ABSTRACT
Introduction: Hypercoagulability in COVID-19 has been attributed to immunothrombosis, a process that involves the formation of neutrophils extracellular traps (NETs). The moment of the COVID-19 evolution in which immunothrombosis mechanisms are triggered is not established. Aim: To describe the kinetics of NETs release during COVID-19 hospitalization associating with thrombosis and death. Methods: We quantified citrullinated H3 and inflammatory cytokines (TNF-α, IL-6), markers of NETs release, on 4 time points during COVID-19 hospitalization (admission, day 4, day 8 and last day) between May and July 2020. The association between changes in these markers levels and clinical outcomes was determined. Results: 101 patients were included, the median days in-hospital were 15, 62% were men, 27% were obese, 43% were diabetic, 54% were hypertensive, 59% were critically ill, 11% had a thrombotic event and 21% died. IL-6 levels were high on admission in survivors (median 25.32, IQR 24.19-28.15) and non-survivors (median 24.19, IQR 12.51-27.19), but gradually decreased on day 4 (median 12.07, IQR 6.32-17.81), day 8 (median 9.34, IQR 5.18-17.59) and last day (median 8.64, IQR 4.81-14.89) in survivors. TNF-α levels remained 2 times higher in non-survivors: admission (median 1.60, IQR 0.64-2.26), day 4 (median 1.78, IQR 1.02-2.60), day 8 (median 1.65, IQR 0.93-2.5), last day (median 2.41, IQR 1.31-4.06);than in survivors: admission (median 0.81, IQR 0.52-1.26), day 4 (median 0.84, IQR 0.44-1.16), day 8 (median 0.72, IQR 0.44-1.24), last day (median 0.69, IQR 0.4-1.14). CitH3 levels were similar between non-survivors at the beginning of hospitalization: admission (median 1.03, IQR 0.43-4.34), day 4 (median 1.1, IQR 0.65-3.45);as for survivors: admission (median 1.20, IQR 0.45-2.60), day 4 (median 1.27, IQR 0.64-3.29). On day 8, citH3 increased by 3-fold (median 3.80, IQR 1.98-10.15) in non-survivors and 2-fold (median 2.60, IQR 1.22-5.01) in survivors. While IL-6 and TNF-α levels were similar between patients with and without thrombosis, citH3 levels increased shortly on day 4, before the occurrence of a thrombotic event: admission (median 1.64, IQR 0.44-4.14), day 4 (median 3.21, IQR 2.57-9.31);but it didn't change on non-thrombotic event patients: admission (median 1.05, IQR 0.44-2.50), day 4 (median 1.06, IQR 0.58-2.95). Conclusion: Markers of inflammation and immunothrombosis were associated with poor outcomes in COVID-19;however, these disorders were detected in different moments during COVID-19 course. While an increased inflammatory response was observed since the beginning of hospitalization, markers of immunothrombosis arose latter during the course of the disease. Acknowledgment of the time-course of immunothrombosis development in COVID-19 is important for planning therapeutic strategies against this pathological process.
