Purinergic P2X7 receptor expression increases in leukocytes from intra-abdominal septic patients.

Inflammation is a tightly coordinated response of the host immune system to bacterial and viral infections, triggered by the production of inflammatory cytokines. Sepsis is defined as a systemic inflammatory response followed by immunosuppression of the host and organ dysfunction. This imbalance of the immune response increases the risk of mortality of patients with sepsis, making it a major problem for critical care units worldwide. The P2X7 receptor plays a crucial role in activating the immune system by inducing the activation of peripheral blood mononuclear cells. In this study, we analyzed a cohort of abdominal origin septic patients and found that the expression of the P2X7 receptor in the plasma membrane is elevated in the different subsets of lymphocytes. We observed a direct relationship between the percentage of P2X7-expressing lymphocytes and the early inflammatory response in sepsis. Additionally, in patients whose lymphocytes presented a higher percentage of P2X7 surface expression, the total lymphocytes populations proportionally decreased. Furthermore, we found a correlation between elevated soluble P2X7 receptors in plasma and inflammasome-dependent cytokine IL-18. In summary, our work demonstrates that P2X7 expression is highly induced in lymphocytes during sepsis, and this correlates with IL-18, along with other inflammatory mediators such as IL-6, IL-8, and procalcitonin.

NLRP3 inflammasome activation and symptom burden in KRAS-mutated CMML patients is reverted by IL-1 blocking therapy.

Chronic myelomonocytic leukemia (CMML) is frequently associated with mutations in the rat sarcoma gene (RAS), leading to worse prognosis. RAS mutations result in active RAS-GTP proteins, favoring myeloid cell proliferation and survival and inducing the NLRP3 inflammasome together with the apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC), which promote caspase-1 activation and interleukin (IL)-1ß release. Here, we report, in a cohort of CMML patients with mutations in KRAS, a constitutive activation of the NLRP3 inflammasome in monocytes, evidenced by ASC oligomerization and IL-1ß release, as well as a specific inflammatory cytokine signature. Treatment of a CMML patient with a KRASG12D mutation using the IL-1 receptor blocker anakinra inhibits NLRP3 inflammasome activation, reduces monocyte count, and improves the patient's clinical status, enabling a stem cell transplant. This reveals a basal inflammasome activation in RAS-mutated CMML patients and suggests potential therapeutic applications of NLRP3 and IL-1 blockers.

The prognostic impact of SIGLEC5-induced impairment of CD8+ T cell activation in sepsis.

BACKGROUND: Sepsis is associated with T-cell exhaustion, which significantly reduces patient outcomes. Therefore, targeting of immune checkpoints (ICs) is deemed necessary for effective sepsis management. Here, we evaluated the role of SIGLEC5 as an IC ligand and explored its potential as a biomarker for sepsis. METHODS: In vitro and in vivo assays were conducted to both analyse SIGLEC5's role as an IC ligand, as well as assess its impact on survival in sepsis. A multicentre prospective cohort study was conducted to evaluate the plasmatic soluble SIGLEC5 (sSIGLEC5) as a mortality predictor in the first 60 days after admission in sepsis patients. Recruitment included sepsis patients (n = 346), controls with systemic inflammatory response syndrome (n = 80), aneurism (n = 11), stroke (n = 16), and healthy volunteers (HVs, n = 100). FINDINGS: SIGLEC5 expression on monocytes was increased by HIF1α and was higher in septic patients than in healthy volunteers after ex vivo LPS challenge. Furthermore, SIGLEC5-PSGL1 interaction inhibited CD8+ T-cell proliferation. Administration of sSIGLEC5r (0.8 mg/kg) had adverse effects in mouse endotoxemia models. Additionally, plasma sSIGLEC5 levels of septic patients were higher than HVs and ROC analysis revealed it as a mortality marker with an AUC of 0.713 (95% CI, 0.656-0.769; p < 0.0001). Kaplan-Meier survival curve showed a significant decrease in survival above the calculated cut-off (HR of 3.418, 95% CI, 2.380-4.907, p < 0.0001 by log-rank test) estimated by Youden Index (523.6 ng/mL). INTERPRETATION: SIGLEC5 displays the hallmarks of an IC ligand, and plasma levels of sSIGLEC5 have been linked with increased mortality in septic patients. FUNDING: Instituto de Salud Carlos III (ISCIII) and "Fondos FEDER" to ELC (PIE15/00065, PI18/00148, PI14/01234, PI21/00869), CDF (PI21/01178), RLR (FI19/00334) and JAO (CD21/00059).

