COVID-19 Convalescent Plasma Research Articles

Challenges in Establishing a Coronavirus Disease 2019 (COVID-19) Convalescent Plasma Donation Program in a Multicultural Environment.

In the face of the coronavirus disease 2019 (COVID-19) pandemic response, it was worthwhile to test the safety and efficacy of COVID-19 convalescent plasma (CCP) transfusion. To establish a CCP donation program based on the availability of recovered COVID-19 patients and the practical limitations in recruiting clinically valid donors in a multicultural setting. From March to June 2020, we developed a program for collection of COVID-19 CCP as part of the treatment options for patients affected with COVID-19. From an initial population of 3746 candidates, only those with positive polymerase chain reaction results in at least 2 separate tests were considered. This filter reduced the eligible donor pool to 488 patients. After other exclusions were applied, such as language barrier, age, accessibility to donation, and comorbidities, the final count was 267 potentially eligible donors, which represented only 54.7% (267 of 488) of preselected candidates. Eighty donors were called. Approximately a third of the calls provided additional challenges as outlined by the following 4 reasons: limited functional understanding of English; schedule availability due to rotating work timetables; transportation restrictions since public transport services were severely restricted during lockdown; and lost to follow-up. Finally, a total of 38 valid donors participated, upon whom 45 apheresis procedures were performed. As a summary of our experience, we can conclude that despite the limitations we were able to establish an effective program. A total of 90 units of CCP were collected before the pandemic curve began to flatten toward the end of June 2020.

CONVALESCENT plasma for COVID-19: A meta-analysis of clinical trials and real-world evidence.

BackgroundThere is still a lack of consensus on the efficacy of convalescent plasma (CP) treatment in COVID‐19 patients. We performed a systematic review and meta‐analysis to investigate the efficacy of CP vs standard treatment/non‐CP on clinical outcomes in COVID‐19 patients.MethodsCochrane Library, PubMed, EMBASE and ClinicalTrials.gov were searched from December 2019 to 16 July 2021, for data from clinical trials and observational studies. The primary outcome was all‐cause mortality. Risk estimates were pooled using a random‐effect model. Risk of bias was assessed by Cochrane Risk of Bias tool for clinical trials and Newcastle‐Ottawa Scale for observational studies.ResultsIn total, 18 peer‐reviewed clinical trials, 3 preprints and 26 observational studies met the inclusion criteria. In the meta‐analysis of 18 peer‐reviewed trials, CP use had a 31% reduced risk of all‐cause mortality compared with standard treatment use (pooled risk ratio [RR] = 0.69, 95% confidence interval [CI]: 0.56‐0.86, P = .001, I 2 = 50.1%). Based on severity and region, CP treatment significantly reduced risk of all‐cause mortality in patients with severe and critical disease and studies conducted in Asia, pooled RR = 0.61, 95% CI: 0.47‐0.81, P = .001, I 2 = 0.0%; pooled RR = 0.67, 95% CI: 0.49‐0.92, P = .013, I 2 = 0.0%; and pooled RR = 0.62, 95% CI: 0.48‐0.80, P < .001, I 2 = 20.3%, respectively. The meta‐analysis of observational studies showed the similar results to the clinical trials.ConclusionsConvalescent plasma use was associated with reduced risk of all‐cause mortality in severe or critical COVID‐19 patients. However, the findings were limited with a moderate degree of heterogeneity. Further studies with well‐designed and larger sample size are needed.

