Identification of Marker Compounds and In Vitro Toxicity Evaluation of Two Portuguese Asphodelus Leaf Extracts

This article belongs to the Special Issue Discovery of Bioactive Ingredients from Natural Products III.The leaves of Asphodelus bento-rainhae subsp. bento-rainhae, an endemic Portuguese species, and Asphodelus macrocarpus subsp. macrocarpus have been used as food, and traditionally as medicine, for treating ulcers, urinary tract, and inflammatory disorders. The present study aims to establish the phytochemical profile of the main secondary metabolites, together with the antimicrobial, antioxidant and toxicity assessments of both Asphodelus leaf 70% ethanol extracts. Phytochemical screenings were conducted by the TLC and LC-UV/DAD-ESI/MS chromatographic technique, and quantification of the leading chemical classes was performed by spectrophotometric methods. Liquid-liquid partitions of crude extracts were obtained using ethyl ether, ethyl acetate, and water. For in vitro evaluations of antimicrobial activity, the broth microdilution method, and for the antioxidant activity, the FRAP and DPPH methods were used. Genotoxicity and cytotoxicity were assessed by Ames and MTT tests, respectively. Twelve known compounds including neochlorogenic acid, chlorogenic acid, caffeic acid, isoorientin, p-coumaric acid, isovitexin, ferulic acid, luteolin, aloe-emodin, diosmetin, chrysophanol, and β-sitosterol were identified as the main marker compounds, and terpenoids and condensed tannins were found to be the major class of secondary metabolites of both medicinal plants. The ethyl ether fractions demonstrated the highest antibacterial activity against all the Gram-positive microorganisms, (MIC value of 62 to 1000 µg/mL), with aloe-emodin as one of the main marker compounds highly active against Staphylococcus epidermidis (MIC value of 0.8 to 1.6 µg/mL). Ethyl acetate fractions exhibited the highest antioxidant activity (IC50 of 800 to 1200 µg/mL, respectively). No cytotoxicity (up to 1000 µg/mL) or genotoxicity/mutagenicity (up to 5 mg/plate, with/without metabolic activation) were detected. The obtained results contribute to the knowledge of the value and safety of the studied species as herbal medicines.This research was funded by the Foundation for Science and Technology (FCT, Portugal) through national funds FCT/MCTES to iMed.ULisboa (UIDP/04138/2020, UIDB/04138/2020) and MEtRICs (UIDP/04077/2020, UIDB/04077/2020) research projects, as well as doctoral scholarship (SFRH/BD/125310/2016) granted to the first author.info:eu-repo/semantics/publishedVersio

COVID-19 symptoms at hospital admission vary with age and sex: results from the ISARIC prospective multinational observational study

Background: The ISARIC prospective multinational observational study is the largest cohort of hospitalized patients with COVID-19. We present relationships of age, sex, and nationality to presenting symptoms. Methods: International, prospective observational study of 60 109 hospitalized symptomatic patients with laboratory-confirmed COVID-19 recruited from 43 countries between 30 January and 3 August 2020. Logistic regression was performed to evaluate relationships of age and sex to published COVID-19 case definitions and the most commonly reported symptoms. Results: ‘Typical’ symptoms of fever (69%), cough (68%) and shortness of breath (66%) were the most commonly reported. 92% of patients experienced at least one of these. Prevalence of typical symptoms was greatest in 30- to 60-year-olds (respectively 80, 79, 69%; at least one 95%). They were reported less frequently in children (≤ 18 years: 69, 48, 23; 85%), older adults (≥ 70 years: 61, 62, 65; 90%), and women (66, 66, 64; 90%; vs. men 71, 70, 67; 93%, each P < 0.001). The most common atypical presentations under 60 years of age were nausea and vomiting and abdominal pain, and over 60 years was confusion. Regression models showed significant differences in symptoms with sex, age and country. Interpretation: This international collaboration has allowed us to report reliable symptom data from the largest cohort of patients admitted to hospital with COVID-19. Adults over 60 and children admitted to hospital with COVID-19 are less likely to present with typical symptoms. Nausea and vomiting are common atypical presentations under 30 years. Confusion is a frequent atypical presentation of COVID-19 in adults over 60 years. Women are less likely to experience typical symptoms than men

