Extracellular vesicles are a late marker of inflammation, hypercoagulability and COVID-19 severity.

Exacerbated inflammation and coagulation are a hallmark of COVID-19 severity. Extracellular vesicles (EVs) are intercellular transmitters involved in inflammatory conditions, which are capable of triggering prothrombotic mechanisms. Since the release of EVs is potentially associated with COVID-19-induced coagulopathy, the aim of this study was to evaluate changes in inflammation- and hypercoagulability-related EVs during the first month after symptom onset and to determine whether they are associated with disease severity. Blood samples of patients with mild or severe forms of the disease were collected on three occasions: in the second, third and fourth weeks after symptom onset for the quantification by flow cytometry of CD41A (platelet glycoprotein IIb/IIIa), CD162 (PSGL-1), CD31 (PECAM-1) and CD142 cells (tissue factor). Analysis of variance (ANOVA) with repeated measures, Kruskal-Wallis and correlation tests were used. Eighty-five patients were enrolled, 71% of whom had mild disease. Seventeen uninfected individuals served as controls. Compared to controls, both mild and severe COVID-19 were associated with higher EV-CD31+, EV-CD41+ and EV-CD142+ levels. All EV levels were higher in severe than in mild COVID-19 only after the third week from symptom onset, as opposed to C-reactive protein and D-dimer levels, which were higher in severe than in mild COVID-19 earlier during disease progression. EV levels were also associated with C-reactive protein and D-dimer levels only after the third week of symptoms. In conclusion, EVs expressing CD41A, CD31, TF, and CD162 appear as late markers of COVID-19 severity. This finding may contribute to the understanding of the pathogenesis of acute and possibly long COVID-19.

Optimization of von Willebrand factor multimer analysis in vertical mini-gel electrophoresis systems: a rapid procedure

Von Willebrand disease (VWD) is a common cause of bleeding worldwide. Analysis of von Willebrand factor (VWF) multimer distribution (VWF:MD) is essential to properly classify and treat different types of VWD, and it is performed using a SDS agarose gel electrophoresis followed by Western blotting, a handmade technique that demands days to be completed and requires skillful execution. Aiming both to facilitate gel production and to shorten the preparation time, we developed an uncomplicated technique to provide agility in the analysis of VWF:MD, so that it can be easily accomplished in the routine practice of hemostasis laboratories. On that account, we used a commercial vertical mini-gel electrophoresis system for SDS-PAGE and a semi-dry transfer system, which allowed us to analyze VWF:MD of various samples in a period shorter than 12?h. This technique differentiated VWF:MD in human and animal plasmas under normal, congenital and acquired (experimental envenomation by Bothrops jararaca snake) conditions. This optimized method is cheap, rapid, reproducible, easy to be performed, and uses electrophoresis and Western blotting systems available in most laboratories. All these advantages encourage hemostasis professionals to use it in their routine practices. In order to facilitate the setup and accomplishment of the whole procedure step by step, videos were appended to the article.

Optimization of von Willebrand factor multimer analysis in vertical mini-gel electrophoresis systems: a rapid procedure

Von Willebrand disease (VWD) is a common cause of bleeding worldwide. Analysis of von Willebrand factor (VWF) multimer distribution (VWF:MD) is essential to properly classify and treat different types of VWD, and it is performed using a SDS agarose gel electrophoresis followed by Western blotting, a handmade technique that demands days to be completed and requires skillful execution. Aiming both to facilitate gel production and to shorten the preparation time, we developed an uncomplicated technique to provide agility in the analysis of VWF:MD, so that it can be easily accomplished in the routine practice of hemostasis laboratories. On that account, we used a commercial vertical mini-gel electrophoresis system for SDS-PAGE and a semi-dry transfer system, which allowed us to analyze VWF:MD of various samples in a period shorter than 12?h. This technique differentiated VWF:MD in human and animal plasmas under normal, congenital and acquired (experimental envenomation by Bothrops jararaca snake) conditions. This optimized method is cheap, rapid, reproducible, easy to be performed, and uses electrophoresis and Western blotting systems available in most laboratories. All these advantages encourage hemostasis professionals to use it in their routine practices. In order to facilitate the setup and accomplishment of the whole procedure step by step, videos were appended to the article.

Study of pro-thrombotic and pro-inflammatory factors in Chagas cardiomyopathy.

