RESUMO
BACKGROUND: Nipah virus (NiV) is 1 of 10 potential causes of imminent public health emergencies of international concern. We investigated the NiV outbreak that occurred in May 2018 in Kerala, India. Here we describe the longitudinal characteristics of cell-mediated and humoral immune responses to NiV infection during the acute and convalescent phases in 2 human survivors. METHODS: Serial blood samples were obtained from the only 2 survivors of the NiV outbreak in Kerala. We used flow cytometry to determine the absolute T-lymphocyte and B-lymphocyte counts and the phenotypes of both T and B cells. We also detected and quantitated the humoral immune response to NiV by virus-specific immunoglobulin M (IgM) and immunoglobulin G (IgG) enzyme-linked immunosorbent assay. RESULTS: Absolute numbers of T lymphocytes remained within normal limits throughout the period of illness studied in both survivors. However, a marked elevation of activated CD8 T cells was observed in both cases. More than 30% of total CD8 T cells expressed Ki67, indicating active proliferation. Proliferating (Ki-67+) CD8 T cells expressed high levels of granzyme B and PD-1, consistent with the profile of acute effector cells. Total B-lymphocyte, activated B-cell, and plasmablast counts were also elevated in NiV survivors. These individuals developed detectable NiV-specific IgM and IgG antibodies within a week of disease onset. Clearance of NiV RNA from blood preceded the appearance of virus-specific IgG and coincided with the peak of activated CD8 T cells. CONCLUSIONS: We describe for the first time longitudinal kinetic data on the activation status of human B- and T-cell populations during acute NiV infection. While marked CD8 T-cell activation was observed with effector characteristics, activated CD4 T cells were less prominent.
Assuntos
Imunidade Adaptativa , Linfócitos B/imunologia , Linfócitos T CD4-Positivos/imunologia , Infecções por Henipavirus/imunologia , Ativação Linfocitária , Doença Aguda , Anticorpos Antivirais/sangue , Linfócitos T CD8-Positivos/imunologia , Convalescença , Feminino , Infecções por Henipavirus/sangue , Humanos , Imunidade Humoral , Imunoglobulina G/sangue , Imunoglobulina M/sangue , Índia , Cinética , Contagem de Linfócitos , Masculino , Vírus Nipah , Adulto JovemRESUMO
Background: COVID-19 disease has a wide range of persisting and new onset clinical manifestations even long after the acute phase. This study was conducted to identify the persisting and new onset symptomatology of post-COVID-19 syndrome patients from clinics in urban and peri-urban Kozhikode, South India, as well as to grade their functional limitation; assess the determinants and predictors. Material and Methods: A cross-sectional study was conducted among 938 subjects attending the post-COVID clinics. Symptom profile, functional assessment, and limitation grading were done using the Post-COVID-19 Functional Status (PCFS) scale. Statistical analyses were done using the SPSS ver.20. Results: Mean age was 41.50 ± 16.90 years. Fever, anosmia, dysgeusia, headache, and myalgia were the common acute COVID-19 symptoms (505,54%; 433,46.3%; 420,44.9%; 323,34.4%; 252,26.9%, respectively). Post-COVID-19, common persisting symptoms were myalgia (167,17.8%), fatigue (149,15.9%), dyspnea (113,12%), and headache (85,9.1%); the common new onset symptoms were shortness of breath and fatigue (228,24.3% and 220,23.4%, respectively). A total of 91 cases (9.7%) had post-COVID sleep disturbances; 16 (1.7%) had symptoms of anxiety and depressive thoughts. PCFS grading showed that 552 (63.8%) had negligible limitations (Grade I). Only one person had Grade IV limitation. Significant association (p < 0.05) was found between functional impairment grading by PCFS and age, gender, locality, type of family, duration of hospitalization, duration of unemployment following illness, source of infection, diabetes mellitus, and hypertension. Male gender, married status, CAD, and smoking had significant higher risks; urban locality and hospitalization decreased the risk. Conclusions: SARS-CoV-2 cases have persistent and new onset symptoms and some degree of functional impairment post-COVID. Significant association was identified for various sociodemographic and clinical variables with the PCFS functional impairment grading.
RESUMO
The special pair of the bacterial photosystem has been modeled with a porphyrin dimer (the partial structure is shown). As with the natural system, only one pyrrole ring from each monomer subunit participates in π overlap.