Low levels of circulating methylated IRX3 are related to worse outcome after transcatheter aortic valve implantation in patients with severe aortic stenosis.

BACKGROUND: Aortic stenosis (AS) is one of the most common cardiac diseases and major cause of morbidity and mortality in the elderly. Transcatheter aortic valve implantation (TAVI) is performed in such patients with symptomatic severe AS and reduces mortality for the majority of these patients. However, a significant percentage dies within the first two years after TAVI, such that there is an interest to identify parameters, which predict outcome and could guide pre-TAVI patient selection. High levels of cardiac fibrosis have been identified as such independent predictor of cardiovascular mortality after TAVI. Promoter hypermethylation commonly leads to gene downregulation, and the Iroquois homeobox 3 (IRX3) gene was identified in a genome-wide transcriptome and methylome to be hypermethylated and downregulated in AS patients. In a well-described cohort of 100 TAVI patients in which cardiac fibrosis levels were quantified histologically in cardiac biopsies, and which had a follow-up of up to two years, we investigated if circulating methylated DNA of IRX3 in the peripheral blood is associated with cardiac fibrosis and/or mortality in AS patients undergoing TAVI and thus could serve as a biomarker to add information on outcome after TAVI. RESULTS: Patients with high levels of methylation in circulating IRX3 show a significantly increased survival as compared to patients with low levels of IRX3 methylation indicating that high peripheral IRX3 methylation is associated with an improved outcome. In the multivariable setting, peripheral IRX3 methylation acts as an independent predictor of all-cause mortality. While there is no significant correlation of levels of IRX3 methylation with cardiac death, there is a significant but very weak inverse correlation between circulating IRX3 promoter methylation level and the amount of cardiac fibrosis. Higher levels of peripheral IRX3 methylation further correlated with decreased cardiac IRX3 expression and vice versa. CONCLUSIONS: High levels of IRX3 methylation in the blood of AS patients at the time of TAVI are associated with better overall survival after TAVI and at least partially reflect myocardial IRX3 expression. Circulating methylated IRX3 might aid as a potential biomarker to help guide both pre-TAVI patient selection and post-TAVI monitoring.

Elimination of oncogenic KRAS in genetic mouse models eradicates pancreatic cancer by inducing FAS-dependent apoptosis by CD8+ T cells.

Oncogenic KRASG12D (KRAS∗) is critical for the initiation and maintenance of pancreatic ductal adenocarcinoma (PDAC) and is a known repressor of tumor immunity. Conditional elimination of KRAS∗ in genetic mouse models of PDAC leads to the reactivation of FAS, CD8+ T cell-mediated apoptosis, and complete eradication of tumors. KRAS∗ elimination recruits activated CD4+ and CD8+ T cells and promotes the activation of antigen-presenting cells. Mechanistically, KRAS∗-mediated immune evasion involves the epigenetic regulation of Fas death receptor in cancer cells, via methylation of its promoter region. Furthermore, analysis of human RNA sequencing identifies that high KRAS expression in PDAC tumors shows a lower proportion of CD8+ T cells and demonstrates shorter survival compared with tumors with low KRAS expression. This study highlights the role of CD8+ T cells in the eradication of PDAC following KRAS∗ elimination and provides a rationale for the combination of KRAS∗ targeting with immunotherapy to control PDAC.

Single-cell analysis of senescent epithelia reveals targetable mechanisms promoting fibrosis.

Progressive fibrosis and maladaptive organ repair result in significant morbidity and millions of premature deaths annually. Senescent cells accumulate with aging and after injury and are implicated in organ fibrosis, but the mechanisms by which senescence influences repair are poorly understood. Using 2 murine models of injury and repair, we show that obstructive injury generated senescent epithelia, which persisted after resolution of the original injury, promoted ongoing fibrosis, and impeded adaptive repair. Depletion of senescent cells with ABT-263 reduced fibrosis in reversed ureteric obstruction and after renal ischemia/reperfusion injury. We validated these findings in humans, showing that senescence and fibrosis persisted after relieved renal obstruction. We next characterized senescent epithelia in murine renal injury using single-cell RNA-Seq. We extended our classification to human kidney and liver disease and identified conserved profibrotic proteins, which we validated in vitro and in human disease. We demonstrated that increased levels of protein disulfide isomerase family A member 3 (PDIA3) augmented TGF-ß-mediated fibroblast activation. Inhibition of PDIA3 in vivo significantly reduced kidney fibrosis during ongoing renal injury and as such represented a new potential therapeutic pathway. Analysis of the signaling pathways of senescent epithelia connected senescence to organ fibrosis, permitting rational design of antifibrotic therapies.

