Neutrophil Extracellular Traps and Thrombolysis Resistance: New Insights for Targeting Therapies.

BACKGROUND: Thrombosis is linked to neutrophil release of neutrophil extracellular traps (NETs). NETs are proposed as a mechanism of resistance to thrombolysis. This study intends to analyze the composition of thrombi retrieved after mechanical thrombectomy, estimate the age and organization of thrombi, and evaluate associations with the use of thrombolysis, antiplatelets, and heparin. METHODS: This retrospective observational study involved 72 samples (44 from cerebral and 28 coronary arteries), which were stained with hematoxylin and eosin, anti-NE (neutrophil elastase) antibody, and anti-histone H2B (histone H2B) antibody, representing different components in NET formation, all detectable during the later stages of NETosis, for histochemical and digital quantification of NET content. The histological and morphological evaluations of the specimens were correlated, through univariate and mediation analyses, with clinical information and therapy administered before intervention. RESULTS: The results demonstrated that the composition of cerebral and coronary thrombi differs, and there were significantly more lytic cerebral thrombi than coronary thrombi (66% versus 14%; P=0.005). There was a considerably higher expression of NETs in the cerebral thrombi as testified by the higher expression of H2B (P=0.031). Thrombolysis was remarkably associated with higher NE positivity (average marginal effect, 6.461 [95% CI, 0.7901-12.13]; P=0.02555), regardless of the origin of thrombi. There was no notable association between the administration of antiaggregant therapy/heparin and H2B/NE amount when adjusted for the thrombus location. Importantly, the age of the thrombus was the only independent predictor of NET content without any mediation of the thrombolytic treatment (P=0.014). CONCLUSIONS: The age of the thrombus is the driving force for NET content, which correlates with impaired clinical outcomes. The therapy that is currently administered does not modify NET content. This study supports the need to investigate new pharmacological approaches added to thrombolysis to prevent NET formation or enhance their disruption, such as recombinant human DNase I (deoxyribonuclease I).

Report of the 2022 Banff Heart Concurrent: Focus on non-human leukocyte antigen antibodies in rejection and the pathology of "mixed" rejection.

The Banff Heart Concurrent Session, held as part of the 16th Banff Foundation for Allograft Pathology Conference at Banff, Alberta, Canada, on September 21, 2022, focused on 2 major topics: non-human leukocyte antigen (HLA) antibodies and mixed rejection. Each topic was addressed in a multidisciplinary fashion with clinical, immunological, and pathology perspectives and future developments and prospectives. Following the Banff organization model and principles, the collective aim of the speakers on each topic was to • Determine current knowledge gaps in heart transplant pathology • Identify limitations of current pathology classification systems • Discuss next steps in addressing gaps and refining classification system.

MST1 mediates doxorubicin-induced cardiomyopathy by SIRT3 downregulation.

Heart failure is a major side effect of doxorubicin (DOX) treatment in patients with cancer. However, the mechanisms underlying the development of DOX-induced heart failure need to be addressed. This study aims to test whether the serine/threonine kinase MST1, a major Hippo pathway component, contributes to the development of DOX-induced myocardial injury. C57BL/6J WT mice and mice with cardiomyocyte-specific dominant-negative MST1 (kinase-dead) overexpression received three weekly injections of DOX, reaching a final cumulative dose of 18 mg/kg. Echocardiographic, histological and biochemical analyses were performed six weeks after the first DOX administration. The effects of MST1 inhibition on DOX-induced cardiomyocyte injury were also tested in vitro. MST1 signaling was significantly activated in cardiomyocytes in response to DOX treatment in vitro and in vivo. Wild-type (WT) mice treated with DOX developed cardiac dysfunction and mitochondrial abnormalities. However, these detrimental effects were abolished in mice with cardiomyocyte-specific overexpression of dominant-negative MST1 (DN-MST1) or treated with XMU-MP-1, a specific MST1 inhibitor, indicating that MST1 inhibition attenuates DOX-induced cardiac dysfunction. DOX treatment led to a significant downregulation of cardiac levels of SIRT3, a deacetylase involved in mitochondrial protection, in WT mice, which was rescued by MST1 inhibition. Pharmacological inhibition of SIRT3 blunted the protective effects of MST1 inhibition, indicating that SIRT3 downregulation mediates the cytotoxic effects of MST1 activation in response to DOX treatment. Finally, we found a significant upregulation of MST1 and downregulation of SIRT3 levels in human myocardial tissue of cancer patients treated with DOX. In summary, MST1 contributes to DOX-induced cardiomyopathy through SIRT3 downregulation.

