromosomes and plasmids. These results suggest that the internal replication origins of the linear replicons vary widely, in contrast to the high degree of conservation of their telomeres.

A complex insertion sequence cluster at a point of interaction between the linear plasmid SCP1 and the linear chromosome of Streptomyces coelicolor A3(2)

The giant linear plasmid SCP1 can integrate into the central region of the linear chromosome of Streptomyces coelicolor A3(2). Nucleotide sequence analysis around the target site for SCP1 integration in strain M145 identified a total of five copies of four insertion sequences (ISs) in a 6.5-kb DNA stretch. Three of the four (IS468, IS469, and IS470) are new IS elements, and the other is IS466. All of these elements contain one open reading frame which encodes a transposase-like protein. Two copies of IS468 (IS468A and -B) are tandemly aligned at the left end of the cluster. Following these, IS469 and IS466 are located in a tail-to-tail orientation with 69.3% identity to each other. IS470 is located at the right end of the cluster. The activities of IS466 and IS468 were demonstrated by transposition experiments and sequence comparison of several copies, respectively.

Identification of two polyketide synthase gene clusters on the linear plasmid pSLA2-L in Streptomyces rochei

The 200kb linear plasmid pSLA2-L was suggested to be involved in the production of two macrolide antibiotics, lankamycin (Lm) and lankacidin (Lc), in Streptomyces rochei 7434AN4. Hybridization experiments with the polyketide synthase (PKS) genes for erythromycin and actinorhodin identified two eryAI-homologous regions and an actI-homologous region on pSLA2-L. The nucleotide sequence of a 3.6kb SacI fragment carrying one of the eryAI-homologs revealed that it codes for part of a large protein with four domains for ketoreductase, acyl carrier protein, ketosynthase, and acyltransferase. Gene disruption confirmed that the two eryAI-homologs are parts of a large type-I PKS gene cluster for Lm. A 4.8kb DNA carrying the actI-homologous region contains four open reading frames (ORF1-ORF4) as well as an additional ORF, i.e. ORF5, which might code for a thioesterase. Deletion of the ORF2-ORF4 region showed that it is not involved in the synthesis of Lm or Lc. Thus, it was confirmed that pSLA2-L contains two PKS gene clusters for Lm and an unknown type-II polyketide.