ABSTRACT
Objetivos: Evidências prévias sugerem que o risco trombótico é maior na COVID-19 do que em outros tipos de síndrome respiratória aguda grave (SRAG). Contudo, tal comparação se baseou principalmente em coortes históricas. O objetivo deste estudo foi avaliar a incidência de eventos tromboembólicos em pacientes com COVID-19 e outras SRAG internados em um mesmo período de tempo. Material e métodos: Foram selecionados pacientes internados entre março e junho de 2020 no Hospital de Clínicas - UNICAMP que atendiam aos critérios clínicos de SRAG segundo o Ministério da Saúde e a Definição de Berlim, e que apresentavam ao menos 2 resultados de RT-PCR ou ELISA confirmando ou excluindo o diagnóstico de COVID-19. Dos 253 indivíduos internados por SRAG nesse período, foram incluídos 101 pacientes COVID-19 e 102 pacientes não-COVID-19. Os demais foram excluídos por prontuário médico incompleto (n = 16) ou falta de exame laboratorial para COVID-19 (n = 34). Análise descritiva, testes de qui-quadrado, testes-t e regressão logística binária foram usados para comparar os pacientes COVID-19 e não COVID-19. Resultados: Pertenciam ao sexo masculino 62% e 48% dos pacientes COVID-19 e não-COVID-19, respectivamente (P = 0.07). A mediana de idade, em anos, foi 55.77 (IQR 42.31 a 66.68) no grupo COVID-19 e 59.04 (IQR 45.13 a 69.73, P = 0.39) no grupo não-COVID-19. Ambos os grupos apresentaram um escore de Pádua (COVID-19: 3 IQR 2 a 4;não-COVID-19: 3 IQR 2 a 5, P = 0.47) e uma saturação de oxigênio (COVID-19: 92% IQR 90% a 96%;não-COVID-19: 94% IQR 91% a 97%, P = 0.44) semelhantes à admissão. Contudo, a necessidade de suporte de oxigenação invasiva (37.6% vs. 14.7%, P = 0.0002), de drogas vasoativas (44.6% vs. 21.6%, P=0.0006) e de internação em UTI (55.4% vs. 40.2%, P = 0.04) foi maior entre aqueles infectados por SARS-CoV-2. Em conformidade, esses mesmos pacientes permaneceram internados por mais tempo (15 dias IQR 6 a 30.5 vs. 7 dias IQR 3 a 16.3, P < 0.0001) e vieram a óbito com mais frequência (27.7% vs. 14.7%, P = 0.03). Em relação a marcadores de coagulação, não houve diferença estatisticamente relevante entre os grupos quanto a tempo de protrombina, fibrinogênio e D-dímero (COVID-19: 1488 ng/mL IQR 726.5 a 3476;não COVID-19: 1773 ng/mL IQR 807.5 a 4153.8, P = 0.57). Apesar do uso de tromboprofilaxia ter sido mais comum entre pacientes COVID-19 (76.2% vs. 41.2%, P < 0.0001), a incidência de eventos tromboembólicos confirmados por exame de imagem se mostrou similar entre os grupos, mesmo após ajuste para múltiplos fatores (idade, sexo, tromboprofilaxia, hipertensão arterial, diabetes mellitus, escore de Pádua, internação em UTI, tempo de internação total): houve 7 eventos em 7 pacientes não COVID-19 e 13 eventos em 9 pacientes COVID-19 (OR ajustado 0.91, 95% IC 0.28-2.95, P = 0.87). Os eventos mais recorrentes no grupo COVID-19 foram embolismo pulmonar (53.8%) e trombose venosa profunda (23.1%), que representaram 57.1% (P = 0.37) e 14.3% (P = 0.37) dos eventos não-COVID-19, respectivamente. Discussão: Ao analisar pacientes internados em um mesmo período de tempo, constatamos que, embora elevado, o risco tromboembólico na COVID-19 é semelhante ao de outros tipos de SRAG, indicando que um estado de hipercoagulabilidade é inerente à SRAG em geral. Além disso, os resultados obtidos revelam que o uso de tromboprofilaxia foi significativamente maior no grupo COVID-19, e que não houve diferença estatisticamente relevante entre os níveis de D-dímero dos pacientes COVID-19 e não COVID-19. Conclusão: Tais achados fornecem uma melhor compreensão sobre o risco tromboembólico associado à infecção por SARS-CoV-2, e sugerem que evidências prévias de taxas de trombose mais elevadas na COVID-19 sofreram viés pelo uso de coortes históricas.
