The Predictive Value of Sepsis Scores for In-Hospital Mortality in Patients with Left-Sided Infective Endocarditis.

BACKGROUND: As infective endocarditis has particular characteristics compared to other infectious diseases, it is not clear if sepsis scores are reported with good accuracy in these patients. The aim of this study is to evaluate the accuracy of the qSOFA and SOFA scores to predict mortality in patients with infective endocarditis. METHODS: Between January 2010 and June 2019, 867 patients with suspected left-sided endocarditis were evaluated; 517 were included with left-sided infective endocarditis defined as "possible" or "definite" endocarditis, according to the Modified Duke Criteria. ROC curves were constructed to assess the accuracy of qSOFA and SOFA sepsis scores for the prediction of in-hospital mortality. RESULTS: The median age was 57 years, 65% were male, 435 (84%) had pre-existing heart valve disease, and the overall mortality was 28%. The most frequent etiologies were Streptococcus spp. (36%), Enterococcus spp. (10%), and Staphylococcus aureus (9%). The sepsis scores from the ROC curves used to predict in-hospital mortality were qSOFA 0.601 (CI95% 0.522-0.681) and SOFA score 0.679 (CI95% 0.602-0.756). A sub-group analysis in patients with and without pre-existing valve disease for SOFA ≥ 2 showed ROC curves of 0.627 (CI95% 0.563-0.690) and 0.775 (CI95% 0.594-0.956), respectively. CONCLUSIONS: qSOFA and SOFA scores were associated with increased in-hospital mortality in patients with infective endocarditis. However, as accuracy was relatively lower compared to other sites of bacterial infections, we believe that this score may have lower accuracy when predicting the prognosis of patients with IE, because, in this disease, the patient's death may be more frequently linked to valvular and cardiac dysfunction, as well as embolic events, and less frequently directly associated with sepsis.

Patterns of Circulating Cytokines and Vascular Markers' Response in the Presence of COVID-19 in Kidney Transplant Recipients Compared with Non-Transplanted Patients.

COVID-19's severity has been associated with a possible imbalance in the cross-regulation of cytokines and vascular mediators. Since the beginning of the pandemic, kidney transplant recipients (KTRs) have been identified as patients of high vulnerability to more severe diseases. Thus, aiming to describe the patterns of cytokines and vascular mediators and to trace patients' differences according to their KTR status, this prospective study enrolled 67 COVID-19 patients (20 KTRs) and 29 non-COVID-19 controls before vaccination. A panel comprising 17 circulating cytokines and vascular mediators was run on samples collected at different time points. The cytokine and mediator patterns were investigated via principal component analysis (PCA) and correlation-based network (CBN). In both groups, compared to their respective controls, COVID-19 was associated with higher levels of cytokines and vascular mediators. Differentiating between the KTRs and non-KTRs, the number of correlations was much higher in the non-KTRs (44 vs. 14), and the node analysis showed the highest interactions of NGAL and sVCAM-1 in the non-KTRs and KTRs (9 vs. 4), respectively. In the PCA, while the non-KTRs with COVID-19 were differentiated from their controls in their IL-10, IFN-α, and TNF-α, this pattern was marked in the NGAL, sVCAM-1, and IL-8 of the KTRs.

Understanding COVID-19 progression with longitudinal peripheral blood mononuclear cell proteomics: Changes in the cellular proteome over time.

The clinical presentation of COVID-19 is highly variable, and understanding the underlying biological processes is crucial. This study utilized a proteomic analysis to investigate dysregulated processes in the peripheral blood mononuclear cells of patients with COVID-19 compared to healthy volunteers. Samples were collected at different stages of the disease, including hospital admission, after 7 days of hospitalization, and 30 days after discharge. Metabolic pathway alterations and increased abundance of neutrophil-related proteins were observed in patients. Patients progressing to critical illness had significantly low-abundance proteins in the pentose phosphate and glycolysis pathways compared with those presenting clinical recovery. Important biological processes, such as fatty acid concentration and glucose metabolism disorder, remained altered even after 30 days of hospital discharge. Temporal proteomic changes revealed distinct pathways in critically ill and non-critically ill patients. Our study emphasizes the significance of longitudinal cellular proteomic studies in identifying disease progression-related pathways and persistent protein changes post-hospitalization.

