RESUMO
Understanding the immune response generated by SARS-CoV-2 is critical for assessing efficient therapeutic protocols and gaining insights into the durability of protective immunity. The current work was aimed at studying the specific humoral responses against SARS-CoV-2 in Cuban COVID-19 convalescents. We developed suitable tools and methods based on ELISA methodology, for supporting this evaluation. Here, we describe the development of an ELISA for the quantification of anti-RBD IgG titers in a large number of samples and a similar test in the presence of NH4SCN as chaotropic agent for estimating the RBD specific antibody avidity. Additionally, a simple and rapid ELISA based on antibody-mediated blockage of the binding RBD-ACE2 was implemented for detecting, as a surrogate of conventional test, the levels of anti-RBD inhibitory antibodies in convalescent sera. In a cohort of 273 unvaccinated convalescents, we identified higher anti-RBD IgG titer (1 : 1,330, p < 0.0001) and higher levels of inhibitory antibodies blocking RBD-ACE2 binding (1 : 216, p < 0.05) among those who had recovered from severe illness. Our results suggest that disease severity, and not demographic features such as age, sex, and skin color, is the main determinant of the magnitude and neutralizing ability of the anti-RBD antibody response. An additional paired longitudinal assessment in 14 symptomatic convalescents revealed a decline in the antiviral antibody response and the persistence of neutralizing antibodies for at least 4 months after the onset of symptoms. Overall, SARS-CoV-2 infection elicits different levels of antibody response according to disease severity that declines over time and can be monitored using our homemade serological assays.
Assuntos
Anticorpos Neutralizantes , Anticorpos Antivirais , COVID-19 , Ensaio de Imunoadsorção Enzimática , Imunidade Humoral , Imunoglobulina G , SARS-CoV-2 , Humanos , COVID-19/imunologia , SARS-CoV-2/imunologia , Anticorpos Antivirais/sangue , Anticorpos Antivirais/imunologia , Cuba , Masculino , Feminino , Imunoglobulina G/sangue , Imunoglobulina G/imunologia , Pessoa de Meia-Idade , Adulto , Anticorpos Neutralizantes/imunologia , Anticorpos Neutralizantes/sangue , Glicoproteína da Espícula de Coronavírus/imunologia , Idoso , Enzima de Conversão de Angiotensina 2/metabolismo , Afinidade de Anticorpos/imunologiaRESUMO
BACKGROUND: In response to the coronavirus disease 2019 (Covid-19) pandemic, Brazil authorised the Astra Zeneca/Fiocruz vaccine in January 2021. As the Delta variant emerged in May 2021, interval between vaccine doses was adjusted. By September 2021, the Brazilian National Immunisation Program recommended a booster dose for individuals over 70, and later expanded the recommendation to all adults. OBJECTIVES: Assess the equivalence of IgG antibody response against the Covid-19 S protein before and approximately 28 days after the third dose of a Covid-19 recombinant vaccine. Two groups received initial two doses with intervals of eight and 12 weeks. METHODS: This is a phase IV clinical study, uncontrolled, non-randomised. The study proposes calculating the ratio of geometric means titres (GMT) 28 days after the third dose, with a target ratio of confidence interval (CI) between 0.77 and 1.3. FINDINGS: In the primary endpoint, there was no equivalence between the eight- and 12-week intervals with a slight variation favouring the eight-week group. Post-third dose, both groups showed increases titres at 28 days, three months, six months and 12 months. Both groups responded similarly to Delta and Omicron BA.1, with a more significant increase for Delta. MAIN CONCLUSIONS: The study showed strong and consistent immune response in all age groups receiving the Covid-19 recombinant vaccine. Third dose elicited an increase in GMT by at least three times aligned with Ministry of Health strategies emphasising Bio-Manguinhos crucial role in pandemic control in the country.
Assuntos
Anticorpos Antivirais , Vacinas contra COVID-19 , COVID-19 , Esquemas de Imunização , Imunização Secundária , Imunogenicidade da Vacina , Imunoglobulina G , SARS-CoV-2 , Vacinas Sintéticas , Humanos , Vacinas contra COVID-19/imunologia , Vacinas contra COVID-19/administração & dosagem , COVID-19/prevenção & controle , COVID-19/imunologia , Masculino , Adulto , Feminino , Pessoa de Meia-Idade , SARS-CoV-2/imunologia , Anticorpos Antivirais/sangue , Imunoglobulina G/sangue , Vacinas Sintéticas/imunologia , Vacinas Sintéticas/administração & dosagem , Adulto Jovem , Idoso , Brasil , Adolescente , Fatores de TempoRESUMO
BACKGROUND: Orally transmitted acute Chagas disease (ACD) primarily affects low-visibility and low-income individuals in tropical and subtropical zones. Managing ACD remains challenging even after more than 100 years of its discovery. Its spread to non-endemic areas has made it a global health issue. The aim of this work is to demonstrate the difficulties encountered in handling a real-life situation. METHODOLOGY AND FINDINGS: This report examines an outbreak of 39 cases of ACD due to oral transmission by bacaba juice ingestion that occurred in Pedro do Rosário, Maranhão, Brazil. A clinical and epidemiological investigation, including an entomological search, was conducted. Diagnosis criteria included positive peripheral blood smear (PBS), seroconversion of IgG, and a two-fold increase in IgG titer (laboratory criteria); and clinical findings, epidemiological exposure, and at least one positive IgG test (clinical-epidemiological criteria). In-house conventional polymerase chain reaction (PCR) was performed on 33 samples. All patients were treated with benznidazole. After 4.5 years, IgG levels were reassessed in 26 individuals. The mean age was 33.6 years, with no gender difference. The mean incubation period was 13.8 days, and the mean between symptom onset and treatment was 16.6 days. The most common symptoms were fever and lymphadenopathy (90%). Diagnostic success rates were 66.6% (laboratory criteria), 23% (clinical-epidemiological criteria), and 10.2% (high clinical suspicion despite negative tests). Test positivity rates were 69.7% (PBS), 91.4% (serology), and 100% (PCR). There were no deaths. Serological cure was achieved in 34.6% of cases, and IgG titers decreased in 15.3%. CONCLUSIONS AND SIGNIFICANCE: We encountered several barriers in managing ACD, including population vulnerability, reliance on outdated diagnostic techniques, lack of standardized molecular biology methods, and limited therapeutic options. This report underscores the importance of rapid surveillance and early treatment to prevent fatalities. We recommend the standardization of conventional PCR in diagnostic routines.
