COVID-19 Convalescent Plasma Donors Research Articles

Blood Group Variations in COVID-19 Convalescent Plasma and Regular Blood Donors: A Comparative Analysis in the Serbian Population.

This research explores the association between ABO blood groups and susceptibility to SARS-CoV-2 infection, analyzing Convalescent COVID-19 plasma (CCP) donors (n = 500) and healthy whole blood donors (BDs) (n = 9678) during the pandemic (1 May 2020 to 30 April 2021). A comparison is made with pre-pandemic BDs (n = 11,892) from 1 May 2018 to 30 April 2019. Significant differences in blood group distribution are observed, with blood group A individuals being three times more likely to be CCP donors. Conversely, blood groups B, O, and AB are less associated with CCP donation. Notably, blood group O is more prevalent among regular BDs, suggesting potential resistance to SARS-CoV-2 infection. This study underscores variations in blood group distribution during the pandemic compared to pre-pandemic periods. The findings support previous research indicating a link between blood group antigens and viral susceptibility, including SARS-CoV-2. Understanding these associations has implications for public health strategies, with potential for predicting COVID-19 outcomes and transmission patterns. Further research is crucial to explore molecular and immunological mechanisms, providing valuable insights for targeted preventive strategies and personalized healthcare in managing the impact of COVID-19.

Prevalence of anti-HLA antibodies in COVID-19 convalescent plasma donors: An Indian experience

BackgroundCOVID-19 convalescent plasma is one of the experimental therapies used widely in moderately sick COVID-19 patients. However, there are a few risks involved in plasma transfusion; notably, transfusion-related acute lung injury (TRALI) caused by antibodies against human leukocyte antigens (HLA). This study was designed to assess the prevalence of anti-HLA antibodies in convalescent plasma donors using the single antigen bead method. Study Design and MethodsThis was a hospital-based observational study of consecutive plasma donors. A total of 252 samples were screened for anti-HLA Class I and Class II antibodies using the microbead assay with the identification of anti-HLA Ab in positive samples being performed using a single antigen bead assay. Luminex-based normalized background cutoff ratios of 10.8 for Class I and 6.9 for Class II and mean fluorescence intensity cutoffs of 2500 for Class I and 1500 for Class II were used for screening and the single bead assay, respectively. ResultsOf 252 screened samples, 28 (11.1%) were positive for Class I, Class II or both Class I and Class II anti-HLA antibodies in donors with no history of a previous immunizing event. Moreover, 20/252 (7.9 %) donors without any history of prior immunization had specific anti-HLA antibodies of Class I or Class II or both by the single bead assay. ConclusionsThe high prevalence of anti-HLA antibodies in our cohort of donors raises an urgent and immediate need for anti-HLA antibody screening in all convalescent plasma donors for safe therapy of COVID-19 patients.

Characteristics and Motivational Factors of Whole Blood and Convalescent Plasma Donors during the SARS-CoV-2 Pandemic in Israel.

Demands for whole blood (WB) and COVID-19 convalescent plasma (CCP) donations during the SARS-CoV-2 (COVID-19) pandemic presented unprecedented challenges for blood services throughout the world. This study aims to understand the motivating factors that drive WB and CCP donations in the context of the pandemic. This cross-sectional study is based on data extracted from surveys of the two volunteer donor cohorts. The findings reveal that when compared to CCP donors, WB donors were more likely to view donation as a form of social engagement (97.7% vs. 87.1%, p < 0.01), advantageous in the workplace (46.4% vs. 28.6%, p < 0.01), advantageous in their social network (58.6% vs. 47.0%, p = 0.01), and view their donation in the context of positive self-satisfaction (99% vs. 95.1%, p = 0.01). The average age of CCP donors was 7.1 years younger than those who donated WB (p < 0.01). Motivational factors were also analyzed by sex and religiosity. In conclusion, whereas both donor groups showed a high motivation to partake in these life-saving commitments, WB donors were more likely to be motivated by factors that, when better-understood and implemented in policies concerning plasma donations, may help to increase these donations.

