Kidney vascular congestion exacerbates acute kidney injury in mice.

Heart failure is frequently accompanied by kidney failure and co-incidence of these organ failures worsens the mortality in patients with heart failure. Recent clinical observations revealed that increased kidney venous pressure, rather than decreased cardiac output, causes the deterioration of kidney function in patients with heart failure. However, the underlying pathophysiology is unknown. Here, we found that decreased blood flow velocity in peritubular capillaries by kidney congestion and upregulation of endothelial nuclear factor-κB (NF-κB) signaling synergistically exacerbate kidney injury. We generated a novel mouse model with unilateral kidney congestion by constriction of the inferior vena cava between kidney veins. Intravital imaging highlighted the notable dilatation of peritubular capillaries and decreased kidney blood flow velocity in the congestive kidney. Damage after ischemia reperfusion injury was exacerbated in the congestive kidney and accumulation of polymorphonuclear leukocytes within peritubular capillaries was noted at the acute phase after injury. Similar results were obtained in vitro, in which polymorphonuclear leukocytes adhesion on activated endothelial cells was decreased in flow velocity-dependent manner but cancelled by inhibition of NF-κB signaling. Pharmacological inhibition of NF-κB for the mice subjected by both kidney congestion and ischemia reperfusion injury ameliorated the accumulation of polymorphonuclear leukocytes and subsequent exacerbation of kidney injury. Thus, our study demonstrates the importance of decreased blood flow velocity accompanying activated NF-κB signaling in aggravation of kidney injury. Hence, inhibition of NF-κB signaling may be a therapeutic candidate for the vicious cycle between heart and kidney failure with increased kidney venous pressure.

Intratubular epithelial-mesenchymal transition and tubular atrophy after kidney injury in mice.

Tubular atrophy is a common pathological feature of kidney fibrosis. Although fibroblasts play a predominant role in tissue fibrosis, the role of repairing tubular epithelia in tubular atrophy is unclear. We demonstrated the essential role of focal adhesion kinase (FAK)-mediated intratubular epithelial-mesenchymal transition (EMT) in the pathogenesis of tubular atrophy after severe ischemia-reperfusion injury (IRI). Actively proliferating tubular epithelia undergoing intratubular EMT were noted in the acute phase of severe IRI, resulting in tubular atrophy in the chronic phase, reflecting failed tubular repair. Furthermore, FAK was phosphorylated in the tubular epithelia in the acute phase of severe IRI, and its inhibition ameliorated both tubular atrophy and interstitial fibrosis in the chronic phase after injury. In vivo clonal analysis of single-labeled proximal tubular epithelial cells after IRI using proximal tubule reporter mice revealed substantial clonal expansion after IRI, reflecting active epithelial proliferation during repair. The majority of these proliferating epithelia were located in atrophic and nonfunctional tubules, and FAK inhibition was sufficient to prevent tubular atrophy. In vitro, transforming growth factor-ß induced FAK phosphorylation and an EMT phenotype, which was also prevented by FAK inhibition. In an in vitro tubular epithelia gel contraction assay, transforming growth factor-ß treatment accelerated gel contraction, which was suppressed by FAK inhibition. In conclusion, injury-induced intratubular EMT is closely related to tubular atrophy in a FAK-dependent manner.

Antibody-mediated pure red cell aplasia related with epoetin-beta pegol (C.E.R.A.) as an erythropoietic agent: case report of a dialysis patient.

