A potent inflammatory response is triggered in asymptomatic blood donors with recent SARS-CoV-2 infection.

BACKGROUND: The inflammatory response plays a significant role in the outcome of coronavirus disease (COVID-19). METHODS: We investigated plasma cytokine and chemokine concentrations in non-infected (NI), asymptomatic severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2)-infected blood donors (AS), and patients with severe COVID-19 (SC). RESULTS: The SC group showed significantly higher levels of interleukin 6 (IL-6), IL-10, and CCL5 than the AS and NI groups. The SC and AS groups had considerably greater CXCL9 and CXCL10 concentrations than the NI group. Only NI and infected people showed separate clusters in the principal component analysis. CONCLUSIONS: SC, as well as AS was characterized by an inflammatory profile.

Pro-inflammatory immune profile mediated by TNF and IFN-γ and regulated by IL-10 is associated to IgG anti-SARS-CoV-2 in asymptomatic blood donors.

The SARS-CoV-2 virus has infected and killed millions of people, but little is known about the risk factors that lead to the development of severe, mild or asymptomatic conditions after infection. The individual immune response and the balance of cytokines and chemokines have been shown to be important for the prognosis of patients. Additionally, it is essential to understand how the production of specific antibodies with viral neutralizing capacity is established. In this context, this study aimed to identify positive individuals for IgG anti-SARS-CoV-2 in a large population of blood donors (n = 7837) to establish their immune response profile and to evaluate its viral neutralization capacity. The prevalence found for IgG anti-SARS-CoV-2 was 5.6% (n = 441), with male blood donors (61.9%) being more prevalent among the positive ones. The results showed that positive individuals for IgG anti-SARS-CoV-2 have high serum concentrations of chemokines, TNF, IFN-γ and IL-10. The analyses showed that the positivity index for IgG anti-SARS-CoV-2 is associated with the neutralizing capacity of the antibodies, which, in turn, is significantly related to lower serum concentrations of CCL5 and CXCL10. The results allow us to hypothesize that the development and maintenance of IgG anti-SARS-CoV-2 antibodies in infected individuals occurs in a pro-inflammatory microenvironment well regulated by IL-10 with great capacity for recruiting cells from the innate and adaptive immune systems.

Impact of COVID-19 on the efficacy of meeting the transfusion demand by a Brazilian blood banks network.

One of the effects of the pandemic in the hemotherapy services was the reduction in the attendance of blood donors and production of blood components. It is relevant to investigate how the capacity to meet the demand for blood components was affected, especially in blood centers located in the regions most affected by the pandemic, such as Brazil. This study aimed to describe the impact of the pandemic on the capacity to meet the demand for different types of blood components by a Brazilian blood center in 2020, compared to the historical series of 2016-2019 and to discuss the measures adopted to mitigate the effects of the pandemic. Retrospective cross-sectional study was carried out with comparative analysis of the blood components requested and attended in the period from 2016 to 2020. Data analysis was performed by Graphpad Prism 5. The spread of COVID-19 cases since March 2020 had impact on the blood components production and transfusions. The reduction in the production of blood components was observed prior to the restriction measures, in March 2020. In comparison to 2016-2019, there was a reduction in the number of transfusions performed in all months of 2020. The results suggest that the measures adopted in a Brazilian blood center to face the COVID-19 pandemic resulted in reasonable regularity in the supply of blood components. The sharing of experiences between blood banks in different regions, social and epidemiological contexts can contribute to the improvement of strategies to reduce the impact of COVID-19 in transfusion medicine.

SARS-CoV-2 IgG Seroprevalence among Blood Donors as a Monitor of the COVID-19 Epidemic, Brazil.

During epidemics, data from different sources can provide information on varying aspects of the epidemic process. Serology-based epidemiologic surveys could be used to compose a consistent epidemic scenario. We assessed the seroprevalence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) IgG in serum samples collected from 7,837 blood donors in 7 cities of Brazil during March-December 2020. Based on our results, we propose a modification in a compartmental model that uses reported number of SARS-CoV-2 cases and serology results from blood donors as inputs and delivers estimates of hidden variables, such as daily values of SARS-CoV-2 transmission rates and cumulative incidence rate of reported and unreported SARS-CoV-2 cases. We concluded that the information about cumulative incidence of a disease in a city's population can be obtained by testing serum samples collected from blood donors. Our proposed method also can be extended to surveillance of other infectious diseases.

Analysis of current SARS-CoV-2 infection in a large population of blood donors evidenced that RNAemia is rare in plasma.

BACKGROUND: Transmission of SARS-CoV-2 by asymptomatic individuals and by blood transfusion are important issues to understand to control the viral spread. In this work, we estimated the current SARS-CoV-2 infection rate in blood donors from Belo Horizonte, Brazil. STUDY DESIGN AND METHODS: Saliva and blood samples were collected from 4103 blood donors from June 15 to September 30, 2020. Saliva samples were tested by real-time RT-PCR for SARS-CoV-2 in mini-pools of four samples. Individual samples were tested for positive or inconclusive pools, and positive donors had their plasma tested. RESULTS: Twenty-seven (0.66%) blood donors were positive for SARS-CoV-2 in their saliva, but their plasma was negative, except for one, who presented a high viral load in saliva and nasopharyngeal samples and RNAemia in the plasma close to the limit of detection. Fourteen (56%) positive blood donors reported mild symptoms related to COVID-19 after donation, but the viral load levels were not statistically different between symptomatic and asymptomatic individuals. DISCUSSION: Despite the measures taken by Blood Centers to avoid blood donors with SARS-CoV-2 infection, asymptomatic or presymptomatic carriers are able to donate. The risk of the virus transmission by transfusion seems to be negligible since plasma RNAemia was seen at a very low level in only one (3.7%) of the positive donors, but other studies must be performed to confirm this finding.

Impact of COVID-19 in the attendance of blood donors and production on a Brazilian Blood Centres.

BACKGROUND: One of the effects of the coronavirus disease 2019 (COVID-19) pandemic is the risk of shortages in Blood Centres. OBJECTIVES: To verify the impact of the COVID-19 pandemic on the blood donor's attendance and production of blood components in Fundação Hemominas, a Brazilian public institution was formed by several Blood Centres. METHODS: A cross-sectional study was carried out from January to June 2020. Data collected were compared to a historical series from 2016 to 2019. RESULTS: The study showed a reduction in the attendance of blood donors, whole blood collections and blood component production from March 2020, when the first case of COVID-19 was notified in Minas Gerais, Brazil. The results evidenced that Hemominas Blood Centres were affected in a very distinct way by the pandemic with a general mean reduction around 17% in attendance of blood donors and in production of blood components in the period of March to June. On the other hand, the return of blood donors rate increased. CONCLUSION: The reduction in blood donation during the pandemic period was significant, despite the measures adopted. Still, the recruitment of return donors appears to be an important measure to be considered to decrease the pandemic's effect on blood stocks.