Assuntos
Doença de Chagas , Surtos de Doenças , Trypanosoma cruzi , Humanos , Doença de Chagas/epidemiologia , Doença de Chagas/tratamento farmacológico , Doença de Chagas/diagnóstico , Masculino , Adulto , Feminino , Brasil/epidemiologia , Trypanosoma cruzi/imunologia , Pessoa de Meia-Idade , Adulto Jovem , Adolescente , Imunoglobulina G/sangue , Sucos de Frutas e Vegetais , Tripanossomicidas/uso terapêutico , Nitroimidazóis/uso terapêutico , Animais , Criança , Anticorpos Antiprotozoários/sangue , IdosoRESUMO
The COVID-19 pandemic was characterized by the emergence and succession of SARS-CoV-2 variants able to evade the antibody response induced by natural infection and vaccination. To evaluate the IgG reactivity and neutralizing capacity of the serum of individuals vaccinated with Sputnik V (105 volunteers vaccinated) against different viral variants. IgG reactivity to the Spike protein (S) was evaluated by ELISA. A plaque reduction neutralization test was performed using different viral variant isolates. At 42 days post-vaccination, the frequency of recognition and reactivity to the S protein of the Omicron variant was lower compared to that of the other variants. In general, a higher average neutralization titer was seen against the ancestral variant compared to the variants, especially Omicron. However, some sera exhibited a higher neutralization titer to the Gamma variant compared to the ancestral variant, suggesting unapparent exposure during the clinical trial. Antibodies induced by Sputnik V can recognize, persist, and neutralize SARS-CoV-2 variants, with Omicron being the one that best evades this response. These results represent a unique report on the humoral response induced by a globally lesser-studied vaccine in terms of efficacy and immune escape, offering insights into developing vaccines targeting unknown coronaviruses.
Assuntos
Anticorpos Neutralizantes , Anticorpos Antivirais , COVID-19 , Imunoglobulina G , Testes de Neutralização , SARS-CoV-2 , Glicoproteína da Espícula de Coronavírus , Humanos , SARS-CoV-2/imunologia , SARS-CoV-2/genética , Anticorpos Antivirais/sangue , Anticorpos Antivirais/imunologia , COVID-19/imunologia , COVID-19/prevenção & controle , COVID-19/virologia , COVID-19/epidemiologia , Anticorpos Neutralizantes/imunologia , Anticorpos Neutralizantes/sangue , Imunoglobulina G/sangue , Imunoglobulina G/imunologia , Glicoproteína da Espícula de Coronavírus/imunologia , Glicoproteína da Espícula de Coronavírus/genética , Venezuela/epidemiologia , Vacinas contra COVID-19/imunologia , Vacinas contra COVID-19/administração & dosagem , Adulto , Feminino , Masculino , Vacinação , Pessoa de Meia-IdadeRESUMO
BACKGROUND: To report a case of IgG4-related pachymeningitis presenting with cystic lesions mimicking neurocysticercosis. CASE PRESENTATION: A 40-year-old female patient with tetraparesis, dysphagia and dysphonia was evaluated with clinical examination, magnetic resonance imaging, and meningeal biopsy. Magnetic resonance imaging (MRI) revealed diffuse pachymeningeal enhancement involving the cranial, cervical, thoracic, and lumbar segments with spinal cord compression and cystic lesions. CSF immunology was initially positive for cysticercus cellulosae. After disease progression a meningeal biopsy was compatible with IgG4 related disease. The patient had partial response to rituximab and needed multiple surgical procedures for spinal cord decompression and CSF shunting. CONCLUSIONS: This case highlights the possibility of IgG4-related disease in patients with diffuse pachymeningitis causing spinal cord compression, even with cystic lesions on MRI. Diagnosis of IgG4-related pachymeningitis is paramount due to the possibility of treatment response to immunotherapy, particularly to anti-CD20 agents.