Oncogenic collagen I homotrimers from cancer cells bind to α3ß1 integrin and impact tumor microbiome and immunity to promote pancreatic cancer.

In contrast to normal type I collagen (Col1) heterotrimer (α1/α2/α1) produced by fibroblasts, pancreatic cancer cells specifically produce unique Col1 homotrimer (α1/α1/α1). Col1 homotrimer results from epigenetic suppression of the Col1a2 gene and promotes oncogenic signaling, cancer cell proliferation, tumor organoid formation, and growth via α3ß1 integrin on cancer cells, associated with tumor microbiome enriched in anaerobic Bacteroidales in hypoxic and immunosuppressive tumors. Deletion of Col1 homotrimers increases overall survival of mice with pancreatic ductal adenocarcinoma (PDAC), associated with reprograming of the tumor microbiome with increased microaerophilic Campylobacterales, which can be reversed with broad-spectrum antibiotics. Deletion of Col1 homotrimers enhances T cell infiltration and enables efficacy of anti-PD-1 immunotherapy. This study identifies the functional impact of Col1 homotrimers on tumor microbiome and tumor immunity, implicating Col1 homotrimer-α3ß1 integrin signaling axis as a cancer-specific therapeutic target.

Calreticulin Shortage Results in Disturbance of Calcium Storage, Mitochondrial Disease, and Kidney Injury.

Renal Ca2+ reabsorption plays a central role in the fine-tuning of whole-body Ca2+ homeostasis. Here, we identified calreticulin (Calr) as a missing link in Ca2+ handling in the kidney and showed that a shortage of Calr results in mitochondrial disease and kidney pathogenesis. We demonstrated that Calr+/- mice displayed a chronic physiological low level of Calr and that this was associated with progressive renal injury manifested in glomerulosclerosis and tubulointerstitial damage. We found that Calr+/- kidney cells suffer from a disturbance in functionally active calcium stores and decrease in Ca2+ storage capacity. Consequently, the kidney cells displayed an abnormal activation of Ca2+ signaling and NF-κB pathways, resulting in inflammation and wide progressive kidney injury. Interestingly, the disturbance in the Ca2+ homeostasis and signaling in Calr+/- kidney mice cells triggered severe mitochondrial disease and aberrant mitophagy, resulting in a high level of oxidative stress and energy shortage. These findings provide novel mechanistic insight into the role of Calr in kidney calcium handling, function, and pathogenesis.

PP2A phosphatase inhibition is anti-fibrotic through Ser77 phosphorylation-mediated ARNT/ARNT homodimer formation.

Aryl hydrocarbon receptor nuclear translocator (ARNT) mediates anti-fibrotic activity in kidney and liver through induction of ALK3-receptor expression and subsequently increased Smad1/5/8 signaling. While expression of ARNT can be pharmacologically induced by sub-immunosuppressive doses of FK506 or by GPI1046, its anti-fibrotic activity is only realized when ARNT-ARNT homodimers form, as opposed to formation of ARNT-AHR or ARNT-HIF1α heterodimers. Mechanisms underlying ARNTs dimerization decision to specifically form ARNT-ARNT homodimers and possible cues to specifically induce ARNT homodimerization have been previously unknown. Here, we demonstrate that phosphorylation of the Ser77 residue is critical for ARNT-ARNT homodimer formation and stabilization. We further demonstrate that inhibition of PP2A phosphatase activity by LB100 enhances ARNT-ARNT homodimers both in vivo and in vitro (mouse tubular epithelial cells and human embryonic kidney cells). In murine models of kidney fibrosis, and also of liver fibrosis, combinations of FK506 or GPI1046 (to induce ARNT expression) with LB100 (to enhance ARNT homodimerization) elicit additive anti-fibrotic activities. Our study provides additional evidence for the anti-fibrotic activity of ARNT-ARNT homodimers and reveals Ser77 phosphorylation as a novel pharmacological target to realize the therapeutic potential of increased ARNT transactivation activity.