Modulating mesenchymal stem cells to overcome impaired wound healing

Mesenchymal stem cells (MSCs) have emerged as a promising strategy to the repair of damaged tissues, due to characteristics such as immunomodulation, anti-inflammatory properties, homing, protective and reparative effects. Additionally, MSCs have shown to exert their therapeutic activity by homing into injured tissues, cellular crosstalk and inducing tissue regeneration response through paracrine signalling, namely through exosomes. This thesis aimed to evaluate the role of the secretome (CM) and exosomes (Exo) derived from umbilical cord tissue (UC)-MSCs for damaged tissue treatment. Three-dimensional (3D) cultures were employed to prime UC-MSCs towards a healing-inducing secretome (CM3D); whereas the mechanism by which Exo/CM induced tissue regeneration was further explored including the stimulation of endogenous regeneration programmes. The use of two disease models, rheumatoid arthritis, and cutaneous wounds, highlighted the different UC-MSC functions, namely their immunomodulatory and tissue regeneration abilities. Moreover, the administration of CM3D in adjuvant-induced rat model for arthritis, ameliorated the arthritic signs and accelerated the remission of local and systemic arthritic manifestations. The analysis of relevant trophic factors in CM3D confirmed the prevalence of anti-inflammatory cytokines, along with trophic factors involved in different mechanisms leading to tissue regeneration. Accordingly, CM3D-treated wounds also presented signs of faster and better wound resolution, with a more mature vascular system already showing glands and hair follicles. Deeper and integrated analysis of the secretome unveiled the role of exosomes and its content on cutaneous wound healing. Furthermore, loading of Exo with an immunosuppressive oligodeoxynucleotide resulted in reduced systemic levels of pro-inflammatory cytokines at the late stage of wound healing. Lastly, mechanistic studies disclosed the role of granulocyte colony-stimulating factor (G-CSF) on UC-MSC homing and recruitment capacities that further contributed to accelerated closure of impaired wounds. Overall, this thesis set up the technical grounds for the development of an effective and novel advanced therapy medicinal product (ATMP) for injured tissue treatment