Assuntos
Doença Relacionada a Imunoglobulina G4 , Meningite , Neurocisticercose , Compressão da Medula Espinal , Humanos , Feminino , Adulto , Meningite/diagnóstico , Neurocisticercose/complicações , Neurocisticercose/diagnóstico , Neurocisticercose/diagnóstico por imagem , Compressão da Medula Espinal/etiologia , Diagnóstico Diferencial , Doença Relacionada a Imunoglobulina G4/diagnóstico , Doença Relacionada a Imunoglobulina G4/complicações , Imageamento por Ressonância Magnética , Imunoglobulina G/sangue , Imunoglobulina G/líquido cefalorraquidianoRESUMO
INTRODUCTION: Due to the cross-reactivity between SARS-CoV-2 and common human coronaviruses, previous infections with these viruses could contribute to serological or cellular cross-protection against severe COVID-19. However, protective immunity may not develop, or pre-existing immunity could increase COVID-19 severity. OBJECTIVE: To determine the seroprevalence of IgG antibodies against HCoV-NL63 and HCoV-HKU1 and correlate previous exposure with COVID-19 signs in patients from Villavicencio. MATERIALS AND METHODS: A cross-sectional retrospective study was conducted. ELISA technique was used to search for IgG antibodies against HCoV-NL3 and HCoV-HKU1 in patients with positive RT-qPCR results for SARS-CoV-2. Patients were grouped according to COVID-19 clinical characteristics in four groups: group 1: asymptomatic (n = 23); group 2: hospitalized (n = 24); group 3: intensive care units (n = 24), and group 4: dead (n = 22). RESULTS: The overall seroprevalence of IgG antibodies against HCoV was 74.2% (n = 69; 95% CI: 65.3-83.1), with 66.7% of HCoV-NL63 (n = 62; 95% CI: 57,1-76,2), and 25.8% of HCoV-HKU1 (n = 24; 95% CI: 16,9-34,7). Based on crosstab analysis, prior exposure to HCoV-NL63 was associated with protection against severe COVID-19 (p = 0.042; adjusted OR = 0.159; 95% CI: 0.027-0.938), and previous coinfection of HCoV-NL63 and HCoVHKU1 was considered a positive association to severe COVID-19 (p = 0.048; adjusted OR = 16.704; 95% CI: 1.020 - 273.670). CONCLUSION: To our knowledge, this is the first study addressing seroprevalence of HCoV IgG antibodies in Colombia and Latin America. Previous exposure to HCoV-NL63 could protect against severe COVID-19, whereas patients with underlying HCoV-NL63 and HCoVHKU1 coinfection could be hospitalized with severe signs of COVID-19.
Introducción: Debido a la reactividad cruzada entre SARS-CoV-2 y los coronavirus humanos comunes, las infecciones previas con estos virus podrían contribuir a la protección cruzada serológica o celular contra la COVID-19 grave. Sin embargo, la inmunidad protectora puede no desarrollarse o la inmunidad preexistente podría generar COVID-19 grave. Objetivo: Determinar la seroprevalencia de anticuerpos IgG frente a HCoV-NL63 y HCoVHKU1, y correlacionar su previa exposición con los signos de COVID-19 en pacientes de Villavicencio. Materiales y métodos: Se realizó un estudio retrospectivo observacional analítico y transversal. Se utilizó la técnica ELISA para buscar anticuerpos IgG contra HCoV-NL3 y HCoV-HKU1 en pacientes con resultado positivo de RT-qPCR para SARS-CoV-2. Los pacientes se agruparon según los signos de COVID-19 en cuatro grupos: grupo 1: asintomáticos (n = 23); grupo 2: hospitalizados (n = 24); grupo 3: unidad de cuidados intensivos (n = 24), y grupo 4: fallecidos (n = 22). Resultados: La seroprevalencia general de IgG anti-HCoV fue de 74.2 % (n = 69; IC95%: 65,3-83,1), con 66,7 % de HCoV-NL63 (n = 62; IC95% :57,1-76,2) y 25,8 % de HCoV-HKU1 (n = 24; [IC95%:16,9-34,7). Según el análisis de las tablas de contingencia, la exposición previa a HCoV-NL63 se asoció con protección de una COVID-19 grave (p = 0,042; OR ajustado = 0,159; IC95%: 0,027-0,938) y la previa coinfección de HCoV-NL63 y HCoV-HKU1 se asoció con padecimiento de signos clínicos graves por COVID-19 (p = 0,048; OR ajustado = 16,704; IC95%: 1,020- 73,670). Conclusión: Según la literatura revisada hasta la fecha, este es el primer estudio sobre la seroprevalencia de anticuerpos IgG de HCoV en Colombia y Latinoamérica. La exposición previa a HCoV-NL63 podría proteger contra la COVID-19 grave, mientras que los pacientes con coinfección subyacente de HCoV-NL63 y HCoV-HKU1 podrían resultar hospitalizados con signos graves de COVID-19.