Different Patterns of Kidney Fibrosis Are Indicative of Injury to Distinct Renal Compartments.

Kidney fibrosis is a common manifestation and hallmark of a wide variety of chronic kidney disease (CKD) that appears in different morphological patterns, suggesting distinct pathogenic causes. Broad macroscopically visible scars are the sequelae of severe focal injury and complete parenchymal destruction, reflecting a wound healing response as a consequence of infarction. In the kidney, chronic glomerular injury leads to atrophy of the corresponding tubule, degeneration of this specific nephron, and finally interstitial fibrosis/tubular atrophy (IF/TA). Compared to this glomerulus-induced focal replacement scar, diffuse fibrosis independent of tubular atrophy appears to be a different pathogenic process. Kidney fibrosis appears to develop in a compartment-specific manner, but whether focal and diffuse fibrosis has distinct characteristics associated with other glomerular or tubulointerstitial lesions remains elusive. In the present study, we aimed to analyze renal fibrotic patterns related to renal lesions, which directly contribute to renal fibrogenesis, to unravel fibrotic patterns and manifestations upon damage to distinct renal compartments. Patterns of kidney fibrosis were analyzed in experimental models of CKD and various renal pathologies in correlation with histopathological and ultrastructural findings. After the induction of isolated crescentic glomerulonephritis (GN) in nephrotoxic serum-nephritis (NTN), chronic glomerular damage resulted in predominantly focal fibrosis adjacent to atrophic tubules. By contrast, using unilateral ureteral obstruction (UUO) as a model of primary injury to the tubulointerstitial compartment revealed diffuse fibrosis as the predominant pattern of chronic lesions. Finally, folic acid-induced nephropathy (FAN) as a model of primary tubular injury with consecutive tubular atrophy independent of chronic glomerular damage equally induced predominant focal IF/TA. By analyzing several renal pathologies, our data also suggest that focal and diffuse fibrosis appear to contribute as chronic lesions in the majority of human renal disease, mainly being present in antineutrophil cytoplasmic antibody (ANCA)-associated GN, lupus nephritis, and IgA nephropathy (IgAN). Focal IF/TA correlated with glomerular damage and irreversible injury to nephrons, whereas diffuse fibrosis in ANCA GN was associated explicitly with interstitial inflammation independent of glomerular damage and nephron loss. Ultrastructural analysis of focal IF/TA versus diffuse fibrosis revealed distinct matrix compositions, further supported by different collagen signatures in transcriptome datasets. With regard to long-term renal outcome, only the extent of focal IF/TA correlated with the development of end-stage kidney disease (ESKD) in ANCA GN. In contrast, diffuse kidney fibrosis did not associate with the long-term renal outcome. In conclusion, we here provide evidence that a focal pattern of kidney fibrosis seems to be associated with nephron loss and replacement scarring. In contrast, a diffuse pattern of kidney fibrosis appears to result from primary interstitial inflammation and injury.

Calreticulin Deficiency Disturbs Ribosome Biogenesis and Results in Retardation in Embryonic Kidney Development.

