Individuals with pre-existing chronic systemic low-grade inflammation are prone to develop severe COVID-19 and stronger anti-SARS-CoV-2 antibody responses. Whether this phenomenon reflects a differential expansion of antiviral B cells or a failure to regulate antibody synthesis remains unknown. Here, we compared the antiviral B cell repertoire of convalescent healthcare personnel to that of hospitalized patients with pre-existing comorbidities. Out of 277,500 immortalized B cell clones, antiviral B cell frequencies were determined by indirect immunofluorescence screening on SARS-CoV-2 infected cells. Surprisingly, frequencies of SARS-CoV-2 specific clones from the two groups were not statistically different, despite higher antibody levels in hospitalized patients. Moreover, functional analyses revealed that several B cell clones from healthcare personnel with low antibody levels had neutralizing properties. This study reveals for the first time a key qualitative defect of antibody synthesis in severe patients and calls for caution regarding estimated protective immunity based only on circulating antiviral antibodies.
【저자키워드】 COVID-19, SARS-CoV-2, anti-SARS-CoV-2, Human monoclonal antibody, B cell repertoire, 【초록키워드】 severe COVID-19, Antiviral, antibody, Comorbidities, hospitalized patients, B cell, anti-SARS-CoV-2 antibody, protective immunity, Neutralizing, Severe patient, immunofluorescence, convalescent, antiviral antibodies, low-grade inflammation, Frequency, Analysis, regulate, healthcare personnel, antibody synthesis, determined by, indirect immunofluorescence, two groups, severe patients, frequencies, failure, infected cells, caution, individual, circulating, clones, SARS-CoV-2 infected cells, clone, responses, develop, functional, hospitalized patient, reveal, two group, reflect, statistically, immortalized, 【제목키워드】 Impact, status, Level,