Assuntos
Anticorpos Antivirais , COVID-19 , Coronavirus Humano NL63 , Imunoglobulina G , SARS-CoV-2 , Humanos , Estudos Soroepidemiológicos , COVID-19/epidemiologia , COVID-19/imunologia , Colômbia/epidemiologia , Estudos Transversais , Estudos Retrospectivos , Coronavirus Humano NL63/imunologia , Masculino , Pessoa de Meia-Idade , Feminino , Adulto , Imunoglobulina G/sangue , Anticorpos Antivirais/sangue , SARS-CoV-2/imunologia , Idoso , Adulto Jovem , AdolescenteRESUMO
Rapid virus identification is crucial for preventing outbreaks. The COVID-19 pandemic has highlighted the critical nature of rapid virus detection. Here, we designed a label-free electrochemical biosensor modified with gold nanoparticles (AuNPs) to detect IgG antibodies from human serum, enabling rapid point-of-care diagnostics. AuNPs were synthesized and characterized. A multivariate optimization was carried out to determine the optimal condition for functionalizing AuNPs with anti-IgG. Subsequently, using a glassy carbon electrode (GCE), a modified AuNPs/GCE electrochemical biosensor was developed for IgG detection. The results indicated that AuNPs displayed a spherical morphology with a size distribution of 19.54 nm. Additionally, the zeta potential was recorded at -7.84 mV. Central composite design (CCD) analysis determined the optimal conditions for functionalizing AuNPs to be an anti-IgG concentration of 320 µg mL-1, a temperature of 25 °C, and pH of 7.4. The characterization study confirmed the successful synthesis and functionalization of AuNPs. Through electrochemical impedance spectroscopy measurement, the biosensor demonstrated a limit of detection (LOD) of 0.2 ng mL-1 and limit of quantification (LOQ) of 0.8 ng mL-1. Furthermore, tests in real samples showed the interaction between IgG antibodies in serum samples and AuNPs/GCE, confirming the biosensor's ability to detect and quantify IgG in clinical samples.
Assuntos
Técnicas Biossensoriais , Técnicas Eletroquímicas , Ouro , Imunoglobulina G , Limite de Detecção , Nanopartículas Metálicas , SARS-CoV-2 , Humanos , Técnicas Biossensoriais/métodos , Ouro/química , Nanopartículas Metálicas/química , Técnicas Eletroquímicas/métodos , Imunoglobulina G/sangue , SARS-CoV-2/imunologia , SARS-CoV-2/isolamento & purificação , COVID-19/diagnóstico , COVID-19/sangue , COVID-19/virologia , Anticorpos Antivirais/sangue , Anticorpos Antivirais/imunologia , EletrodosRESUMO
BACKGROUND: In Brazil, despite the increase in coverage and access to rapid testing for syphilis in primary health care, no reduction in cases of syphilis and congenital syphilis was observed. Poor and low-educated populations are disproportionately affected by infection caused by T. pallidum. This study aims to estimate the prevalence of syphilis and associated factors among people aged 18 to 49 years old in the city of Belém, brazilian amazon. METHODS: Observational, cross-sectional study carried out in a sanitary administrative district of a capital of the Brazilian Amazon, Belém, state of Pará, Brazil. Data collection was conducted from August 2021 to February 2022. The participantes consisted of residents of the Montese, Guamá and Condor neighborhoods. People aged 18 to 49 years were included. This variable was treated as dichotomous (reagent and non-reagent). The selected response event was 'reagent result'. The independent variables were the social factors and access to health services. To identify associated factors with the presence of markers of the bacteria studied, multiple logistic rules were performed. RESULTS: 178 people participated in the study; the median age was 35.0 years. The prevalence of IgG and/or IgM antibodies against T. pallidum was 7 % (13). In the final regression model, it was observed that participants who had sexual intercourse after using alcohol and drugs and those who did not know about the prevention of sexually transmitted infections were five times more likely to have tested positive for T. pallidum. CONCLUSIONS: Aspects of individual vulnerability and access to health services must be managed to reduce the exposure of poor urban populations to T. pallidum.
Assuntos
Sífilis , Treponema pallidum , População Urbana , Humanos , Brasil/epidemiologia , Adulto , Estudos Transversais , Masculino , Pessoa de Meia-Idade , Feminino , Adulto Jovem , Adolescente , Prevalência , Sífilis/epidemiologia , População Urbana/estatística & dados numéricos , Treponema pallidum/imunologia , Fatores de Risco , Anticorpos Antibacterianos/sangue , Pobreza , Imunoglobulina M/sangue , Imunoglobulina G/sangueRESUMO
Three lateral flow immunoassay prototypes developed to detect IgM, IgG and IgM/IgG antibodies against Hantavirus were evaluated. A total of 163 samples were tested: 10 from Hantavirus patients, 103 from related diseases, and 50 from healthy controls. The prototypes exhibited 100 % sensitivity, 97.5 % to 99.3 % specificity, indicating promising improved diagnosis.