BACKGROUND: Erythropoietin-stimulating agents (ESAs) are used to treat anemia in patients with chronic kidney disease, enabling maintenance of stable hemoglobin levels and eliminating the need for multiple transfusions. Epoetin-beta pegol (C.E.R.A.) is a continuous erythropoietin receptor activator created by integrating a large methoxy-polyethylene-glycol-polymer chain into the erythropoietin molecule, which provides it with a longer half-life. On rare occasions, cases of antibody-mediated pure red cell aplasia (PRCA) related to ESAs are reported. They are characterized by abrupt onset of severe transfusion-dependent anemia, despite ESA therapy. We herein report a case of antibody-mediated PRCA in a dialysis patient receiving C.E.R.A. CASE PRESENTATION: A 44-year-old man with end-stage renal failure had been receiving continuous ambulatory peritoneal dialysis for 2 years. C.E.R.A. was administered subcutaneously as a sole ESA once a month at the hospital since 4 years ago for the treatment of renal anemia and his hemoglobin level was well controlled at 12 g/dl. From 10 months before diagnosis, however, his hemoglobin level suddenly declined, necessitating frequent transfusions. Based on the results of a bone marrow examination and detection of anti-C.E.R.A. antibodies, the patient was diagnosed with antibody-mediated PRCA. After successful elimination of the antibodies using oral prednisolone plus cyclosporine, the patient was re-administrated C.E.R.A. intravenously, as there are few reports of antibody-mediated PRCA related to ESA using that administration route. He responded to the C.E.R.A., and his anemia dramatically improved, eliminating the need for blood transfusions. CONCLUSIONS: This is the first reported case of recovery from an antibody-mediated PRCA with C.E.R.A. after its re-administration following a reversal of the antibody. It has been suggested that the additional large pegylation chain makes C.E.R.A. less likely to trigger antibody generation than other ESAs. Following successful treatment of antibody-mediated PRCA using immunosuppressive therapy, C.E.R.A. can be re-administered intravenously to treat renal anemia.

IgA nephropathy in a patient receiving infliximab for generalized pustular psoriasis.

BACKGROUND: IgA nephropathy is the most common glomerulonephritis. Secondary IgA nephropathy complicated with systemic diseases, including psoriasis, is also often reported. Generalized pustular psoriasis is a form of psoriasis characterized by sterile pustules on reddened skin and fever. Infliximab, one of the first-line therapies for severe psoriasis, has also been reported to cause systemic vasculitis and IgA nephropathy. We herein report a case of IgA nephropathy activated during infliximab treatment for generalized pustular psoriasis. CASE PRESENTATION: A 28-year-old woman presented with episodic gross hematuria, increasing proteinuria, and renal dysfunction. She had been receiving anti-TNFα therapy with infliximab because of generalized pustular psoriasis for 3 years, but her skin symptoms worsened following withdrawal during pregnancy. After delivery, her skin symptoms improved with the resumption of infliximab, but clinical signs suggested glomerulonephritis, and renal biopsy showed active IgA nephropathy. Infliximab was discontinued, and the combination of corticosteroids, tonsillectomy, and secukinumab, an IL-17A inhibitor, improved both the skin symptoms and the glomerulonephritis. CONCLUSIONS: In our case, the activity of IgA nephropathy was exacerbated by anti-TNFα therapy but was improved by the combination of corticosteroids, tonsillectomy, and an IL-17A inhibitor against the original disease. Autoimmune diseases may underlie the development of secondary IgA nephropathy associated with anti-TNFα therapy, and so further studies are needed to better understand the association between molecular-targeted drugs and IgA nephropathy.

Association between preexisting lung involvements and the risk of diffuse alveolar hemorrhage in patients with microscopic polyangiitis: A multi-center retrospective cohort study.

Objectives: To identify the factors associated with the risk of diffuse alveolar hemorrhage (DAH) in patients with microscopic polyangiitis (MPA), focusing on other preexisting lung involvements such as interstitial lung disease (ILD) and airway disease.Methods: In this retrospective cohort study, we analyzed consecutive patients with myeloperoxidase-antineutrophil cytoplasmic antibody-positive MPA who had undergone chest computed tomography (CT) before starting treatment between 2006 and 2016. Patients who already had DAH at initial CT imaging were excluded. CT images were evaluated for the presence of ILD and airway disease. The association between preexisting lung involvements and the development of DAH was assessed using logistic regression models adjusted for various clinical characteristics.Results: We identified 113 patients (median age 72 years; median follow-up duration 39 months), and 27 (24%) of them developed DAH during the follow-up. Airway disease was identified in 41 (36%) patients and was independently associated with the development of DAH (adjusted odds ratio 6.86, 95% confidence interval 1.85-25.4). However, ILD identified in 45 (40%) patients was not associated with DAH.Conclusion: Our findings suggest that DAH in MPA occurs frequently in patients with airway disease. Attention to preexisting airway disease may help predict the development of DAH.