COMPARISON OF SARS-CoV ANTIBODY TITER LEVELS AGAINST ABO BLOOD TYPE, AGE, AND GENDER IN CONVALESCENT PLASMA DONATIONS

An important requirement to become a convalescent plasma donor is a standardized SARS-CoV antibody titer. However, not all Covid-19 survivors pass the plasma donor selection due to low antibody titer. This research aims to determine the comparison of SARS-CoV antibody titer levels with blood type, age and gender of Covid-19 convalescent plasma donors at blood donation unit PMI Semarang City. This study is an analytical observational study with a cross sectional design, using 300 data on convalescent plasma donors. The sampling technique used was purposive sampling. Differences in SARS-CoV antibody titer levels based on blood type, age, and gender were tested using SPSS 25. Donors involved in this study were divided based on the conversion of convalescent plasma titer levels, namely 1:80 (37%), 1:160 (4%), 1:250 (10.3%) and 1:640 (48.7%). Based on blood type data, most convalescent plasma donors have blood type O (42%) with the highest titer levels in the 1:640 category (48.7%). The highest mean titer level was found in blood group B which was 382.09. The results of the Kruskal-Wallis test showed no significant difference in titer levels by blood group, p=0.622 (&gt;0.05). In the parameter of donor age, SARS-CoV antibody titer levels also showed no significant difference in donor age, both adolescent, adult and elderly donors with a value of p=0.598 (p&gt;0.05). In line with these results, the chi square test of differences in antibody titres based on gender also showed no significant difference, p value=0.127 (p&gt;0.05). High and low antibody titres of convalescent plasma donors are not determined by blood type, age and gender of the donor.

A real-world study on the effectiveness of BBIBP-CorV and CoronaVac in Nanjing area

Since the advent of COVID-19 vaccine, the long-term monitoring and evaluation of vaccine effectiveness worldwide has never stopped. Real-world research of the mainstream vaccines in China (BBIBP-CorV and CoronaVac) is extremely valuable as a supplement to clinical research data. Venous blood of this study was collected from 111 blood donors and from 6 volunteers, who had received 2 doses of SAR-CoV-2 vaccine. Cross-sectional study and cohort study was adopted. Venous blood of 11 COVID-19 convalescent plasma donors was collected as a positive control. The seroconversion rate of neutralizing antibodies in 111 vaccine recipients was 90.99% (101/111); The level of SAR-CoV-2 antibodies peaked around 28 days after inoculation, then fast descended followed by gentle descended until it was still detectable around 280 days later. The changes in antibody levels were similar to those of the 6 participants and those of convalescent plasma donors after infection. 5 of the 6 participants still maintained a high level of neutralizing antibodies (> 60% of the peak value) around 28 days after receiving 2 doses of vaccine; one participant had an antibody reaction that was almost always negative for 4 weeks. BBIBP-CorV and CoronaVac can produce good immune effects in most vaccinators aged 20 to 59 years in Nanjing area. Nevertheless, significant individual discrepancies of the humoral immunity are still existed.

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

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. 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. 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). 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.

Hundred-fold increase in SARS-CoV-2 spike antibody levels over three years in a hospital clinical laboratory.

Natural infection with the SARS-CoV-2 virus and vaccination increase the serum spike antibody levels. These levels, which differ among the various commercial assays, are used by the FDA to qualify individuals as potential COVID-19 convalescent plasma (CCP) donors. Over a 3-year period (April 2020-February 2023), we performed a retrospective analysis of spike IgG antibodies measured by a tertiary hospital clinical immunology laboratory using the Euroimmun SARS-CoV-2 IgG ELISA. The 3-year interval was classified into five periods based on the SARS-CoV-2 strain variant epidemiology. A total of 15,820 sera, derived from 11,022 individuals (6,362 females and 4,660 males) ranging from severe immunocompromised state to routine health visits, were tested. Spike IgG levels rose significantly over time, from a median ELISA 0.13 Arbitrary Units (AU) in the first period to 48.7 in the last period (P < 0.0001). The 80th percentile of the spike IgG distribution was 0.55, 8.1, 9.6, 64.9, and 151 AU in the five periods. Using 3.5 AU, the FDA threshold for qualifying CCP donors with this Euroimmun assay, the percentage of subjects eligible for CCP donation would have been 11%, 44%, 61%, 81%, and 91% in the five time periods. Overall, spike antibody levels have risen more than 100-fold during the pandemic, while SARS-CoV-2 variants have become resistant to monoclonal antibodies. Since CCP containing high titers of spike antibodies is known to be most effective against variants, restricting CCP donors to those with antibody values in the upper two deciles may allow greater therapeutic transfusion protection.IMPORTANCEDespite the evolution of SARS-CoV-2 variants of concern and ongoing transmission, COVID-19 hospitalization and mortality rates continue to decline. Both the percent seropositive and antibody levels have risen over the past 3 years. Here, we observe more than 90% seropositivity as well as more than a hundred-fold increase in spike IgG levels in a tertiary hospital clinical immunology laboratory setting. Antibody effector functions (such as neutralization, opsonization, and complement activation) and cell-mediated immunity all contribute to protection from COVID-19 progression to hospitalization, and all correlate to the total SARS-CoV-2 antibody levels. We recommend therapeutic COVID-19 convalescent plasma be restricted to the top 20% of potential donors to maintain activity against ongoing SARS-CoV-2 variant evolution.