Assuntos
Anticorpos Antivirais , Infecções por Hantavirus , Imunoglobulina G , Imunoglobulina M , Orthohantavírus , Sensibilidade e Especificidade , Imunoglobulina M/sangue , Humanos , Imunoglobulina G/sangue , Anticorpos Antivirais/sangue , Infecções por Hantavirus/diagnóstico , Infecções por Hantavirus/imunologia , Orthohantavírus/imunologia , Imunoensaio/métodosRESUMO
INTRODUCTION: Ascaris lumbricoides has dual effects on the immune system of infected hosts. The IgE response to this parasite has been thoroughly studied, but little is known about cellular responses induced by infection. This study aims to explore the interplay between A. lumbricoides infection and B cell responses, especially B regulatory cells. METHODS: Participants from Santa Catalina, Bolívar, Colombia, a helminth-endemic town, were screened for soil-transmitted helminthiasis (STH) using stool examinations. Eighteen A. lumbricoides-infected and 11 non-infected subjects were selected. Blood samples were analyzed for Breg cells and related cytokines, and immunoglobulins specific to the A. lumbricoides excretory/secretory product, ABA-1. RESULTS: Infected subjects exhibited higher frequencies of Breg cells, especially those with a higher A. lumbricoides egg burden. Higher frequencies of different Breg subsets were observed in infected individuals, with CD25+CD71+CD73- B cells being notably increased in strongly infected individuals. Additionally, A. lumbricoides infection was associated with reduced levels of circulating ABA-1-specific IgG1 and IgE. IL-10+ B cell frequencies correlated inversely with ABA-1-specific IgE. CONCLUSIONS: A. lumbricoides infection has a significant impact on the immune response, particularly on Breg cell populations and antibody responses. Our findings suggest that A. lumbricoides infection mediates a dose-dependent immunosuppressive response characterized by an increase in Breg cells and concomitant suppression of ABA-1-specific humoral responses.
Assuntos
Anticorpos Anti-Helmínticos , Ascaríase , Ascaris lumbricoides , Imunoglobulina E , Interleucina-10 , Humanos , Ascaríase/imunologia , Ascaríase/parasitologia , Interleucina-10/imunologia , Animais , Ascaris lumbricoides/imunologia , Feminino , Masculino , Colômbia , Adulto , Anticorpos Anti-Helmínticos/sangue , Anticorpos Anti-Helmínticos/imunologia , Imunoglobulina E/sangue , Adulto Jovem , Pessoa de Meia-Idade , Imunoglobulina G/sangue , Linfócitos B/imunologia , Linfócitos B Reguladores/imunologia , AdolescenteRESUMO
Neosporosis is one of the major causes of abortion in cattle, and it is responsible for significant economic losses in those animals. Thus, this study aimed to evaluate indirect ELISA using subcellular fractions of Neospora caninum obtained via sucrose gradient separation. Eighty-five sera from dairy cattle previously tested using indirect immunofluorescence assay (IFA) were used. Three distinct bands were separated at 1.0 M, 1.4 M, 1.6 M, and the pellet at 1.8 M, which were identified as fractions one (F1), two (F2), three (F3), and four (F4), respectively. These fractions showed parasite membranes in the F1, rhoptry and conoids in the F2, mitochondria in the F3, and tachyzoite ghosts remain in F4. Indirect ELISAs for IgM, and IgG were performed. Additionally, sensitivity, specificity, and kappa values were defined considering the IFA as the gold standard. The highest and lowest specificities were observed for F1 (76 %) and F3 (16 %), respectively. F2 and F4 showed the highest sensitivity (93.3 %), kappa agreement (0.46), and Negative Preventive Value (NPV) (73 %) respectively. It was possible to standardize indirect ELISAs using whole soluble antigen and subcellular fractions of N. caninum, and F2 and F4 showed higher sensitivity (93.3 %), kappa (0.41), and NPV values (75 %) than F1, and F3, which could be used for epidemiology studies such as screening.
Assuntos
Anticorpos Antiprotozoários , Antígenos de Protozoários , Doenças dos Bovinos , Coccidiose , Ensaio de Imunoadsorção Enzimática , Neospora , Animais , Bovinos , Neospora/imunologia , Coccidiose/veterinária , Coccidiose/diagnóstico , Coccidiose/imunologia , Doenças dos Bovinos/diagnóstico , Doenças dos Bovinos/imunologia , Doenças dos Bovinos/parasitologia , Doenças dos Bovinos/sangue , Antígenos de Protozoários/imunologia , Anticorpos Antiprotozoários/sangue , Anticorpos Antiprotozoários/imunologia , Frações Subcelulares/metabolismo , Imunoglobulina G/sangue , Imunoglobulina G/imunologia , Feminino , Imunoglobulina M/sangue , Imunoglobulina M/imunologia , Sensibilidade e Especificidade , Técnica Indireta de Fluorescência para Anticorpo/métodosRESUMO
BACKGROUND AND PURPOSE: The diagnostic criteria for myelin oligodendrocyte glycoprotein antibody (MOG-IgG)-associated disease (MOGAD) were published in 2023. We aimed to determine the performance of the new criteria in Latin American (LATAM) patients compared with the 2018 criteria and explore the significance of MOG-IgG titers in diagnosis. METHODS: We retrospectively reviewed the medical records of LATAM (Argentina, Chile, Brazil, Peru, Ecuador, and Colombia) adult patients with one clinical MOGAD event and MOG-IgG positivity confirmed by cell-based assay. Both 2018 and 2023 MOGAD criteria were applied, calculating diagnostic performance indicators. RESULTS: Among 171 patients (predominantly females, mean age at first attack = 34.1 years, mean disease duration = 4.5 years), 98.2% patients met the 2018 criteria, and of those who did not fulfill diagnostic criteria (n = 3), all tested positive for MOG-IgG (one low-positive and two without reported titer). Additionally, 144 (84.2%) patients met the 2023 criteria, of whom 57 (39.5%) had MOG-IgG+ titer information (19 clearly positive and 38 low-positive), whereas 87 (60.5%) patients had no MOG-IgG titer. All 144 patients met diagnostic supporting criteria. The remaining 27 patients did not meet the 2023 MOGAD criteria due to low MOG-IgG (n = 12) or lack of titer antibody access (n = 15), associated with the absence of supporting criteria. The 2023 MOGAD criteria showed a sensitivity of 86% (95% confidence interval = 0.80-0.91) and specificity of 100% compared to the 2018 criteria. CONCLUSIONS: These findings support the diagnostic utility of the 2023 MOGAD criteria in an LATAM cohort in real-world practice, despite limited access to MOG-IgG titration.