Impact of Carotid Stent Design on Embolic Filter Debris Load During Carotid Artery Stenting.

BACKGROUND: The carotid stent design may influence the risk of embolization during carotid artery stenting. The aim of the study was to assess this risk by comparing the quantity of embolized material captured by filters during carotid artery stenting, using different stent designs. METHODS: We conducted a single-center retrospective study of patients undergoing carotid artery stenting for asymptomatic carotid stenosis >70% (2010-2022) in a tertiary academic hospital (Padua University Hospital, Italy). Carotid stents were classified according to their design as open-cell (OCS), closed-cell (CCS), or micromesh stents (MMS). A distal filter protection was used in all patients, and the amount of captured embolized particles was semiautomatically analyzed using a dedicated software (Image-Pro Plus, Media Cybernetics). Primary end point was embolic filter debris (EFD) load, defined as the ratio of the filter area covered by particulate material to the total filter area. Secondary end points were 30 days major stroke and death. RESULTS: Four-hundred-eighty-one carotid artery stentings were included; 171 (35%) using an OCS, 68 (14%) a CCS, and 242 (50%) a MMS. Thirty-days mortality was 0.2% (n=1) and major stroke rate was 0.2% (P=0.987). Filters of patients receiving MMS were more likely to be free from embolized material (OCS, 30%; CCS, 13%; MMS, 41%; P<0.001) and had a lower EFD load (OCS, 9.1±14.5%; CCS, 7.9±14.0%; MMS, 5.0±9.1%; P<0.001) compared with other stent designs. After stratification by plaque characteristics, MMS had a lower EFD load in cases of hypoechogenic plaque (OCS, 13.4±9.9%; CCS, 10.9±8.7%; MMS, 6.5±13.1%; P<0.001), plaque length>15 mm (OC, 10.2±15.3; CC, 8.6±12.4; MM, 8.2±13.6; P<0.001), and preoperative ipsilateral asymptomatic ischemic cerebral lesion (OCS, 12.9±16.8%; CCS, 8.7±19.5%; MMS, 5.4±9.7%; P<0.001). After multivariate linear regression, use of MMS was associated with lower EFD load (P=0.038). CONCLUSIONS: The use of MMS seems to be associated with a lower embolization rate and EFD load, especially in hypoechogenic and long plaques and in patients with a preoperative evidence of asymptomatic ischemic cerebral lesion.

Banff Human Organ Transplant Consensus Gene Panel for the Detection of Antibody Mediated Rejection in Heart Allograft Biopsies.

The molecular refinement of the diagnosis of heart allograft rejection based on whole-transcriptome analyses faces several hurdles that greatly limit its widespread clinical application. The targeted Banff Human Organ Transplant gene panel (B-HOT, including 770 genes of interest) has been developed to facilitate reproducible and cost-effective gene expression analysis of solid organ allografts. We aimed to determine in silico the ability of this targeted panel to capture the antibody-mediated rejection (AMR) molecular profile using whole-transcriptome data from 137 heart allograft biopsies (71 biopsies reflecting the entire landscape of histologic AMR, 66 non-AMR control biopsies including cellular rejection and non-rejection cases). Differential gene expression, pathway and network analyses demonstrated that the B-HOT panel captured biologically and clinically relevant genes (IFNG-inducible, NK-cells, injury, monocytes-macrophage, B-cell-related genes), pathways (interleukin and interferon signaling, neutrophil degranulation, immunoregulatory interactions, endothelial activation) and networks reflecting the pathophysiological mechanisms underlying the AMR process previously identified in whole-transcriptome analysis. Our findings support the potential clinical use of the B-HOT-gene panel as a reliable proxy to whole-transcriptome analysis for the gene expression profiling of cardiac allograft rejection.