ALTERED LEVELS OF H3K9AC, H3K4ME3, AND H3K27ME3 IN PROMOTERS OF DIFFERENTIALLY EXPRESSED GENES RELATED TO INNATE IMMUNE RESPONSE IN SEPTIC PATIENTS WITH DIFFERENT CLINICAL OUTCOMES.

ABSTRACT: Sepsis is one of the leading causes of morbidity and mortality worldwide. Monocytes seem to undergo functional reprogramming during sepsis, resulting in dysregulated host immune response. To clarify this dysregulation mechanism, we investigated three histone modifications found in promoters of genes involved in innate immune response, and associated these findings with gene transcription in septic patients. These results were compared with public transcriptome data of the target genes and epigenetic enzymes that modulate the histone modifications. We used peripheral blood mononuclear cell from surviving and nonsurviving septic patients, and healthy volunteers to evaluate the expression of genes involved in innate immune response and the enrichment of H3K9ac, H3K4me3, and H3K27me3 in their promoters, by RT-qPCR and ChIP, respectively. Finally, we used transcriptome data sets to validate our findings. We found alterations in the chromatin enrichment of different genes, with an increase in H3K9ac in the anti-inflammatory cytokine IL-10 and the antimicrobial gene FPR1 , as well as an increase in H3K27me3 in the IL-10 and HLA-DR promoter in nonsurvivors septic patients when compared with survivors. These alterations were partially associated with the gene expression profile. In addition, we found moderate to strong correlation between gene transcription and the enzymes that modulate these histone modifications in the transcriptome data sets. Our study, one of the pioneering by evaluating septic patients' samples, suggests that epigenetic enzymes modulate the prevalent histone marks in promoters of genes involved in the immune-inflammatory response, altering the transcription of these specific genes during sepsis. Furthermore, nonsurviving sepsis patients have a more pronounced epigenetic dysregulation compared with survivors, suggesting a more dysfunctional response.

Immune Profile and Body Composition of Independent Oldest Old: The Longevous Project.

INTRODUCTION: Immunosenescence is associated with changes in lymphocyte function, thymus atrophy, and a chronic inflammatory process referred to as "inflammaging," which may in part be linked to eating disorders. OBJECTIVE: The aim of the study was to determine the prevalence rate of immunological alterations, including immune risk profile (IRP), and their association with body composition in the oldest old individuals. METHODS: A cross-sectional study of 201 older adults aged 80 years and over, able to walk unaided, with no cognitive or immunological impairment, and with no serious diseases was conducted. Blood samples were collected between 2012 and 2014 during the morning period, and the following tests were conducted: urea, creatinine, hemogram, fasting glucose, glycated hemoglobin, transferrin, albumin, 25-OH vitamin D, and high-sensitivity CRP. Plasma cytokines were measured and mononuclear cell counts were performed by flow cytometry. Anthropometric measurements and densitometry using dual-energy X-ray absorptiometry (DXA) were performed to assess body composition. RESULTS: Mean age was 84.4 ± 3.7 years, and the numbers of T cells were CD4, 784.0 cell/µL; CD8, 371.0 cell/µL; and CD4/CD8, 2.4. The rate of CD4/CD8 <1 (IRP) was 9.4%, CD4/CD8 1-5 was 85.6%, while CD4/CD8 >5 was only 5.5%. CRP, tumor necrosis factor, IL1, IL4, IL6, and IL10 variables showed a high coefficient of variation but low mean values of 1.1 ± 3.1 mg/L for CRP (reference range <3 mg/L) and 3.9 ± 5.0 pg/mL for IL6 (reference range <7.0 pg/mL). The same pattern was found for all other inflammatory variables assessed, characterizing a population whose values indicated low level of inflammation, considering age. Lean mass, as measured by DXA, was higher in men than in women, while the inverse was found for fat % (p < 0.001). A positive association between CRP values and DXA fat % (p value: 0.007, r: 0.49) and a negative association between CRP values and DXA lean mass (p value: 0.046, r:-0.37) was observed. CONCLUSION: In the independent oldest old, IRP rate proved low and high-sensitivity CRP was shown to be associated with body composition.

