Glycine by enteral route does not improve major clinical outcomes in severe COVID-19: a randomized clinical pilot trial.

There is a worrying scarcity of drug options for patients with severe COVID-19. Glycine possesses anti-inflammatory, cytoprotective, endothelium-protective, and platelet-antiaggregant properties, so its use in these patients seems promising. In this open label, controlled clinical trial, inpatients with severe COVID-19 requiring mechanical ventilation randomly received usual care (control group) or usual care plus 0.5 g/kg/day glycine by the enteral route (experimental group). Major outcomes included mortality, time to weaning from mechanical ventilation, total time on mechanical ventilation, and time from study recruitment to death. Secondary outcomes included laboratory tests and serum cytokines. Patients from experimental (n = 33) and control groups (n = 23) did not differ in basal characteristics. There were no differences in mortality (glycine group, 63.6% vs control group, 52.2%, p = 0.60) nor in any other major outcome. Glycine intake was associated with lower fibrinogen levels, either evaluated per week of follow-up (p < 0.05 at weeks 1, 2, and 4) or as weighted mean during the whole hospitalization (608.7 ± 17.7 mg/dl vs control 712.2 ± 25.0 mg/dl, p = 0.001), but did not modify any other laboratory test or cytokine concentration. In summary, in severe COVID-19 glycine was unable to modify major clinical outcomes, serum cytokines or most laboratory tests, but was associated with lower serum fibrinogen concentration.Registration: ClinicalTrials.gov NCT04443673, 23/06/2020.

The systemic-level repercussions of cancer-associated inflammation mediators produced in the tumor microenvironment.

The tumor microenvironment is a dynamic, complex, and redundant network of interactions between tumor, immune, and stromal cells. In this intricate environment, cells communicate through membrane-membrane, ligand-receptor, exosome, soluble factors, and transporter interactions that govern cell fate. These interactions activate the diverse and superfluous signaling pathways involved in tumor promotion and progression and induce subtle changes in the functional activity of infiltrating immune cells. The immune response participates as a selective pressure in tumor development. In the early stages of tumor development, the immune response exerts anti-tumor activity, whereas during the advanced stages, the tumor establishes mechanisms to evade the immune response, eliciting a chronic inflammation process that shows a pro-tumor effect. The deregulated inflammatory state, in addition to acting locally, also triggers systemic inflammation that has repercussions in various organs and tissues that are distant from the tumor site, causing the emergence of various symptoms designated as paraneoplastic syndromes, which compromise the response to treatment, quality of life, and survival of cancer patients. Considering the tumor-host relationship as an integral and dynamic biological system, the chronic inflammation generated by the tumor is a communication mechanism among tissues and organs that is primarily orchestrated through different signals, such as cytokines, chemokines, growth factors, and exosomes, to provide the tumor with energetic components that allow it to continue proliferating. In this review, we aim to provide a succinct overview of the involvement of cancer-related inflammation at the local and systemic level throughout tumor development and the emergence of some paraneoplastic syndromes and their main clinical manifestations. In addition, the involvement of these signals throughout tumor development will be discussed based on the physiological/biological activities of innate and adaptive immune cells. These cellular interactions require a metabolic reprogramming program for the full activation of the various cells; thus, these requirements and the by-products released into the microenvironment will be considered. In addition, the systemic impact of cancer-related proinflammatory cytokines on the liver-as a critical organ that produces the leading inflammatory markers described to date-will be summarized. Finally, the contribution of cancer-related inflammation to the development of two paraneoplastic syndromes, myelopoiesis and cachexia, will be discussed.

Role of HMGB1 in Cisplatin-Persistent Lung Adenocarcinoma Cell Lines.