Peripheral neuropathy as clinical onset of monoclonal IgM/k-related amyloidosis.

AIM: Neuropathy is a frequent complication of Waldenström's macroglobulinemia (WM), the most common being a demyelinating polyneuropathy with anti-myelin associated glycoprotein (MAG) antibodies, but also cryoglobulins, vasculitis, neurolymphomatosis, and amyloidosis. We describe a patient with IgM/kappa WM who presented with a severe, not length-dependent, peripheral neuropathy as clinical onset of IgM/kappa-related amyloidosis. METHODS: A 69-year-old woman came to our attention for weight loss, gait imbalance and sensory loss at upper limbs. In her medical history, she was in hematological follow-up for WM, and had undergone left carpal tunnel release. At neurological evaluation she had weakness and loss of sensation at upper limbs up to the elbows, more at the left side, gait was unsteady with right foot drop. Hypotrophy and areflexia were present at four limbs. Sensory loss and vibration sense were dramatically reduced. She underwent extensive diagnostic workup. RESULTS: Laboratory workup revealed an IgM/kappa monoclonal paraprotein of 16 g/L and increased NT-proBNP; anti-MAG antibodies were absent. Bone marrow biopsy demonstrated a population of neoplastic B-lymphocytes. Total-body CT scan and echocardiogram were negative. Neurophysiology revealed a symmetric, no length dependent sensory-motor polyneuropathy Periumbilical fat biopsy was positive for amyloid. Sural nerve biopsy detected amyloid in the wall of an epineurial vein. CONCLUSIONS: This case report describes a rare and unusual manifestation of IgM-related AL amyloidosis in WM. The patient presented with a subacute clinically asymmetric neuropathy with no pain or dysautonomic features as clinical onset of IgM/kappa-related amyloidosis. Sural nerve biopsy was crucial for the diagnosis.

Poly(lipoic acid)-based nanoparticles as a new therapeutic tool for delivering active molecules.

Pluronic-coated polylipoic acid-based nanoparticles (F127@PLA-NPs) have great potential as biodegradable nanovectors for delivering active molecules to different organs in complex diseases. In this study we describe the in vivo biodistribution, safety and ability to deliver molecules of F127@PLA-NPs in healthy rats following intravenous administration. Adult rats were injected with 10 mg/kg of rhodamine B-labeled F127@PLA-NPs, and NPs fluorescence and MFI rate were measured by confocal microscopy in whole collected organs. The NPs accumulation rate was maximal in the heart, compared to the other organs. At the cellular level, myocytes and kidney tubular cells showed the highest NPs uptake. Neither histopathological lesion nor thrombogenicity were observed after NPs injection. Finally, F127@PLA-NPs were tested in vitro as miRNAs delivery nanosystem, and they showed good ability in targeting cardiomyocytes. These results demonstrated that our F127@PLA-NPs constitute a biological, minimally invasive and safe delivery tool targeting organs and cells, such as heart and kidney.

Poly(lipoic acid)-Based Nanoparticles as Self-Organized, Biocompatible, and Corona-Free Nanovectors.

Herein we present an innovative approach to produce biocompatible, degradable, and stealth polymeric nanoparticles based on poly(lipoic acid), stabilized by a PEG-ended surfactant. Taking advantage of the well-known thiol-induced polymerization of lipoic acid, a universal and nontoxic nanovector consisted of a solid cross-linked polymeric matrix of lipoic acid monomers was prepared and loaded with active species with a one-step protocol. The biological studies demonstrated a high stability in biological media, the virtual absence of "protein" corona in biological fluids, the absence of acute toxicity in vitro and in vivo, complete clearance from the organism, and a relevant preference for short-term accumulation in the heart. All these features make these nanoparticles candidates as a promising tool for nanomedicine.