Exploiting hnMSC 3D cultures conditioned medium for tissue regeneration

Tese de mestrado. Biologia (Biologia Evolutiva e do Desenvolvimento). Universidade de Lisboa, Faculdade de Ciências, 2014Wound healing is impaired in several chronic diseases, where several factors are responsible for non-healing wounds. Over the time, treatment for these disabling conditions remains limited and largely ineffective. Mesenchymal stromal cells are valid candidates for cell therapy due to their beneficial effects on tissue regeneration. Besides these effects that could be mediated by cellular proliferation and differentiation, the secretion of growth factors and cytokines that enhance tissue repair has gained more attention. UCX®, in particular, is a specific population of human neonatal umbilical cord matrix derived MSCs that was found promising in this field and which paracrine mechanisms, for promoting cutaneous healing, have been studied. In this work, UCX® 3D cultures were exploited for conditioned media (CM) production. In contrast to 2D cultures, 3D mimic the complex in vivo environment, thus CM obtained by this methodology is expected to be more efficient in promoting wound healing. CM was obtained from UCX® traditional monolayer (CM2D) and 3D cultures (CM3D) and concentrated up 10x. Cell viability/proliferation assays in keratinocytes (HaCaT) and dermal fibroblasts (HDF), were performed, proving that CM3D and CM2D 10x could be applied in the in vivo assays. In addition, the therapeutic potential of the CM was evaluated in vivo in a rat wound healing model. CM2D and CM3D were applied via subcutaneous injection, to dorsal full-thickness incisions. The wound closure was monitored daily by size measurements. Skin biopsies were also taken at several time points for histological analyses to assess and compare different healing stages. Results showed that CM-treated wounds presented healing enhancement when compared to controls. In particular, CM3D-treated wounds have an improvement of wound healing profile with regards to accelerated wound closure, re-epithelialization and granulation tissue formation. Overall, these results indicate that UCX®-derived CM from 3D cultures may have a place in novel therapies for skin regeneration.A biologia das células estaminais é uma das áreas mais estudadas nos últimos anos. O imenso potencial atribuído a estas células continua a ser motivação para muitos investigadores. De facto, quando se descobrir e perceber o seu funcionamento, as aplicações terapêuticas serão vastas e inovadoras. A definição de célula estaminal baseia-se em três parâmetros [1]. Primeiro, as células estaminais têm de ter a capacidade de se autorrenovarem ao longo de toda a vida, isto é, assegurarem a divisão contínua a fim de manterem uma população de células indiferenciadas [1–4]. O segundo parâmetro está relacionado com a capacidade das células se diferenciarem dando origem a uma progenia especializada [1–2]. Neste ponto, o estádio de potência das células é o fator limitante para o destino a seguir. Por último, uma célula estaminal deve ser competente para repovoar o tecido no qual reside, em caso de lesão do mesmo [1–2]. Todos os tecidos contêm células que satisfazem estas premissas [5], contudo a taxa a que estas células os renovam, varia [1]. Ao longo do desenvolvimento embrionário, as células experienciam diferentes graus de estaminalidade. Até à terceira clivagem, os blastómeros são totipotentes, capazes de originar qualquer célula do organismo; após a mesma, apenas se encontram células pluripotentes que ao serem isoladas a partir do botão embrionário, se conhecem como células estaminais embrionárias (CEE) [2, 4, 6]. Depois do nascimento, as células estaminais existentes, designadas por células estaminais adultas, têm maior especificidade pelo que em princípio, originam células de um determinado órgão ou tecido [4, 6]. No entanto, há evidências de alguma plasticidade, nomeadamente nas células estaminais mesenquimais (CEM) [4, 7], que são células estaminais multipotentes capazes de diferenciar nos vários tecidos da mesoderme e que podem ser isoladas a partir de um largo número de tecidos quer neonatais, como sejam a placenta [8] ou o sangue [9] e a