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Background: The effects of convalescent plasma (CP) therapy in hospitalised patients with coronavirus disease 2019 (COVID-19) remain uncertain. This study investigates the effect of CP on clinical improvement in these patients. Methods: This is an investigator-initiated, randomised, parallel arm, open-label, superiority clinical trial. Patients were randomly (1:1) assigned to two infusions of CP plus standard of care (SOC) or SOC alone. The primary outcome was the proportion of patients with clinical improvement 28 days after enrolment. Results: A total of 160 (80 in each arm) patients (66.3% critically ill, 33.7% severely ill) completed the trial. The median (interquartile range (IQR)) age was 60.5 (48–68) years; 58.1% were male and the median (IQR) time from symptom onset to randomisation was 10 (8–12) days. Neutralising antibody titres >1:80 were present in 133 (83.1%) patients at baseline. The proportion of patients with clinical improvement on day 28 was 61.3% in the CP+SOC group and 65.0% in the SOC group (difference −3.7%, 95% CI −18.8–11.3%). The results were similar in the severe and critically ill subgroups. There was no significant difference between CP+SOC and SOC groups in pre-specified secondary outcomes, including 28-day mortality, days alive and free of respiratory support and duration of invasive ventilatory support. Inflammatory and other laboratory marker values on days 3, 7 and 14 were similar between groups. Conclusions: CP+SOC did not result in a higher proportion of clinical improvement on day 28 in hospitalised patients with COVID-19 compared to SOC alone.

Base teórica: A Fibrose Cística (FC) é uma doença genética que acomete diversos órgãos, entretanto, as infecções crônicas das vias aéreas são uma das principais comorbidades que afetam estes indivíduos. A determinação do perfil microbiológico destas infecções crônicas é realizada através de técnicas tradicionais de cultivo. Dentre as bactérias comumente isoladas nas técnicas de cultivo predominam de forma mais significativa a Pseudomonas aeruginosa, o Staphylococcus aureus e espécies do complexo Burkholderia cepacia. Essas bactérias provocam infecções persistentes no pulmão do paciente com FC e são de difícil erradicação. Com base em tecnologias moleculares, sugere-se que há uma diferença na diversidade bacteriana nas vias aéreas e a qual pode estar associada a uma melhor evolução clínica da doença. As metodologias moleculares independem do cultivo bacteriano em meios de cultura e tem como base o sequenciamento do gene 16S rRNA que é bastante conservado em bactérias e permite identificar diferentes espécies. O sequenciamento do gene 16S rRNA tem a potencial capacidade de apresentar maior sensibilidade que as técnicas de cultivo tradicional, o que pode antecipar a detecção de um patógeno ou indicar a persistência deste no pulmão de pacientes com FC. Objetivo: Determinar o microbioma de pacientes com FC em amostras de escarro, afim de correlacionar a microbiota de pacientes jovens com o resultado da cultura bacteriológica tradicional, mutações em CFTR e presença de leucócitos no escarro. Métodos: Amostras de escarros de pacientes com FC foram coletadas para dois estudos distintos. No primeiro estudo uma amostra de escarro de 27 pacientes diferentes foram obtidos e, em um segundo estudo, foi determinado a presença do gênero Burkholderia através do microbioma em 22 amostras de escarros de 9 pacientes diferentes. Para ambos os trabalhos a biblioteca do 16S rRNA foi preparada usando a região V3V4 do gene e o produto de amplificação foi submetido a sequenciamento usando Illumina MiSeq. A determinação dos táxons presente na amostra foi realizado por Amplicon Sequence Variants (ASV). Resultado: Em relação ao primeiro estudo, a análise do microbioma detectou os gêneros Staphylococcus e Pseudomonas em todas as amostras de escarro. Na técnica de cultivo tradicional a espécie mais prevalente foi Staphylococcus aureus presente em 70,4% (19/27) das amostras de escarros analisadas, seguida por Pseudomonas aeruginosa em 33,3% (9/27) e complexo Burkholderia cepacia em 29,63% (8/27). Foi possível observar pelo microbioma uma diminuição significativa da diversidade bacteriana nas amostras de escarro com presença de leucócito e o mesmo ocorreu nas amostras oriundas de pacientes internados. Entretanto não foi observado variações estatisticamente significativas entre os microbiomas de pacientes com diferentes mutações no