Course and clinical severity of the SARS-CoV-2 Omicron variant infection in Tianjin, China.

There is limited information describing the course and severity of illness in subjects infected by the severe acute respiratory syndrome coronavirus 2 Omicron variant, especially in children. In this population-based cohort study, subjects with Omicron variant infection during the outbreak between January 8 and February 12, 2022 in Tianjin, China were included (n = 429). The main outcomes were the distribution of asymptomatic, mild, moderate, and severe patients, and clinical courses including the interval from positive polymerase chain reaction (PCR) test to the onset, aggravation or relief of symptoms, and the interval of reversing positive PCR-test into negative, and length of hospital stay. Of the 429 subjects (113 [26.3%] children; 239 [55.7%] female; median age, 36 years [interquartile range 15.0 to 55.0 years]), the proportion (95% CI) of symptomatic subjects on admission was 95.6% (93.2%, 97.2%), including 60.4% (55.7%, 64.9%) mild, 35.0% (30.6%, 39.6%) moderate, and 0.2% (0.0%, 1.3%) severe. Compared with adults, children had lower proportion of moderate Covid-19 (8.8% vs 44.3%). On discharge, 45.9% (41.3%, 50.7%) and 42.2% (37.6%, 46.9%) of the subjects were diagnosed as having experienced mild and moderate Covid-19. The median (interquartile range) length of hospital stay was 14.0 (12.0, 15.0) days. The median interval of reversing positive PCR-test into negative was 12.0 (10.0, 13.0) days. Symptomatic and moderate Covid-19 in Omicron infections was common in adults and children, recovery from Omicron infections took around 2 weeks of time. The severe acute respiratory syndrome coronavirus 2 Omicron infection in this study was not as mild as previously suggested.

Multiomic characterisation of the long-term sequelae of SARS survivors: a clinical observational study.

Background: We aimed to characterise the long-term health outcomes of survivors of severe acute respiratory syndrome (SARS) and determine their recovery status and possible immunological basis. Methods: We performed a clinical observational study on 14 health workers who survived SARS coronavirus infection between Apr 20, 2003 and Jun 6, 2003 in Haihe Hospital (Tianjin, China). Eighteen years after discharge, SARS survivors were interviewed using questionnaires on symptoms and quality of life, and received physical examination, laboratory tests, pulmonary function tests, arterial blood gas analysis, and chest imaging. Plasma samples were collected for metabolomic, proteomic, and single-cell transcriptomic analyses. The health outcomes were compared 18 and 12 years after discharge. Control individuals were also health workers from the same hospital but did not infect with SARS coronavirus. Findings: Fatigue was the most common symptom in SARS survivors 18 years after discharge, with osteoporosis and necrosis of the femoral head being the main sequelae. The respiratory function and hip function scores of the SARS survivors were significantly lower than those of the controls. Physical and social functioning at 18 years was improved compared to that after 12 years but still worse than the controls. Emotional and mental health were fully recovered. Lung lesions on CT scans remained consistent at 18 years, especially in the right upper lobe and left lower lobe lesions. Plasma multiomics analysis indicated an abnormal metabolism of amino acids and lipids, promoted host defense immune responses to bacteria and external stimuli, B-cell activation, and enhanced cytotoxicity of CD8+ T cells but impaired antigen presentation capacity of CD4+ T cells. Interpretation: Although health outcomes continued to improve, our study suggested that SARS survivors still suffered from physical fatigue, osteoporosis, and necrosis of the femoral head 18 years after discharge, possibly related to plasma metabolic disorders and immunological alterations. Funding: This study was funded by the Tianjin Haihe Hospital Science and Technology Fund (HHYY-202012) and Tianjin Key Medical Discipline (Specialty) Construction Project (TJYXZDXK-063B, TJYXZDXK-067C).

The Relation between Immunological Features and the Positive SARS-CoV-2 Nucleic Acid in Patients with Nonsevere COVID⁃19.

Objective: The novel coronavirus nucleic acid results are the core indicators of illness monitoring. This study aimed to evaluate the relationship between immunological features and positive SARS-CoV-2 nucleic acid by analyzing the clinical and immunological features in nonsevere COVID-19 cases. Methods: Data from nonsevere COVID-19 patients admitted to Haihe Hospital from May 2020 to June 2021 were retrospectively reviewed and analyzed. Results: (1) A total of 122 cases were reviewed in the present study, including 38 mild and 84 moderate cases. The average age of mild cases was significantly different from moderate cases (P < 0.001). Eight patients complained of hyposmia and it was more frequent in mild cases (P < 0.001). The nucleic acid positive duration (NPD) of nonsevere novel coronavirus was 20.49 (confidence interval (CI) 17.50-3.49) days. (2) The levels of specific IgM and IgG for COVID-19 were higher in mild cases than in moderate cases (P=0.023 and P=0.047, respectively). (3) The correlation analysis with antibodies and T-cell subtypes showed that the lymphocyte (LYM) count, T cells, CD4+T cells, and CD8+T cells had a linear correlation with NPD. (4) Among the 93 patients monitored, 62 COVID-19 cases presented a progressive rise of specific IgM and IgG. The daily increase rates of IgM and IgG were 38.42% (CI 28.22-48.61%) and 24.90% (CI 0.23-29.58%), respectively. Conclusion: The levels and daily increase rates of specific IgM and IgG against the virus can vary between cases. The NPD presented a linear correlation with the LYM, T cells, CD4+T cells, and CD8+T cells. Hence, more attention should be paid to these indicators in clinical practice.

