ABSTRACT
BACKGROUND: We investigated the utility of an automated chemiluminescent SARS-CoV-2 IgG antibody assay platform in quantifying the amount of binding antibodies present in donated convalescent plasma. METHODS: A total of 179 convalescent plasma units were analyzed for the presence of SARS-CoV-2 IgG antibodies using the Beckman-Coulter chemiluminescent immunoassay (CLIA) platform. The equipment-derived numerical values (S/Co ratio) were recorded. Aliquots from the same units were subjected to enzyme-linked immunosorbent assay (ELISA) that detects IgG antibodies against the receptor-binding domain (RBD) of the SARS-CoV-2 S1 protein. The relationship between ELISA titers and CLIA S/Co values was analyzed using linear regression and receiver operating characteristics (ROC) curve. RESULTS: Twenty-one samples (11.7%) had S/Co values of less than 1.0 and were deemed negative for antibodies and convalescent plasma had S/Co values between >1.0 and 5.0 (70/179, 39.1%). Fifteen units (8.4%) had negative ELISA titer. The majority of the units (95/179. 53.1%) had titers ≥1:1024. The sensitivities of ELISA to CLIA were comparable (90.5% vs 88.3%, respectively; p=0.18). There was positive linear correlation between CLIA S/Co values and ELISA IgG titer (Rho = 0.75; Spearman's rank = 0.82, p-value = <0.0001). The agreement between the two methods was fair, with a κ index of 0.2741. Using the ROC analysis, we identified a CLIA S/Co cutoff value of 8.2, which gives a sensitivity of 90% and a specificity of 82% in predicting a titer dilution of ≥1:1024. CONCLUSION: The utility of automated antibody detection systems can be extended from simply a screening method to a semi-quantitative and quantitative functional antibody analysis. CLIA S/Co values can be used to reliably estimate the ELISA antibody titer. Incorporation of chemiluminescent-based methods can provide rapid, cost-effective means of identifying anti-SARS-CoV-2 antibody titers in donated plasma for use in the treatment of COVID-19 infection.
ABSTRACT
Introduction: Patients infected with SARS-Cov-2, the causative virus behind the coronavirus disease-19 (COVID-19) pandemic, have been increasing rapidly in New York City. New York City has the highest incidence in the United States and fully 45% of all deaths from COVID-19. Our medical center is located within a high-density region of cases in south Brooklyn and, in fact, three of our neighborhood zip codes are in the top seven in New York in incidence. As a result, our center has experienced a dramatic increase in hospitalizations, particularly respiratory distress secondary to COVID-19, which rapidly exceeded the capacity of our internal medicine service. This necessitated the formation of new COVID-19 units throughout the hospital, replacing all former service lines. These units employed management teams composed of residents from many medical and surgical disciplines, including general surgery residents. Methods: Our general surgery residency program established a surgical COVID-19 (SCOVID) management team. Initially, 4 surgical residents (2 senior and 2 junior), 1 attending surgeon, and 1 attending internal medicine physician were allocated to the initial SCOVID team. On day 3 of implementation, to achieve more rapid competence in the complex management of these patients, a senior medicine resident with direct experience in the care of COVID-19 patients was added in an advisory capacity. Results: The addition of an experienced senior medical resident and attending allowed for the quick adoption of uniform management protocols by surgical residents and attendings. Discussion: We describe a protocol for the establishment of COVID-19 management teams staffed with general surgical residents, as well as a strategy for the achievement of rapid increases in competency. The addition of a senior internal medicine resident and attending to our SCOVID team allowed for rapid achievement of competency in the care of COVID-19 patients in our large institution at the epicenter of the COVID-19 pandemic.