Assuntos
Autoanticorpos , Glicoproteína Mielina-Oligodendrócito , Humanos , Glicoproteína Mielina-Oligodendrócito/imunologia , Feminino , Masculino , Adulto , Autoanticorpos/sangue , Estudos Retrospectivos , Pessoa de Meia-Idade , Imunoglobulina G/sangue , Estudos de Coortes , Chile , Brasil , Peru , Colômbia , Argentina , Equador , América LatinaRESUMO
The present study aimed to verify the impact of etiological treatment on the genotype-specific serological diagnosis of chronic Chagas disease patients (CH), using the Chagas-Flow ATE IgG1 methodology. For this purpose, a total of 92 serum samples from CH, categorized as Not Treated (NT, n = 32) and Benznidazole-Treated (Bz-T, n = 60), were tested at Study Baseline and 5Years Follow-up. At Study Baseline, all patients have the diagnosis of Chagas disease confirmed by Chagas-Flow ATE IgG1, using the set of attributes ("antigen/serum dilution/cut-off"; "EVI/250/30%"). The genotype-specific serodiagnosis at Study Baseline demonstrated that 96% of patients (44/46) presented a serological profile compatible with TcII genotype infection. At 5Years Follow-up monitoring, NT and Bz-T presented no changes in anti-EVI IgG1 reactivity. However, significant differences were detected in the genotype-specific IgG1 reactivity for Bz-T. The most outstanding shift comprised the anti-amastigote TcVI/(AVI), anti-amastigote TcII/(AII) and anti-epimastigote TcVI/(EVI) reactivities. Regardless no changes in the genotype-specific serology of NT (TcI = 6%; TcII = 94%), distinct T. cruzi genotype-specific sero-classification was detected for Bz-T samples at 5Years Follow-up (TcII = 100%) as compared to Baseline (TcII = 97%; TcVI = 3%). The anti-trypomastigote TcI/(TI) was the attribute accountable for the change in genotype-specific sero-classification. In conclusion, our findings of dissimilar T. cruzi genotype-specific serology upon Bz-treatment re-emphasize the relevance of accomplishing the genotype-specific serodiagnosis during clinical pos-therapeutic management of chronic Chagas disease patients.
Assuntos
Anticorpos Antiprotozoários , Doença de Chagas , Genótipo , Imunoglobulina G , Nitroimidazóis , Tripanossomicidas , Trypanosoma cruzi , Humanos , Doença de Chagas/tratamento farmacológico , Doença de Chagas/parasitologia , Nitroimidazóis/uso terapêutico , Trypanosoma cruzi/genética , Trypanosoma cruzi/imunologia , Imunoglobulina G/sangue , Anticorpos Antiprotozoários/sangue , Masculino , Feminino , Pessoa de Meia-Idade , Adulto , Tripanossomicidas/uso terapêutico , Testes Sorológicos , Doença Crônica , Idoso , Adulto JovemRESUMO
BACKGROUND: PPE 59, which is absent from bacillus Calmette Guérin (BCG) strains, seems to induce a humoral immune response in patients with tuberculosis (TB). Additional studies are needed to better evaluate this protein in immune response to tuberculosis. OBJECTIVES: To evaluate the response of antibodies to PPE59 in TB individuals, its combination with IgG response to other, previously tested mycobacterial antigens (Ag) and with sputum smear microbiology (SM) results. METHODS: We have cloned and expressed the rv3429 gene that encodes PPE59, then IgG, IgM, and IgA against PPE59 antigens measured by enzyme-linked immunosorbent assay (ELISA) in 212 sera samples obtained from the following subject cohorts: TB residents from Italy (79) and in Brazil (52); and an all-Brazilian cohort of 55 patients with other respiratory disorders; 10 patients infected with non-tuberculous mycobacteria, and 16 asymptomatic subjects. Drawing on results from a previous study(17) of serum samples from Brazilian subjects tested for IgG by ELISA against mycobacterial antigens ESAT-6, 16kDa, MT10.3, MPT-64 and 38kDa, the results were analysed in combination with those of the PPE59 and SM tests. FINDINGS: Keeping the specificity rate at 97%, the overall PPE59 IgA sensitivity was 42.7%, while IgG and IgM showed lower performance (p < 0.0001). Combining PPE59 IgA/16kDa IgG results increased sensitivity to 71%, and even higher rates when the results were combined with SM results (86.5%, p = 0.001), at 88.9% specificity. Positive IgA was associated with pulmonary image alterations of high TB probability (p < 0.05). MAIN CONCLUSIONS: Tests with TB patients found a moderate frequency of positivity for PPE59 IgA. However, the higher level of sensitivity attained in combination with PPE59 IgA/16kDa IgG/SM results unheard of before, although imperfect, suggests that this may be a potential additional tool for rapid detection of TB in low-resource areas.