Glucose metabolism is upregulated in the mononuclear cell proteome during sepsis and supports endotoxin-tolerant cell function.

Metabolic adaptations shape immune cell function. In the acute response, a metabolic switch towards glycolysis is necessary for mounting a proinflammatory response. During the clinical course of sepsis, both suppression and activation of immune responses take place simultaneously. Leukocytes from septic patients present inhibition of cytokine production while other functions such as phagocytosis and production of reactive oxygen species (ROS) are preserved, similarly to the in vitro endotoxin tolerance model, where a first stimulation with lipopolysaccharide (LPS) affects the response to a second stimulus. Here, we sought to investigate how cellular metabolism is related to the modulation of immune responses in sepsis and endotoxin tolerance. Proteomic analysis in peripheral blood mononuclear cells (PBMCs) from septic patients obtained at intensive care unit admission showed an upregulation of proteins related to glycolysis, the pentose phosphate pathway (PPP), production of ROS and nitric oxide, and downregulation of proteins in the tricarboxylic acid cycle and oxidative phosphorylation compared to healthy volunteers. Using the endotoxin-tolerance model in PBMCs from healthy subjects, we observed increased lactate production in control cells upon LPS stimulation, while endotoxin-tolerant cells presented inhibited tumor necrosis factor-α and lactate production along with preserved phagocytic capacity. Inhibition of glycolysis and PPP led to impairment of phagocytosis and cytokine production both in control and in endotoxin-tolerant cells. These data indicate that glucose metabolism supports leukocyte functions even in a condition of endotoxin tolerance.

Effects of the PARP Inhibitor Olaparib on the Response of Human Peripheral Blood Leukocytes to Bacterial Challenge or Oxidative Stress.

Prior studies demonstrate the activation of poly-(ADP-ribose) polymerase 1 (PARP1) in various pathophysiological conditions, including sepsis. We have assessed the effect of olaparib, a clinically used PARP1 inhibitor, on the responses of human peripheral blood leukocytes (PBMCs) obtained from healthy volunteers in response to challenging with live bacteria, bacterial lipopolysaccharide (LPS), or oxidative stress (hydrogen peroxide, H2O2). The viability of PBMCs exposed to olaparib or to the earlier generation PARP inhibitor PJ-34 (0.1-1000 µM) was monitored using Annexin V and 7-aminoactinomycin D. To evaluate the effects of olaparib on the expression of PARP1 and its effects on protein PARylation, PBMCs were stimulated with Staphylococcus aureus with or without olaparib (1-10 µM). Changes in cellular levels of nicotinamide adenine dinucleotide (NAD+) and adenosine triphosphate (ATP), as well as changes in mitochondrial membrane potential (MMP), were measured in PBMCs exposed to H2O2. Bacterial killing was evaluated in PBMCs and polymorphonuclear leukocytes (PMNs) incubated with S. aureus. Cytokine production was measured in supernatants using a cytometric bead array. Reactive oxygen species (ROS), nitric oxide (NO) production, and phagocytic activity of monocytes and neutrophils were measured in whole blood. For ROS and NO production, samples were incubated with heat-killed S. aureus; phagocytic activity was assessed using killed Escherichia coli conjugated to FITC. Olaparib (0.1-100 µM) did not adversely affect lymphocyte viability. Olaparib also did not interfere with PARP1 expression but inhibits S. aureus-induced protein PARylation. In cells challenged with H2O2, olaparib prevented NAD+ and ATP depletion and attenuated mitochondrial membrane depolarization. LPS-induced production of TNF-α, MIP-1α, and IL-10 by PBMCs was also reduced by olaparib. Monocytes and neutrophils displayed significant increases in the production of ROS and NO after stimulation with S. aureus and phagocytic (E. coli) and microbicidal activity, and these responses were not suppressed by olaparib. We conclude that, at clinically relevant concentrations, olaparib exerts cytoprotective effects and modulates inflammatory cytokine production without exerting adverse effects on the cells' ability to phagocytose or eradicate pathogens. The current data support the concept of repurposing olaparib as a potential experimental therapy for septic shock.