matriz do cordão umbilical [10], quer adultos, como por exemplo, a medula óssea, o músculo, ou o tecido adiposo [11–12]. As células estaminais mesenquimais foram caracterizadas pela Sociedade Internacional para a Terapia Celular, como sendo células capazes de aderir a superfícies plásticas, quando em condições normais de cultura celular; expressar os marcadores de superfície CD105, CD73 e CD90, não apresentando CD45, CD34, CD14 ou CD11b, CD79α ou CD19 e HLA II; e de serem competentes na diferenciação em osteoblastos, adipócitos e condroblastos [13]. A facilidade de isolamento não controverso e a dispensa de células de suporte, como precisam as CEE [1], assim como a ultrapassagem da instabilidade genética subsequente da cultura de células pluripotentes induzidas [14], fazem das CEM, um vantajoso alvo de interesse científico. Nomeadamente, as CEM apresentam uma extraordinária capacidade de replicação in vitro traduzindo-se num ponto a favor das terapias celulares, visto necessitarem de grande número de células [1]. A competência das CEM em modular o sistema imunitário assim como a propriedade anti-inflamatória [1, 15] despertaram interesse clínico ao nível, por exemplo, da doença enxerto contra o hospedeiro, comum em transplantes de medula óssea [15–16]; e de outras doenças autoimunes [17–18]. Outra das propriedades apontadas a estas células tem que ver com o seu tropismo para migrar especificamente para locais lesionados onde a interação com outras células promove a diferenciação e libertação de fatores pró-regeneradores do tecido [1]. A capacidade de diferenciação particular das CEM também tem sido evidenciada nomeadamente em mioblastos [19], hepatócitos [20] ou neurónios [21]. Apesar de todas estas propriedades, as CEM têm demonstrado apetência para induzir a regeneração de tecidos sem que seja necessário o seu transplante nem diferenciação [22–23]. Neste sentido, foi proposto que estas células secretam citocinas e fatores de crescimento que promovem a reparação e regeneração de tecidos lesionados de forma mais eficiente, através de ação parácrina das células circundantes [22, 24]. Estesbiofatores secretados suprimem localmente o sistema imunitário, inibem a fibrose e a apoptose e ainda, impulsionam a angiogénese [22]. A pele, em particular, representa uma barreira contra o ambiente externo ao organismo evitando dessa forma a entrada de agentes patogénicos. São igualmente sua função a regulação da temperatura corporal e a prevenção da desidratação [25–27]. Dadas as suas funções, cruciais à sobrevivência do organismo, a sua capacidade de regeneração é de extrema importância. A cicatrização da pele consiste em três fases que, embora distintas, não são independentes: inflamação, proliferação e remodelação [25, 28]. Várias atividades celulares reguladas por diversos fatores parácrinos, como migração e proliferação celulares, nomeadamente de queratinócitos e fibroblastos, representam passos essenciais para a re-epitelização e formação do tecido de granulação, com subsequente vascularização, todos processos inerentes ao sucesso da cicatrização na pele [27–29]. Uma vez que o processo de cicatrização se caracteriza como complexo, o seu sucesso é prejudicado em diversas patologias, como a diabetes e insuficiência renal crónica, resultando em complicações [30]. Assim, novas estratégias têm sido estudadas nomeadamente a aplicação de fatores de crescimento e células estaminais, para promover a cicatrização/regeneração [31]. Neste trabalho, CEM neonatais humanas (CEMnh) isoladas a partir da matriz do cordão umbilical (UCX®; ECBio, PCT/IB08/54067), cuja ação parácrina sugere que estas secretam fatores pró-mitogénicos e motogénicos que induzem a regeneração cutânea [32], foram avaliadas no sentido de promoverem a cicatrização da pele. As UCX® são normalmente cultivadas em culturas bidimensionais (2D), no entanto, estas condições podem eventualmente conduzir à perda de capacidades das células [33], além de estarem longe do ambiente in vivo, melhor representado em sistemas tridimensionais (3D). De facto, as culturas 3D de CEM têm ganho maior destaque [33–37], nomeadamente por aumentarem o seu potencial terapêutico [33–34]. De entre estes modelos, optou-se por culturas