Clinicopathological analysis of ANCA-associated glomerulonephritis focusing on plasma cell infiltrate.

BACKGROUND: When we encounter glomerulonephritis of antineutrophil cytoplasmic antibody (ANCA)-associated vasculitides demonstrating many plasma cell infiltrations, histological overlapping of immunoglobulin G4-related disease (IgG4-RD) often comes into the differential diagnosis. No previous study has focused on the degree of plasma cells in the kidney infiltrate in ANCA-associated glomerulonephritis (ANCA-GN), and the significance of massive plasma cell infiltrate has not been investigated. METHODS: To clarify the plasma cell ratio in renal biopsy specimens of ANCA-GN and the histological characteristic of "plasma cell-rich" ANCA-GN, 20 cases of ANCA-GN were reviewed and clinicopathologically analyzed. RESULTS: Plasma cell ratio was widely distributed between 1.4 and 81%, and the median ratio was 10%. Three patients were categorized in "plasma cell-rich" ANCA-GN, defined as over 45% plasma cell ratio. They tended to include many active glomerular lesions compared to chronic lesions and to display severe tubulointerstitial inflammation. It is suggested that plasma cell-rich ANCA-GN may be acute onset of the disease, and the target of early inflammation may also be in the tubulointerstitial region. Two of the three plasma cell-rich ANCA-GN cases demonstrated numerous IgG4+ cells, but no bird's-eye pattern fibrosis or obliterative phlebitis. CONCLUSIONS: Plasma cell-rich ANCA-GN is not rare and demonstrates distinct clinicopathological characteristics. This study also reminds us that the presence of the significant number of plasma cells in ANCA-GN, as such, is not a histological diagnostic basis for overlap ANCA-GN and IgG4-related disease.

Impact of salt taste dysfunction on interdialytic weight gain for hemodialysis patients; a cross-sectional study.

BACKGROUND: Little is known about salt taste dysfunction among hemodialysis (HD) patients. This study aimed to elucidate the prevalence of salt taste dysfunction and its relationship with interdialytic weight gain (IDWG) among HD patients. METHODS: A single-center cross-sectional study involving 99 maintenance HD patients was conducted in September 2015. Salt taste threshold was measured using a salt-impregnated test strip. Salt taste dysfunction was defined as a recognition threshold of ≥0.8%. IDWG was calculated as the mean value of weight gain at the beginning of each week during a 1-month period before the taste test. We performed a multivariate analysis using the standard linear regression model to investigate the association between salt taste dysfunction and IDWG. RESULTS: Among the 99 participants, 42% had a recognition threshold of 0.6%, whereas 38% had a recognition threshold of ≥1.6%. Overall, the prevalence of salt taste dysfunction was 58%. The mean (±SD) IDWG was 4.9% (±1.7%), and there was no significant difference in IDWG between the two groups with (4.9%) and without (4.8%) salt taste dysfunction (P = 0.90). A multivariate analysis indicated that salt taste dysfunction is not significantly associated with IDWG (mean difference = 0.06; 95% confidence interval = - 0.27 to 0.40). CONCLUSIONS: The prevalence of salt taste dysfunction was very high among HD patients who had a unique distribution of salt taste recognition thresholds with two peaks. We found no significant association between salt taste dysfunction and IDWG.

Detection of Splicing Abnormalities and Genotype-Phenotype Correlation in X-linked Alport Syndrome.