Immunogenicity of personalized dendritic-cell therapy in HIV-1 infected individuals under suppressive antiretroviral treatment: interim analysis from a phase II clinical trial.

BACKGROUND: We developed a personalized Monocyte-Derived Dendritic-cell Therapy (MDDCT) for HIV-infected individuals on suppressive antiretroviral treatment and evaluated HIV-specific T-cell responses. METHODS: PBMCs were obtained from 10 HIV+ individuals enrolled in trial NCT02961829. Monocytes were differentiated into DCs using IFN-α and GM-CSF. After sequencing each patient's HIV-1 Gag and determining HLA profiles, autologous Gag peptides were selected based on the predicted individual immunogenicity and used to pulse MDDCs. Three doses of the MDDCT were administered every 15 days. To assess immunogenicity, patients' cells were stimulated in vitro with autologous peptides, and intracellular IL-2, TNF, and interferon-gamma (IFN-γ) production were measured in CD4+ and CD8+ T-cells. RESULTS: The protocol of ex-vivo treatment with IFN-α and GM-CSF was able to induce maturation of MDDCs, as well as to preserve their viability for reinfusion. MDDCT administration was associated with increased expression of IL-2 in CD4+ and CD8+ T-cells at 15 and/or 30 days after the first MDDCT administration. Moreover, intracellular TNF and IFN-γ expression was significantly increased in CD4+ T-cells. The number of candidates that increased in vitro the cytokine levels in CD4+ and CD8+ T cells upon stimulation with Gag peptides from baseline to day 15 and from baseline to day 30 and day 120 after MDDCT was significant as compared to Gag unstimulated response. This was accompanied by an increasing trend in the frequency of polyfunctional T-cells over time, which was visible when considering both cells expressing two and three out of the three cytokines examined. CONCLUSIONS: MDDC had a mature profile, and this MDDCT promoted in-vitro T-cell immune responses in HIV-infected patients undergoing long-term suppressive antiretroviral treatment. Trial registration NCT02961829: (Multi Interventional Study Exploring HIV-1 Residual Replication: a Step Towards HIV-1 Eradication and Sterilizing Cure, https://www.clinicaltrials.gov/ct2/show/NCT02961829 , posted November 11th, 2016).

The clinical course of hospitalized moderately ill COVID-19 patients is mirrored by routine hematologic tests and influenced by renal transplantation.

