B-Cell Receptor Features and Database Establishment in Recovered COVID-19 Patients by Combining 5'-RACE with PacBio Sequencing.

Background: Antibodies induced by viral infection can not only prevent subsequent virus infection, but can also mediate pathological injury following infection. Therefore, understanding the B-cell receptor (BCR) repertoire of either specific neutralizing or pathological antibodies from patients convalescing from Coronavirus disease 2019 (COVID-19) infection is of benefit for the preparation of therapeutic or preventive antibodies, and may provide insight into the mechanisms of COVID-19 pathological injury.

Methods: In this study, we used a molecular approach of combining 5' Rapid Amplification of cDNA Ends (5'-RACE) with PacBio sequencing to analyze the BCR repertoire of all 5 and 2 genes in B-cells harvested from 35 convalescent patients after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection.

A new strategy: identification of specific antibodies for neutralizing epitope on SARS-CoV-2 S protein by LC-MS/MS combined with immune repertoire.

Although the SARS-CoV-2 vaccine has been widely used worldwide, not all individuals can produce neutralization antibodies, so it is still urgent to find and prepare neutralization antibodies for COVID-19 prevention or treatment. In this study, we created a new strategy to effectively obtain neutralizing antibodies or complementary determining region 3 (CDR3) of neutralizing antibodies against SARS-CoV-2. We first predicted and synthesized several B cell epitopes on RBD and adjacent RBD of S protein, then the B cell epitopes were used to prepare affinity chromatography columns respectively and purify the binding IgG from serum samples of convalescent COVID-19 patients.

Lymphocytes screening on admission is essential for predicting in-hospital clinical outcome in COVID-19 patients: A retrospective cohort study.

Introduction: We aimed to identify the associations between the lymphocytes (LYM) absolute count on admission and clinical outcomes in COVID-19 patients.

Methods: In this retrospective study, 224 COVID-19 patients who were admitted to General Hospital of Central Theater Command of the PLA from January 22 to April 4, 2020, were consecutively included. These patients were divided into the lymphopenia group and the nonlymphopenia group according to whether the LYM count on admission was below the normal range.

Neutrophil-to-lymphocyte ratio, a critical predictor for assessment of disease severity in patients with COVID-19.

Introduction: Monitoring of laboratory indicators is important for predicting changes in disease severity and clinical outcomes. We aimed to identify the critical predictors that can effectively assess the disease conditions of patients with COVID-19 by analyzing the clinical characteristics and laboratory findings of patients with SARS-CoV-2 infection.

Methods: All consecutive patients (n = 294) with confirmed SARS-CoV-2 infection admitted to the General Hospital of Central Theater Command of the PLA from February 6 to February 21, 2020, were enrolled.

Clinical application of Chemiluminescence Microparticle Immunoassay for SARS-CoV-2 infection diagnosis.

Background: The unsatisfactory accuracy and capacity of real time RT-PCR depends on several unavoidable reasons, which cannot meet the demands for COVID-19 diagnosis.

Methods: 206 serum samples were collected from patients who were treated in the General Hospital of the Central Theater Command of the PLA between January 18 and April 4, 2020. 270 serum samples from healthy blood donors were used as control.

A preliminary study on serological assay for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in 238 admitted hospital patients.

In this study, we aimed to evaluate the diagnostic value of serological assay for SARS-CoV-2. A newly-developed ELISA assay for IgM and IgG antibodies against N protein of SARS-CoV-2 was used to screen the serums of 238 admitted hospital patients between February 6 and February 14, 2020 with confirmed or suspected SARS-CoV-2. SARS-CoV-2 RNA was detected on pharyngeal swab specimens using real time RT-PCR.

Evaluation of Nucleocapsid and Spike Protein-Based Enzyme-Linked Immunosorbent Assays for Detecting Antibodies against SARS-CoV-2.

At present, PCR-based nucleic acid detection cannot meet the demands for coronavirus infectious disease (COVID-19) diagnosis. Two hundred fourteen confirmed COVID-19 patients who were hospitalized in the General Hospital of Central Theater Command of the People's Liberation Army between 18 January and 26 February 2020 were recruited. Two enzyme-linked immunosorbent assay (ELISA) kits based on recombinant severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) nucleocapsid protein (rN) and spike protein (rS) were used for detecting IgM and IgG antibodies, and their diagnostic feasibility was evaluated.