BACKGROUND: The relationship between inflammatory and prothrombotic activity in chagas cardiomyopathy and in other etiologies is unclear. OBJECTIVE: To study the profile of pro-thrombotic and pro-inflammatory markers in patients with Chagas' heart failure and compare them with patients of non-chagas etiology. METHODS: Cross-sectional cohort. INCLUSION CRITERIA: left ventricle ejection fraction (LVEF) < 45% and onset time to symptoms > one month. The patients were divided into two groups: group 1 (G1) - seropositive for Chagas - and group 2 (G2) - seronegative for Chagas. Pro-inflammatory factor: Ultra-sensitive CRP. Pro-thrombotic factors: thrombin-antithrombin factor, fibrinogen, von Willebrand factor antigen, plasma P-selectin and thromboelastography. Sample calculated for 80% power, assuming a standard deviation difference of 1/3; significant p if it is < 0.05. STATISTICAL ANALYSIS: Fisher's exact test for categorical variables; unpaired Student's t-test for parametric continuous variables and Mann-Whitney test for nonparametric continuous variables. RESULTS: Between January and June 2008, 150 patients were included, 80 in G1 and 70 in G2. Both groups maintained the averages of high sensitivity CRP above baseline values, however, there was no significant difference (p = 0.328). The fibrinogen levels were higher in G2 than in G1 (p = 0.015). Among the thromboelastography variables, the parameters MA (p=0.0013), G (p=0.0012) and TG (p =0.0005) were greater in G2 than in G1. CONCLUSION: There is no evidence of greater pro-thrombotic status among patients with Chagas disease. The levels of fibrinogen and the MA, G and TG parameters of the thromboelastography point to pro-thrombotic status among non-chagas patients. Both groups had increased inflammatory activity.

Estudo de fatores pró-trombóticos e pró-inflamatórios na cardiomiopatia chagásica / Study of pro-thrombotic and pro-inflammatory factors in chagas cardiomyopathy

FUNDAMENTO: A relação entre atividade inflamatória e pró-trombótica na cardiomiopatia chagásica e em outras etiologias é obscura. OBJETIVO: Estudar o perfil de marcadores pró-trombóticos e pró-inflamatórios em pacientes com insuficiência cardíaca chagásica e compará-los com os de etiologia não chagásica. MÉTODOS: Coorte transversal. Critérios de inclusão: fração de ejeção do VE (FEVE) < 45 por cento e tempo de início de sintomas > um mês. Os pacientes foram divididos em dois grupos: grupo 1 (G1) - sorologias positivas para Chagas - e grupo 2 (G2) - sorologias negativas para Chagas. Fator pró-inflamatório: PCR ultrassensível. Fatores pró-trombóticos: fator trombina-antitrombina, fibrinogênio, antígeno do fator de von Willebrand, P-selectina plasmática e tromboelastograma. Amostra calculada para poder de 80 por cento, assumindo-se diferença de 1/3 de desvio-padrão; p significativo se < 0,05. Análise estatística: teste exato de Fischer para variáveis categóricas; teste t de Student não pareado para variáveis contínuas paramétricas e teste de Mann-Whitney para variáveis contínuas não paramétricas. RESULTADOS: Entre janeiro e junho de 2008, foram incluídos 150 pacientes, 80 no G1 e 70 no G2. Ambos os grupos mantinham médias de PCR ultrassensível acima dos valores de referência, porém, sem diferença significativa (p=0,328). Os níveis de fibrinogênio foram maiores no G2 do que no G1 (p=0,015). Entre as variáveis do tromboelastograma, os parâmetros MA (p=0,0013), G (p=0,0012) e TG (p=0,0005) foram maiores no G2 em comparação ao G1. CONCLUSÃO: Não há indícios de maior status pró-trombótico entre chagásicos. A dosagem de fibrinogênio e dos parâmetros MA, G e TG do tromboelastograma apontam para status pró-trombótico entre não chagásicos. Ambos os grupos tinham atividade inflamatória exacerbada.