A male Covid-19 convalescent plasma donor with long existence of SARS-Cov-2 antibodies: a case report

Covid-19 Convalescent Plasma (CCP) was one of alternative therapy for Covid-19 patients. The use of convalescent plasma as an adjunct therapy must consider its efficacy, benefits, and risk, both for the patient and the donor. Convalescent Plasma was produced from purified human plasma. Convalescent Plasma was a passive immunity which provide active antibodies. CCP give immunity to the patient through the transfusion of a survivor’s antibodies. We were reporting a case of male CCP donor with long existence of SARS-Cov-2. This donor performed up to 16 donations, which was an unusual case in CCP donor. The SARS-CoV-2 antibody titer was analyzed using Elecsys® Anti-SARS-CoV-2 (Roche Diagnostics). The SARS-CoV-2 antibody showed high level of total SARS-CoV-2 antibodies, with the Cut off Indexes (COI) anti SARS-Cov-2 antibody were still quite high (132 U/mL). The highest donor antibody COI (204.6 U/mL) was seen in 11th donation at 6 months after recovery, while the lowest antibody COI (130.8 U/mL) was in 15th donation at 7 months after recovering. Evaluation of donor health status were performed after the 16th donation and analyzed as well. In conclusion, 16 CCP donations of 600 mL resulting in 48 units of 200 mL plasma in 8 months was safe for the donor, with the SARS-Cov-2 antibody titer remained high in the whole period.

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

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. 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. 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. 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.

Correlation between Clinical Characteristics and Antibody Levels in COVID-19 Convalescent Plasma Donor Candidates.

COVID-19 convalescent plasma (CCP) with high neutralizing antibodies has been suggested in preventing disease progression in COVID-19. In this study, we investigated the relationship between clinical donor characteristics and neutralizing anti-SARS-CoV-2 antibodies in CCP donors. COVID-19 convalescent plasma donors were included into the study. Clinical parameters were recorded and anti-SARS-CoV-2 antibody levels (Spike Trimer, Receptor Binding Domain (RBD), S1, S2 and nucleocapsid protein) as well as ACE2 binding inhibition were measured. An ACE2 binding inhibition < 20% was defined as an inadequate neutralization capacity. Univariate and multivariable logistic regression analysis was used to detect the predictors of inadequate neutralization capacity. Ninety-one CCP donors (56 female; 61%) were analyzed. A robust correlation between all SARS-CoV-2 IgG antibodies and ACE2 binding inhibition, as well as a positive correlation between donor age, body mass index, and a negative correlation between time since symptom onset and antibody levels were found. We identified time since symptom onset, normal body mass index (BMI), and the absence of high fever as independent predictors of inadequate neutralization capacity. Gender, duration of symptoms, and number of symptoms were not associated with SARS-CoV-2 IgG antibody levels or neutralization. Neutralizing capacity was correlated with SARS-CoV-2 IgG antibodies and associated with time since symptom onset, BMI, and fever. These clinical parameters can be easily incorporated into the preselection of CCP donors.

Antiphospholipid antibodies in convalescent plasma of donors recovered from mild COVID-19 infection.