Early Convalescent Plasma for High-Risk Outpatients with Covid-19

BackgroundEarly administration of convalescent plasma obtained from blood donors who have recovered from coronavirus disease 2019 (Covid-19) may prevent disease progression in acutely ill, high-risk patients with Covid-19.MethodsIn this randomized, multicenter, single-blind trial, we assigned patients who were being treated in an emergency department for Covid-19 symptoms to receive either one unit of convalescent plasma with a high titer of antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) or placebo. All the patients were either 50 years of age or older or had one or more risk factors for disease progression. In addition, all the patients presented to the emergency department within 7 days after symptom onset and were in stable condition for outpatient management. The primary outcome was disease progression within 15 days after randomization, which was a composite of hospital admission for any reason, seeking emergency or urgent care, or death without hospitalization. Secondary outcomes included the worst severity of illness on an 8-category ordinal scale, hospital-free days within 30 days after randomization, and death from any cause.ResultsA total of 511 patients were enrolled in the trial (257 in the convalescent-plasma group and 254 in the placebo group). The median age of the patients was 54 years; the median symptom duration was 4 days. In the donor plasma samples, the median titer of SARS-CoV-2 neutralizing antibodies was 1:641. Disease progression occurred in 77 patients (30.0%) in the convalescent-plasma group and in 81 patients (31.9%) in the placebo group (risk difference, 1.9 percentage points; 95% credible interval, −6.0 to 9.8; posterior probability of superiority of convalescent plasma, 0.68). Five patients in the plasma group and 1 patient in the placebo group died. Outcomes regarding worst illness severity and hospital-free days were similar in the two groups.ConclusionsThe administration of Covid-19 convalescent plasma to high-risk outpatients within 1 week after the onset of symptoms of Covid-19 did not prevent disease progression. (SIREN-C3PO ClinicalTrials.gov number, NCT04355767.)

COVID-19 Convalescent Plasma Is More than Neutralizing Antibodies: A Narrative Review of Potential Beneficial and Detrimental Co-Factors.

COVID-19 convalescent plasma (CCP) is currently under investigation for both treatment and post-exposure prophylaxis. The active component of CCP mediating improved outcome is commonly reported as specific antibodies, particularly neutralizing antibodies, with clinical efficacy characterized according to the level or antibody affinity. In this review, we highlight the potential role of additional factors in CCP that can be either beneficial (e.g., AT-III, alpha-1 AT, ACE2+ extracellular vesicles) or detrimental (e.g., anti-ADAMTS13, anti-MDA5 or anti-interferon autoantibodies, pro-coagulant extracellular vesicles). Variations in these factors in CCP may contribute to varied outcomes in patients with COVID-19 and undergoing CCP therapy. We advise careful, retrospective investigation of such co-factors in randomized clinical trials that use fresh frozen plasma in control arms. Nevertheless, it might be difficult to establish a causal link between these components and outcome, given that CCP is generally safe and neutralizing antibody effects may predominate.

Mortality in individuals treated with COVID-19 convalescent plasma varies with the geographic provenance of donors

Successful therapeutics and vaccines for coronavirus disease 2019 (COVID-19) have harnessed the immune response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Evidence that SARS-CoV-2 exists as locally evolving variants suggests that immunological differences may impact the effectiveness of antibody-based treatments such as convalescent plasma and vaccines. Considering that near-sourced convalescent plasma likely reflects the antigenic composition of local viral strains, we hypothesize that convalescent plasma has a higher efficacy, as defined by death within 30 days of transfusion, when the convalescent plasma donor and treated patient were in close geographic proximity. Results of a series of modeling techniques applied to approximately 28,000 patients from the Expanded Access to Convalescent Plasma program (ClinicalTrials.gov number: NCT04338360) support this hypothesis. This work has implications for the interpretation of clinical studies, the ability to develop effective COVID-19 treatments, and, potentially, for the effectiveness of COVID-19 vaccines as additional locally-evolving variants continue to emerge.