ABSTRACT
Previous evidence suggests that the thromboembolic risk is greater among patients with COVID-19 than among those affected by other types of acute respiratory distress syndrome (ARDS). However, such comparison has been primarily based on historical cohorts. In order to reduce the possible influence of such selection bias, the main goal of this study was to evaluate thromboembolic events in patients with COVID-19 and other ARDS hospitalized in the same time period. For this reason, we have selected patients admitted from March to June, 2020 at the UNICAMP Clinical Hospital who met the ARDS clinical criteria established by the Brazilian Ministry of Health and the Berlin Definition by presenting two or more flu-like symptoms and at least one ARDS-specific manifestation (dyspnea, persistent chest pressure, oxygen saturation lower than 95% at hospital admission, or lip/face cyanosis). Symptom onset or worsening occurred 30 days before hospital admission at the latest, and COVID-19 diagnosis was confirmed or excluded by at least 2 real time polymerase chain reactions or enzyme-linked immunosorbent assays. Descriptive analysis, chi-square and t-tests, as well as binary logistic regression, were used to compare COVID-19 and non-COVID-19 patients. Of the 253 patients hospitalized due to ARDS during this period, 101 COVID-19 and 102 non-COVID-19 patients were included in this study. The remaining patients were excluded due to incomplete medical records (n=16) or absence of COVID-19 testing results (n=34). Table 1 demonstrates the included patients' demographic and clinical baseline features. Both COVID-19 and non-COVID-19 groups showed similar baseline risk of hospital-associated thrombosis (assessed by reduced mobility within the past 3 days or more, previous thromboembolism event, recognized “thrombophilia”, and infarction, stroke, trauma or surgery within the past 4 weeks) and oxygen saturation at admission (COVID-19: 92% IQR 90% to 96%;non-COVID-19: 94% IQR 91% to 97%, P=0.44). However, the need for invasive oxygenation support (37.6% vs. 14.7%, P=0.0002) and vasoactive drugs (44.6% vs. 21.6%, P=0.0006) was greater in COVID-19 than in non-COVID-19 patients. Accordingly, those infected by SARS-CoV-2 were more frequently admitted in ICU (55.4% vs. 40.2%, P=0.04) and for a longer period of time (13 days IQR 6 to 22 vs. 3 days IQR 2 to 8.3, P=0.02) than those affected by other types of ARDS. In comparison to the non-COVID-19 group, the COVID-19 group's median total hospital stay was more lasting (15 days IQR 6 to 30.5 vs. 7 days IQR 3 to 16.3, P<0.0001), and its death rate, higher (27.7% vs. 14.7%, P=0.03), as shown in Table 2. With respect to coagulation markers (Table 3), activated partial thromboplastin time and C-reactive protein levels were greater in COVID-19 than in non-COVID-19 patients, while the latter presented higher median platelet counts. There was no statistically significant difference between both study groups in regards to prothrombin time, fibrinogen, and D-dimer levels (COVID-19: 1488 ng/mL IQR 726.5 to 3476;non-COVID-19: 1773 ng/mL IQR 807.5 to 4153.8, P=0.57). Although thromboprophylaxis was more commonly administered to COVID-19 (76.2%) than non-COVID-19 patients (41.2%, P<0.0001), the incidence of thromboembolic events confirmed by imaging examination was similar between groups even after adjusting for multiple factors (age, sex, thromboprophylaxis use, arterial hypertension, and cancer): there were 7 confirmed events in 7 non-COVID-19 patients, and 13 confirmed events in 9 COVID-19 patients (adjusted OR 0.74, 95% CI 0.24-2.25, P=0.59). Table 4 demonstrates the characteristics of such thrombotic manifestations. By analyzing patients hospitalized in the same time period, we have found that although high, the thromboembolic risk in COVID-19 is similar to that in other types of ARDS, indicating that a hypercoagulable state is inherent to ARDS in general. Additionally, the obtained results show that the use of thromboprophylaxis was significantly higher among COVID-19 patients, and that there was no tatistically relevant difference between COVID-19 and non-COVID-19 patients' D-dimer levels, a commonly used coagulation marker. Such findings provide a better understanding of the thromboembolic risk associated with SARS-CoV-2 infection, and suggest that previous evidence of higher thrombosis rates in COVID-19 suffered bias from the use of historical cohorts. [Formula presented] Disclosures: No relevant conflicts of interest to declare.