Porcelain aorta: A surgical dilemma in orthotopic heart transplantation.

BACKGROUND: Circumferential calcification of the ascending aorta, known as porcelain aorta, in a patient candidate to a heart transplant, requires technically demanding and high-risk procedural adjustments. AIMS: This case report showed successful replacement of ascending aorta due to extensive calcification at time of heart transplantation. MATERIALS AND METHODS: In the operating theatre, after median sternotomy, cardiopulmonary bypass (CPB) was achieved via the right femoral artery and vein. Due to the impossibility of replacing the ascending aorta using safe aortic cross-clamping, a moderate hypothermia was established, and circulatory arrest was realized. According to Kazui protocol for selective anterograde cerebral perfusion via anonymous trunk and left carotid artery, ascending aorta was replaced with vascular prosthesis. RESULTS: Thanks to accurate pre-surgical planning, which included hypothermic circulatory arrest, ascending aorta replacement, before orthotopic heart implantation, we were able to perform the procedure successfully and prevent neurological events. DISCUSSION: Although different reports showed the feasibility of heart transplant combined to aortic replacement for aneurysmatic pathology, few cases were described for porcelain aorta, due to technically demanding procedure and prohibitive aortic cross-clamping. To avoid vascular embolization, dissection and mural laceration, aortic cross-clamping is not recommended. We performed aortic replacement at first, to reduce allograft ischemia. CONCLUSION: The use of hypothermic circulatory arrest technique with selective cerebral perfusion for aortic replacement, followed by vascular graft clamping to favour cardiac allograft implantation, could be considered a winning combination to guarantee procedural success and to reduce perioperative complications.

The XVth Banff Conference on Allograft Pathology the Banff Workshop Heart Report: Improving the diagnostic yield from endomyocardial biopsies and Quilty effect revisited.

The XVth Banff Conference on Allograft Pathology meeting was held on September 23-27, 2019, in Pittsburgh, Pennsylvania, USA. During this meeting, two main topics in cardiac transplant pathology were addressed: (a) Improvement of endomyocardial biopsy (EMB) accuracy for the diagnosis of rejection and other significant injury patterns, and (b) the orphaned lesion known as Quilty effect or nodular endocardial infiltrates. Molecular technologies have evolved in recent years, deciphering pathophysiology of cardiac rejection. Diagnostically, it is time to integrate the histopathology of EMBs and molecular data. The goal is to incorporate molecular pathology, performed on the same paraffin block as a companion test for histopathology, to yield more accurate and objective EMB interpretation. Application of digital image analysis from hematoxylin and eosin (H&E) stain to multiplex labeling is another means of extracting additional information from EMBs. New concepts have emerged exploring the multifaceted significance of myocardial injury, minimal rejection patterns supported by molecular profiles, and lesions of arteriolitis/vasculitis in the setting of T cell-mediated rejection (TCMR) and antibody-mediated rejection (AMR). The orphaned lesion known as Quilty effect or nodular endocardial infiltrates. A state-of-the-art session with historical aspects and current dilemmas was reviewed, and possible pathogenesis proposed, based on advances in immunology to explain conflicting data. The Quilty effect will be the subject of a multicenter project to explore whether it functions as a tertiary lymphoid organ.

Hyperdynamic circulatory syndrome in a mouse model transgenic for SerpinB3.