em frascos de agitação onde as células se agregam em esferoides, permitindo interações célula-célula e célula-matriz extracelular, que podem influenciar a atividade de sinalização das células [33–35]. Assim, juntando o potencial parácrino das UCX® com os modelos de cultura 3D apresenta-se uma nova abordagem para o melhoramento das características destas células para a terapêutica de regeneração da pele. Neste contexto, o objetivo deste trabalho consistiu na avaliação do potencial terapêutico do meio condicionado produzido por culturas 3D de UCX® na cicatrização cutânea, através das propriedades secretoras destas células. Neste sentido, foi produzido meio condicionado por esferoides de UCX® cultivadas em frascos de agitação (CM3D). Uma vez que as células são adaptadas a condições de cultura sem soro, o diâmetro e a morfologia dos agregados foi monitorizado ao longo do tempo de cultura, no sentido de se garantir a manutenção de células viáveis em cultura e evitar a formação de centros necróticos. Verificadas estas condições, as mesmas foram utilizadas para a produção de CM3D, utilizado posteriormente em ensaios in vitro de viabilidade celular e ensaios in vivo utilizando o modelo de ferida. Para determinar o efeito do meio condicionado (CM) na viabilidade/proliferação celular bem como definir a concentração a ser aplicada nos ensaios in vivo, realizou-se uma curva dose-resposta. A citotoxicidade do CM3D, bem como a do meio condicionado derivado de culturas em monocamada de UCX® (CM2D) foi avaliada em tipos celulares da pele, nomeadamente, fibroblastos dérmicos e queratinócitos. Em geral, os resultados mostraram ausência de citotoxicidade de CM3D em ambos os tipos celulares. Além disso, verificou-se que o CM3D induziu a proliferação de queratinócitos numa vasta gama de concentrações (0,5x; 1x; 3x; 6x), enquanto apenas as mais altas (3x, 6x, 10x) aumentaram a proliferação de fibroblastos. Por outro lado, CM2D 10x não teve impacto na viabilidade de fibroblastos e queratinócitos, no entanto, em baixas concentrações (0,5x; 1x, 3x) mostrou reduzir a viabilidade dos fibroblastos. Desta forma, CM concentrado 10x foi adotado para os ensaios in vivo. O modelo de ferida utilizado foi descrito como prevenindo a contração da pele, pelo que permite que a cicatrização ocorra essencialmente pelos processos de granulação e re-epitelização, tal como acontece na espécie humana. Assim, os efeitos do CM em contexto de ferida foram testados no modelo animal de rato. Em cada animal, foram realizadas quatro feridas no dorso, sendo que cada ferida foi tratada separadamente com CM2D, CM3D, meio de controlo (veículo) ou deixada a cicatrizar ao ar (controlo). Os efeitos foram avaliados macroscopicamente através de medições da ferida e microscopicamente por análise histológica. Os resultados mostraram que feridas tratadas com CM apresentam uma clara aceleração do fecho de ferida, sendo que as feridas tratadas com CM3D fecharam em média ao dia 12 e as feridas de controlo ao ar nunca fecharam antes do final do ensaio (dia 14). Histologicamente, a melhoria significativa da cicatrização observou-se a partir do dia 9, com especial relevância ao nível da re-epitelização, da presença de tecido de granulação, da vascularização e da distância entre as margens da ferida. Ainda de referir que enquanto as feridas tratadas com CM2D e CM3D não apresentaram diferenças significativas macroscopicamente, cortes histológicos das feridas ao dia 14 revelaram um tecido completamente regenerado no caso do CM3D e um tecido ainda com resquícios de tecido de granulação nas feridas CM2D. Os resultados demonstram que CM provenientes de diferentes modelos de cultura de UCX® têm efeitos distintos no que respeita a viabilidade e proliferação celulares, bem como no processo de cicatrização da pele, sugerindo que o secretoma destas células varia de acordo com as suas condições de cultura. Em especial, CM3D demonstrou promover uma melhoria no perfil de regeneração cutânea. Deste modo, evidenciou-se que CEMnh podem ser uma fonte de fatores parácrinos com um importante efeito na cicatrização cutânea e que a sua cultura em modelos 3D, poderá introduzir o CM3D como potencial terapêutica na regeneração de tecidos