Nephrogenesis is driven by complex signaling pathways that control cell growth and differentiation. The endoplasmic reticulum chaperone calreticulin (Calr) is well known for its function in calcium storage and in the folding of glycoproteins. Its role in kidney development is still not understood. We provide evidence for a pivotal role of Calr in nephrogenesis in this investigation. We show that Calr deficiency results in the disrupted formation of an intact nephrogenic zone and in retardation of nephrogenesis, as evidenced by the disturbance in the formation of comma-shaped and s-shaped bodies. Using proteomics and transcriptomics approaches, we demonstrated that in addition to an alteration in Wnt-signaling key proteins, embryonic kidneys from Calr-/- showed an overall impairment in expression of ribosomal proteins which reveals disturbances in protein synthesis and nephrogenesis. CRISPR/cas9 mediated knockout confirmed that Calr deficiency is associated with a deficiency of several ribosomal proteins and key proteins in ribosome biogenesis. Our data highlights a direct link between Calr expression and the ribosome biogenesis.

Cytokine adsorption therapy in lymphoma-associated hemophagocytic lymphohistiocytosis and allogeneic stem cell transplantation.

Lymphoma-associated Hemophagocytic lymphohistiocytosis (HLH) represents a severe complication of disease progression, mediated through cytokine release from the lymphoma cells. Cytokine adsorption may contribute as a supportive treatment to stabilize organ function by reduction of cytokine levels. So far, no experiences of cytokine adsorption and simultaneous stem cell transplantation were published. We report the case of a patient with aggressive lymphoma secondary to chronic lymphocytic leukemia with rapidly progressive HLH (Richter's transformation) upon conditioning chemotherapy prior to allogeneic stem cell transplantation (ASCT). Continuous hemodiafiltration was initiated in the treatment of shock with acute renal failure, lactacidosis and need for high-dose catecholamine therapy, integrating an additional cytokine-adsorbing filter (CytoSorb®) to reduce cytokine levels. This was followed by scheduled allogenic stem cell transplantation. We observed a marked decrease in interleukin-6 plasma levels, associated with a reduced need for vasopressor therapy and organ function stabilization. Hematopoietic engraftment was present at day 14 post-ASCT, leading to disease-free discharge at day 100 post-transplantation. Cytokine adsorption may serve as a safe adjunct to HLH/sepsis treatment during allogeneic stem cell transplantation. Clinical studies are required to make future treatment recommendations.

The Secretome Analysis of Activated Human Renal Fibroblasts Revealed Beneficial Effect of the Modulation of the Secreted Peptidyl-Prolyl Cis-Trans Isomerase A in Kidney Fibrosis.

The secretome is an important mediator in the permanent process of reciprocity between cells and their environment. Components of secretome are involved in a large number of physiological mechanisms including differentiation, migration, and extracellular matrix modulation. Alteration in secretome composition may therefore trigger cell transformation, inflammation, and diseases. In the kidney, aberrant protein secretion plays a central role in cell activation and transition and in promoting renal fibrosis onset and progression. Using comparative proteomic analyses, we investigated in the present study the impact of cell transition on renal fibroblast cells secretome. Human renal cell lines were stimulated with profibrotic hormones and cytokines, and alterations in secretome were investigated using proteomic approaches. We identified protein signatures specific for the fibrotic phenotype and investigated the impact of modeling secretome proteins on extra cellular matrix accumulation. The secretion of peptidyl-prolyl cis-trans isomerase A (PPIA) was demonstrated to be associated with fibrosis phenotype. We showed that the in-vitro inhibition of PPIA with ciclosporin A (CsA) resulted in downregulation of PPIA and fibronectin (FN1) expression and significantly reduced their secretion. Knockdown studies of PPIA in a three-dimensional (3D) cell culture model significantly impaired the secretion and accumulation of the extracellular matrix (ECM), suggesting a positive therapeutic effect on renal fibrosis progression.

Endothelial-to-mesenchymal transition compromises vascular integrity to induce Myc-mediated metabolic reprogramming in kidney fibrosis.