Passive immunization by the infusion of convalescent plasma (CP) obtained from patients who have recently recovered from COVID-19, thus having antibodies to severe acute respiratory syndrome coronavirus 2, is a potential strategy to reduce the severity of illness. A high prevalence of antiphospholipid antibodies (APLA) in patients with COVID-19 has been reported during the pandemic, raising a concern whether the use of CP could increase the risk of thrombosis in transfused patients. We aimed to evaluate the prevalence of APLA in COVID-19 CP (CCP) in order to assess the potential prothrombotic influence of transfused CCP to COVID-19 patients. We studied the prevalence of APLA in 122 CCP samples collected from healthy donors who recovered from mild-COVID-19 at two time periods: September 2020-January 2021 (defined as 'early period' samples) and April-May 2021 (defined as 'late period' samples). Thirty-four healthy subjects unexposed to COVID-19 were used as controls. APLA were present in 7 of 122 (6%) CCP samples. One donor had anti-β2-glycoprotein 1(anti-β2GP1) IgG, one had anti-β2GP1 IgM and five had lupus anticoagulant (LAC) using silica clotting time (SCT), all in 'late period' donors. In the control group, one subject had anti-β2GP1 IgG, two had LAC using dilute Russell viper venom time (dRVVT) and four had LAC SCT (both LAC SCT and LAC dRVVT in one subject). The low prevalence of APLA in CCP donors reassures the safety of CCP administration to patients with severe COVID-19.

HLA-E*01:01+HLA-E*01:01 genotype confers less susceptibility to COVID-19, while HLA-E*01:03+HLA-E*01:03 genotype is associated with more severe disease.

HLA-E interaction with inhibitory receptor, NKG2A attenuates NK-mediated cytotoxicity. NKG2A overexpression by SARS-CoV-2 exhausts NK cells function, whereas virus-induced down-regulation of MHC-Ia reduces its derived-leader sequence peptide levels required for proper binding of HLA-E to NKG2A. This leads HLA-E to become more complex with viral antigens and delivers them to CD8+ T cells, which facilitates cytolysis of infected cells. Now, the fact that alleles of HLA-E have different levels of expression and affinity for MHC Ia-derived peptide raises the question of whether HLA-E polymorphisms affect susceptibility to COVID-19 or its severity. 104 COVID-19 convalescent plasma donors with/without history of hospitalization and 18 blood donors with asymptomatic COVID-19, all were positive for anti-SARS-CoV-2 IgG antibody as well as a group of healthy control including 68 blood donors with negative antibody were subjected to HLA-E genotyping. As a privilege, individuals hadn't been vaccinated against COVID-19 and therefore naturally exposed to the SARS-CoV-2. The absence of HLA-E*01:03 allele significantly decreases the odds of susceptibility to SARS-CoV-2 infection [p=0.044; OR (95%CI)=0.530 (0.286 - 0.983)], suggesting that HLA-E*01:01+HLA-E*01:01 genotype favors more protection against SARS-CoV-2 infection. HLA-E*01:03+HLA-E*01:03 genotype was also significantly associated with more severe COVID-19 [p=0.020; 2.606 (1.163 - 5.844) CONCLUSION: Here, our observation about lower susceptibility of HLA-E*01:01+HLA-E*01:01 genotype to COVID-19 could be clinical evidence in support of some previous studies suggesting that the lower affinity of HLA-E*01:01 to peptides derived from the leader sequence of MHC class Ia may instead shift its binding to virus-derived peptides, which then facilitates target recognition by restricted conventional CD8+ T cells and leads to efficient cytolysis. On the other hand, according to other studies, less reactivity of HLA-E*01:01 with NKG2A abrogates NK cells or T cells inhibition, which may also lead to a greater cytotoxicity against SARS-CoV-2 infected cells compared to HLA-E*01:03. Taken together given HLA-E polymorphisms, the data presented here may be useful in identifying more vulnerable individuals to COVID-19 for better care and management. Especially since along with other risk factors in patients, having HLA-E*01:03+HLA-E*01:03 genotype may also be associated with the possibility of severe cases of the disease.

Assessment of the impact of pathogen reduction technologies on the neutralizing activity of COVID-19 convalescent plasma.