Significant advances have been made recently in the development of targeted therapy for lung adenocarcinoma. However, platinum-based chemotherapy remains as the cornerstone in the treatment of this neoplasm. This is the treatment option for adenocarcinomas without EGFR gain-of-function mutations or tumors that have developed resistance to targeted therapy. The High-Mobility Group Box 1 (HMGB1) is a multifunctional protein involved in intrinsic resistance to cisplatin. HMGB1 is released when cytotoxic agents, such as cisplatin, induce cell death. In the extracellular milieu, HMGB1 acts as adjuvant to induce an antitumor immune response. However, the opposite effect favoring tumor progression has also been reported. In this study, the effects of cisplatin in lung adenocarcinoma cell lines harboring clinically relevant mutations, such as EGFR mutations, were studied. Subcellular localization of HMGB1 was detected in the cell lines and in viable cells after a single exposure to cisplatin, which are designated as cisplatin-persistent cells. The mRNA expression of the receptor for advanced glycation end products (RAGE), TLR-2, and TLR-4 receptors was measured in parental cell lines and their persistent variants. Finally, changes in plasma HMGB1 from a cohort of lung adenocarcinoma patients without EGFR mutation and treated with cisplatin-based therapy were analyzed. Cisplatin-susceptible lung adenocarcinoma cell lines died by apoptosis or necrosis and released HMGB1. In cisplatin-persistent cells, nuclear relocalization of HMGB1 and overexpression of HMGB1 and RAGE, but not TLR-2 or TLR-4, were observed. In tumor cells, this HMGB1-RAGE interaction may be associated with the development of cisplatin resistance. The results indicate a direct relationship between the plasma levels of HMGB1 and overall survival. In conclusion, HMGB1 may be an effective biomarker associated with increased overall survival of lung adenocarcinoma patients.

Case-control study about magnitude of exposure to wood smoke and risk of developing lung cancer.

INTRODUCTION: Exposure to biomass combustion products, particularly firewood, has been considered as a potential carcinogen for developing lung cancer. In this regard, current evidence is widely heterogeneous; besides, in most studies, wood smoke exposure is not appropriately quantified, which further complicates the analysis of wood smoke as a potential carcinogen. The aim of the present study was to estimate the risk of developing lung cancer according to the degree of exposure to wood smoke in patients who use firewood for cooking. MATERIAL AND METHODS: We performed a case-control study that included 482 patients with lung cancer (cases) and 592 hospital controls. Exposure to wood smoke was evaluated as a dichotomous variable (i.e. yes or no); in patients with prior wood smoke exposure, an index of exposure in hours per year was calculated (WSEI). Using bivariate and multivariate logistic regression analyses, the odds ratio (OR) between wood smoke exposure and lung cancer were calculated. RESULTS: The ORs for developing lung cancer (raw and adjusted) for a WSEI > 100 h/year were OR 1.55 [95% confidence interval (CI), 1.06-2.26) and OR 2.26 (95% CI, 1.50-3.40), respectively; the ORs (raw and adjusted) for WSEI >300 h/year were OR 1.76 (95% CI, 1.06-2.91) and OR 3.19 (95% CI, 1.83-5.55), respectively. CONCLUSIONS: Exposure to wood smoke is a risk factor for lung cancer; furthermore, this effect maintains a dose-response relationship which has a multiplicative effect with smoking.

IL-6, NLR, and SII Markers and Their Relation with Alterations in CD8+ T-Lymphocyte Subpopulations in Patients Treated for Lung Adenocarcinoma.

Cytokines, key contributors to tumorigenesis, are mediators between inflammatory immune or nonimmune and cancer cells. Here, IL-6 production by tumor cells was assessed in a cohort of patients with lung adenocarcinoma treated with conventional therapy. IL-6 levels and neutrophil-lymphocyte ratio (NLR) or systemic immune-inflammation index (SII) markers were evaluated. Changes in pro- and anti-inflammatory cytokines, HMGB1 concentration, and CD4+ and CD8+ T-lymphocyte populations and their subpopulations were investigated. IL-6 expression was detected immunohistochemically in lung adenocarcinoma biopsies. Cytokines were quantified using the cytometric bead array, and TGF-ß and HMGB-1 through ELISA. Clinical parameters were collected to assess NLR and SII. CD4+ and CD8+ T-lymphocytes and naïve, memory, and effector subpopulations were quantified by flow cytometry. The data obtained were associated with patients' median overall survival (OS). IL-6 showed the highest increase, probably because the lung adenocarcinoma cells produced IL-6. Patients with higher OS had lower NLR and SII from the third cycle of chemotherapy. Patients with lower OS had significantly lower percentages of CD8+ T-lymphocyte and its effector subpopulations, with a concomitant increase in the naïve subpopulation. This study suggests that in addition to the known inflammatory markers, IL-6, CD8+ T-lymphocytes and their effector and naïve subpopulations could be useful as predictive markers in lung adenocarcinoma.