Several studies of patients with COVID-19 have evaluated biological markers for predicting outcomes, most of them retrospectively and with a wide scope of clinical severity. We followed a prospective cohort of patients admitted in hospital wards with moderate COVID-19 disease, including those with a history of kidney transplantation, and examined the ability of changes in routine hematologic laboratory parameters to predict and mirror the patients' clinical course regarding the severity of their condition (classified as critical vs. non-critical) and in-hospital mortality or hospital discharge. Among the 68 patients, 20 (29%) were kidney transplanted patients (KT), and they had much higher mortality than non-kidney transplanted patients in this cohort (40% X 8.3%). Lymphocytes, neutrophils and neutrophils/lymphocytes ratio (NLR) at admission and platelets as well as the red blood cells parameters hemoglobin, hematocrit, and RDW by the time of hospital discharge or death clearly differentiated patients progressing to critical disease and those with clinical recovery. Patients with deteriorating clinical courses presented elevated and similar NLRs during the first week of hospitalization. However, they were dramatically different at hospital discharge, with a decrease in the survivors (NLR around 5.5) and sustained elevation in non-survivors (NLR around 21). Platelets also could distinguish survivors from non-survivors among the critical patients. In conclusion, routine hematologic tests are useful to monitor the clinical course of COVID-19 patients admitted with moderate disease. Unexpectedly, changes in hematologic tests, including lymphopenia, were not predictive of complicated outcomes among KT recipients.

Combined Transcriptome and Proteome Leukocyte's Profiling Reveals Up-Regulated Module of Genes/Proteins Related to Low Density Neutrophils and Impaired Transcription and Translation Processes in Clinical Sepsis.

Sepsis is a global health emergency, which is caused by various sources of infection that lead to changes in gene expression, protein-coding, and metabolism. Advancements in "omics" technologies have provided valuable tools to unravel the mechanisms involved in the pathogenesis of this disease. In this study, we performed shotgun mass spectrometry in peripheral blood mononuclear cells (PBMC) from septic patients (N=24) and healthy controls (N=9) and combined these results with two public microarray leukocytes datasets. Through combination of transcriptome and proteome profiling, we identified 170 co-differentially expressed genes/proteins. Among these, 122 genes/proteins displayed the same expression trend. Ingenuity Pathway Analysis revealed pathways related to lymphocyte functions with decreased status, and defense processes that were predicted to be strongly increased. Protein-protein interaction network analyses revealed two densely connected regions, which mainly included down-regulated genes/proteins that were related to the transcription of RNA, translation of proteins, and mitochondrial translation. Additionally, we identified one module comprising of up-regulated genes/proteins, which were mainly related to low-density neutrophils (LDNs). LDNs were reported in sepsis and in COVID-19. Changes in gene expression level were validated using quantitative real-time PCR in PBMCs from patients with sepsis. To further support that the source of the upregulated module of genes/proteins found in our results were derived from LDNs, we identified an increase of this population by flow cytometry in PBMC samples obtained from the same cohort of septic patients included in the proteomic analysis. This study provides new insights into a reprioritization of biological functions in response to sepsis that involved a transcriptional and translational shutdown of genes/proteins, with exception of a set of genes/proteins related to LDNs and host-defense system.

HIF-1α and Hypoxia Responsive Genes are Differentially Expressed in Leukocytes From Survivors and Non-Survivors Patients During Clinical Sepsis.

ABSTRACT: Hypoxia inducible factor 1 alpha (HIF-1α) is linked to the metabolic and immune alterations in septic patients. Stabilization of HIF-1α by hypoxia or inflammation promotes the expression of several genes related to glycolytic metabolism, angiogenesis, coagulation, cell proliferation, and apoptosis. Here, we analyzed public available blood transcriptome datasets from septic patients and evaluated by PCR array the expression of HIF-1α and other hypoxia responsive genes in peripheral blood mononuclear cells from patients with sepsis secondary to community acquired infections. Samples were collected at intensive care unit admission (D0, n=29) and after 7 days follow-up (D7, n = 18); healthy volunteers (n = 10) were included as controls. Hypoxia and glycolysis were among the top scored molecular signatures in the transcriptome datasets. PCR array showed that 24 out of 78 analyzed genes were modulated in septic patients compared with healthy volunteers; most of them (23/24) were downregulated at admission. This same pattern was observed in surviving patients, while non-survivors presented more upregulated genes. EGLN1, EGLN2, and HIF1AN, inhibitors of HIF-1α activation were downregulated in patients, regardless of the outcome, while HIF-1α and other target genes, such as PDK1 and HMOX1, expression were higher in non-survivors than in survivors, mainly at D7. Non-survivor patients also presented a higher SOFA score and lower PaO2/FiO2 ratio. Our results indicate a differential modulation of hypoxia pathway in leukocytes between septic patients who survived and those who did not survive with an increased intensity at D7, which is possibly influenced by disease severity and may affect the immune response in sepsis.