BACKGROUND: X-linked Alport syndrome (XLAS) is a progressive hereditary nephropathy caused by mutations in the COL4A5 gene. Genotype-phenotype correlation in male XLAS is relatively well established; relative to truncating mutations, nontruncating mutations exhibit milder phenotypes. However, transcript comparison between XLAS cases with splicing abnormalities that result in a premature stop codon and those with nontruncating splicing abnormalities has not been reported, mainly because transcript analysis is not routinely conducted in patients with XLAS. METHODS: We examined transcript expression for all patients with suspected splicing abnormalities who were treated at one hospital between January of 2006 and July of 2017. Additionally, we recruited 46 males from 29 families with splicing abnormalities to examine genotype-phenotype correlation in patients with truncating (n=21, from 14 families) and nontruncating (n=25, from 15 families) mutations at the transcript level. RESULTS: We detected 41 XLAS families with abnormal splicing patterns and described novel XLAS atypical splicing patterns (n=14) other than exon skipping caused by point mutations in the splice consensus sequence. The median age for developing ESRD was 20 years (95% confidence interval, 14 to 23 years) among patients with truncating mutations and 29 years (95% confidence interval, 25 to 40 years) among patients with nontruncating mutations (P=0.001). CONCLUSIONS: We report unpredictable atypical splicing in the COL4A5 gene in male patients with XLAS and reveal that renal prognosis differs significantly for patients with truncating versus nontruncating splicing abnormalities. Our results suggest that splicing modulation should be explored as a therapy for XLAS with truncating mutations.

Lower blood pressure and risk of cisplatin nephrotoxicity: a retrospective cohort study.

BACKGROUND: The pathophysiological mechanisms of cisplatin nephrotoxicity include the reduction of renal blood flow, as well as tubular epithelial cell toxicity. The objective of this study was to investigate the influence of lower blood pressure and decreased food intake on the incidence of cisplatin nephrotoxicity. METHODS: We conducted a retrospective cohort study at a university hospital between 2011 and 2012. We identified hospitalized adult patients with head and neck cancer, esophageal cancer, or gastric cancer, who received intravenous cisplatin administration. The primary outcome was the incidence of cisplatin nephrotoxicity defined as the increase in serum creatinine after cisplatin administration more than 1.5 times from baseline. RESULTS: The study participants included 182 patients, in whom we observed a total of 442 cycles of cisplatin chemotherapy. The incidence of cisplatin nephrotoxicity was observed in 41 of 182 cycles with initial administration. Multivariate logistic regression analysis showed that systolic blood pressure was independently associated with cisplatin nephrotoxicity (adjusted odds ratio 0.75, 95% confidence interval 0.57 to 0.95 for each 10 mmHg). The use of renin-angiotensin system (RAS) inhibitors was also associated with cisplatin nephrotoxicity (3.39, 1.30 to 8.93). Among quartiles of systolic blood pressure in all cycles of chemotherapy, the incidence of nephrotoxicity in the lower blood pressure group was significantly higher than that in the higher blood pressure group for patients taking non-solid food (P = 0.037), while there was no significant difference for patients taking solid food (P = 0.67). CONCLUSIONS: Lower blood pressure and the use of RAS inhibitors were associated with the incidence of cisplatin nephrotoxicity, and lower blood pressure had a greater influence on nephrotoxicity in patients who could not take solid food. Discontinuation of antihypertensive medication including RAS inhibitors before cisplatin chemotherapy should be considered, which may be beneficial for patients with lower blood pressure.

A Case of the nephrotic syndrome in bone marrow transplantation recipient, histologically showing overlapped glomerular lesions of thrombotic microangiopathy and membranous nephropathy.

Nephrotic syndrome (NS) rarely occurs in post-hematopoietic stem cell transplantation (HSCT) recipients but represents the renal manifestation of graft-versus-host disease (GVHD). Membranous nephropathy (MN) accounts for almost two thirds of post-HSCT NS and is caused by immune complex deposition. Renal thrombotic microangiopathy (TMA) without fulfillment of clinical criteria for TMA has been underreported because of reduced opportunity for histological examination. However, renal TMA has recently been reported in association with GVHD and humoral immunological reactions. Although both MN and TMA after HSCT are associated with GVHD and immunological abnormalities, these diseases are exceptionally coexistent in renal biopsy specimens. We herein describe a case of post-HSCT NS, histologically showing overlapped lesions of TMA and MN. Renal biopsy specimen after presentation of NS revealed early stage MN and TMA with evidence of chronicity. TMA was thought to have preceded MN, and renal biopsy at the phase of pre-nephrotic proteinuria might reveal earlier histological changes of isolated renal TMA. Detection of subclinical renal TMA earlier by spontaneous renal biopsy can help prevent progression of renal injury or overlapping of other renal pathologies. We also demonstrated Th2 predominant intraglomerular infiltration of lymphocytes by immunohistochemistry.

