The demographic and serological characteristics of COVID-19 convalescent plasma donors: Identification of basic criteria for optimal donor selection.

BACKGROUND AND OBJECTIVES: Convalescent plasma has attracted significant attention as a therapeutic option against infectious agents for more than a century. In March 2020, the use of Convalescent COVID-19 plasma (CCP) as a new research drug for COVID-19 treatment was approved by the FDA. The development of SARS-CoV-2 IgG antibodies following infection or vaccination is likely to be essential to provide adequate immunity for the population to halt the COVID19 pandemic. This study aimed to identify the criteria that would be used to determine the most appropriate CCP donors with the highest effective antiviral antibody titers. MATERIALS AND METHODS: In this prospective cohort, univariate analyses and multivariate regression analyses were performed to evaluate the relationship between characteristics of 11949 CCP donors and COVID-19 disease severity prior to donation with antibody titers estimated using ELISA technique and rapid tests. RESULTS: The antibody titer was measured among 8206 (68.7 %) donors. Elderly male and nulliparous female CCP donors who resided in the areas with high load of virus had positive ELISA and rapid test results as well as high levels of SARS-CoV-2 IgG antibodies titer. Moreover, the long hospital stay and elderly donors were the variables associated with high levels of SARS-CoV-2 IgG antibodies. CONCLUSION: This study suggests that nulliparous female and male donors with positive rapid tests who resided in areas with a higher prevalence of SARS-CoV-2, with more than 40 years of age and long hospitalization time can be the preferred donors for CCP donation.

Early high-titer convalescent plasma therapy in patients with moderate and severe COVID-19.

BACKGROUND AND OBJECTIVES: The use of COVID-19 convalescent plasma (CCP) has been approved by the FDA. We assessed the outcome of patients with moderate and severe COVID-19 following convalescent plasma therapy and the association with variables such as antibody titer in CCP units and transfusion time. MATERIALS AND METHODS: In this prospective cohort study, 3097 patients with moderate and severe COVID-19 (according to WHO Progression Scale) had heterogeneous demographic and clinical characteristics received plasma with an unknown titer at the transfusion time. Firstly, information about age, sex, blood group, the time interval from hospitalization to CCP transfusion, underlying disease, and antibody titer with the outcome were investigated. Then, multivariate logistic regression and area under the curve (AUC) were performed for the association between disease severity and intubation variables with transfusion time and outcome. RESULTS: Patients with younger age receiving CCP in the first five days of hospitalization had lower mortality (P < 0.0001). Moreover, patients without the underlying disease had lower mortality (P < 0.001). The mortality rate also decreased in severe patients who were intubated receiving CCP for less than five days (P < 0.001). In patients with moderate severity (score less than 5) who received IgG antibody levels above 1:320 in less than five days had lower mortality (P < 0.0001). CONCLUSION: Our findings suggested that COVID-19 patients with the moderate type of disease receiving CCP units with high antibody titers in the early stages of the disease experienced greater effectiveness of CCP therapy.