Should timing be considered before abandoning convalescent plasma in covid-19? Results from the Turkish experience

IntroductionsResults with convalescent plasma therapy in coronavirus disease 2019 (COVID-19) have been contradictory. Timing seems to be an important factor for COVID-19 convalescent plasma(CCP) to be effective. Aim of this study is to compare disease outcomes in hospitalized COVID-19 patients who were treated with CCP within first three or seven days of symptoms to patients with symptoms longer than seven days. Material and methodsA multicenter retrospective study was conducted to evaluate disease outcomes in hospitalized COVID-19 patients who received CCP in addition to standard of care (SOC) approach. Patients were subgrouped according to time of CCP administration; within three days of symptoms, seven days of symptoms and after seven days of symptoms. A control group was formed from age, gender and comorbidity matched hospitalized patients who received SOC treatments without CCP. Length of hospital stay, rates of anti-inflammatory treatment initiation, intensive care unit (ICU) admission and mortality was set as outcome measures. ResultsA total of 223 patients were enrolled in this study, 113 patients received CCP (38 within three days, 63 within seven days, 50 after seven days of symptom onset). Rate of anti-inflammatory treatment initiation was significantly lower (38.1 % vs 62.7 %, p = 0.002, relative risk, 0.60,73; 95 % confidence interval [CI], 0.42 to 0.85) and length of hospital stay was significantly shorter (median(IQR) 8(4) days vs 9.5(5.25) days, p = 0.0025) in patients who received CCP within seven days of symptom onset when compared to SOC group. ConclusionCCP therapy may provide better outcomes when applied within seven days of symptoms.

Knowledge and Attitudes of Young Adults Towards Donation of COVID-19 Convalescent Plasma and Its Therapeutic Properties.

PurposeThe aim of this study is to investigate the level of knowledge of the young adults towards the possible use of the convalescent plasma (CP) in the treatment of COVID-19 infection and their attitudes towards its donation.MethodsCross-sectional questionnaire was administered online to 1058 university students, representing 4 different colleges. The questionnaire included demographic data and 20 questions related to the knowledge and attitudes of respondents about possible use of the convalescent plasma in the treatment of COVID-19 infection and its donation. Comparative analyses were made using the Mann–Whitney and Kruskal–Wallis tests and the Spearman correlation coefficient.ResultsSignificant relationships were found between dependent variables (level of knowledge and intensity of attitude) and gender, age, and student’s college affiliation. There was no statistically significant correlation between dependent variables and respondents’ social background and religious commitment. Studied young adults show a satisfactory knowledge relating to the therapeutic and preventive properties of the COVID-19 convalescent plasma. They also express a sufficient intensity of positive attitude towards CP donation.ConclusionThis study confirms the need for appropriate health promotional campaigns and educational programs aimed at popularization of CP donation in the general public, which would increase the chances of involving more patients recovered from COVID-19 disease.

Effectiveness of COVID-19 Convalescent Plasma Infusion Within 48 Hours of Hospitalization With SARS-CoV-2 Infection.

On January 30, 2020, the World Health Organization (WHO) declared the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic a worldwide emergency. Worldwide there have been 170 million cases of the resulting disease coronavirus 2019 (COVID-19), of those, 3.53 million have resulted in death. The Food and Drug Administration (FDA) with Mayo Clinic as the lead institution authorized COVID-19 convalescent plasma (CCP) for treatment of SARS-CoV-2 infection. Effective therapeutic window for CCP administration had yet to be defined. We addressed this gap by characterizing longitudinal biologic response and clinical outcomes of COVID-19 patients treated with CCP. Primary outcome was discharged to home/home health.

Early but not late convalescent plasma is associated with better survival in moderate-to-severe COVID-19.