Bioguided Identification of Active Antimicrobial Compounds from <i>Asphodelus bento-rainhae</i> and <i>Asphodelus macrocarpus</i> Root Tubers

Root tubers of Asphodelus bento-rainhae subsp. bento-rainhae (AbR), a vulnerable endemic species, and Asphodelus macrocarpus subsp. macrocarpus (AmR) have traditionally been used in Portugal to treat inflammatory and infectious skin disorders. The present study aims to evaluate the in vitro antimicrobial activity of crude 70% and 96% hydroethanolic extracts of both medicinal plants, specifically against multidrug-resistant skin-related pathogens, to identify the involved marker secondary metabolites and also to assess the pre-clinical toxicity of these medicinal plant extracts. Bioguided fractionation of the 70% hydroethanolic extracts of both species using solvents of increasing polarity, namely diethyl ether (DEE: AbR-1, AmR-1), ethyl acetate (AbR-2, AmR-2) and aqueous (AbR-3, AmR-3) fractions, enabled the identification of the DEE fractions as the most active against all the tested Gram-positive microorganisms (MIC: 16 to 1000 µg/mL). Furthermore, phytochemical analyses using TLC and LC-UV/DAD-ESI/MS techniques revealed the presence of anthracene derivatives as the main constituents of DEE fractions, and five known compounds, namely 7′-(chrysophanol-4-yl)-chrysophanol-10’-C-beta-D-xylopyranosyl-anthrone (p), 10,7′-bichrysophanol (q), chrysophanol (r), 10-(chrysophanol-7′-yl)-10-hydroxychrysophanol-9-anthrone (s) and asphodelin (t), were identified as the main marker compounds. All these compounds showed high antimicrobial activity, particularly against Staphylococcus epidermidis (MIC: 3.2 to 100 µg/mL). Importantly, no cytotoxicity against HepG2 and HaCaT cells (up to 125 µg/mL) for crude extracts of both species and genotoxicity (up to 5000 µg/mL, with and without metabolic activation) for AbR 96% hydroethanolic extract was detected using the MTT and Ames tests, respectively. Overall, the obtained results contribute to the concrete validation of the use of these medicinal plants as potential sources of antimicrobial agents in the treatment of skin diseases

Respiratory support in patients with severe COVID-19 in the International Severe Acute Respiratory and Emerging Infection (ISARIC) COVID-19 study: a prospective, multinational, observational study

Background: Up to 30% of hospitalised patients with COVID-19 require advanced respiratory support, including high-flow nasal cannulas (HFNC), non-invasive mechanical ventilation (NIV), or invasive mechanical ventilation (IMV). We aimed to describe the clinical characteristics, outcomes and risk factors for failing non-invasive respiratory support in patients treated with severe COVID-19 during the first two years of the pandemic in high-income countries (HICs) and low middle-income countries (LMICs). Methods: This is a multinational, multicentre, prospective cohort study embedded in the ISARIC-WHO COVID-19 Clinical Characterisation Protocol. Patients with laboratory-confirmed SARS-CoV-2 infection who required hospital admission were recruited prospectively. Patients treated with HFNC, NIV, or IMV within the first 24 h of hospital admission were included in this study. Descriptive statistics, random forest, and logistic regression analyses were used to describe clinical characteristics and compare clinical outcomes among patients treated with the different types of advanced respiratory support. Results: A total of 66,565 patients were included in this study. Overall, 82.6% of patients were treated in HIC, and 40.6% were admitted to the hospital during the first pandemic wave. During the first 24 h after hospital admission, patients in HICs were more frequently treated with HFNC (48.0%), followed by NIV (38.6%) and IMV (13.4%). In contrast, patients admitted in lower- and middle-income countries (LMICs) were less frequently treated with HFNC (16.1%) and the majority received IMV (59.1%). The failure rate of non-invasive respiratory support (i.e. HFNC or NIV) was 15.5%, of which 71.2% were from HIC and 28.8% from LMIC. The variables most strongly associated with non-invasive ventilation failure, defined as progression to IMV, were high leukocyte counts at hospital admission (OR [95%CI]; 5.86 [4.83-7.10]), treatment in an LMIC (OR [95%CI]; 2.04 [1.97-2.11]), and tachypnoea at hospital admission (OR [95%CI]; 1.16 [1.14-1.18]). Patients who failed HFNC/NIV had a higher 28-day fatality ratio (OR [95%CI]; 1.27 [1.25-1.30]). Conclusions: In the present international cohort, the most frequently used advanced respiratory support was the HFNC. However, IMV was used more often in LMIC. Higher leucocyte count, tachypnoea, and treatment in LMIC were risk factors for HFNC/NIV failure. HFNC/NIV failure was related to worse clinical outcomes, such as 28-day mortality. Trial registration This is a prospective observational study; therefore, no health care interventions were applied to participants, and trial registration is not applicable

Respiratory support in patients with severe COVID-19 in the International Severe Acute Respiratory and Emerging Infection (ISARIC) COVID-19 study: a prospective, multinational, observational study