COVID-19 convalescent plasma (CCP) could improve the clinical outcome of COVID-19 patients when high-titer CCP is administered in early stages of disease. However, CCP donors have a risk profile like first-time donors, pathogen reduction treatment (PRT) may mitigate such risk but should not impact CCP quality. The current study aims to assess the impact of PRT-technologies available in Saudi Arabia on the neutralizing activity of CCP. Study designand Methods: CCP was collected from eligible donors by plasmapheresis. The neutralization titer was determined with an in-house microneutralization assay (MNA) using a local SARS-CoV-2 clinical isolate. Selected units were split and subject to PRT with amotosalen/UVA (AS) or Riboflavin/UVB (RB) (pairwise side-by-side comparison) followed by a second MNA analysis. 51 CCP units were collected, 27 were included in the analysis reaching the minimum MNA titer of 1:40 (4 reached high titer (≥1:250)). 27 CCP units were treated with AS and 14 with RB, the median MNA pre-treatment titer was 1:80 (1:40–640). The impact of AS and RB PRT on CCP neutralizing activity was not significantly different, nor in the total analysis neither in the pairwise comparison (94.6 vs 96.4 % retention, p > 0.05). No correlation of titer and blood group was observed, but a trend for increasing MNA titer with donor age, choosing donors with an age > 45 years would increase the number of high-titer CCP donors. The difference in impact of AS and RB on CCP MNA titer was below the limit of detection of the assay (0.5-fold).

COVID-19 convalescent plasma donors: Unique motivations in unique times?

Early in the SARS-CoV-2 pandemic, many blood collection organizations (BCOs) were asked to collect and distribute COVID-19 convalescent plasma (CCP) as a potential treatment for this new virus and resulting disease. However, recruiting CCP donors presented unique challenges for BCOs, as there were few recovered patients at this time, and like the general population, most potential CCP donors had no blood donation experience. Thus, many CCP donors were new donors, and their donation motivations were unknown. Donors who gave CCP at least once between April 27th and September 15th, 2020, were emailed a link to an online survey regarding their experience with COVID-19 and their motivations for donating CCP and blood. Of the 14,225 invitations sent, 3471 donors responded (24.4%). Most donors had never donated blood before (n=1406), followed by lapsed donors (n=1050), and recent donors (n=951). There was a significant relationship between self-reported donation experience and fear of CCP donation (X2 =119.2, p < .001). Motivations ranked "very important" by responding donors were wanting to help someone in need, a feeling of responsibility, and feeling a duty to donate. Donors with more severe disease were more likely to respond with feelings of a sense of duty to donate CCP (Χ2 =8.078, p=.044) or altruism (Χ2 =8.580, p=.035). Overwhelmingly, altruism and a sense of duty and responsibility were the reasons that CCP donors decided to donate. These insights can be useful for motivating donors for specialized donation programs or if wide scale CCP recruitment is needed in the future.

Demographics of first-time donors returning for donation during the pandemic: COVID-19 convalescent plasma versus standard blood product donors.

Previous studies have demonstrated low first-time donor return rates (DRR) following catastrophic events. Little is known, however, about the influence of demographic factors on the DRR of first-time donors during the COVID-19 pandemic, including the unique motivation of COVID-19 convalescent plasma (CCP) donors as compared to non-CCP donors. Thirteen blood collection organizations submitted deidentified data from first-time CCP and non-CCP donors returning for regular (non-CCP) donations during the pandemic. DRR was calculated as frequencies. Demographic factors associated with returning donors: race/ethnicity, gender, and generation (Gen Z: 19-24, Millennial: 25-40, Gen X: 41-56, and Boomer: ≥57 years old), within the CCP and non-CCP first-time cohorts were compared using chi-square test at p < .05 statistical significance. From March 2020 through December 2021, there were a total of 44,274 first-time CCP and 980,201 first-time non-CCP donors. DRR were 14.6% (range 11.9%-43.3%) and 46.6% (range 10.0%-76.9%) for CCP and non-CCP cohorts, respectively. Age over 40 years (Gen X and Boomers), female gender, and White race were each associated with higher return in both donor cohorts (p < .001). For the non-CCP return donor cohort, the Millennial and Boomers were comparable. The findings demonstrate differences in returning donor trends between the two donor cohorts. The motivation of a first-time CCP donor may be different than that of a non-CCP donor. Further study to improve first-time donor engagement would be worthwhile to expand the donor base with a focus on blood donor diversity emphasizing engagement of underrepresented minorities and younger donors.