Assuntos
Anticorpos Antibacterianos , Antígenos de Bactérias , Biomarcadores , Ensaio de Imunoadsorção Enzimática , Imunoglobulina A , Imunoglobulina G , Imunoglobulina M , Humanos , Anticorpos Antibacterianos/sangue , Antígenos de Bactérias/imunologia , Imunoglobulina G/sangue , Imunoglobulina M/sangue , Masculino , Feminino , Biomarcadores/sangue , Adulto , Imunoglobulina A/sangue , Sensibilidade e Especificidade , Pessoa de Meia-Idade , Mycobacterium tuberculosis/imunologia , Tuberculose/diagnóstico , Tuberculose/imunologia , Tuberculose/sangue , Adulto Jovem , Tuberculose Pulmonar/diagnóstico , Tuberculose Pulmonar/imunologia , Tuberculose Pulmonar/sangue , Escarro/microbiologia , Brasil , Proteínas de Bactérias/imunologia , Idoso , Adolescente , Estudos de CoortesRESUMO
To achieve global herd immunity, widespread vaccination is the most effective strategy. Vaccines stimulate the immune system, generating cytokines and chemokines, isotype antibodies, and neutralizing antibodies; all these molecules collectively provide a more comprehensive characterization of the immune response post-vaccination. We conducted a longitudinal study in northwestern Mexico, involving 120 individuals before vaccination and after the first dose of the SARS-CoV-2 vaccine, and 46 individuals after their second dose. Our findings reveal that antibody levels stabilize over time; cytokine levels generally increase following the first dose but decrease after the second dose and higher than normal levels in IgG1 and IgG3 concentrations are present. Most of the innate cytokines determined in this study were higher after the first dose of the vaccine. Regardless of previous infection history, this finding suggests that the first dose of the vaccine is crucial and may stimulate immunity by enhancing the innate immune response. Conversely, increased levels of IL-4, indicative of a Th2 response, were found in individuals without prior exposure to the virus and in those vaccinated with CoronaVac. These results suggest that the immune response to COVID-19 vaccines is multi-faceted, with preexisting immunity potentiating a more robust innate response. Vaccine type plays a critical role, with genetic vaccines favoring a Th1 response and inactivated vaccines like CoronaVac skewing toward a Th2 profile.
Assuntos
Anticorpos Neutralizantes , Anticorpos Antivirais , Vacina BNT162 , Vacinas contra COVID-19 , COVID-19 , ChAdOx1 nCoV-19 , Citocinas , SARS-CoV-2 , Humanos , COVID-19/imunologia , COVID-19/prevenção & controle , Anticorpos Antivirais/sangue , Anticorpos Antivirais/imunologia , Masculino , Vacinas contra COVID-19/imunologia , Vacinas contra COVID-19/administração & dosagem , Citocinas/imunologia , Feminino , Adulto , Pessoa de Meia-Idade , Anticorpos Neutralizantes/sangue , Anticorpos Neutralizantes/imunologia , Vacina BNT162/imunologia , Vacina BNT162/administração & dosagem , México , Estudos Longitudinais , ChAdOx1 nCoV-19/imunologia , ChAdOx1 nCoV-19/administração & dosagem , SARS-CoV-2/imunologia , Células Th2/imunologia , Células Th1/imunologia , Imunoglobulina G/sangue , Vacinação , Vacinas de Produtos Inativados/imunologia , Vacinas de Produtos Inativados/administração & dosagem , Adulto Jovem , IdosoRESUMO
BACKGROUND: The immunological response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and immunisation is variable. OBJECTIVES: To describe the humoral immune response by correlating IgA and IgG antibodies with NAbs titration following CoronaVac® immunisation and an mRNA (Comirnaty®) booster among healthcare workers (HCWs) and to compare the cytokine and interleukin profiles between HCWs vaccinated with CoronaVac and coronavirus disease 2019 (COVID-19) infected patients. METHODS: Samples from 133 HCWs collected at 20 (T1) and 90 (T2) days after CoronaVac immunisation and 15 (T3) days after a booster dose with the Comirnaty vaccine were analysed for IgA and IgG EIA and neutralisation assay. Cytokine levels from vaccinated individuals at T1 day and COVID-19 patients were compared. FINDINGS: Neutralising antibodies (NAbs) were observed in 81.7% of participants at T1, but only 49.2% maintained detectable NAbs after 90 days. The booster dose increased NAbs response in all participants. The cytokines with the highest levels post-vaccination were IL-6 and MCP-1. The MCP-1, IL-18, and IFN- γ levels were higher in COVID-19 patients than in vaccinated HCWs, while IL-22 levels increased in the vaccinated HCWs group. MAIN CONCLUSIONS: The neutralisation titres in the T2 samples decreased, and antibody levels detected at T2 showed a more significant reduction than the neutralisation. The higher IL-22 expression in immunised individuals compared to those with COVID-19 suggests that IL-22 may be beneficial in protecting against severe disease.