Steroid-resistant nephrotic syndrome as the initial presentation of nail-patella syndrome: a case of a de novo LMX1B mutation.

BACKGROUND: Nail-patella syndrome (NPS) is an autosomal dominant disorder caused by mutations in the LMX1B gene and is characterized by nail dysplasia, skeletal abnormalities, and nephropathy. We herein report a case of steroid-resistant nephrotic syndrome (SRNS) prior to overt orthopedic symptoms in a patient with NPS. CASE PRESENTATION: A 24-year-old woman presented to our hospital with knee pain. She had poorly developed nails, hypoplastic patellas, dislocation of the elbows, and iliac horns in the pelvis. At the age of 7, she developed nephrotic syndrome and was diagnosed with primary focal segmental glomerulosclerosis by renal biopsy. She received long-term corticosteroid therapy with no obvious response. Her clinical course and orthopedic manifestations indicated NPS, and a genetic analysis showed a de novo mutation in the LMX1B gene (c.819 + 1G > A). Nephropathy in this case was considered to be associated with NPS. Therefore, we discontinued corticosteroids without the exacerbation of nephrotic syndrome. CONCLUSIONS: Patients with NPS may develop nephrotic syndrome prior to overt orthopedic symptoms and only show non-specific findings in renal biopsy at an early stage of NPS nephropathy. Hereditary nephrotic syndrome, often presenting as childhood-onset SRNS, may also be difficult to diagnose in patients with the following conditions: renal symptoms prior to overt extrarenal symptoms, de novo mutations, and non-specific findings in renal biopsy. Therefore, in the management of SRNS in children, we need to reconsider the possibility of hereditary diseases such as NPS even without a family history.

Renal artery stenosis following nilotinib administration in a patient with chronic myelogenous leukemia.

A 63-year-old male was diagnosed as having chronic phase CML in 2001. He obtained a major molecular response with imatinib (IM). In 2012, amulodipin was started for hypertension. In January 2013, IM was switched to nilotinib (NIL) in a clinical trial, and in February 2015, NIL was discontinued because MR4.5 had been maintained for two years. One month later, he was admitted to our hospital because of headache and high blood pressure (194/108 mmHg). His urine test showed protein 3+ and occult blood 2+. His eGFR rapidly deteriorated from 45.6 to 28.5 after admission. MR angiography showed left renal artery stenosis. He thus underwent angioplasty of the left renal artery with a stent implantation. His renal function subsequently improved. Cardiovascular events such as PAOD (peripheral artery occlusive disease) during NIL treatment were recently reported. However, to date, only four cases including our present patient with renal artery stenosis associated with NIL have been reported. These observations suggest assessment of risk factors for cardiovascular events at the start of NIL and careful monitoring to be important during tyrosine kinase inhibitor treatment of CML patients.

Aversion to a High Salt Taste is Disturbed in Patients With CKD.

Introduction: A reduced salt intake is a vital lifestyle modification in the management of hypertension. Initiatives aimed at decreasing the intake of salt are based on the preference by humans for a salt taste. Salt intake behavior appears to be affected by the balance between attraction to a low salt taste and aversion to a high salt taste. However, aversion to a high salt taste has not yet been quantitively investigated in both healthy individuals and patients with chronic kidney disease (CKD). Methods: Assessments of gustatory and aversion thresholds for salt, bitter, sour, and sweet tastes were performed using a stimulant-impregnated test strip in healthy subjects and patients with CKD. Results: In a pilot taste test of 125 healthy subjects, the number of participants with an aversive reaction increased at higher salt concentrations. The threshold for normal taste perception was arbitrarily defined as 10% NaCl, with 47.2% of healthy subjects displaying an aversive reaction. In taste tests performed by 70 patients with CKD, 10% were unable to recognize a salt taste, even at the highest concentration (20% NaCl), suggesting a significant impairment in taste perception in patients with CKD. Only 15.7% of patients with CKD exhibited a normal aversion to NaCl, whereas 78.6% showed the complete loss of aversion to salt. Conclusion: The present results confirmed the anticipated aversive response to a high salt taste in humans and demonstrated its impairment in patients with CKD, implying that patients with CKD have reduced resistance to a high salt intake.