BackgroundLimited therapeutic options exist for coronavirus disease 2019 (COVID-19). COVID-19 convalescent plasma (CCP) is a potential therapeutic, but there is limited data for patients with moderate-to-severe disease.Research questionWhat are outcomes associated with administration of CCP in patients with moderate-to-severe COVID-19 infection?Study design and methodsWe conducted a propensity score-matched analysis of patients with moderate-to-severe COVID-19. The primary endpoints were in-hospital mortality. Secondary endpoints were number of days alive and ventilator-free at 30 days; length of hospital stay; and change in WHO scores from CCP administration (or index date) to discharge. Of 151 patients who received CCP, 132 had complete follow-up data. Patients were transfused after a median of 6 hospital days; thus, we investigated the effect of convalescent plasma before and after this timepoint with 77 early (within 6 days) and 55 late (after 6 days) recipients. Among 3,217 inpatients who did not receive CCP, 2,551 were available for matching.ResultsEarly CCP recipients, of whom 31 (40%) were on mechanical ventilation, had lower 14-day (15% vs 23%) and 30-day (38% vs 49%) mortality compared to a matched unexposed cohort, with nearly 50% lower likelihood of in-hospital mortality (HR 0.52, [95% CI 0.28–0.96]; P = 0.036). Early plasma recipients had more days alive and ventilator-free at 30 days (+3.3 days, [95% CI 0.2 to 6.3 days]; P = 0.04) and improved WHO scores at 7 days (-0.8, [95% CI: -1.2 to -0.4]; P = 0.0003) and hospital discharge (-0.9, [95% CI: -1.5 to -0.3]; P = 0.004) compared to the matched unexposed cohort. No clinical differences were observed in late plasma recipients.InterpretationEarly administration of CCP improves outcomes in patients with moderate-to-severe COVID-19, while improvement was not observed with late CCP administration. The importance of timing of administration should be addressed in specifically designed trials.

Predicting the efficacy of COVID-19 convalescent plasma donor units with the Lumit Dx anti-receptor binding domain assay.

BackgroundThe novel coronavirus SARS-CoV2 that causes COVID-19 has resulted in the death of more than 2.5 million people, but no cure exists. Although passive immunization with COVID-19 convalescent plasma (CCP) provides a safe and viable therapeutic option, the selection of optimal units for therapy in a timely fashion remains a barrier.Study design and methodsSince virus neutralization is a necessary characteristic of plasma that can benefit recipients, the neutralizing titers of plasma samples were measured using a retroviral-pseudotype assay. Binding antibody titers to the spike (S) protein were also determined by a clinically available serological assay (Ortho-Vitros total IG), and an in-house ELISA. The results of these assays were compared to a measurement of antibodies directed to the receptor binding domain (RBD) of the SARS-CoV2 S protein (Promega Lumit Dx).ResultsAll measures of antibodies were highly variable, but correlated, to different degrees, with each other. However, the anti-RBD antibodies correlated with viral neutralizing titers to a greater extent than the other antibody assays.DiscussionOur observations support the use of an anti-RBD assay such as the Lumit Dx assay, as an optimal predictor of the neutralization capability of CCP.

Evaluation of a multiplexed coronavirus antigen array for detection of SARS-CoV-2 specific IgG in COVID-19 convalescent plasma

Mitigation of the COVID-19 pandemic requires an understanding of the antibody response to SARS-CoV-2. However, throughout the development of SARS-CoV-2 IgG antibody assays during the past year, cross-reactivity to other coronaviruses remained a question. To address these issues, we evaluated IgG in COVID-19 convalescent plasma samples for reactivity against three SARS-CoV-2 antigens including full-length spike, receptor binding domain, and the proximal extracellular fusion domain, and spike antigens from other coronaviruses (SARS-CoV, MERS-CoV, hCoV-HKU1, hCoV-OC43, hCoV-229E and hCoV-NL63) using the VaxArray Coronavirus SeroAssay which is a multiplexed antigen assay developed by InDevR Inc. These results were compared to two commercial SARS-CoV-2 IgG ELISAs targeting either the SARS-CoV-2 nucleocapsid or spike antigens and a live virus focus reduction neutralizing antibody test (FRNT). The VaxArray platform showed high specificity for detection of SARS-CoV-2 IgG, evident from lack of reactivity to SARS-CoV-2 antigens despite significant reactivity to endemic coronavirus antigens in pre-pandemic samples. SARS-CoV-2 IgG positive samples reacted weakly to SARS-CoV spike but not to MERS-CoV. While the VaxArray platform had overall comparable results to the spike and nucleocapsid IgG ELISAs, results were more similar to the spike antigen ELISA and the platform displayed a higher sensitivity and specificity than both ELISAs. Samples with FRNT titers below 1/23 reported negative on VaxArray, while positive samples on VaxArray had significantly higher neutralizing antibody titers. These results suggest that the VaxArray Coronavirus SeroAssay performs with high sensitivity and specificity for the detection of SARS-CoV-2 IgG, and positive results on the platform indicate SARS-CoV-2 neutralizing activity.