Deficient glucose uptake is linked to impaired Glut1 expression upon CD3/CD28 stimulation in memory T cells from pleural effusions secondary to lung cancer.

Glucose and nutrient uptake is essential in supporting T cell activation and is increased upon CD3/CD28 stimulation. As T cells from pleural effusions secondary to lung cancer show impaired function, we hypothesized that these cells might have altered expression of nutrient transporters. Here, we analysed by flow cytometry the expression of the transferrin receptor CD71, amino acid transporter CD98 and glucose transporter Glut1 and glucose uptake in pleural effusion-derived T cells from lung cancer patients, after stimulation via CD3/CD28 under normoxia or hypoxia (2% O2 ). We compared the response of T cells from pleural effusions secondary to lung cancer with that of T cells from nonmalignant effusions. In memory T cells from both groups, anti-CD3/CD28-stimulation under normoxia upregulated CD98 and CD71 expression (measured as median fluorescence intensity, MFI) in comparison with anti-CD3-stimulation. Costimulation under hypoxia tended to increase CD98 expression compared to CD3-stimulation in memory T cells from both groups. Remarkably, in the cancer group, memory T cells stimulated via CD3/CD28 under hypoxia failed to increase CD71 and Glut1 expression levels compared to the cells receiving anti-CD3 stimulation, a phenomenon that contrasted with the behaviour of memory T cells from nonmalignant effusions. Consequently, glucose uptake by memory T cells from the cancer group was not increased after CD3/CD28 stimulation under hypoxia, implying that their glycolytic metabolism is defective. As this process is required for inducing an antitumoural response, our study suggests that memory T cells are rendered dysfunctional and are unable to eliminate lung tumour cells.

Accuracy of closed pleural biopsy in the diagnosis of malignant pleural effusion / Exactitud de la biopsia pleural cerrada para el diagnóstico de derrame pleural maligno

ABSTRACT Objective: Previous studies have demonstrated that closed pleural biopsy (CPB) has a sensitivity of less than 60% for diagnosing malignancy. Therefore, controversy has recently emerged regarding the value of CPB as a diagnostic test. Our objective was to assess the accuracy of CPB in diagnosing malignancy in patients with pleural effusion. Methods: This was a prospective 8-year study of individuals who underwent CPB to establish the etiology of pleural effusion. Information on each patient was obtained from anatomopathological reports and medical records. When CPB findings showed malignancy or tuberculosis, the biopsy was considered diagnostic, and that was the definitive diagnosis. In cases in which biopsy histopathological findings were nonspecific, a definitive diagnosis was established on the basis of other diagnostic procedures, such as thoracoscopy, thoracotomy, fiberoptic bronchoscopy, biochemical and cellular measurements in pleural fluid, and/or microbiological tests. The accuracy of CPB was determined with 2 × 2 contingency tables. Results: A total of 1034 biopsies from patients with pleural effusion were studied. Of those, 171 (16.54%) were excluded from the accuracy analysis either because of inadequate samples or insufficient information. The results of the accuracy analysis were as follows: sensitivity, 77%; specificity, 98%; positive predictive value, 99%; negative predictive value, 66%; positive likelihood ratio, 38.5; negative likelihood ratio, 0.23; pre-test probability, 2.13; and post-test probability, 82. Conclusions: CPB is useful in clinical practice as a diagnostic test, because there is an important change from pre-test to post-test probability.