The importance of proinflammatory failed-repair tubular epithelia as a predictor of diabetic kidney disease progression.

The immense public health burden of diabetic kidney disease (DKD) has led to an increase in research on the pathophysiology of advanced DKD. The present study focused on the significance of proinflammatory vascular cell adhesion molecule 1 (VCAM1)+ tubules in DKD progression. A retrospective cohort study of DKD patients showed that the percentage of VCAM1+ tubules in kidney samples was correlated with poor renal outcomes. We established an advanced DKD model by partial resection of the kidneys of db/db mice and demonstrated that it closely resembled the human advanced DKD phenotype, with tissue hypoxia, tubular DNA damage, tissue inflammation, and high tubular VCAM1 expression. Luseogliflozin ameliorated tissue hypoxia and proinflammatory responses, including VCAM1+ expression, in tubules. These findings suggest the potential of tubular VCAM1 as a histological marker for poor DKD outcomes. SGLT2 inhibitors may attenuate tissue hypoxia and subsequent tissue inflammation in advanced DKD, thereby ameliorating tubular injury.

Evaluation of postoperative nephrolithiasis and renal dysfunction in gastric cancer patients.

BACKGROUND: Roux-en-Y (R-Y) gastric bypass, also known as bariatric surgery, sometimes causes postoperative hyperoxaluria and subsequent oxalate nephrolithiasis in obese patients. In this study, we retrospectively investigated the frequency of occurrence of nephrolithiasis and renal dysfunction in postoperative gastric cancer patients with respect to the surgical procedures employed. METHODS: Two hundred and twenty-six consecutive gastric cancer patients, who underwent distal gastrectomy with Billroth-I reconstruction (DGBI, 60 patients), distal gastrectomy with R-Y reconstruction (DGRY, 81 patients), and total gastrectomy with R-Y reconstruction (TGRY, 85 patients), were investigated for postoperative nephrolithiasis and renal dysfunction. We also examined the risk factors for postoperative nephrolithiasis in these patients with gastric cancer. RESULTS: Nephrolithiasis was detected in 3 (5%), 7 (9%), and 21 (25%) patients in the DGBI, DGRY, and TGRY groups, respectively. There were significant differences in the frequency of nephrolithiasis between the DGBI and TGRY groups (p = 0.004), and between the DGRY and TGRY groups (p = 0.011), but there was no significant difference between the DGBI and DGRY groups. Multivariate logistic regression analysis revealed that gender and extent of gastrectomy were independent risk factors associated with nephrolithiasis. Renal dysfunction was found in 5 patients (6%) in the TGRY group, but was not found in either the DGBI or the DGRY group. Nephrolithiasis was detected in all these 5 patients, and a renal biopsy performed in one patient revealed the presence of intratubular calcium oxalate crystals with chronic tubulointerstitial nephritis. CONCLUSION: Total gastrectomy with R-Y reconstruction was an independent predictive factor for nephrolithiasis in patients with gastric cancer.

Prognostic utility of plasma S100A12 levels to establish a novel scoring system for predicting mortality in maintenance hemodialysis patients: a two-year prospective observational study in Japan.