Characteristics of High-Titer Convalescent Plasma and Antibody Dynamics After Administration in Patients With Severe Coronavirus Disease 2019.

We characterized the antibody composition of coronavirus disease 2019 (COVID-19) convalescent plasma (CCP) and the immunologic responses of hospitalized COVID-19 patients after receiving CCP or nonimmune fresh frozen plasma. Despite selection of CCP with significantly higher total immunoglobulin G than recipients, neutralizing antibody levels did not differ between donor plasma and CCP recipients.

A high-throughput cell- and virus-free assay shows reduced neutralization of SARS-CoV-2 variants by COVID-19 convalescent plasma.

The detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-specific antibodies in the serum of an individual indicates previous infection or vaccination. However, it provides limited insight into the protective nature of this immune response. Neutralizing antibodies recognizing the viral spike protein are more revealing, yet their measurement traditionally requires virus- and cell-based systems that are costly, time-consuming, inflexible, and potentially biohazardous. Here, we present a cell-free quantitative neutralization assay based on the competitive inhibition of trimeric SARS-CoV-2 spike protein binding to the angiotensin-converting enzyme 2 (ACE2) receptor. This high-throughput method matches the performance of the gold standard live virus infection assay, as verified with a panel of 206 seropositive donors with varying degrees of infection severity and virus-specific immunoglobulin G titers, achieving 96.7% sensitivity and 100% specificity. Furthermore, it allows for the parallel assessment of neutralizing activities against multiple SARS-CoV-2 spike protein variants of concern. We used our assay to profile serum samples from 59 patients hospitalized with coronavirus disease 2019 (COVID-19). We found that although most sera had high activity against the 2019-nCoV parental spike protein and, to a lesser extent, the α (B.1.1.7) variant, only 58% of serum samples could efficiently neutralize a spike protein derivative containing mutations present in the β (B.1.351) variant. Thus, we have developed an assay that can evaluate effective neutralizing antibody responses to SARS-CoV-2 spike protein variants of concern after natural infection and that can be applied to characterize vaccine-induced antibody responses or to assess the potency of monoclonal antibodies.

Immature platelets in COVID-19 infection.

Immature platelets in COVID-19 infection.

COVID-19 convalescent plasma cohort study: Evaluation of the association between both donor and recipient neutralizing antibody titers and patient outcomes.

BackgroundCurrent evidence regarding COVID‐19 convalescent plasma (CCP) transfusion practices is limited and heterogeneous. We aimed to determine the impact of the use of CCP transfusion in patients with previous circulating neutralizing antibodies (nAbs) in COVID‐19.MethodsProspective cohort including 102 patients with COVID‐19 transfused with ABO compatible CCP on days 0–2 after enrollment. Clinical status of patients was assessed using the adapted World Health Organization (WHO) ordinal scale on days 0, 5, and 14. The nAbs titration was performed using the cytopathic effect‐based virus neutralization test with SARS‐CoV‐2 (GenBank MT126808.1). The primary outcome was clinical improvement on day 14, defined as a reduction of at least two points on the adapted WHO ordinal scale. Secondary outcomes were the number of intensive care unit (ICU)‐free days and the number of invasive mechanical ventilation‐free days.ResultsBoth nAbs of CCP units transfused (p < 0.001) and nAbs of patients before CCP transfusions (p = 0.028) were associated with clinical improvements by day 14. No significant associations between nAbs of patients or CCP units transfused were observed in the number of ICU or mechanical ventilation‐free days. Administration of CCP units after 10 days of symptom onset resulted in a decrease in ICU‐free days (p < 0.001) and mechanical ventilation‐free days (p < 0.001).ConclusionTransfusion of high titer nAbs CCP units may be a determinant in clinical strategies against COVID‐19. We consider these data as useful parameters to guide future CCP transfusion practices.