BACKGROUND: The relationship between inflammatory and prothrombotic activity in chagas cardiomyopathy and in other etiologies is unclear. OBJECTIVE: To study the profile of pro-thrombotic and pro-inflammatory markers in patients with Chagas' heart failure and compare them with patients of non-chagas etiology. METHODS: Cross-sectional cohort. Inclusion criteria: left ventricle ejection fraction (LVEF) < 45 percent and onset time to symptoms > one month. The patients were divided into two groups: group 1 (G1) - seropositive for Chagas - and group 2 (G2) - seronegative for Chagas. Pro-inflammatory factor: Ultra-sensitive CRP. Pro-thrombotic factors: thrombin-antithrombin factor, fibrinogen, von Willebrand factor antigen, plasma P-selectin and thromboelastography. Sample calculated for 80 percent power, assuming a standard deviation difference of 1/3; significant p if it is < 0.05. Statistical analysis: Fisher's exact test for categorical variables; unpaired Student's t-test for parametric continuous variables and Mann-Whitney test for nonparametric continuous variables. RESULTS: Between January and June 2008, 150 patients were included, 80 in G1 and 70 in G2. Both groups maintained the averages of high sensitivity CRP above baseline values, however, there was no significant difference (p = 0.328). The fibrinogen levels were higher in G2 than in G1 (p = 0.015). Among the thromboelastography variables, the parameters MA (p=0.0013), G (p=0.0012) and TG (p =0.0005) were greater in G2 than in G1. CONCLUSION: There is no evidence of greater pro-thrombotic status among patients with Chagas disease. The levels of fibrinogen and the MA, G and TG parameters of the thromboelastography point to pro-thrombotic status among non-chagas patients. Both groups had increased inflammatory activity.

Antiplatelet activity of Croton celditifolius / Atividade antiplaquetária do Croton celtidifolius

Croton celtidifolius Baill is a tree found in the Atlantic Forest South of Brazil, mainly in Santa Catarina. The bark and leaf infusions of this medicinal plant have been popularly used for the treatment of inflammatory diseases. The anti-aggregant activity of C. celtidifolius crude extract (CE) and the column chromatography (CC) isolated compounds flavonoids, catechin and gallocatechin were evaluated in human blood platelets. The platelet-rich plasma (PRP) was incubated with different concentrations of flavonóides (50 - 200 µg/mL) to be tested before platelet aggregation was induced by the agonists adenosine 5'diphosphate (ADP) and collagen. At 200 µg/mL the CE, catechin and gallocatechin markedly inhibited platelet aggregation with the aggregant agents. Using ATP production as an index of platelet secretory capacity, we observed a decreased production of ATP in platelets treated with flavonoids when stimulated by collagen. On the other hand, the flavonoids did not promote inhibitory effect on prothrombin time (PT), thromboplastin time (APTT) and thrombin time (TT). In conclusion, these observations suggest that C. celtidifolius is likely to exert an inhibitory action on platelets in vitro by suppressing secretion and platelet aggregation.

Croton celtidifolius Baill é uma árvore encontrada na Mata Atlântica, no sul do Brasil, principalmente no estado de Santa Catarina. A infusão da casca e folhas dessa planta medicinal é utilizada na medicina popular para o tratamento de doenças inflamatórias. A atividade antiagregante do extrato bruto de C. celtidifolius (CE) e de seus flavonóides isolados por coluna cromatográfica (CC), catequina e galocatequina, foi avaliada em plaquetas humanas. O plasma rico em plaquetas (PRP) foi incubado com diferentes concentrações dos flavonóides testados (50 - 200 µg/mL) e posteriormente a agregação foi induzida pelos agonistas adenosina 5'difosfato (ADP) e colágeno. Na concentração de 200 µg/mL o CE, a catequina e a galocatequina inibiram a agregação plaquetária induzida pelos agonistas. A produção de ATP foi utilizada como um índice de capacidade de secreção plaquetária e observamos uma diminuição na produção de ATP nas plaquetas tratadas com os flavonóides e estimuladas com o colágeno. Por outro lado, os flavonóides não promoveram um efeito inibitório no tempo de protrombina (PT), tempo de tromboplastina parcial ativada (APTT) e tempo de trombina (TT). Essas observações sugerem que o C. celtidifolius exerce, in vitro, uma ação inibitória nas plaquetas através da inibição da secreção e agregação plaquetária.

Síndrome da imunodeficiência adquirida: estudo clínico e imunológico de um caso / Acquired immunodeficiency syndrome: clinical and immunological study of a case

É descrito um caso de Síndrome da Deficiência Imunológica Adquirida (AIDS) com estudo clínico e imunológico. O paciente apresentava quadro geral (febre, adinamia, anorexia e emagrecimento), pneumonias lobares, herpes zóster, diarréia, quadro intersticial pulmonar, acometimento linfático diagnosticado como linfadenite angio-imunoblástica e leucopenia. A avaliaçäo imunológica revelou grave depressäo da imunidade celular, tanto in vitro quanto in vivo com relaçäo invertida entre as subpopulaçöes de células T (T auxiliares e T supressoras)