Epigenetic Regulation in Sepsis, Role in Pathophysiology and Therapeutic Perspective.

Sepsis is characterized by an initial hyperinflammatory response, with intense cell activation and cytokine storm. In parallel, a prolonged compensatory anti-inflammatory response, known as immunological tolerance, can lead to immunosuppression. Clinically, this condition is associated with multiple organ failure, resulting in the patient's death. The mechanisms underlying the pathophysiology of sepsis are not yet fully understood, but evidence is strong showing that epigenetic changes, including DNA methylation and post-translational modifications of histones, modulate the inflammatory response of sepsis. During the onset of infection, host cells undergo epigenetic changes that favor pathogen survival. Besides, epigenetic changes in essential genes also orchestrate the patient's inflammatory response. In this review, we gathered studies on sepsis and epigenetics to show the central role of epigenetic mechanisms in various aspects of the pathogenesis of sepsis and the potential of epigenetic interventions for its treatment.

Repurposing of Clinically Approved Poly-(ADP-Ribose) Polymerase Inhibitors for the Therapy of Sepsis.

ABSTRACT: Sepsis' pathogenesis involves multiple mechanisms that lead to a dysregulation of the host's response. Significant efforts have been made in search of interventions that can reverse this situation and increase patient survival. Poly (ADP-polymerase) (PARP) is a constitutive nuclear and mitochondrial enzyme, which functions as a co-activator and co-repressor of gene transcription, thus regulating the production of inflammatory mediators. Several studies have already demonstrated an overactivation of PARP1 in various human pathophysiological conditions and that its inhibition has benefits in regulating intracellular processes. The PARP inhibitor olaparib, originally developed for cancer therapy, paved the way for the expansion of its clinical use for nononcological indications. In this review we discuss sepsis as one of the possible indications for the use of olaparib and other clinically approved PARP inhibitors as modulators of the inflammatory response and cellular dysfunction. The benefit of olaparib and other clinically approved PARP inhibitors has already been demonstrated in several experimental models of human diseases, such as neurodegeneration and neuroinflammation, acute hepatitis, skeletal muscle disorders, aging and acute ischemic stroke, protecting, for example, from the deterioration of the blood-brain barrier, restoring the cellular levels of NAD+, improving mitochondrial function and biogenesis and, among other effects, reducing oxidative stress and pro-inflammatory mediators, such as TNF-α, IL1-ß, IL-6, and VCAM1. These data demonstrated that repositioning of clinically approved PARP inhibitors may be effective in protecting against hemodynamic dysfunction, metabolic dysfunction, and multiple organ failure in patients with sepsis. Age and gender affect the response to PARP inhibitors, the mechanisms underlying the lack of many protective effects in females and aged animals should be further investigated and be cautiously considered in designing clinical trials.

Assessment of the Effect of Perioperative Venous Lidocaine on the Intensity of Pain and IL-6 Concentration After Laparoscopic Gastroplasty.