INTRODUCTION AND OBJECTIVES: SerpinB3 is a cysteine protease inhibitor involved in several biological activities. It is progressively expressed in chronic liver disease, but not in normal liver. The role in vascular reactivity of this serpin, belonging to the same family of Angiotensin II, is still unknown. Our aim was to evaluate the in vivo and in vitro effects of SerpinB3 on systemic and splanchnic hemodynamics. MATERIAL AND METHODS: Different hemodynamic parameters were evaluated by ultrasonography in two colonies of mice (transgenic for human SerpinB3 and C57BL/6J controls) at baseline and after chronic carbon tetrachloride (CCl4) treatment. In vitro SerpinB3 effect on mesenteric microvessels of 5 Wistar-Kyoto rats was analyzed measuring its direct action on: (a) preconstricted arteries, (b) dose-response curves to phenylephrine, before and after inhibition of angiotensin II type 1 receptors with irbesartan. Hearts of SerpinB3 transgenic mice and of the corresponding controls were also analyzed by morphometric assessment. RESULTS: In SerpinB3 transgenic mice, cardiac output (51.6±21.5 vs 30.1±10.8ml/min, p=0.003), hepatic artery pulsatility index (0.85±0.13 vs 0.65±0.11, p<0.001) and portal vein blood flow (5.3±3.2 vs 3.1±1.8ml/min, p=0.03) were significantly increased, compared to controls. In vitro, recombinant SerpinB3 had no direct hemodynamic effect on mesenteric arteries, but it increased their sensitivity to phenylephrine-mediated vasoconstriction (p<0.01). This effect was suppressed by inhibiting angiotensin II type-1 receptors. CONCLUSIONS: In transgenic mice, SerpinB3 is associated with a hyperdynamic circulatory syndrome-like pattern, possibly mediated by angiotensin receptors.

Cardiac sympathetic innervation network shapes the myocardium by locally controlling cardiomyocyte size through the cellular proteolytic machinery.

KEY POINTS: The heart is innervated by a dense sympathetic neuron network which, in the short term, controls chronotropy and inotropy and, in the long term, regulates cardiomyocyte size. Acute neurogenic control of heart rate is achieved locally through direct neuro-cardiac coupling at specific junctional sites (neuro-cardiac junctions). The ventricular sympathetic network topology is well-defined and characteristic for each mammalian species. In the present study, we used cell size regulation to determine whether long-term modulation of cardiac structure is achieved via direct sympatho-cardiac coupling. Local density of cardiac innervation correlated with cell size throughout the myocardial walls in all mammalian species analysed, including humans. The data obtained suggest that constitutive neurogenic control of cardiomyocyte trophism occurs through direct intercellular signalling at neuro-cardiac junctions. ABSTRACT: It is widely appreciated that sympathetic stimulation of the heart involves a sharp increase in beating rate and significant enhancement of contractility. We have previously shown that, in addition to these evident functions, sympathetic neurons (SNs) also provide trophic input to cardiomyocytes (CMs), regulating cell and organ size. More recently, we have demonstrated that cardiac neurons establish direct interactions with CMs, allowing neuro-cardiac communication to occur locally, with a 'quasi-synaptic' mechanism. Based on the evidence that cardiac SNs are unevenly distributed throughout the myocardial walls, we investigated the hypothesis that CM size distribution reflects the topology of neuronal density. In vitro analyses of SN/CM co-cultures, ex vivo confocal and multiphoton imaging in clarified hearts, and biochemical and molecular approaches were employed, in both rodent and human heart biopsies. In line with the trophic effect of SNs, and with local neuro-cardiac communication, CMs, directly contacted by SNs in co-cultures, were larger than the non-targeted ones. This property reflects the distribution of CM size throughout the ventricles of intact mouse heart, in which cells in the outer myocardial layers, which were contacted by more neuronal processes, were larger than those in the less innervated subendocardial region. Such differences disappeared upon genetic or pharmacological interference with the trophic SN/CM signalling axis. Remarkably, CM size followed the SN distribution pattern in other mammals, including humans. Our data suggest that both the acute and chronic influence of SNs on cardiac function and structure is enacted as a result of the establishment of specific intercellular neuro-cardiac junctions.

Quantitative analysis and predictors of embolic filter debris load during carotid artery stenting in asymptomatic patients.

