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

Association between clinical symptoms during the COVID-19 infection and SARS-CoV-2 immunoglobulin G titers in COVID-19 convalescent whole-blood donors in China

BACKGROUND

Limited studies have explored the association between clinical symptoms and titers of SARS-CoV-2 antibodies.

STUDY DESIGN AND METHODS

In this cross-sectional study, whole-blood donors who had experienced a confirmed or suspected COVID-19 infection completed questionnaires at the time of blood donation. Plasma SARS-CoV-2 immunoglobulin G (IgG) titers were measured using an enzyme-linked immunosorbent assay. Logistic regression models were used to calculate odds ratios (ORs) for high-titer COVID-19 convalescent plasma (CCP) for each variable.

RESULTS

Among the total 386 donors, 120 (31%) donors with IgG titers ≥1:160 were classified as high-titer donors. The multivariable ORs (95% confidence intervals [CIs]) for high titers were 2.33 (1.45-3.75), 2.11 (1.29-3.43), 1.10 (1.01-1.21), 1.19 (1.00-1.43), and 1.97 (1.05-3.71) for sore throat, cough, symptom count, fever duration, and low fever (compared with non-fever), respectively. No significant association was observed between other symptoms and medical visits and the odds of high-titer CCP. The association between high-titer CCP and fever duration was restricted to confirmed COVID-19-infected donors, while associations with sore throat and cough remained significant in suspected infected donors. In addition, medical visit was positively associated with high-titer CCP in suspected donors, but not in confirmed donors. In bootstrapped logistic regression models, the associations remained significant and reproducible for medical visit in suspected donors and for sore throat and cough in both suspected donors and total donors.

DISCUSSION

Experiencing a sore throat and cough were associated with high-titer CCP in overall donors. We also identified sore throat, cough, and medical visits as potential predictors of high-titer CCP for suspected donors during the pandemic.

Factors related to the development of high antibody titres against SARS-CoV-2 in convalescent plasma donors from the ConPlas-19 trial

BACKGROUND AND OBJECTIVES

The efficacy of COVID-19 convalescent plasma (CP) associates with high titres of antibodies. ConPlas-19 clinical trial showed that CP reduces the risk of progression to severe COVID-19 at 28 days. Here, we aim to study ConPlas-19 donors and characteristics that associate with high anti-SARS-CoV-2 antibody levels.

MATERIALS AND METHODS

Four-hundred donors were enrolled in ConPlas-19. The presence and titres of anti-SARS-CoV-2 antibodies were evaluated by EUROIMMUN anti-SARS-CoV-2 S1 IgG ELISA.

RESULTS

A majority of 80.3% of ConPlas-19 donor candidates had positive EUROIMMUN test results (ratio ≥1.1), and of these, 51.4% had high antibody titres (ratio ≥3.5). Antibody levels decline over time, but nevertheless, out of 37 donors tested for an intended second CP donation, over 90% were still EUROIMMUN positive, and nearly 75% of those with high titres maintained high titres in the second sample. Donors with a greater probability of developing high titres of anti-SARS-CoV-2 antibodies include those older than 40 years of age (RR 2.06; 95% CI 1.24-3.42), with more than 7 days of COVID-19 symptoms (RR 1.89; 95% CI 1.05-3.43) and collected within 4 months from infection (RR 2.61; 95% CI 1.16-5.90). Male donors had a trend towards higher titres compared with women (RR 1.67; 95% CI 0.91-3.06).

CONCLUSION

SARS-CoV-2 CP candidate donors' age, duration of COVID-19 symptoms and time from infection to donation associate with the collection of CP with high antibody levels. Beyond COVID-19, these data are relevant to inform decisions to optimize the CP donor selection process in potential future outbreaks.

Predictors of high SARS-CoV-2 immunoglobulin G titers in COVID-19 convalescent whole-blood donors: a cross-sectional study in China

Background

Demographic information has been shown to help predict high antibody titers of COVID-19 convalescent plasma (CCP) in CCP donors. However, there is no research on the Chinese population and little evidence on whole-blood donors. Therefore, we aimed to investigate these associations among Chinese blood donors after SARS-CoV-2 infection.

Methods

In this cross-sectional study, 5,064 qualified blood donors with confirmed or suspected SARS-CoV-2 infection completed a self-reported questionnaire and underwent tests of SARS-CoV-2 Immunoglobulin G (IgG) antibody and ABO blood type. Logistic regression models were used to calculate odds ratios (ORs) for high SARS-CoV-2 IgG titers according to each factor.

