Chinese expert consensus on intestinal microecology and management of digestive tract complications related to tumor treatment (version 2022).

The human gut microbiota represents a complex ecosystem that is composed of bacteria, fungi, viruses, and archaea. It affects many physiological functions including metabolism, inflammation, and the immune response. The gut microbiota also plays a role in preventing infection. Chemotherapy disrupts an organism's microbiome, increasing the risk of microbial invasive infection; therefore, restoring the gut microbiota composition is one potential strategy to reduce this risk. The gut microbiome can develop colonization resistance, in which pathogenic bacteria and other competing microorganisms are destroyed through attacks on bacterial cell walls by bacteriocins, antimicrobial peptides, and other proteins produced by symbiotic bacteria. There is also a direct way. For example, Escherichia coli colonized in the human body competes with pathogenic Escherichia coli 0157 for proline, which shows that symbiotic bacteria compete with pathogens for resources and niches, thus improving the host's ability to resist pathogenic bacteria. Increased attention has been given to the impact of microecological changes in the digestive tract on tumor treatment. After 2019, the global pandemic of novel coronavirus disease 2019 (COVID-19), the development of novel tumor-targeting drugs, immune checkpoint inhibitors, and the increased prevalence of antimicrobial resistance have posed serious challenges and threats to public health. Currently, it is becoming increasingly important to manage the adverse effects and complications after chemotherapy. Gastrointestinal reactions are a common clinical presentation in patients with solid and hematologic tumors after chemotherapy, which increases the treatment risks of patients and affects treatment efficacy and prognosis. Gastrointestinal symptoms after chemotherapy range from nausea, vomiting, and anorexia to severe oral and intestinal mucositis, abdominal pain, diarrhea, and constipation, which are often closely associated with the dose and toxicity of chemotherapeutic drugs. It is particularly important to profile the gastrointestinal microecological flora and monitor the impact of antibiotics in older patients, low immune function, neutropenia, and bone marrow suppression, especially in complex clinical situations involving special pathogenic microbial infections (such as clostridioides difficile, multidrug-resistant Escherichia coli, carbapenem-resistant bacteria, and norovirus).

Detection of SARS-CoV-2 Specific Antibodies in Saliva Samples.

Molecular assays on nasopharyngeal swabs act as a confirmatory test in coronavirus disease (COVID-19) diagnosis. However, the technical requirements of nasopharyngeal sampling and molecular assays limit the testing capabilities. Recent studies suggest the use of saliva for the COVID-19 diagnostic test. In this study, 44 patients diagnosed with COVID-19 in The Third People's Hospital of Shenzhen were enrolled. Saliva and serum specimens were obtained at different time points and the immunoglobulins against SARS-CoV-2 were measured. The results showed that saliva IgA presented a higher COI value than IgG and IgM. In matched saliva and serum samples, all saliva samples presented lower IgG levels than serum samples, and only one saliva sample presented a higher IgM level. The conversion rates of saliva IgA and the detection of viral nucleic acids were analyzed in the first and second weeks after hospitalization. The positive rates increased when combining saliva IgA and viral nucleic acid detection. In conclusion, our results provide evidence that saliva IgA could serve as a useful index for the early diagnosis of COVID-19.

Clinical status of patients 1 year after hospital discharge following recovery from COVID-19: a prospective cohort study.

BACKGROUND: The long-term clinical status of coronavirus disease 2019 (COVID-19) in recovered patients remains largely unknown. This prospective cohort study evaluated clinical status of COVID-19 and explored the associated risk factors. METHODS: At the outpatient visit, patients underwent routine blood tests, physical examinations, pulmonary function tests, 6-min walk test, high-resolution computed tomography (CT) of the chest, and extrapulmonary organ function tests. RESULTS: 230 patients were analyzed. Half (52.7%) reported at least one symptom, most commonly fatigue (20.3%) and sleep difficulties (15.8%). Anxiety (8.2%), depression (11.3%), post-traumatic symptoms (10.3%), and sleep disorders (26.3%) were also reported. Diffusion impairments were found in 35.4% of the patients. Abnormal chest CT scans were present in 63.5% of the patients, mainly reticulation and ground-glass opacities. Further, a persistent decline in kidney function was observed after discharge. SARS-CoV-2-specific antibodies of IgA, IgG, and IgM were positive in 56.4%, 96.3%, and 15.2% of patients, respectively. Multivariable logistic regression showed that disease severity, age, and sex were closely related to patient recovery. CONCLUSIONS: One year after hospital discharge, patients recovered from COVID-19 continued to experience both pulmonary and extrapulmonary dysfunction. While paying attention to pulmonary manifestations of COVID-19, follow-up studies on extrapulmonary manifestations should be strengthened.