RESUMEN Objetivo: Estudios previos demuestran que la biopsia pleural cerrada (BPC) para diagnóstico de malignidad tiene una sensibilidad menor al 60%, por lo que recientemente ha despertado controversia su valor como prueba diagnóstica. Nuestro objetivo fue evaluar la exactitud de la BPC para diagnóstico de malignidad en pacientes con derrame pleural. Métodos: Estudio prospectivo de 8 años en individuos que se sometieron a la realización de BPC para establecer la etiología del derrame. La información de cada paciente se tomó de los registros de anatomopatología y del expediente clínico. Cuando el resultado de la BPC demostró malignidad o tuberculosis, esto se tomó como biopsia diagnóstica y quedó éste como diagnóstico definitivo. En los casos en que el resultado del estudio histopatológico de la biopsia resultó inespecífico, el diagnóstico definitivo se estableció en base a otros procedimientos diagnósticos, como toracoscopia, toracotomía, fibrobroncoscopia, estudio bioquímico y celular del líquido pleural y/o pruebas microbiológicas. Mediante una tabla de contingencia de 2 × 2 se midieron los indicadores para una prueba diagnóstica. Resultados: Se estudiaron 1034 biopsias de pacientes con derrame pleural, de las cuales se excluyeron 171 (16.54%) por muestra inadecuada o información insuficiente. El desempeño para malignidad fue: sensibilidad, 77%; especificidad, 98%; valores predictivos positivo y negativo, 99% y 66%, respectivamente; índices de probabilidad positivo y negativo, 38.5 y 0.23, respectivamente; probabilidad antes y después de la prueba, 2.13 y 82, respectivamente. Conclusión: La BPC es útil como prueba diagnóstica en la práctica clínica, debido a que produce un cambio importante de la probabilidad antes de la prueba a la probabilidad después de la prueba.

The PD-L1/PD-1 pathway promotes dysfunction, but not "exhaustion", in tumor-responding T cells from pleural effusions in lung cancer patients.

Malignant pleural effusions are frequent in patients with advanced stages of lung cancer and are commonly infiltrated by lymphocytes and tumor cells. CD8+ T cells from these effusions have reduced effector functions. The programmed death receptor 1(PD-1)/programmed death ligand 1 (PD-L1) pathway is involved in T-cell exhaustion, and it might be responsible for T-cell dysfunction in lung cancer patients. Here, we show that PD-L1 is expressed on tumor cell samples from malignant effusions, on lung cancer cell lines, and, interestingly, on MRC-5 lung fibroblasts. PD-L1 was up-regulated in lung cancer cell lines upon treatment with IFN-gamma, but not under hypoxic conditions, as detected by RT-qPCR and flow cytometry. Blockade of PD-L1 on tumor cells restored granzyme-B expression in allogenic CD8+ T cells in vitro. Remarkably, pleural effusion CD8+ T cells that responded to the tumor antigens MAGE-3A and WT-1 (identified as CD137+ cells) were lower in frequency than CMV pp65-responding CD8+ T cells and did not have an exhausted phenotype (PD-1+ TIM-3+). Nonetheless, tumor-responding CD8+ T cells had a memory phenotype and expressed higher levels of PD-1. A PD-L1 blocking antibody increased the expression of granzyme-B and perforin on polyclonal- and tumor-stimulated CD8+ T cells. Taken together, our data show that rather than being exhausted, tumor-responding CD8+ T cells are not completely differentiated into effector cells and are prone to negative regulation by PD-L1. Hence, our study provides evidence that lung cancer patients respond to immunotherapy due to blockade of the PD-L1/PD-1 pathway.

Accuracy of closed pleural biopsy in the diagnosis of malignant pleural effusion.