Inflammatory and Coagulation Biomarkers in Patients with Sars-COV2 Infection Receiving COVID-19 Convalescent Plasma: The Bergamo Registry

INTRODUCTION: Passive immunization therapy with convalescent plasma has been successfully used in prior viral pandemics. For these reasons, from the beginning of the COVID-19 outbreak in March 2020, our hospital has been actively involved in the collection of COVID-19 convalescent plasma (CCP) and its administration to hospitalized COVID-19 patients. We set up a registry to collect prospectively clinical and laboratory data, and blood samples, from CCP donors and CCP recipients (IMMUNOCOVID registry, clinicaltrials.gov identifier #04614012, approved by the local Ethics Committee). In the present study, in a cohort of COVID-19 plasma recipients, we prospectively assessed the effect of CCP treatment on different clinical and laboratory parameters, including anti-SARS-CoV2 IgG antibody (Ab) levels, inflammatory and coagulation biomarkers. METHODS: Hospitalized COVID-19 patients were treated with maximum 3 CCP units (200 ml/unit), each given every other day, and followed-up clinically for 30 days after first CCP infusion. Venous blood samples were collected on days 0 (D0), 3 (D3), and 5 (D5) before each CCP administration, and on day 7 (D7) after the first administration. The following laboratory measurements were performed: IgG anti-SARS-CoV2 Nucleocapsid protein (anti-N) and IgG anti-Spike protein (anti-S) Ab (quantitative assay); fibrinogen, D-dimer, C reactive protein (CRP), procalcitonin, LDH, Hb, blood cell counts, AST, ALT, creatinine, and GFR. Results are expressed as median and 5th-95th percentile range. RESULTS: From May 2020 to April 2022, 334 (103F/231M) hospitalized COVID-19 patients received CCP treatment. The median age of the cohort was 67 (41-86) years; 89 were admitted to the intensive care unit (ICU) and 245 were in the medical general ward (non-ICU patients). Among this cohort, 255 patients received 3 CCP units, 47 patients 2 CCP units, and 32 only 1 CCP unit. The median time from hospital admission to CCP infusion was 2 days (0 - 70) and a total of 890 CCP units were infused with a median value of 153 AU/ml (100-400) anti-S IgG Ab. Treatment with CCP led to a significant (p<0.001) 7.1-fold increase in anti-S and 1.7-fold increase in anti-N Ab at day 7. By multivariate analysis, the percentage increase in anti-S Ab [i.e., delta = (D7-D0/D0)] was significantly (p<0.05) associated with younger age (beta=-0.181) and male gender (beta=-0.195), but not with disease severity (ICU vs non-ICU), with the highest increment occurring in males <60 years (9.8-fold). Regarding inflammatory and coagulation biomarkers, at enrollment, CRP, neutrophil count, LDH, procalcitonin, fibrinogen and D-dimer levels were all significantly elevated, while lymphocytes and Hb were significantly lower than the normal range. Compared to non-ICU patients, the ICU group, at D0, had higher levels (p<0.05) of inflammatory biomarkers and D-dimer, and significantly lower (p<0.05) lymphocyte count, Hb, and fibrinogen level. In the subgroup of 255 patients who received 3 CCP infusions, in parallel to anti-SARS-CoV2 IgG increment, a significant (p<0.001) reduction in CRP, LDH, ferritin, procalcitonin, and fibrinogen levels occurred. This was particularly apparent in the non-ICU subgroup. Among the whole cohort of 334 patients, 66 had cancer (28 hematological tumors, 33 solid tumors, and 5 both hematological and solid tumors). The median age of this subgroup was 70 years (49-88), with 16 of them admitted to ICU. In this category of patients, a significant increase (p<0.01) of both anti-S (4.7-fold) and anti-N (1.3-fold) IgG occurred, not differently from the rest of patients. Four out of 890 CCP infusions were associated with a mild adverse event with a resolution in 24 hours. Regarding overall mortality, 48 patients (14%) died after 30 days follow-up [15F/33M, median age 64 years (40-81)], 16 of them were in ICU. CONCLUSIONS: In our study, CCP treatment leads to an increase in antibody levels in the recipients, particularly in males <60 years. This occurs also in subjects with cancer and those with severe COVID-19. Notably, the increase of humoral immune response is associated with a decrease in inflammatory parameters and fibrinogen levels. The low incidence of adverse events observed supports the safety of CCP administration.