The safety of COVID-19 convalescent plasma donation: A multi-institutional donor hemovigilance study.

BackgroundAlthough the safety and therapeutic efficacy of COVID‐19 convalescent plasma (CCP) has been extensively evaluated, the safety of CCP donation has not been explored in a multi‐institutional context.Study design and methodsNine blood collection organizations (BCOs) participated in a multi‐institutional donor hemovigilance effort to assess the safety of CCP donation. Donor adverse events (DAEs) were defined according to the Standard for Surveillance of Complications Related to Blood Donation, and severity was assessed using the severity grading tool. Multivariate analysis was performed to determine attributes associated with DAE severity.ResultsThe overall DAE rate was 37.7 per 1000 donations. Repeat apheresis and apheresis‐naïve donors experienced adverse event rates of 19.9 and 49.8 per 1000 donations, respectively. Female donors contributed 51.9% of CCP donations with a DAE rate of 49.4 per 1000 donations. The DAE rate for male donors was 27.4 per 1000 donations. Vasovagal reactions accounted for over half of all reported DAEs (51.1%). After adjustment, volume of CCP donated was associated with vasovagal reaction severity (odds ratio [OR] 6.5, 95% confidence interval [CI] 2.5–17.1). Donor age and donation history were also associated with DAE severity. Considerable differences in DAE types and rates were observed across the participating BCOs despite the use of standardized hemovigilance definitions.ConclusionThe safety of CCP donation appears comparable to that of conventional apheresis plasma donation with similar associated risk factors for DAE types and severity.

Progression and Predictors of SARS-CoV-2 Antibody Seroreactivity In US Blood Donors.

The second largest US blood center began testing for antibodies to SARS-CoV-2, the etiologic agent of Coronavirus Disease-2019 (COVID-19) to identify potential COVID-19 Convalescent Plasma (CCP) donors and encourage blood donation. We report the non-vaccine seroprevalence of total immunoglobulin directed against the S1 spike protein of SARS-CoV-2 in our donors. Unique non-CCP donor sera from June 01to December 31, 2020 were tested with the Ortho VITROS Anti-SARS-CoV-2 total immunoglobulin assay (reactive: signal-to-cutoff (S/C) ≥ 1). Multivariate regressions including age, sex, race-ethnicity, ABO, RhD, highest education level, donor experience, regional collection center and drive type factors were conducted to identify demographics associated with the presence of antibodies and with S/C values. Unique donors (n = 523,068) showed an overall seroprevalence of 6.12% over 7 months, with the highest prevalence in December 2020 around Lubbock, TX (24.3%). In a subset of donors with demographic information (n = 394,470), lower odds of antibody reactivity were associated with female sex, non-Hispanic White or Asian race/ethnicity, age ≥ 65, graduate education, blood Group O, and history of blood donation. In reactive donors (n = 24,028), antibody signal was associated with male sex, race/ethnicity other than non-Hispanic White, low educational attainment, age 16-17 years and geographic location. Seroprevalence continues to grow in US blood donors but varies significantly by region. Temporal trends in reactivity may be useful to estimate effectiveness of public health measures. Before generalizing these data from healthy donors to the general population, rates must be corrected for false-positive test results and adjusted to match the wider US demography.

Characteristics of US Blood Donors Testing Reactive for Antibodies to SARS-CoV-2 Prior to the Availability of Authorized Vaccines.