Comparison of 20% mannitol and 3% hypertonic saline for intraoperative brain relaxation during supratentorial brain tumour craniotomy in patients with a midline shift.

PURPOSE OF THE STUDY: A prospective, randomized, double-blind study was designed to assess differences in brain relaxation between 20% mannitol and 3% hypertonic saline (HS) during elective supratentorial brain tumour surgery in patients with midline shift. MATERIAL AND METHODS: Sixty patients undergoing supratentorial craniotomy for tumour resection were enrolled to receive either 5mL/kg of 20% mannitol (n=30) or 3% HS (n=30) administered at skin incision. PCO2 in arterial blood was maintained within 35-40mmHg and arterial blood pressure was controlled within baseline values ±20%. The primary outcome was the proportion of satisfactory brain relaxation. The surgeon assessed brain relaxation on a four-point scale (1=excellent with no swelling, 2=minimal swelling, 3=serious swelling not requiring treatment, 4=severe swelling requiring treatment). Postsurgical intracranial changes determined by imaging techniques, postoperative complications, PACU and hospital stay, and mortality at 30 days were also recorded. Appropriate statistical tests were used for comparison; P<0.05 was considered as significant. This trial was registered in Eudract.ema.europa.eu (#2021-006290-40). RESULTS: There was no difference in brain relaxation: 2.00 [1.00-2.00] and 2.00 [1.75-3.00] for patients in mannitol and HS groups, respectively (P=0.804). Tumour size (OR: 0.99, 95% CI: 0.99-1.01; P=0.371), peritumoral oedema classification (OR: 0.57, 95% CI: 0.11-2.84; P=0.493), mass effect (OR: 0.86, 95% CI: 0.16-4.87; P=0.864), anaesthesia (OR: 4.88, 95% CI: 0.82-28.96; P=0.081) and midline shift (OR: 5.00, 95% CI: 0.84-29.70; P=0.077) did not have a significant influence on brain swelling in patients treated with either mannitol or HS. No significant differences in perioperative outcomes, mortality and length of PACU and hospital stay were observed. CONCLUSIONS: 5mL/kg of 20% mannitol or 3% HS result in similar brain relaxation scores in patients undergoing craniotomy for supratentorial brain tumour with midline shift.

Acute renal disease in patients with ovarian peritoneal carcinomatosis treated with cytoreduction and HIPEC: the influence of surgery and the cytostatic agent used.

BACKGROUND: The main objective of this study was to evaluate the differences between cisplatin and paclitaxel in the development of postoperative renal toxicity, using as a reference the RIFLE (Risk, Injury, Insufficiency, Loss, and End-stage renal function) and AKIN (Acute Kidney Injury Network) criteria in patients with primary or recurrent ovarian cancer with peritoneal dissemination treated with cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (HIPEC). METHODS: One hundred fifty-two patients who were treated between December 2007 and June 2017 were analyzed. RESULTS: Patients who received previous platinum-based chemotherapy had higher baseline creatinine levels than those who had not (p = 0.05). A total of 11 (7.2%) and 4 (2.6%) patients developed an acute renal dysfunction (ARD) during the postoperative period of cytoreduction and HIPEC according to the RIFLE and AKI criteria respectively. RIFLE detects a higher rate of ARD due to different parameters such as GFR (7.2% versus 2.6%, p = 0.016). Performing ostomy (p = 0.007; OR: 39.320; 95% CI = 2.74-56.13) and using of cisplatin during HIPEC treatment (p = 0.017; OR = 13.619; 95% IC = 1.600-25.95) were factors independently related to a higher rate of ARD. CONCLUSION: ARD has a multifactorial origin. Cisplatin was associated with the development of a higher rate of ARD than paclitaxel. Diagnosis of ARD did not correlate with worse survival figures.