Absence of pathogenic viruses in COVID-19 convalescent plasma.

It is important to maintain the safety of blood products by avoiding the transfusion of units with known and novel viral pathogens. It is unknown whether COVID-19 convalescent plasma (CCP) may contain pathogenic viruses (either newly acquired or reactivated) that are not routinely screened for by blood centers. The DNA virome was characterized in potential CCP donors (n=30) using viral genome specific PCR primers to identify DNA plasma virome members of the Herpesviridae [Epstein Barr Virus (EBV), cytomegalovirus (CMV), human herpesvirus 6A/B, human herpesvirus 7] and Anelloviridae [Torque teno viruses (TTV), Torque teno mini viruses (TTMV), and Torque teno midi viruses (TTMDV)] families. In addition, the RNA plasma virome was characterized using unbiased metagenomic sequencing. Sequencing was done on a HiSeq2500 using high output mode with a read length of 2X100 bp. The sequencing reads were taxonomically classified using Kraken2. CMV and EBV seroprevalence were evaluated using a chemiluminescent immunoassay. TTV and TTMDV were detected in 12 (40%) and 4 (13%) of the 30 study participants, respectively; TTMDV was always associated with infection with TTV. We did not observe TTMV DNAemia. Despite CMV and EBV seroprevalences of 33.3% and 93.3%, respectively, we did not detect Herpesviridae DNA among the study participants. Metagenomic sequencing did not reveal any human RNA viruses in CCP, including no evidence of circulating SARS-CoV-2. There was no evidence of pathogenic viruses, whether newly acquired or reactivated, in CCP despite the presence of non-pathogenic Anelloviridae. These results confirm the growing safety data supporting CCP.

Multistep screening and selection of COVID-19 convalescent plasma donors at the early stage of the SARS-CoV-2 pandemic: A retrospective analysis.

Background and AimsThe COVID‐19 pandemic reached Bavaria in February 2020. Almost simultaneously, Chinese physicians published reports on the first successful treatments with plasma from COVID‐19 convalescent donors. With these silver linings on the horizon, we decided to establish the manufacturing of anti‐severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) antibody‐containing plasma from COVID‐19 convalescent donors at our site. Here we describe our donor selection process, built from the ground up, which enabled us to cope with the immense resonance after our social media call for donors.MethodsAs a first step, we created a specific questionnaire for telephone interviews applied by trained students to filter the wave of callers interested in plasma donation. Afterward, the medical staff evaluated the hotline questionnaires and chose eligible donors to be invited for on‐site donor evaluation. Data documentation was performed with MS Excel, and statistical analyses were calculated with GraphPad Prism 8. A quantitative in‐house ELISA was used to detect anti‐SARS‐CoV‐2 antibodies and determine specific titers.ResultsOut of 1465 calls from potential plasma donors, we could register 420 persons with a completed questionnaire. Evaluation of questionnaires identified 222 of 420 persons as eligible for donation, and 55 were directly asked for on‐site donor qualification. Subsequently, as anti‐SARS‐CoV‐2 antibody titers ≥1:800 were required, we invited 89 of 222 potential donors for an antibody screening. This procedure resulted in another 28 potential donors for an on‐site evaluation. Finally, 12 donors qualified with a titer of 1:400 and 24 with ≥1:800.ConclusionIdentifying suitable COVID‐19 convalescent plasma donors was expected to be highly time‐consuming. Implementing a screening procedure with our hotline questionnaire helped us streamline the donor selection process and reduce the workload for the staff. We propose combining the described selection process with the later introduced on‐site antibody screening as an effective strategy.