International audienceBackground: Up to 30% of hospitalised patients with COVID-19 require advanced respiratory support, including high-flow nasal cannulas (HFNC), non-invasive mechanical ventilation (NIV), or invasive mechanical ventilation (IMV). We aimed to describe the clinical characteristics, outcomes and risk factors for failing non-invasive respiratory support in patients treated with severe COVID-19 during the first two years of the pandemic in high-income countries (HICs) and low middle-income countries (LMICs).Methods: This is a multinational, multicentre, prospective cohort study embedded in the ISARIC-WHO COVID-19 Clinical Characterisation Protocol. Patients with laboratory-confirmed SARS-CoV-2 infection who required hospital admission were recruited prospectively. Patients treated with HFNC, NIV, or IMV within the first 24 h of hospital admission were included in this study. Descriptive statistics, random forest, and logistic regression analyses were used to describe clinical characteristics and compare clinical outcomes among patients treated with the different types of advanced respiratory support.Results: A total of 66,565 patients were included in this study. Overall, 82.6% of patients were treated in HIC, and 40.6% were admitted to the hospital during the first pandemic wave. During the first 24 h after hospital admission, patients in HICs were more frequently treated with HFNC (48.0%), followed by NIV (38.6%) and IMV (13.4%). In contrast, patients admitted in lower- and middle-income countries (LMICs) were less frequently treated with HFNC (16.1%) and the majority received IMV (59.1%). The failure rate of non-invasive respiratory support (i.e. HFNC or NIV) was 15.5%, of which 71.2% were from HIC and 28.8% from LMIC. The variables most strongly associated with non-invasive ventilation failure, defined as progression to IMV, were high leukocyte counts at hospital admission (OR [95%CI]; 5.86 [4.83-7.10]), treatment in an LMIC (OR [95%CI]; 2.04 [1.97-2.11]), and tachypnoea at hospital admission (OR [95%CI]; 1.16 [1.14-1.18]). Patients who failed HFNC/NIV had a higher 28-day fatality ratio (OR [95%CI]; 1.27 [1.25-1.30]).Conclusions: In the present international cohort, the most frequently used advanced respiratory support was the HFNC. However, IMV was used more often in LMIC. Higher leucocyte count, tachypnoea, and treatment in LMIC were risk factors for HFNC/NIV failure. HFNC/NIV failure was related to worse clinical outcomes, such as 28-day mortality. Trial registration This is a prospective observational study; therefore, no health care interventions were applied to participants, and trial registration is not applicable

Association of Country Income Level With the Characteristics and Outcomes of Critically Ill Patients Hospitalized With Acute Kidney Injury and COVID-19

Introduction: Acute kidney injury (AKI) has been identified as one of the most common and significant problems in hospitalized patients with COVID-19. However, studies examining the relationship between COVID-19 and AKI in low- and low-middle income countries (LLMIC) are lacking. Given that AKI is known to carry a higher mortality rate in these countries, it is important to understand differences in this population. Methods: This prospective, observational study examines the AKI incidence and characteristics of 32,210 patients with COVID-19 from 49 countries across all income levels who were admitted to an intensive care unit during their hospital stay. Results: Among patients with COVID-19 admitted to the intensive care unit, AKI incidence was highest in patients in LLMIC, followed by patients in upper-middle income countries (UMIC) and high-income countries (HIC) (53%, 38%, and 30%, respectively), whereas dialysis rates were lowest among patients with AKI from LLMIC and highest among those from HIC (27% vs. 45%). Patients with AKI in LLMIC had the largest proportion of community-acquired AKI (CA-AKI) and highest rate of in-hospital death (79% vs. 54% in HIC and 66% in UMIC). The association between AKI, being from LLMIC and in-hospital death persisted even after adjusting for disease severity. Conclusions: AKI is a particularly devastating complication of COVID-19 among patients from poorer nations where the gaps in accessibility and quality of healthcare delivery have a major impact on patient outcomes