In the United States, many blood collection organizations initiated programs to test all blood donors for antibodies to SARS-CoV-2, as a measure to increase donations and to assist in the identification of potential donors of COVID-19 convalescent plasma (CCP). As a result, it was possible to investigate the characteristics of healthy blood donors who had previously been infected with SARS-CoV-2. We report the findings from all blood donations collected by the American Red Cross, representing 40% of the national blood supply covering 44 States, in order to characterize the seroepidemiology of SARS-CoV-2 infection among blood donors in the United States, prior to authorized vaccine availability. We performed an observational cohort study from June 15th to November 30th, 2020 on a population of 1.531 million blood donors tested for antibodies to the S1 spike antigen of SARS-CoV-2 by person, place, time, ABO group and dynamics of test reactivity, with additional information from a survey of a subset of those with reactive test results. The overall seroreactivity was 4.22% increasing from 1.18 to 9.67% (June 2020 - November 2020); estimated incidence was 11.6 per hundred person-years, 1.86-times higher than that based upon reported cases in the general population over the same period. In multivariable analyses, seroreactivity was highest in the Midwest (5.21%), followed by the South (4.43%), West (3.43%) and Northeast (2.90%). Seroreactivity was highest among donors aged 18-24 (Odds Ratio 3.02 [95% Confidence Interval 2.80-3.26] vs age >55), African-Americans and Hispanics (1.50 [1.24-1.80] and 2.12 [1.89-2.36], respectively, vs Caucasian). Group O frequency was 51.5% among nonreactive, but 46.1% among seroreactive donors (P< .0001). Of surveyed donors, 45% reported no COVID-19-related symptoms, but 73% among those unaware of testing. Signal levels of antibody tests were stable over 120 days or more and there was little evidence of reinfection. Evaluation of a large population of healthy, voluntary blood donors provided evidence of widespread and increasing SARS-CoV-2 seroprevalence and demonstrated that at least 45% of those previously infected were asymptomatic. Epidemiologic findings were similar to those among clinically reported cases.

Comparison of Indigenous Enzyme-linked Immunosorbent Assay and Chemiluminescent Immunoassays for Screening for Immunoglobulin G Antibodies Against SARS-CoV-2 in India

Serological screening for antibody against SARS-CoV-2 has been gaining more attention in view of selection for an appropriate donor for COVID-19 convalescent plasma, documenting the past/ recent infection due to the virus as well as now for evaluating the immune response to the vaccination. In beginning of the pandemic an indigenous ELISA kits were developed in India to screen for IgG type of antibody against the whole-cell virus particle. Our retrospective analysis provides a head-to-head comparison of an indigenous ELISA kits (COVID KAWACH IgG MICROLISA) and CLIA (SARS-CoV-2 IgG by Abbott) platform for screening of IgG type of antibody. Total 380 samples from adults were screened on both the platforms, out of which 250 had a history of a positive RT-PCR report and 130 were RT-PCR negative but with a history of symptoms suggestive of COVID-19 or exposure to COVID-19 individual. The overall concordance of detection IgG type of antibody by both the platforms was 52.2% (higher in individuals with known RT-PCR positivity; 70%). The median S/CO ratio (on CLIA) was 3.34 in concordant positive samples and 2.48 in cases of CLIA yield samples. Our study highlights the variation in detection of the antibody by both the platforms due to inherent difference in the design of these platforms and kits.

Minimally reduced levels of anti-Spike IgG after nine COVID-19 convalescent plasma donations: a case report

Despite intensive research, the physiology of the serological response to SARS-CoV-2 infection and its dynamics during the recovery period remain incompletely understood. Regulation of the immune response seems all the more important as it plays a role in both virus clearance during infection and the potential development of long-term resistance to reinfection. A case of convalescent plasma donor is described in whom was observed a prolonged enhanced immune response to infection in the form of a persistently high level of anti-Spike IgG despite subsequent plasma donations. The presented donor experienced COVID-19 interstitial pneumonia, requiring pharmacotherapy in a hospital setting (therapy involving azithromycin, chloroquine and protease inhibitors), which allowed him to achieve remission. The described donor donated plasma nine times during convalescence, each time showing a satisfactory level of anti-Spike IgG. The presented case highlights the multifactorial regulation of the serological response in the course of SARS-CoV-2 infection, which may include the long-term effect of pharmacotherapy, especially in the field of antiretroviral drugs. While the authors are not yet able to clearly define the importance of antiretroviral therapy in regulating the humoral response in COVID-19 patients, it is supposed it may be important in the subsequent antibody production.