Analysis of the IgG subclass profile and IgG sum-total discrepancy in COVID-19 convalescent plasma donors: A single-centre prospective cohort study

IntroductionAlthough IgG1 and IgG3 have been shown to be the dominant subclasses in the acute phase of SARS-CoV-2 infection, little is known about the distribution of IgG subclasses during the recovery phase of COVID-19. The aim of the study was to analyze the profile of IgG subclasses in COVID-19 convalescent plasma donors. MethodsA total of 36 convalescent plasma donors were included in the analysis. IgG and IgG subclass levels were measured using a nephelometric assay in plasma samples obtained directly from the plasma container. ResultsAlthough there was no significant difference in the concentration of IgG subclasses between the study and control groups, the contribution of IgG1 to the total IgG pool between the study and control groups was statistically significant (p = 0.0478). In addition, there was a discrepancy between the total IgG and IgG sum values in the study group, exceeding 15 % in 19,4 % of samples (n = 7), while in the control group no samples with a sum/ total IgG difference > 15 % were observed. ConclusionsThe selective affinity of the IgG1 subclass for the polyclonal anti-IgG reagent may interfere with the determination of total IgG and should be considered when interpreting the results of enzyme immunoassays Data AvailabilityThe data that support the findings of this study are available on request from the corresponding author.

P1622: ANTIPHOSPHOLIPID ANTIBODIES IN CONVALESCENT PLASMA OF DONORS RECOVERED FROM MILD COVID-19

Background: High prevalence of antiphospholipid antibodies (APLA) in patients with COVID-19 has been reported. A meta-analysis concluded that APLA were detected in nearly half of hospitalized patients with COVID-19, and even higher prevalence was found in patients with severe disease.These reports raised questions about the true prevalence and clinical impact of APLA on disease course, long term complications and the prothrombotic influence of COVID-19 convalescent plasma (CCP) transfused to COVID-19 patients. Aims: To evaluate the prevalence of APLA in CCP samples collected from otherwise healthy donors who recovered from mild COVID-19. Methods: CCP was collected from volunteer donors in two time periods (September 2020-January 2021 [early period] and April- May 2021 [late period]). The study was approved by the local ethics committee and all donors and controls signed informed consent. The study was supported by a grant from the Laboratory Research Fund, Shamir Medical Center. Convalescence was supported by studying serum anti COVID-19 antibodies (Ab): Anti- N (nucleocapsid protein) Ab during the early period, and anti- S (Spike1 protein) Ab during the late period.Anti- N Ab were tested by a chemiluminescent immunoassay. Positive results were defined as sample/cutoff (S/CO) ≥1.4. Anti-S1 Ab were tested using ELISA. Results ≥ 50 arbitrary units per milliliter (AU/ml) were considered positive. Plasma samples were tested for APLA: Lupus anticoagulant (LAC)testing was performed using dilute Russell Viper Venom Time (dRVVT) and Silica Clotting Time (SCT). Results were reported as normalized ratios. APLA IgG, IgM and anti-β2-glycoprotein IgG, IgM antibodies were detected using an ELISA method and reported as SGU u/ml or SMU u/ml. Results: Table 1 summarizes demographic data and laboratory results of plasma collected from donors. Plasma from 10 healthy volunteers were used as controls (8 women, median age 29 years [range 20-42]). None of the participants had an history of thrombosis. Early period CCP donors were significantly older compared to late period CCP donors, and approximately 80% of donors were male. Two donors had elevated APLA values and 5 had elevated normalized LAC SCT ratio, for a total prevalence of 6%. LAC was positive in the late period while APLA were found in the early period. All controls were negative for LAC and 9 were APLA negative. One woman had an elevated APLA anti-β2GP1 IgM (40.1 SMU u/ml).There was no association between anti-SARS-CoV-2 antibodies titer and the presence of LAC / APLA. Image:Summary/Conclusion: Our results demonstrate low frequency (6%) of APLA / LAC in plasma collected from donors who have fully recovered from mild COVID-19.The low frequency of APLA/LAC can be explained by the mild COVID-19 disease prior to plasma donation or the rapid disappearance of autoantibodies after the acute disease. The presence of LAC in the plasma of late period CCP donors and APLA in the early period donors can be explained by the changed in SARS-CoV-2 viral variants between the two time periods (wild type alpha and non-alpha variants in the early and late periods, respectively).The age of plasma donors in early CCP period was older than the age of those who donated in late period, reflecting the fact that the alpha variant was more common in elderly people during the early pandemic or that there was a careful selection of CCP donors during the course of the pandemic. The fact that convalescent donors had no thromboembolic disease at the time of plasma collection and the low prevalence of APLA/LAC in this cohort, reassures the safety of CCP use.