Thrombotic and hemorrhagic complications of COVID-19 in adults hospitalized in high-income countries compared with those in adults hospitalized in low- and middle-income countries in an international registry

Background: COVID-19 has been associated with a broad range of thromboembolic, ischemic, and hemorrhagic complications (coagulopathy complications). Most studies have focused on patients with severe disease from high-income countries (HICs). Objectives: The main aims were to compare the frequency of coagulopathy complications in developing countries (low- and middle-income countries [LMICs]) with those in HICs, delineate the frequency across a range of treatment levels, and determine associations with in-hospital mortality. Methods: Adult patients enrolled in an observational, multinational registry, the International Severe Acute Respiratory and Emerging Infections COVID-19 study, between January 1, 2020, and September 15, 2021, met inclusion criteria, including admission to a hospital for laboratory-confirmed, acute COVID-19 and data on complications and survival. The advanced-treatment cohort received care, such as admission to the intensive care unit, mechanical ventilation, or inotropes or vasopressors; the basic-treatment cohort did not receive any of these interventions. Results: The study population included 495,682 patients from 52 countries, with 63% from LMICs and 85% in the basic treatment cohort. The frequency of coagulopathy complications was higher in HICs (0.76%-3.4%) than in LMICs (0.09%-1.22%). Complications were more frequent in the advanced-treatment cohort than in the basic-treatment cohort. Coagulopathy complications were associated with increased in-hospital mortality (odds ratio, 1.58; 95% CI, 1.52-1.64). The increased mortality associated with these complications was higher in LMICs (58.5%) than in HICs (35.4%). After controlling for coagulopathy complications, treatment intensity, and multiple other factors, the mortality was higher among patients in LMICs than among patients in HICs (odds ratio, 1.45; 95% CI, 1.39-1.51). Conclusion: In a large, international registry of patients hospitalized for COVID-19, coagulopathy complications were more frequent in HICs than in LMICs (developing countries). Increased mortality associated with coagulopathy complications was of a greater magnitude among patients in LMICs. Additional research is needed regarding timely diagnosis of and intervention for coagulation derangements associated with COVID-19, particularly for limited-resource settings

Characteristics and outcomes of an international cohort of 600 000 hospitalized patients with COVID-19

Background: We describe demographic features, treatments and clinical outcomes in the International Severe Acute Respiratory and emerging Infection Consortium (ISARIC) COVID-19 cohort, one of the world's largest international, standardized data sets concerning hospitalized patients. Methods: The data set analysed includes COVID-19 patients hospitalized between January 2020 and January 2022 in 52 countries. We investigated how symptoms on admission, co-morbidities, risk factors and treatments varied by age, sex and other characteristics. We used Cox regression models to investigate associations between demographics, symptoms, co-morbidities and other factors with risk of death, admission to an intensive care unit (ICU) and invasive mechanical ventilation (IMV). Results: Data were available for 689 572 patients with laboratory-confirmed (91.1%) or clinically diagnosed (8.9%) SARS-CoV-2 infection from 52 countries. Age [adjusted hazard ratio per 10 years 1.49 (95% CI 1.48, 1.49)] and male sex [1.23 (1.21, 1.24)] were associated with a higher risk of death. Rates of admission to an ICU and use of IMV increased with age up to age 60&nbsp;years then dropped. Symptoms, co-morbidities and treatments varied by age and had varied associations with clinical outcomes. The case-fatality ratio varied by country partly due to differences in the clinical characteristics of recruited patients and was on average 21.5%. Conclusions: Age was the strongest determinant of risk of death, with a ∼30-fold difference between the oldest and youngest groups; each of the co-morbidities included was associated with up to an almost 2-fold increase in risk. Smoking and obesity were also associated with a higher risk of death.&nbsp;The size of our international database and the standardized data collection method make this study a comprehensive international description of COVID-19 clinical features. Our findings may inform strategies that involve prioritization of patients hospitalized with COVID-19 who have a higher risk of death