OBJECTIVE: The objective of this study was to perform a quantitative analysis and to identify predictors of embolic filter debris (EFD) load during carotid artery stenting (CAS) in asymptomatic patients. METHODS: All patients with asymptomatic carotid stenosis >70% undergoing CAS between 2008 and 2016 were included in a prospective database. A distal filter protection device was used in all patients. At the end of the procedure, the filter was fixed in formalin and then analyzed with a stereomicroscope. Morphometric analysis was performed with Image-Pro Plus software (Media Cybernetics, Rockville, Md). The total area of the filter membrane and the area covered by particulate material were quantified. The quantity of membrane occupied by debris was expressed as percentage of covered surface area. Anatomic and clinical variables were evaluated for their association with EFD load using multiple logistic regression. RESULTS: Among the 278 patients undergoing CAS, an open-cell stent was implanted in 211 patients (76%); 67 patients (24%) received a closed-cell stent. Overall technical success and clinical success were both 99%; no perioperative death was reported. Stroke rate was 1.8% (major, n = 1 [0.4%]; minor, n = 4 [1.4%]); transient ischemic attacks occurred in 5% of cases (n = 14). The quantitative analysis of the filter revealed that EFD was present in 74% of cases (n = 207). The mean EFD load was 10% of the filter surface (median, 1; range, 0-80); it was <10% in 203 patients (73%), between 11% and 20% in 39 patients (14%), between 21% and 30% in 14 patients (5%), and >31% in 22 (8%). Patients with any type of ischemic neurologic event after CAS (stroke and transient ischemic attack) had a significantly higher mean EFD load compared with uneventful cases (26.7% ± 19.0% vs 8.5% ± 13.5%; P < .001). The observational frequency distribution analysis identified the presence of >12.5% EFD load as the optimal cutoff for the association with clinically relevant perioperative ischemic events (sensitivity, 78%; specificity, 77%; area under the curve, 0.81). The multivariate analysis demonstrated that age >75 years (odds ratio [OR], 2.56; P = .003), pre-existing ipsilateral ischemic cerebral lesions (OR, 2.09; P = .047), hypoechogenic plaque on the preoperative duplex ultrasound examination (OR, 6.05; P < .001), and plaque length >15 mm (OR, 1.79; P = .049) were independent predictors of EFD load >12.5%. CONCLUSIONS: The majority of asymptomatic carotid stenoses treated with CAS have detectable embolic debris in the protecting filter. Age >75 years, pre-existing ipsilateral cerebral ischemic lesions, hypoechogenic plaque, and plaque length >15 mm should be taken into consideration as independent predictors of clinically relevant embolic debris during the procedure.

Idelalisib plus rituximab is effective in systemic AL amyloidosis secondary to chronic lymphocytic leukaemia.

Light chain amyloidosis is characterized by the progressive deposition of immunoglobulin light chains into the extracellular tissue, leading to organ dysfunction. Usually, it is associated with an underlying clonal plasma cell dyscrasia and rarely with chronic lymphocytic leukaemia. Herein, we described the first report of a patient with relapsed chronic lymphocytic leukaemia harbouring TP53 abnormalities who developed, histologically proven, systemic light chain amyloidosis who was treated with the PI3K inhibitor, idelalisib, and rituximab. Unfortunately, the patient had sudden death during sleep, likely caused by arrhythmia secondary to amyloid cardiomyopathy. Idelalisib was at least effective in reducing secretory free light chain, chronic lymphocytic leukaemia burden, and to improve the survival of patient.

Pathological antibody-mediated rejection in pediatric heart transplant recipients: Immunologic risk factors, hemodynamic significance, and outcomes.

Biopsy-diagnosed pAMR has been observed in over half of pediatric HT recipients within 6 years of transplantation. We report the incidence and outcomes of pAMR at our center. All endomyocardial biopsies for all HT recipients transplanted between 2010 and 2015 were reviewed and classified using contemporary ISHLT guidelines. Graft dysfunction was defined as a qualitative decrement in systolic function by echocardiogram or an increase of ≥3 mm Hg in atrial filling pressure by direct measurement. Among 96 patients, pAMR2 occurred in 7 (7%) over a median follow-up period of 3.1 years, while no cases of pAMR3 occurred. A history of CHD, DSA at transplant, and elevated filling pressures were associated with pAMR2. Five-sixths (83%) of patients developed new C1q+ DSA at the time of pAMR diagnosis. There was a trend toward reduced survival, with 43% of patients dying within 2.3 years of pAMR diagnosis.