Results

Totally, 1,799 participants (with SARS-CoV-2 IgG titers≥1:160) had high-titer CCPs. Multivariable analysis showed that a 10-year increment in age and earlier donation were associated with higher odds of high-titer CCP, while medical personnel was associated with lower odds. The ORs (95% CIs) of high-titer CCP were 1.17 (1.10-1.23, p< 0.001) and 1.41 (1.25-1.58, p< 0.001) for each 10-year increment in age and earlier donation, respectively. The OR of high-titer CCP was 0.75 (0.60-0.95, p = 0.02) for medical personnel. Female early donors were associated with increased odds of high-titer CCP, but this association was insignificant for later donors. Donating after 8 weeks from the onset was associated with decreased odds of having high-titer CCP compared to donating within 8 weeks from the onset, and the HR was 0.38 (95% CI: 0.22-0.64, p <0.001). There was no significant association between ABO blood type or race and the odds of high-titer CCP.

Discussion

Older age, earlier donation, female early donors, and non-medical-related occupations are promising predictors of high-titer CCP in Chinese blood donors. Our findings highlight the importance of CCP screening at the early stage of the pandemic.

Analysis of 52 240 source plasma donors of convalescent COVID-19 plasma: Sex, ethnicity, and age association with initial antibody levels and rate of dissipation

Background

COVID‐19 convalescent plasma (CCP) was approved under emergency authorization to treat critically ill patients with COVID‐19 in the United States in 2020. We explored the demographics of donors contributing plasma for a hyperimmune, plasma‐derived therapy to evaluate factors that may be associated with anti‐SARS‐CoV‐2 antibody response variability and, subsequently, antibody titers.

Study Design

An electronic search of CCP donors was performed across 282 US plasma donation centers. Donations were screened for nucleocapsid protein‐binding‐IgG using the Abbott SARS‐CoV‐2 IgG assay.

Results

Overall, 52 240 donors donated 418 046 units of CCP. Donors were of various ethnicities: 43% Caucasian, 34% Hispanic, 17% African American, 2% Native American, 1% Asian, and 3% other. Females had higher initial mean anti‐SARS‐CoV‐2 antibody titers but an overall faster rate of decline (P < .0001). Initial antibody titers increased with age: individuals aged 55 to 66 years had elevated anti‐SARS‐CoV‐2 titers for longer periods compared with other ages (P = .0004). African American donors had the lowest initial antibody titers but a slower rate of decline (P < .0001), while Caucasian (P = .0088) and Hispanic (P = .0193) groups had the fastest rates of decline. Most donor antibody levels decreased below the inclusion criteria (≥1.50) within 30 to 100 days of first donation, but donation frequency did not appear to be associated with rate of decline.

Conclusion

Several factors may be associated with anti‐SARS‐CoV‐2 antibody response including donor age and sex. Evaluating these factors during development of future hyperimmune globulin products may help generation of therapies with optimal efficacy.

Emphasizing the link between blood types in multi-ethnic disparities and COVID-19 infection in Makkah, Saudi Arabia

OBJECTIVES

To analyze the impact and distribution of blood groups in different ethnicities and the extent of susceptibility to infection with COVID-19 in Makkah, Saudi Arabia.

METHODS

A retrospective study was performed on 4,609 COVID-19 patients from five ethnic groups to assess the impact and distribution of different blood types and susceptibility to COVID-19 infection. The study was carried out between November 2020 and June 2021 in the College of Medicine, Umm Al-Qura University in collaboration with the General Directorate of Health Affairs, Makkah, Saudi Arabia.

RESULTS

Blood group (A, B, and O) distributions in 2,617 COVID-19 patients with local control populations was done. Our study found that in both Saudi and non-Saudi populations, blood groups O and A were associated with higher infection rates, whereas blood group AB was associated with lower infection rates (p=0.0001). COVID-19 seems to be associated with blood groups A, B, and AB (RR=3.23, 95% CI=2.702-3.821, p=0.0001). COVID-19 risk was lower in people with O blood group (RR=0.783, 95% CI=0.733-0.836, p=0.0001). South Asians had higher odds of COVID-19 infection when compared to Saudi cases and other ethnic groups (OR=1.12, 95 % CI: 1.074-1.24, p=0.04).

CONCLUSION

We emphasize that COVID-19 infection is not proportional among ethnically related blood groups. Notably, RhD-negative protect against COVID-19, whereas A and O blood types are more susceptible. Thus, when assessing COVID-19 prognosis and vaccination priority, blood groups A and O are critical.