Endothelial-to-mesenchymal transition (EndMT) is a cellular transdifferentiation program in which endothelial cells partially lose their endothelial identity and acquire mesenchymal-like features. Renal capillary endothelial cells can undergo EndMT in association with persistent damage of the renal parenchyma. The functional consequence(s) of EndMT in kidney fibrosis remains unexplored. Here, we studied the effect of Twist or Snail deficiency in endothelial cells on EndMT in kidney fibrosis. Conditional deletion of Twist1 (which encodes Twist) or Snai1 (which encodes Snail) in VE-cadherin+ or Tie1+ endothelial cells inhibited the emergence of EndMT and improved kidney fibrosis in two different kidney injury/fibrosis mouse models. Suppression of EndMT limited peritubular vascular leakage, reduced tissue hypoxia, and preserved tubular epithelial health and function. Hypoxia, which was exacerbated by EndMT, resulted in increased Myc abundance in tubular epithelial cells, enhanced glycolysis, and suppression of fatty acid oxidation. Pharmacological suppression or epithelial-specific genetic ablation of Myc in tubular epithelial cells ameliorated fibrosis and restored renal parenchymal function and metabolic homeostasis. Together, these findings demonstrate a functional role for EndMT in the response to kidney capillary endothelial injury and highlight the contribution of endothelial-epithelial cross-talk in the development of kidney fibrosis with a potential for therapeutic intervention.

Clinical Efficacy of Routinely Administered Belimumab on Proteinuria and Neuropsychiatric Lupus.

Background and Objectives: Belimumab (BEL) is a monoclonal antibody approved for the treatment of active systemic lupus erythematosus (SLE) but not for lupus nephritis (LN) and neuropsychiatric systemic lupus erythematosus (NPSLE). We aimed to assess BEL's effects on these severe, potentially life-threatening manifestations. Methods: Retrospective observational cohort study using routine clinical data in a case series of patients with SLE receiving BEL. Results: Sixteen patients received BEL therapy for active SLE. Nine were excluded because they had no LN or NPSLE. Six suffered from LN, and one patient had NPSLE. All LN patients received BEL in addition to standard therapy including glucocorticoids, hydroxychloroquine, and mycophenolate mofetil in five cases, and tacrolimus in one case. Three patients with proteinuria >1,000 mg/g creatinine responded well (one complete, two partial renal responses); all other patients had decreasing proteinuria and a reduction in anti-dsDNA levels. The patient with NPSLE who had failed previous therapies had persistent clinical improvement of cutaneous and neuropsychiatric manifestations. There was one mild allergic reaction and one lower respiratory tract infection, but no other adverse events. One patient discontinued therapy due to a lack of improvement in clinical symptoms, another because of clinical remission. Conclusions: In our series, BEL led to a decrease of proteinuria in patients with proteinuria of more than 1,000 mg/g creatinine despite standard of care treatment, and led to a marked clinical improvement in one patient with NPSLE. No adverse events were observed. Routinely administered BEL shows clinical efficacy on non-approved manifestations, but careful patient selection is warranted.

Epigenetic Reprogramming of Cancer-Associated Fibroblasts Deregulates Glucose Metabolism and Facilitates Progression of Breast Cancer.

The mechanistic contributions of cancer-associated fibroblasts (CAFs) in breast cancer progression remain to be fully understood. While altered glucose metabolism in CAFs could fuel cancer cells, how such metabolic reprogramming emerges and is sustained needs further investigation. Studying fibroblasts isolated from patients with benign breast tissues and breast cancer, in conjunction with multiple animal models, we demonstrate that CAFs exhibit a metabolic shift toward lactate and pyruvate production and fuel biosynthetic pathways of cancer cells. The depletion or suppression of the lactate production of CAFs alter the tumor metabolic profile and impede tumor growth. The glycolytic phenotype of the CAFs is in part sustained through epigenetic reprogramming of HIF-1α and glycolytic enzymes. Hypoxia induces epigenetic reprogramming of normal fibroblasts, resulting in a pro-glycolytic, CAF-like transcriptome. Our findings suggest that the glucose metabolism of CAFs evolves during tumor progression, and their breast cancer-promoting phenotype is partly mediated by oxygen-dependent epigenetic modifications.

CRISPR/Cas Derivatives as Novel Gene Modulating Tools: Possibilities and In Vivo Applications.