Follicular Helper T Cells in Pulmonary Tuberculosis: A Retrospective Study.

BACKGROUND: Follicular helper T lymphocyte (Tfh) promotes antibody production by B lymphocytes in various diseases, including Pulmonary Tuberculosis (PTB). OBJECTIVE: To explore the potential role of Tfh cells and assess the expression level of PD-1, and IL-21 in PTB. METHODS: 54 newly diagnosed smear-positive PTB, 27 people with latent tuberculosis (LTB) and 27 healthy controls (HC) were enrolled. The PTB group was further divided based on the range of lung field involved (focus number>=3, PTB-X3; <3, PTB-X2). After 6-month therapy, sputum smear (positive, PTB-SP; negative, PTB-SN) or imaging examinations (lesion reduction significant, PTB-os; insignificant, PTB-s) were used to evaluate the conditions of PTB patients. Blood samples were collected from PTB group at month six. CD4+CXCR5+Tfh, and its subsets, CD4+CXCR5+PD-1+Tfh and CD4+CXCR5+ICOS+Tfh in peripheral blood mononuclear cells (PBMCs) were detected. Serum IL-21 concentrations were measured. RESULTS: The frequencies of CD4+CXCR5+Tfh, CD4+CXCR5+ICOS+Tfh and CD4+CXCR5+PD-1+Tfh were higher in PTB group than in HC. IL-21, IL-4 and IFNγ concentrations were significantly higher in PTB group than in HC. The proportion of CD4+CXCR5+Tfh in PTB-X2 was lower than in PTB-X3 group. CD4+CXCR5+PD-1+Tfh proportion in PTB-X2 was lower than that in the PTB-X3. After treatment, CD4+CXCR5+Tfh proportion was significantly lower in the PTB-SN group. CD4+CXCR5+Tfh was lower in the PTB-os group than in the PTB-s group. However, the CD4+CXCR5+PD-1+Tfh and cytokine concentrations of IL-21 were not different. CONCLUSIONS: CD4+CXCR5+Tfh level might predict the sputum results, and lesion decrease rate while CD4+CXCR5+PD-1+Tfh subset and IL-21 were not associated with sputum results or lesion decrease after treatment.

Case Report of China/Tianjin's First Novel Coronavirus Variant Omicron.

COVID-19 is a new acute respiratory infectious disease caused by a novel Coronavirus (2019-COV-2) infection. On November 26, 2021, the World Health Organization announced a new 2019-COV-2 variant strain Omicron (B.1.1.529). Omicron's emergence added further uncertainty to the outbreak. Here we report the first case infected with Omicron in China, a 17-year-old female student. In this paper, the clinical symptoms, laboratory and imaging examinations and treatment of the first Omicron-infected patient in China were analyzed. This report might provide a reference for the diagnosis and treatment of patients infected with Omicron strain across the world. The novel Coronavirus antibody tests were performed on the day of admission: IgM level was normal, novel Coronavirus antibody IgG was 132.666s /CO and IgG was 148.47s /CO on the 7th day of admission. IgG showed an increasing trend, which is consistent with the results of multiple novel Coronavirus non-Omicron strain infections.

Preliminary Analysis of B- and T-Cell Responses to SARS-CoV-2.

BACKGROUND AND OBJECTIVE: Without a specific antiviral treatment or vaccine, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused a global pandemic, affecting over 200 countries worldwide. A better understanding of B- and T-cell immunity is critical to the diagnosis, treatment and prevention of coronavirus disease 2019 (COVID-19). METHODS: A cohort of 129 patients with COVID-19 and 20 suspected cases were enrolled in this study, and a lateral flow immunochromatographic assay (LFIA) and a magnetic chemiluminescence enzyme immunoassay (MCLIA) were evaluated for SARS-CoV-2 IgM/IgG detection. Additionally, 127 patients with COVID-19 were selected for the detection of IgM and IgG antibodies to SARS-CoV-2 to evaluate B-cell immunity, and peripheral blood lymphocyte subsets were quantified in 95 patients with COVID-19 to evaluate T-cell immunity. RESULTS: The sensitivity and specificity of LFIA-IgM/IgG and MCLIA-IgM/IgG assays for detecting SARS-CoV infection were > 90%, comparable with reverse transcription polymerase chain reaction detection. IgM antibody levels peaked on day 13 and began to fall on day 21, while IgG antibody levels peaked on day 17 and were maintained until tracking ended. Lymphocyte and subset enumeration suggested that lymphocytopenia occurred in patients with COVID-19. CONCLUSIONS: LFIA-IgM/IgG and MCLIA-IgM/IgG assays can indicate SARS-CoV-2 infection, which elicits an antibody response. Lymphocytopenia occurs in patients with COVID-19, which possibly weakens the T-cell response.