ABSTRACT
SARS-CoV-2 infection elicits varying degrees of protective immunity conferred by neutralizing antibodies (nAbs). Here we report the persistence of nAb responses over 12 months after infection despite its decreasing trend noticed from 6 months. The study included sera from 358 individuals who had been infected with SARS-CoV-2 between January and May 2020. Samples were collected at 6 and 12 months after onset. The titers of IgG to the viral nucleocapsid protein (NP) and receptor-binding domain of the spike protein (RBD) were measured by CLEIA. The nAb titer was determined using lentivirus-based pseudovirus or authentic virus. Antibody titers of NP-IgG, RBD-IgG, and nAbs were higher in severe and moderate cases than in mild cases at 12 months after onset. While the nAb levels were likely to confer adequate protection against wild-type viral infection, the neutralization activity to recently circulating variants in some of the mild cases ([~]30%) was undermined, implying the susceptibility of reinfection to the variants of concerns (VOCs). COVID-19 convalescent individuals have robust humoral immunity even at 12 months after infection albeit that the medical history and background of patients could affect the function and dynamics of antibody response to the VOCs.
Subject(s)
COVID-19ABSTRACT
The COVID-19 pandemic is an unprecedented threat to humanity provoking global health concerns. Since the etio-pathogenesis of this illness is not fully characterized, the prognostic factors enabling treatment decisions have not been well documented. An accurate prediction of the disease progression can aid in appropriate patient categorization to determine the best treatment option. Here, we have introduced a proteomic approach utilizing data-independent acquisition mass spectrometry (DIA-MS) to identify the serum proteins closely associated with the prognosis of COVID-19. We observed 27 proteins to be differentially expressed between the cohorts of severely ill COVID-19 patients with adverse and favorable prognosis. Ingenuity pathway analysis revealed that 15 out of the 27 proteins might be regulated by cytokine signalling relevant to interleukin (IL)-1b, IL-6 and tumor necrosis factor (TNF), and their differential expression was possibly implicated in the systemic inflammatory response and cardiovascular disorders. We further evaluated the practical prognosticators for the clinical prognosis of severe COVID-19 patients. Subsequent ELISA analyses further uncovered that CHI3L1 and IGFALS could be potent prognostic markers with a high sensitivity. Our findings can help in formulating a diagnostic approach for accurately discriminating severe COVID-19 patients and provide appropriate treatment based on their predicted prognosis.
Subject(s)
Necrosis , Cardiovascular Diseases , COVID-19ABSTRACT
The COVID-19 is an unprecedented threat to humanity provoking global health concerns. Since the etio-pathogenesis of this illness is not fully characterized, the prognostic factors enabling treatment decisions have not been well documented. An accurate prediction of the disease progression can aid in appropriate patient categorization to determine the best treatment option. Here, we introduced an innovative approach utilizing data-independent acquisition (DIA) mass spectrometry to identify the serum proteins closely associated with the COVID-19 severity. We observed 23 proteins to be differentially expressed between the cohorts of critically ill COVID-19 patients with adverse and favorable prognosis. Myoglobin (MB), CHI3L1 and IGFALS were found to have a high sensitivity and specificity for their possible use as independent biomarkers to provide information on the disease prognosis. Our findings can help in formulating a diagnostic approach for accurately discriminating severe COVID-19 patients and provide appropriate treatment based on their predicted prognosis.Funding: This work was in part supported by grants from the Japan Agency for Medical Research and Development (JP19fk0108169 to YK and JP19fk0108110/JP20he0522001 to AR).Conflict of Interest: The authors declare no competing interests.Ethical Approval: This research plan and protocol was approved by the Clinical Ethics Committee of Yokohama City University Hospital (B2002000048). This study was also performed with the approval of the Clinical Ethics Committee in each of the medical facilities. Informed consent was obtained from all patients and/or their guardians before serum samples collection.