Interferon-induced transmembrane protein 3 gene polymorphisms are associated with COVID-19 susceptibility and severity: A meta-analysis.

BACKGROUND: Recent evidence has linked the interferon-induced transmembrane protein 3 gene (IFITM3) to coronavirus disease 2019 (COVID-19) outcomes, but the results are inconsistent. The purpose of this meta-analysis was to evaluate the association of IFITM3 gene polymorphisms with COVID-19 susceptibility and severity. METHOD: A systematic search was performed with PubMed, Web of Science, Cochrane Library, and Embase from the date of inception to 20 December 2021. The results were analyzed with pooled odds ratios (ORs) and 95% confidence intervals (95% CIs). The robustness was performed using the method of sequential removal for each trial. RESULTS: Four studies involving 1989 subjects were included, from which 1114 patients were positive for COVID-19. For IFITM3 rs12252, the pooled OR showed that there was a significant association between the genotype frequencies and infection with COVID-19 in any of the gene models, i.e., the allelic model (OR = 1.91, 95% CI, 1.36-2.68), the dominant model (OR = 1.80, 95% CI, 1.27-2.56), the recessive model (OR = 5.67, 95% CI, 1.01-31.77), the heterozygous model (OR = 1.65, 95% CI, 1.16-2.36) and the homozygous model (OR = 5.88, 95% CI, 1.05-32.98). The results stratified by severity showed that there was a significant correlation only between the allelic (OR = 0.69, 95% CI, 0.49-0.97) and recessive (OR = 0.43, 95% CI, 0.20-0.93) models. Our results did not support the associations between the IFITM3 rs34481144 gene polymorphism and COVID-19 susceptibility or severity in any of the gene models. CONCLUSIONS: The findings indicated that IFITM3 rs12252 gene polymorphisms were associated with COVID-19 susceptibility and that the rs12252-C variant was particularly critical for severity. Genetic factors should be considered in future vaccine development.

Dysregulated hematopoiesis in bone marrow marks severe COVID-19.

Severe coronavirus disease 2019 (COVID-19) is often indicated by lymphopenia and increased myelopoiesis; however, the underlying mechanism is still unclear, especially the alteration of hematopoiesis. It is important to explore to what extent and how hematopoietic stem cells contribute to the impairment of peripheral lymphoid and myeloid compartments in COVID-19 patients. In this study, we used single-cell RNA sequencing to assess bone marrow mononuclear cells from COVID-19 patients with peripheral blood mononuclear cells as control. The results showed that the hematopoietic stem cells in these patients were mainly in the G1 phase and prone to apoptosis, with immune activation and anti-viral responses. Importantly, a significant accumulation of immature myeloid progenitors and a dramatic reduction of lymphoid progenitors in severe cases were identified, along with the up-regulation of transcription factors (such as SPI1, LMO4, ETS2, FLI1, and GATA2) that are important for the hematopoietic stem cell or multipotent progenitor to differentiate into downstream progenitors. Our results indicate a dysregulated hematopoiesis in patients with severe COVID-19.

Applications and analytical tools of cell communication based on ligand-receptor interactions at single cell level.