The field of genome editing started with the discovery of meganucleases (e.g., the LAGLIDADG family of homing endonucleases) in yeast. After the discovery of transcription activator-like effector nucleases and zinc finger nucleases, the recently discovered clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR associated proteins (Cas) system has opened a new window of applications in the field of gene editing. Here, we review different Cas proteins and their corresponding features including advantages and disadvantages, and we provide an overview of the different endonuclease-deficient Cas protein (dCas) derivatives. These dCas derivatives consist of an endonuclease-deficient Cas9 which can be fused to different effector domains to perform distinct in vitro applications such as tracking, transcriptional activation and repression, as well as base editing. Finally, we review the in vivo applications of these dCas derivatives and discuss their potential to perform gene activation and repression in vivo, as well as their potential future use in human therapy.

Serelaxin alleviates cardiac fibrosis through inhibiting endothelial-to-mesenchymal transition via RXFP1.

Rationale: Cardiac fibrosis is an integral constituent of every form of chronic heart disease, and persistence of fibrosis reduces tissue compliance and accelerates the progression to heart failure. Relaxin-2 is a human hormone, which has various physiological functions such as mediating renal vasodilation in pregnancy. Its recombinant form Serelaxin has recently been tested in clinical trials as a therapy for acute heart failure but did not meet its primary endpoints. The aim of this study is to examine whether Serelaxin has an anti-fibrotic effect in the heart and therefore could be beneficial in chronic heart failure. Methods: We utilized two different cardiac fibrosis mouse models (ascending aortic constriction (AAC) and Angiotensin II (ATII) administration via osmotic minipumps) to assess the anti-fibrotic potential of Serelaxin. Histological analysis, immunofluorescence staining and molecular analysis were performed to assess the fibrosis level and indicate endothelial cells which are undergoing EndMT. In vitro TGFß1-induced endothelial-to-mesenchymal transition (EndMT) assays were performed in human coronary artery endothelial cells and mouse cardiac endothelial cells (MCECs) and were examined using molecular methods. Chromatin immunoprecipitation-qPCR assay was utilized to identify the Serelaxin effect on chromatin remodeling in the Rxfp1 promoter region in MCECs. Results: Our results demonstrate a significant and dose-dependent anti-fibrotic effect of Serelaxin in the heart in both models. We further show that Serelaxin mediates this effect, at least in part, through inhibition of EndMT through the endothelial Relaxin family peptide receptor 1 (RXFP1). We further demonstrate that Serelaxin administration is able to increase its own receptor expression (RXFP1) through epigenetic regulation in form of histone modifications by attenuating TGFß-pSMAD2/3 signaling in endothelial cells. Conclusions: This study is the first to identify that Serelaxin increases the expression of its own receptor RXFP1 and that this mediates the inhibition of EndMT and cardiac fibrosis, suggesting that Serelaxin may have a beneficial effect as anti-fibrotic therapy in chronic heart failure.

Histopathological Findings Predict Renal Recovery in Severe ANCA-Associated Vasculitis Requiring Intensive Care Treatment.

Renal involvement is a common and severe complication of AAV as it can cause ESRD. Histopathological subgrouping and ARRS are helpful to predict long-term ESRD in patients with AAV. Because a subgroup of critically ill patients with severe AAV present with deterioration of kidney function requiring RRT at admission, we here aimed to evaluate histopathological findings and predictive value of Berden's histopathological subgrouping and ARRS for severity of AKI and requirement of RRT during the short-term clinical course in critically ill patients requiring intensive care treatment and predictors for short-term renal recovery in patients requiring RRT. A subgroup of 15/46 (32. 6%) AAV patients with biopsy-proven AAV required RRT during the short-term course of disease, associated with requirement of critical care treatment. While histopathological subgrouping and ARRS were associated with requirement of acute RRT, presence of global glomerular scarring was the strongest predictor of failure to recover from RRT after initiation of remission induction therapy. This new aspect requires further investigation in a prospective controlled setting for therapeutic decision making especially in this subgroup.

Variable Expression of Programmed Cell Death Protein 1-Ligand 1 in Kidneys Independent of Immune Checkpoint Inhibition.