gene CFTR. No segundo estudo, através do microbioma foi possível detectar o gênero Burkholderia em pelo menos uma amostra dos 9 (100%) pacientes analisados, o que representou 63,64% (14/22) dos escarros analisados. Em contrapartida, na cultura bacteriológica foi identificada a Bcc em apenas 4 amostras de escarro de 3 diferentes pacientes. Cabe mencionar que os estudos acima foram os primeiros a determinar o microbioma pulmonar de pacientes com FC através da análise por ASV. Conclusão: Os resultados de ambos estudos indicaram que o microbioma pôde antecipar a detecção de gêneros de importância clínica (Pseudomonas, Staphylococcus e Burkholderia) em comparação com técnicas de cultivo laboratorial, e, com isso contribuir para um tratamento mais precoce. Além disso, a menor diversidade do microbioma pode ser relacionada a aumento do processo inflamatório (presença de leucócitos) bem como a necessidade de internação hospitalar. Backgorund: Cystic Fibrosis (CF) is a genetic disease that affects different organs; however, the chronic airway infection is the main comorbidity of these individuals. The evaluation of the microbiological profile of these chronic infections is usually performed by bacteriological culture. Among the bacteria commonly isolated by culture-dependent technique, the main species are Pseudomonas aeruginosa; Staphylococcus aureus and members of Burkholderia cepacia complex (Bcc). These bacteria cause persistent infections in the lung of CF patients which are difficult to eradicate. Based on molecular technologies, it has been suggested that there is a difference in the bacterial diversity from the airways which may be associated with a better prognosis of the disease. These molecular methods are independent of bacteriological culture as they are based on sequencing of the 16S rRNA gene, which is highly conserved in bacteria and allows to differentiate the species. The 16S rRNA sequencing has the potential to be more sensitive than bacteriological culture; and it may anticipate the detection of a pathogen or indicate its persistence in the lung of patients with CF. Objective: To evaluate the microbiome in the respiratory tract of patients with CF in order to correlate the airways microbiota of young patients with the result of bacteriological culture; CFTR mutations and the presence of leukocytes in sputum. Methods: Sputum specimens from patients with CF were collected for two different studies. For the first study, 27 sputa from different patients were obtained; for the second study, the presence of the Burkholderia genus was determined in the microbiome of 22 sputum specimens from 9 different patients. For both studies, library of 16S rRNA was prepared according to a standard protocol using a V3V4 region; the product of amplification was submitted to sequencing into Illumina MiSeq. The determination of the taxa in the specimens was performed using the amplicon sequence variants (ASV). Results: In relation to the first study, microbiome was capable to detect the genera Staphylococcus and Pseudomonas in all sputum samples. In the traditional culture technique, the most prevalent species were Staphylococcus aureus present in 70.4% (19/27) of the sputum specimens analyzed, followed by Pseudomonas aeruginosa in 33.3% (9/27) and Burkholderia cepacia complex in 29, 63% (8/27). It was possible to observe, by microbiome analysis, a significant decrease in bacterial diversity in sputum specimens; lower alpha diversity was directly correlated to the presence of leukocytes and hospitalized patients. There was no significant difference in alpha diversity and CFTR mutations. In the second study, according to the microbiome analysis, it was possible to detect the genus Burkholderia in at least one specimen of all 9 (100%) patients; which represented 63.64% (14/22) of the sputum analyzed. Conversely, the bacteriological culture was capable to detect Bcc in only 4 sputa (18.2%) from 3 different patients. Noteworthy, the studies above were the first to determine the lung microbiome of patients with CF using ASV analysis. Conclusion: The results of both studies indicates that the microbiome could anticipate the detection of clinically important genera (Pseudomonas, Staphylococcus e Burkholderia) compared to bacteriological culture results, and this may contribute to earlier treatment. In addition, the lower alpha diversity may be related to an increase in the inflammatory process (presence of leukocytes) and with hospitalization status.