Perception of level of knowledge, skills, and safety before and after training to perform videolaryngoscopy with the Intubox barrier system for airway management in patients with COVID-19. / Grado de percepción sobre el conocimiento, las habilidades y la seguridad antes y después de un programa de entrenamiento con videolaringoscopia y mecanismo de protección Intubox® en el manejo de la vía aérea de pacientes con COVID-19.

OBJECTIVES: The main objective was to describe physicians' perception of their knowledge, skill, and safety before and after training to perform videolaryngoscopy while using the Intubox barrier system when managing the airway of a patient with the coronavirus 2019 disease (COVID-19). The secondary objective was to assess the safety afforded by the barrier by means of visually evaluating particle dispersion during intubation. MATERIAL AND METHODS: Single-arm clinical simulation trial. The participants were physicians who received training in both a lowfidelity and a high-fidelity simulation zone. The participants assessed their knowledge, skill, and safety when using the Intubox before and after training using a specially designed and validated questionnaire. Droplet contamination was estimated visually. RESULTS: Twenty-seven physicians with a mean (SD) age of 40 (10.8) years participated; 63% were women. They perceived their knowledge, skill, and safety to be significantly higher after training. Droplet contamination was seen to decrease when airway management maneuvers were done with the barrier in place. CONCLUSION: After simulation training the emergency physicians judged their knowledge, skill, and safety to be greater when they used the barrier during airway management in patients with COVID-19. The combined use of a laryngoscope and the Intubox barrier resulted in less particle dispersion during intubation.

OBJETIVO: El objetivo principal fue describir el grado de percepción sobre el conocimiento, las habilidades y la seguridad antes y después de un programa de entrenamiento con videolaringoscopia y mecanismo de protección Intubox® en el manejo de la vía aérea de pacientes con COVID-19. El objetivo secundario fue evaluar la seguridad de los dispositivos de barrera en la intubación a través de un análisis visual de dispersión de partículas. METODO: Ensayo clínico de un solo brazo basado en simulación. Los participantes fueron médicos que realizaron un programa de formación mediante simulación clínica de baja y alta fidelidad. Se usó un instrumento diseñado y validado específico para evaluar la percepción sobre el conocimiento, las habilidades y la seguridad antes y después del programa. Se realizó un análisis visual de la contaminación por gotas. RESULTADOS: La muestra final estuvo compuesta por 27 médicos, con una edad media de 40 (DE 10,8) años y el 63% mujeres. Se obtuvo un incremento estadísticamente significativo en las dimensiones conocimiento, habilidad y seguridad tras el entrenamiento. Se observó una menor contaminación cuando se realizaron las técnicas de manejo de vía aérea con urna protectora. CONCLUSIONES: Los urgenciólogos incrementaron su percepción sobre los conocimientos, habilidades y seguridad en el manejo de la vía aérea en pacientes con COVID-19 tras un programa de formación con simulación. El uso combinado de laringoscopia y dispositivo de barrera Intubox® causó menor dispersión de partículas durante la intubación.

CD14 release induced by P2X7 receptor restricts inflammation and increases survival during sepsis.

P2X7 receptor activation induces the release of different cellular proteins, such as CD14, a glycosylphosphatidylinositol (GPI)-anchored protein to the plasma membrane important for LPS signaling via TLR4. Circulating CD14 has been found at elevated levels in sepsis, but the exact mechanism of CD14 release in sepsis has not been established. Here, we show for first time that P2X7 receptor induces the release of CD14 in extracellular vesicles, resulting in a net reduction in macrophage plasma membrane CD14 that functionally affects LPS, but not monophosphoryl lipid A, pro-inflammatory cytokine production. Also, we found that during a murine model of sepsis, P2X7 receptor activity is important for maintaining elevated levels of CD14 in biological fluids and a decrease in its activity results in higher bacterial load and exacerbated organ damage, ultimately leading to premature deaths. Our data reveal that P2X7 is a key receptor for helping to clear sepsis because it maintains elevated concentrations of circulating CD14 during infection.