BACKGROUND AND OBJECTIVES: Opioids are associated with sedation and respiratory depression. The primary objective of this study was to assess pain intensity after gastric bypass with lidocaine. The secondary objective was to assess the IL-6 concentration, consumption of morphine, time to morphine request, time to extubation, and side effects. METHODS: Sixty patients aged 18 to 60 years, with ASA (American Society of Anesthesiologists) scores of 2 or 3, who underwent bariatric surgery were allocated to two groups. Patients in group 1 were administered lidocaine (1.5 mg/kg) 5 min before the induction of anesthesia, and group 2 was administered 0.9% saline solution in an equal volume. Subsequently, lidocaine (2 mg/kg/h) or 0.9% saline was infused during the entire surgical procedure. Anesthesia was performed with fentanyl (5 µg/kg), propofol, rocuronium, and sevoflurane. Postoperative patient-controlled analgesia was provided with morphine. The following were evaluated: pain intensity, IL-6, 24-h consumption of morphine, time to the morphine request, time to extubation, and adverse effects. RESULTS: The lidocaine group had a lower pain intensity than the saline group for up to 1 h, with no differences between groups in IL-6 and time to extubation. The lidocaine group consumed less morphine within 24 h, had a longer time until the first supplemental morphine request, and had a lower incidence of nausea. CONCLUSIONS: Lidocaine reduced the intensity of early postoperative pain, incidence of nausea, and consumption of morphine within 24 h and increased time to the first morphine request, without reducing the plasma concentrations of IL-6.

Chronic meningococcemia in a vertically HIV-infected adolescent.

Chronic meningococcemia is a rare manifestation of meningococcal disease, characterized by a period of more than one week of intermittent or continuous fever, arthralgia and skin lesions without meningitis. It can occur both in previously healthy and immunocompromised patients. The gold standard for the diagnosis is culture isolation of Neisseria meningitidis in sterile material. We describe a case of a vertically HIV-infected adolescent with chronic meningococcal disease.

Genetic signature related to heme-hemoglobin metabolism pathway in sepsis secondary to pneumonia.

Sepsis is defined as a life-threatening organ dysfunction caused by a dysregulated inflammatory response to pathogens. Bioinformatics and transcriptomics studies contribute to get a better understanding of the pathogenesis of sepsis. These studies revealed differentially expressed genes (DEGs) in sepsis involved in several pathways. Here we investigated the gene expression profiles of blood leukocytes using three microarray datasets of sepsis secondary to pneumonia, focusing on the heme/hemoglobin metabolism pathway. We demonstrate that the heme/hemoglobin metabolism pathway was found to be enriched in these three cohorts with four common genes (ALAS2, AHSP, HBD, and CA1). Several studies show that these four genes are involved in the cytoprotection of non-erythrocyte cells in response to different stress conditions. The upregulation of heme/hemoglobin metabolism in sepsis might be a protective response of white cells to the hostile environment present in septic patients (follow-up samples).

New therapeutic target for pediatric anaplastic ependymoma control: study of anti-tumor activity by a Kunitz-type molecule, Amblyomin-X.

EPNs comprise a heterogeneous group of neuroepithelial tumors, accounting for about 10% of all intracranial tumors in children and up to 30% of brain tumors in those younger than 3 years. Actually, the pattern therapy for low-grade EPNs includes complete surgical resection followed by radiation therapy. Total surgical excision is often not possible due to tumor location. The aim of this study was to evaluate, for the first time, the anti-tumor activity of Amblyomin-X in 4 primary cultures derived from pediatric anaplastic posterior fossa EPN, Group A (anaplastic, WHO grade III) and one primary culture of a high grade neuroepithelial tumor with MN1 alteration, which was initially misdiagnosed as EPN: i) by in vitro assays: comparisons of temozolomide and cisplatin; ii) by intracranial xenograft model. Amblyomin-X was able to induce cell death in EPN cells in a more significant percentage compared to cisplatin. The cytotoxic effects of Amblyomin-X were not detected on hFSCs used as control, as opposed to cisplatin-treatment, which promoted a substantial effect in the hAFSCs viability. TEM analysis showed ultrastructural alterations related to the process of cell death: mitochondrial degeneration, autophagosomes and aggregate-like structures. MRI and histopathological analyzes demonstrated significant tumor mass regression. Our results suggest that Amblyomin-X has a selective effect on tumor cells by inducing apoptotic cell death and may be a therapeutic option for Group AEPNs.