BACKGROUND: Cellular communication is an essential feature of multicellular organisms. Binding of ligands to their homologous receptors, which activate specific cell signaling pathways, is a basic type of cellular communication and intimately linked to many degeneration processes leading to diseases. MAIN BODY: This study reviewed the history of ligand-receptor and presents the databases which store ligand-receptor pairs. The recently applications and research tools of ligand-receptor interactions for cell communication at single cell level by using single cell RNA sequencing have been sorted out. CONCLUSION: The summary of the advantages and disadvantages of analysis tools will greatly help researchers analyze cell communication at the single cell level. Learning cell communication based on ligand-receptor interactions by single cell RNA sequencing gives way to developing new target drugs and personalizing treatment.

Early Viral Clearance and Antibody Kinetics of COVID-19 Among Asymptomatic Carriers.

Asymptomatic carriers contribute to the spread of Coronavirus Disease 2019 (COVID-19), but their clinical characteristics, viral kinetics, and antibody responses remain unclear. A total of 56 COVID-19 patients without symptoms at admission and 19 age-matched symptomatic patients were enrolled. RNA of SARS-CoV-2 was tested using transcriptase quantitative PCR, and the total antibodies (Ab), IgG, IgA, and IgM against the SARS-CoV-2 were tested using Chemiluminescence Microparticle Immuno Assay. Among 56 patients without symptoms at admission, 33 cases displayed symptoms and 23 remained asymptomatic throughout the follow-up period. 43.8% of the asymptomatic carriers were children and none of the asymptomatic cases had recognizable changes in C-reactive protein or interleukin-6, except one 64-year-old patient. The initial threshold cycle value of nasopharyngeal SARS-CoV-2 in asymptomatic carriers was similar to that in pre-symptomatic and symptomatic patients, but the positive viral nucleic acid detection period of asymptomatic carriers (9.63 days) was shorter than pre-symptomatic patients (13.6 days). There were no obvious differences in the seropositive conversion rate of total Ab, IgG, and IgA among the three groups, though the rates of IgM varied largely. The average peak IgG and IgM COI of asymptomatic cases was 3.5 and 0.8, respectively, which is also lower than those in symptomatic patients with peaked IgG and IgM COI of 4.5 and 2.4 (p < 0.05). Young COVID-19 patients seem to be asymptomatic cases with early clearance of SARS-CoV-2 and low levels of IgM generation but high total Ab, IgG, and IgA. Our findings provide empirical information for viral clearance and antibody kinetics of asymptomatic COVID-19 patients.

Early Virus Clearance and Delayed Antibody Response in a Case of Coronavirus Disease 2019 (COVID-19) With a History of Coinfection With Human Immunodeficiency Virus Type 1 and Hepatitis C Virus.

The effect of host immune status on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection remains unknown. Here, we report the first case of coronavirus disease 2019 (COVID-19) with human immunodeficiency virus type 1 (HIV-1)/hepatitis C virus coinfection, who showed a persistently negative SARS-CoV-2 RNA test but delayed antibody response in the plasma. This case highlights the influence of HIV-1-induced immune dysfunction on early SARS-CoV-2 clearance.

Longitudinal Changes on Clinical Features in 28 Children With COVID-19 in Shenzhen, China.

Objective: To investigate the clinical characteristics of children with coronavirus disease 2019 (COVID-19) and identify the occurrence of viral shedding of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) during follow-up. Methods: We retrospectively retrieved data from pediatric patients with COVID-19 from the Shenzhen Third People's Hospital in China. The dynamics of SARS-CoV-2 and antibodies against SARS-CoV-2 were analyzed during hospitalization and after discharge. Results: From January 23 to March 15, 2020, a total of 28 pediatric patients were diagnosed with COVID-19 and were followed for at least 1 month. The median age was 7 years (IQR 3.5-10) and none of the children progressed to severe COVID-19 during hospitalization. Ten patients tested positive for SARS-CoV-2 1 month after discharge while four patients tested positive during the 2nd month after discharge. Only three of 12 children showed detectable immunoglobulin-M (IgM) on day 5, 18, and 21 after illness onset, respectively. Conclusions: COVID-19 disease was relatively mild among children while a number did test positive after discharge from the hospital. Public health initiatives should thus adapt control measures targeted toward children.