Immunization with pentraxin 3 (PTX3) leads to anti-PTX3 antibody production and delayed lupus-like nephritis in NZB/NZW F1 mice.

BACKGROUND: Anti-pentraxin 3 (PTX3) antibodies were associated with the absence of lupus glomerulonephritis in humans. AIM: To explore the effects of anti-PTX3 antibodies in New Zealand Black/White (NZB/NZW F1) mice and their inherent mechanisms of action. MATERIALS AND METHODS: 30 NZB/NZW F1 mice were subdivided into 3 groups of 10 mice each and subcutaneously injected with PTX3, alum and PBS (group 1), alum and PBS (group 2) or PBS alone (group 3), 3 times 3 weeks apart, before development of renal disease. Mice were followed until natural death. Histological analysis and immunohistochemistry were performed on harvested kidneys. Effects of anti-PTX3 antibodies on C1q binding to immobilized PTX3-anti-PTX3 immune complexes were evaluated in vitro using human SLE sera. Qualitative characterization of human IgG anti-PTX3 was performed. RESULTS: Only group 1 mice developed anti-PTX3 antibodies. Anti-dsDNA and anti-C1q antibodies appeared significantly later and at lower levels in group 1 mice vs. controls (p < 0.0001). Proteinuria-free and overall survival were significantly increased in group 1 mice vs. controls (p < 0.05 and p = 0.03, respectively). Histopathological analysis showed that glomerular and tubular PTX3 staining and renal lesions were increased in controls compared with immunized mice. Addition of human SLE sera positive for anti-PTX3 antibodies to C1q and fixed PTX3 interfered with C1q binding to PTX3-anti-PTX3 immune complexes. Qualitative characterization of human IgG anti-PTX3 showed an increased proportion of IgG4. CONCLUSIONS: Anti-PTX3 antibodies delay lupus-like nephritis and prolong survival of NZB/NZW F1 mice. In vitro observations suggest anti-PTX3 antibodies may dampen complement activation via their Fc fragment, likely hindering renal inflammation.

Pro-Apoptotic Effects of Plasma from Patients with Cardiorenal Syndrome on Human Tubular Cells.

BACKGROUND: The pathophysiology of Cardiorenal Syndrome Type 1 (CRS1) is widely studied, although the mechanisms by which renal tubular epithelial cells (TECs) cease to proliferate and embark upon terminal differentiation, following the initial insult of heart failure (HF), remain a key target. This study seeks to provide insight into the pathophysiological pathways in CRS1; we evaluated in vitro the effects of CRS1 plasma on TECs. METHODS: We enrolled 40 acute HF patients and 15 controls (CTR) without HF or acute kidney injury (AKI). Ten out of 40 HF patients exhibited AKI at the time of admission for HF or developed AKI during hospitalization and were classified as CRS1. In vitro, cell viability, DNA fragmentation and caspase-3 levels were investigated in TECs incubated with HF, CRS1, and CTR plasma. We assessed inflammatory cytokines and NGAL expression at the gene and protein levels. RESULTS: We observed a marked pro-apoptotic activity and a significantly increased in vitro level of apoptosis in TECs incubated with plasma from CRS1 patients compared to HF and CTR (p < 0.01). In the CRS1 group, the mRNA expression of IL-6, IL-18 and NGAL resulted significantly higher in TECs incubated with CRS1 plasma compared with those incubated with plasma from HF and CTR (p < 0.01). IL-6, IL-18, NGAL, and RANTES levels were significantly higher in TECs supernatant incubated with CRS1 plasma compared with HF patients and CTR plasma (p < 0.01). CONCLUSION: In vitro exposure to plasma from CRS1 patients altered the expression profile of TECs characterized by increases in proinflammatory mediators, release of tubular damage markers, and apoptosis.