OBJECTIVE: Previous studies have demonstrated that closed pleural biopsy (CPB) has a sensitivity of less than 60% for diagnosing malignancy. Therefore, controversy has recently emerged regarding the value of CPB as a diagnostic test. Our objective was to assess the accuracy of CPB in diagnosing malignancy in patients with pleural effusion. METHODS: This was a prospective 8-year study of individuals who underwent CPB to establish the etiology of pleural effusion. Information on each patient was obtained from anatomopathological reports and medical records. When CPB findings showed malignancy or tuberculosis, the biopsy was considered diagnostic, and that was the definitive diagnosis. In cases in which biopsy histopathological findings were nonspecific, a definitive diagnosis was established on the basis of other diagnostic procedures, such as thoracoscopy, thoracotomy, fiberoptic bronchoscopy, biochemical and cellular measurements in pleural fluid, and/or microbiological tests. The accuracy of CPB was determined with 2 × 2 contingency tables. RESULTS: A total of 1034 biopsies from patients with pleural effusion were studied. Of those, 171 (16.54%) were excluded from the accuracy analysis either because of inadequate samples or insufficient information. The results of the accuracy analysis were as follows: sensitivity, 77%; specificity, 98%; positive predictive value, 99%; negative predictive value, 66%; positive likelihood ratio, 38.5; negative likelihood ratio, 0.23; pre-test probability, 2.13; and post-test probability, 82. CONCLUSIONS: CPB is useful in clinical practice as a diagnostic test, because there is an important change from pre-test to post-test probability.

La exploración del tórax: una guía para descifrar sus mensajes / Thoracic exploration: a guide to decipher their messages

Resumen La exploración adecuada del tórax tiene una secuencia que ayuda al clínico a seguir varios pasos e integrar sus hallazgos en síndromes, mismos que lo llevarán con más seguridad hacia el diagnóstico más adecuado. Al cumplirse los 200 años de la invención del estetoscopio por René Laënec, tomamos esta oportunidad para recordarlo y detallar los pasos de la exploración del tórax. El hecho de contar con más herramientas tecnológicas para el diagnóstico, no le resta importancia a esta etapa tan importante de la relación entre el médico y su paciente, que es la exploración.

Abstract Thoracic exploration has a sequence of steps that help the clinician to integrate its findings in syndromes, which will lead the physician to better diagnosis. This year the stethoscope, invented by René Laënec, turns 200 years old and we use this opportunity to remember him and provide a detailed description of the thoracic exploration. To have access to more sophisticated diagnostic tools should not diminish the relevance of a direct exploration of the patient, which is a very important step in the patient-physician relationship.

Predominance of Th17 over regulatory T-cells in pleural effusions of patients with lung cancer implicates a proinflammatory profile.

BACKGROUND: Regulatory T-(Treg) and pro-inflammatory T-helper 17 (Th17) cells have been reported to be involved in the pathogenesis of pleural effusions caused by lung cancer. However, the presence of these subsets might not be a consequence of tumor pathogenesis, but rather a result of the pleural effusion itself, irrespective of its origin. In the present study, we analyzed the balance between these CD4+ T-cell subsets and compared them with those in non-malignant pleural effusions. PATIENTS AND METHODS: We detected the frequencies of Treg and Th17 cells, identified as cluster of differentiation (CD)3+CD4+CD25+CD127low/- and CD3+CD4+ retinoid-related orphan receptor γt (RORγt)+ cells respectively, and proportions of interleukin (IL)17A-producing CD4+ cells in pleural effusions of patients with lung cancer, tuberculous and non-chronic pathologies by flow cytometry. The cytokine profile of stimulated CD4+ T-cells from tuberculosis and cancer groups was compared. RESULTS: The proportion of Th17 cells were increased whereas Tregs were decreased in both tuberculosis and cancer, but not in non-chronic pathologies. Nevertheless, CD4+ T-cells from lung cancer effusions secreted interferon (IFN)γ, IL6 and IL17A, whereas CD4+ T-cells from tuberculous effusions secreted IL10 and low levels of IFNγ. CONCLUSION: Although effusions from patients with chronic pathologies presented higher proportions of Th17 cells in comparison to those with non-chronic pathologies, only Th17 cells from malignant effusions maintained their proinflammatory profile after stimulation. Thus, in the pleural compartment of patients with lung cancer, a proinflammatory environment might be favored and possibly maintained by Th17 response.