(23, 24). S1 protein or RBD between 8-21 days from symptom onset and the nucleic acid Ct value in throat swab of each patient during their hospitalization period were collected. Fifty samples were included in this figure. Image_3.tif (507K) GUID:?27EEA627-3C7F-45EC-B75D-EB966378CA99 Supplementary Figure 4: The anti-S1 or anti-RBD IgG and IgM antibody titers were comparable in the severe and mild group between 8-63 days from symptom onset. The individuals were grouped by disease symptom. The titers of IgG and IgM antibody against S1 (A) protein or RBD (B) between 8-63 days from sign onset were collected and analyzed. Image_4.tif (707K) GUID:?C9D06250-B33B-4490-BF80-639183279D1B Data Availability StatementThe unique contributions presented in the study are included in the article/ Supplementary Material . Further inquiries can be directed to the related authors. Abstract The coronavirus disease 2019 (COVID-19) emerged around December 2019 and have become a global epidemic disease currently. Specific antibodies against SAS-COV-2 could be recognized AS8351 in COVID-19 individuals serum or plasma, but the medical values PEBP2A2 of these antibodies as well as the effects of medical medicines on humoral reactions have not been fully shown. In this study, 112 plasma samples were collected from 36 individuals diagnosed with laboratory-confirmed COVID-19 in the Fifth Affiliated Hospital of Sun Yat-sen University or college. The IgG and IgM antibodies against receptor binding website (RBD) and spike protein subunit 1 (S1) of SAS-COV-2 were recognized by ELISA. We found that COVID-19 individuals generated specific antibodies against SARS-CoV-2 after illness, and the levels of anti-RBD IgG within 2 to 3 3 weeks from onset were negatively associated with the time of positive-to-negative conversion of SARS-CoV-2 nucleic acid. Patients with severe symptoms experienced higher levels of anti-RBD IgG in 2 to 3 3 weeks from onset. The use of chloroquine did not significantly influence the individuals antibody titer but reduced C-reaction protein (CRP) level. Using anti-viral medicines (lopinavir/ritonavir or arbidol) reduced antibody titer and peripheral lymphocyte count. While glucocorticoid therapy developed lower levels of peripheral lymphocyte count and higher levels of AS8351 CRP, lactate dehydrogenase (LDH), -Hydroxybutyrate dehydrogenase(-HBDH), total bilirubin (TBIL), direct bilirubin (DBIL). From these results, we suggested the anti-RBD IgG may provide an early safety of sponsor humoral reactions against SAS-COV-2 illness within 2 to 3 3 weeks from onset, and medical treatment with different medicines displayed distinct tasks in humoral and inflammatory reactions. Keywords: COVID-19, SARS-CoV-2, antibody, chloroquine, humoral response Intro The coronavirus disease 2019 (COVID-19) emerged around December 2019 (1). From now on, there have been over 1 billion confirmed instances of COVID-19 (2). Even though epidemic scenario in China has been reduced, the international scenario is still not optimistic. The infectious pathogen has been recognized a SARS-related coronavirus and named as SARS-COV-2. Viral-specific antibodies play an important role in obstructing viral infection. The SAS-COV-2 specific antibodies AS8351 could be recognized in individuals serum or plasma, and has been used like a diagnose marker for COVID-19 (3, 4). Moreover, transfusion plasma or serum from recovered individuals has been applied like a potential therapy in medical trials (5). Lover Wu et al. recognized specific antibodies against SARS-COV-2 in COVID-19 individuals within three weeks from onset, and found that elderly and middle-age individuals had significantly higher plasma neutralizing Ab titers (6). However, whether the antibody titers correlated with disease progression has not been fully explored. Currently, chloroquine, antiviral medicines like lopinavir/ritonavir, as well as glucocorticoids have been widely used in COVID-19 therapy. Several studies shown that chloroquine may be a cost-effective therapy.