Context: Due to recent advantages in cancer therapy, immune checkpoint inhibitors (ICIs) are new classes of drugs targeting programmed cell death protein 1 (PD-1) or its ligand programmed cell death protein 1-ligand 1 (PD-L1) used in many cancer therapies. Acute interstitial nephritis (AIN) is a potential and deleterious immune-related adverse events (irAE) in the kidney observed in patients receiving ICIs and the most common biopsy-proven diagnosis in patients who develop acute kidney injury (AKI). Based on previous reports, AIN in patients receiving ICIs is associated with tubular positivity for PD-L1, implicating that PD-L1 positivity reflects susceptibility to develop renal complications with these agents. It remains unclear if PD-L1 positivity is acquired specifically during ICI therapy or expressed independently in the kidney. Methods: PD-L1 was analyzed in experimental mouse models of ischemia-reperfusion injury (IRI), folic acid-induced nephropathy (FAN), unilateral ureteral obstruction (UUO), and nephrotoxic serum nephritis (NTN) by immunostaining, SDS-PAGE, and subsequent immunoblotting. In addition, we included a total number of 87 human kidney samples (six renal biopsies with AIN related to ICI therapy, 13 nephrectomy control kidneys, and 68 ICI-naïve renal biopsies with various underlying kidney diseases to describe PD-L1 expression. Results: We here report distinct PD-L1 expression in renal compartments in multiple murine models of kidney injury and human cases with various underlying kidney diseases, including ICI-related AIN and renal pathologies independent of ICI therapy. PD-L1 is frequently expressed in various renal pathologies independent of ICI therapy and could potentially be a pre-requisit for susceptibility to develop AKI and deleterious immune-related AIN. In addition, we provide evidence that tubular PD-L1 positivity in the kidney is associated with detection of urinary PD-L1+ tubular epithelial cells. Conclusion: Our study implicates that PD-L1 is frequently expressed in various renal pathologies independent of ICI therapy and could potentially be a pre-requisit for susceptibility to develop AKI and deleterious immune-related AIN. Because non-invasive detection of PD-L1+ cells in corresponding urine samples correlates with intrarenal PD-L1 positivity, it is attractive to speculate that further non-invasive detection of PD-L1+ cells may identify patients at risk for ICI-related AIN.

Rheopheresis for Digital Ulcers and Raynaud's Phenomenon in Systemic Sclerosis Refractory to Conventional Treatments.

Raynaud's phenomenon (RP) is almost universally present in patients with Systemic Sclerosis (SSc). RP represents a generalized vasculopathy and potentially lead to digital ulcers (DU), which may be complicated by superinfection, tissue necrosis, and limb loss. We report the analysis of an extracorporeal procedure in a 36-year-old female patient with diffuse SSc with refractory RP and DU despite treatment with diltiazem, candesartan, sildenafil, and intravenous iloprost. We performed rheopheresis (RheoP), a variant of double-filtration plasmapheresis, as a potential new treatment option for refractory patients despite optimal medical therapy. We performed two RheoP per week every 4 weeks for a total of 3 months. Clinical improvement in DU healing occurred with no adverse events directly related to the treatment. While there was no reduction in the number of Raynaud attacks with RheoP, a significant reduction of the duration of attacks from a median of 15 (5-45, 95% CI 10-15) to 7 (3-30, 95% CI 6-10) minutes with an improvement of the Raynaud Condition Score (RCS) improved from 4 to 2. In conclusion, RheoP is a feasible and potentially beneficial treatment modality in patients with refractory RP and DU. We propose that RheoP should be investigated in a larger number of patients in a clinical trial setting.

Causal Connections From Chronic Kidney Disease to Cardiac Fibrosis.

Cardiovascular disease and heart failure are the primary cause of morbidity and mortality in patients with chronic kidney disease. Because impairment of kidney function correlates with heart failure and cardiac fibrosis, a kidney-heart axis is suspected. Although our understanding of the underlying mechanisms still is evolving, the possibility that kidney-heart messengers could be intercepted offers ample reason to focus on this clinically highly relevant problem. Here, we review the current knowledge of how kidney injury causes heart failure and fibrosis.