When the immune system detects an infection, it often launches an inflammatory response to fight off the disease. This defense mechanism is activated by a cascade of signaling molecules that can aggravate inflammation, causing it to damage the body's own tissues and organs. This life-threatening reaction is referred to as sepsis, and kills around 11 million people each year. New approaches are therefore needed to help alleviate the damage caused by this condition. The inflammatory response is often triggered by proteins called receptors, which sit on the surface of immune cells. When these receptors are activated, they induce cells to secrete proteins that travel around the body and activate immune cells that can eliminate the infection. In 2016, a group of researchers showed that a receptor called P2X7 stimulates the release of a signaling molecule called CD14. Patients with sepsis often have elevated amounts of CD14 in their bloodstream. Yet, it remained unclear what causes this rise in CD14 and what role this molecule plays in the development of sepsis. Now, Alarcón-Vila et al. ­ including some of the researchers involved in the 2016 study ­ have investigated the role of P2X7 in mice undergoing sepsis. This was done by puncturing the mice's intestines, causing bacteria to leak out and initiate an over-active immune response. Alarcón-Vila et al. found that mice lacking the P2X7 receptor had less CD14 and struggled to eliminate the bacterial infection from their system. This increase in bacteria caused excessive damage to the mice's organs, ultimately leading to premature death. These findings suggest that P2X7 plays an important role in preventing the onset of sepsis by helping maintain high levels of CD14 following infection. This result could help to identify new therapies that reduce the mortality rates of septic infections.

P2X7 receptor induces mitochondrial failure in monocytes and compromises NLRP3 inflammasome activation during sepsis.

Sepsis is characterized by a systemic inflammatory response followed by immunosuppression of the host. Metabolic defects and mitochondrial failure are common in immunocompromised patients with sepsis. The NLRP3 inflammasome is important for establishing an inflammatory response after activation by the purinergic P2X7 receptor. Here, we study a cohort of individuals with intra-abdominal origin sepsis and show that patient monocytes have impaired NLRP3 activation by the P2X7 receptor. Furthermore, most sepsis-related deaths are among patients whose NLRP3 activation is profoundly altered. In monocytes from sepsis patients, the P2X7 receptor is associated with mitochondrial dysfunction. Furthermore, activation of the P2X7 receptor results in mitochondrial damage, which in turn inhibits NLRP3 activation by HIF-1α. We show that mortality increases in a mouse model of sepsis when the P2X7 receptor is activated in vivo. These data reveal a molecular mechanism initiated by the P2X7 receptor that contributes to NLRP3 impairment during infection.

Effect on oximetry of dyes used for sentinel lymph node biopsy.

HYPOTHESIS: There are differences between readings of peripheral blood oxygen saturation when the effect on saturation values of methylene blue is compared with that of isosulfan blue when used in sentinel lymph node biopsy in patients with breast cancer. DESIGN: Prospective randomized study. SETTING: University tertiary care center. PATIENTS: Thirty-two women undergoing surgery for breast cancer using sentinel lymph node biopsy. INTERVENTIONS: Sentinel lymph node biopsy using methylene blue (16 patients) and isosulfan blue (16 patients); there was also a control group of 6 surgical patients in whom dyes were not used. MAIN OUTCOME MEASURES: Peripheral saturation of blood using pulse oximetry, oxygen saturation by blood-gas analysis, partial oxygen pressure by blood-gas analysis, and plasma dye levels, recorded before dye injection and 15, 30, and 60 minutes afterward. RESULTS: The 2 dyes interfered with the peripheral saturation reading, but only isosulfan blue showed significant differences. The differences in blood-gas analysis values between the 2 groups and with regard to the controls were not significant. CONCLUSIONS: Methylene blue interferes less than isosulfan blue in the peripheral saturation reading. Desaturation is factitious in both cases, and does not correspond to alterations in blood-gas analysis values.