ABSTRACT
Patients with chronic lymphocytic leukemia (CLL) treated with B-cell pathway inhibitors and anti-CD20 antibodies exhibit low humoral response rate (RR) following SARS-CoV-2 vaccination. To investigate the relationship between the initial transcriptional response to vaccination with ensuing B and T cell immune responses, we performed a comprehensive immune transcriptome analysis flanked by antibody and T cell assays in peripheral blood prospectively collected from 15 CLL/SLL patients vaccinated with heterologous BNT162b2/ChAdOx1 with follow up at a single institution. The two-dose antibody RR was 40% increasing to 53% after booster. Patients on BTKi, venetoclax ± anti-CD20 antibody within 12 months of vaccination responded less well than those under BTKi alone. The two-dose T cell RR was 80% increasing to 93% after booster. Transcriptome studies revealed that seven patients showed interferon-mediated signaling activation within 2 days and one at 7 days after vaccination. Increasing counts of COVID-19 specific IGHV genes correlated with B-cell reconstitution and improved humoral RR. T cell responses in CLL patients appeared after vaccination regardless of treatment status. A higher humoral RR was associated with BTKi treatment and B-cell reconstitution. Boosting was particularly effective when intrinsic immune status was improved by CLL-treatment.
Subject(s)
COVID-19 , Leukemia, Lymphocytic, Chronic, B-CellABSTRACT
Introduction: As vaccination against SARS-CoV-2 progresses rapidly around the world, reliable detection of SARS-CoV-2 specific neutralizing antibodies (NAb) has become an indispensable component of serological diagnostics. We evaluated the performance of four commercially available tests, i.e. two lateral flow assays (Coris BioConcept COVID-19 Sero NP/RBD and Concile InfectCheck COVID-19 NAb) and two surrogate ELISA (sELISA) tests (EUROIMMUN SARS-CoV-2 NeutraLISA and AdipoGen SARS-CoV-2 Neutralizing Antibodies Detection Kit) in comparison with an in-house SARS-CoV-2 micro neutralization test as reference. Methods: A total of 334 sera were tested, including 30 samples collected prior to the emergence of SARS-CoV-2, 128 sera from convalescent patients as well as 176 sera from partially or fully vaccinated individuals.Results: The overall sensitivity of LFAs differed and was 71.6% for the Coris and 98.4% for the Concile. In contrast, overall sensitivity of the NeutraLISA was 86% and 98% for the AdipoGen. All test showed the highest sensitivity when testing samples from fully vaccinated individuals with both sELISA achieving 100% sensitivity. Overall specificity was 89.3% for the Coris and only 58.3% for the Concile. Similarly significant differences were observed for both sELISA, with an overall specificity of 82.1% for the NeutraLISA and only 54.8% for the AdipoGen. All tests showed a 100% specificity when testing negative control samples while specificities were lowest when testing samples from only partially vaccinated individuals. Conclusion: Our findings support the potential use of the Concile LFA and both sELISA for the detection of NAbs against SARS-CoV-2, especially to determine NAb levels after complete vaccination.
Subject(s)
COVID-19ABSTRACT
Abstract: Spike-specific antibodies contribute significantly to the neutralizing activity against SARS-CoV-2 and are important for the therapeutic effect of convalescent plasma. B.1.1.7 is a recently emerged variant of SARS-CoV-2 that has several mutations in the gene encoding for the spike-protein. To assess the potential effect these mutations could have on the neutralizing efficacy of antibodies, we evaluated 96 serum samples from convalescent plasma donors collected before the first occurrence of B.1.1.7 and tested their neutralizing effect on wild-type SARS-CoV-2 and B.1.1.7. We found that B.1.1.7 is more resistant to neutralization by convalescent plasma from patients infected with wild-type SARS-CoV-2 with an overall decrease in neutralizing activity of 47.7%. Thus, the neutralizing effect of convalescent plasma should be determined against the major circulating virus clades whenever possible to ensure the best possible therapeutic effect.
ABSTRACT
Introduction: Reliable methods for the detection of SARS-CoV-2 neutralizing antibodies (NAbs) are essential for the evaluation of vaccine candidates and for the selection of convalescent plasma donors. Virus neutralization tests (NTs) are the gold standard for the detection and quantification of NAbs, but they are complex and require BSL3 facilities. In contrast, surrogate enzyme-linked immunosorbent assays (sELISA) offer the possibility of high-throughput testing under standard laboratory safety conditions. In this study, we investigated two commercial sELISA kits (GenScript, AdipoGen) designed for the detection of SARS-CoV-2 NAbs.Methods: 276 plasma samples were screened using commercial IgG-ELISA and NAbs titers were determined by micro-neutralization test (micro-NT). In addition, all samples were tested in both sELISA. Sensitivity and specificity for both sELISA were determined in comparison to the micro-NT results.Results: 57% of the samples were positive for SARS-CoV-2 NAbs in micro-NT, while 43% tested negative. Comparison with micro-NT results showed a sensitivity of 98.2% and a specificity of 69.5% for the GenScript ELISA. The AdipoGen ELISA had a sensitivity of 83.5% and a specificity of 97.8%. False negative results were obtained mainly on samples with low NAbs titers.Conclusion: Both sELISA were able to qualitatively detect NAbs in plasma samples. Sensitivity and specificity differed between sELISA with GenScript superior in sensitivity and AdipoGen superior in specificity. Both sELISA were unable to quantify NAbs, thus neither of them can completely replace conventional NTs. However, in a two-step diagnostic algorithm, AdipoGen could potentially replace NT as a subsequent confirmatory test due to its high specificity.