BACKGROUND: S100A12 protein is an endogenous receptor ligand for advanced glycation end products. In this study, the plasma S100A12 level was assessed as an independent predictor of mortality, and its utility in clinical settings was examined. METHODS: In a previous cross-sectional study, plasma S100A12 levels were measured in 550 maintenance hemodialysis patients to determine the association between S100A12 and the prevalence of cardiovascular diseases (CVD). In this prospective study, the risk of mortality within a two-year period was determined. An integer scoring system was developed to predict mortality on the basis of the plasma S100A12 levels. RESULTS: Higher plasma S100A12 levels (≥18.79 ng/mL) were more closely associated with higher all-cause mortality than lower plasma S100A12 levels (<18.79 ng/mL; P = 0.001). Multivariate Cox proportional hazards analysis revealed higher plasma S100A12 levels [hazard ratio (HR), 2.267; 95% confidence interval (CI), 1.195-4.302; P = 0.012], age ≥65 years (HR, 1.961; 95%CI, 1.017-3.781; P = 0.044), serum albumin levels <3.5 g/dL (HR, 2.198; 95%CI, 1.218-3.968; P = 0.012), and history of CVD (HR, 2.068; 95%CI, 1.146-3.732; P = 0.016) to be independent predictors of two-year all-cause mortality. The integer score was derived by assigning points to these factors and determining total scores. The scoring system revealed trends across increasing scores for predicting the all-cause mortality [c-statistic = 0.730 (0.656-0.804)]. The resulting model demonstrated good discriminative power for distinguishing the validation population of 303 hemodialysis patients [c-statistic = 0.721 (0.627-0.815)]. CONCLUSION: The results indicate that plasma S100A12 level is an independent predictor for two-year all-cause mortality. A simple integer scoring system was therefore established for predicting mortality on the basis of plasma S100A12 levels.

Streptozotocin induces renal proximal tubular injury through p53 signaling activation.

Streptozotocin (STZ), an anti-cancer drug that is primarily used to treat neuroendocrine tumors (NETs) in clinical settings, is incorporated into pancreatic ß-cells or proximal tubular epithelial cells through the glucose transporter, GLUT2. However, its cytotoxic effects on kidney cells have been underestimated and the underlying mechanisms remain unclear. We herein demonstrated that DNA damage and subsequent p53 signaling were responsible for the development of STZ-induced tubular epithelial injury. We detected tubular epithelial DNA damage in NET patients treated with STZ. Unbiased transcriptomics of STZ-treated tubular epithelial cells in vitro showed the activation of the p53 signaling pathway. STZ induced DNA damage and activated p53 signaling in vivo in a dose-dependent manner, resulting in reduced membrane transporters. The pharmacological inhibition of p53 and sodium-glucose transporter 2 (SGLT2) mitigated STZ-induced epithelial injury. However, the cytotoxic effects of STZ on pancreatic ß-cells were preserved in SGLT2 inhibitor-treated mice. The present results demonstrate the proximal tubular-specific cytotoxicity of STZ and the underlying mechanisms in vivo. Since the cytotoxic effects of STZ against ß-cells were not impaired by dapagliflozin, pretreatment with an SGLT2 inhibitor has potential as a preventative remedy for kidney injury in NET patients treated with STZ.

A multi-institutional, observational study of outcomes after catheter placement for peritoneal dialysis in Japan.

BACKGROUND: This multi-institutional, observational study examined whether the outcomes after peritoneal dialysis (PD) catheter placement in Japan meet the audit criteria of the International Society for Peritoneal Dialysis (ISPD) guideline and identified factors affecting technique survival and perioperative complications. METHODS: Adult patients who underwent first PD catheter placement for end-stage kidney disease between April 2019 and March 2021 were followed until PD withdrawal, kidney transplantation, transfer to other facilities, death, 1 year after PD start or March 2022, whichever came first. Primary outcomes were time to catheter patency failure and technique failure, and perioperative infectious complications within 30 days of catheter placement. Secondary outcomes were perioperative complications. Appropriate statistical analyses were performed to identify factors associated with the outcomes of interest. RESULTS: Of the total 409 patients, 8 who underwent the embedded catheter technique did not have externalised catheters. Of the 401 remaining patients, catheter patency failure occurred in 25 (6.2%). Technical failure at 12 months after PD catheter placement calculated from cumulative incidence function was 15.3%. On Cox proportional hazards model analysis, serum albumin (hazard ratio (HR) 0.44; 95% confidence interval (CI) 0.27-0.70) and straight type catheter (HR 2.14; 95% CI 1.24-3.69) were the independent risk factors for technique failure. On logistic regression analysis, diabetes mellitus was the only independent risk factor for perioperative infectious complications (odds ratio 2.70, 95% CI 1.30-5.58). The occurrence rate of perioperative complications generally met the audit criteria of the ISPD guidelines. CONCLUSION: PD catheter placement in Japan was proven to be safe and appropriate.