Assuntos
Anticorpos Neutralizantes , Anticorpos Antivirais , Vacinas contra COVID-19 , COVID-19 , Citocinas , Pessoal de Saúde , Imunização Secundária , Imunoglobulina G , SARS-CoV-2 , Humanos , COVID-19/imunologia , COVID-19/prevenção & controle , Masculino , Feminino , Anticorpos Antivirais/sangue , Adulto , Anticorpos Neutralizantes/sangue , Anticorpos Neutralizantes/imunologia , SARS-CoV-2/imunologia , Vacinas contra COVID-19/imunologia , Vacinas contra COVID-19/administração & dosagem , Imunoglobulina G/sangue , Imunoglobulina G/imunologia , Pessoa de Meia-Idade , Citocinas/imunologia , Citocinas/sangue , Imunoglobulina A/sangue , Imunoglobulina A/imunologia , Imunoglobulina A/análise , Vacinação , Adulto Jovem , Imunidade Humoral/imunologia , Vacinas de Produtos InativadosRESUMO
SARS-CoV-2 caused the pandemic situation experienced since the beginning of 2020, and many countries faced the rapid spread and severe form of the disease. Mechanisms of interaction between the virus and the host were observed during acute phase, but few data are available when related to immunity dynamics in convalescents. We conducted a longitudinal study, with 51 healthy donors and 62 COVID-19 convalescent patients, which these had a 2-month follow-up after symptoms recovery. Venous blood sample was obtained from all participants to measure blood count, subpopulations of monocytes, lymphocytes, natural killer cells and dendritic cells. Serum was used to measure cytokines, chemokines, growth factors, anti-N IgG and anti-S IgG/IgM antibodies. Statistic was performed by Kruskal-Wallis test, and linear regression with days post symptoms and antibody titers. All analysis had confidence interval of 95%. Less than 35% of convalescents were anti-S IgM+, while more than 80% were IgG+ in D30. Anti-N IgG decreased along time, with loss of seroreactivity of 13%. Eosinophil count played a distinct role on both antibodies during all study, and the convalescence was orchestrated by higher neutrophil-to-lymphocyte ratio and IL-15, but initial stages were marked by increase in myeloid DCs, B1 lymphocytes, inflammatory and patrolling monocytes, G-CSF and IL-2. Later convalescence seemed to change to cytotoxicity mediated by T lymphocytes, plasmacytoid DCs, VEGF, IL-9 and CXCL10. Anti-S IgG antibodies showed the longest perseverance and may be a better option for diagnosis. The inflammatory pattern is yet present on initial stage of convalescence, but quickly shifts to a reparative dynamic. Meanwhile eosinophils seem to play a role on anti-N levels in convalescence, although may not be the major causative agent. We must highlight the importance of immunological markers on acute clinical outcomes, but their comprehension to potentialize adaptive system must be explored to improve immunizations and further preventive policies.
Assuntos
Anticorpos Antivirais , COVID-19 , Convalescença , Citocinas , Imunoglobulina G , SARS-CoV-2 , Humanos , COVID-19/imunologia , COVID-19/sangue , Masculino , Feminino , Adulto , Pessoa de Meia-Idade , SARS-CoV-2/imunologia , Imunoglobulina G/sangue , Imunoglobulina G/imunologia , Anticorpos Antivirais/sangue , Anticorpos Antivirais/imunologia , Citocinas/sangue , Imunoglobulina M/sangue , Imunoglobulina M/imunologia , Estudos Longitudinais , Idoso , Eosinófilos/imunologia , Eosinófilos/metabolismoRESUMO
Sporotrichosis diagnosis involves a series of analyses, including culture and antibody detection in serum samples. Serologic methods may sometimes yield false-negative or false-positive results, leading to inaccurate diagnoses. This study assessed specific patient groups in which antibody detection of different isotypes and subclasses may lack sensitivity. An enzyme-linked immunosorbent assay (ELISA) with Sporothrix brasiliensis exoantigens was used to investigate IgM, IgG, IgG1, IgG2, IgG3, IgG4, IgA, IgA1 and IgA2 antibodies in human serum samples. Eighty serum samples from patients with different sporotrichosis clinical manifestations, including cutaneous forms with and without hypersensitivity manifestations, extracutaneous forms (bone, ocular, meningeal and pulmonary), disseminated cutaneous forms and disseminated forms in individuals living with HIV/AIDS, diabetics and alcoholics, were evaluated. The ELISA sensitivities in the detection of different antibodies ranged from 0.85 to 0.60 for the detection of IgG2 and IgG3, respectively. The antibodies with higher area under ROC curves were IgG2, IgG, IgA and IgA1. There were no significant differences in the immunological reactivity of the tested antibodies among different clinical forms of sporotrichosis. The data revealed a higher likelihood of a false-negative outcome in patients with lesions in the nasal mucosa regarding the detection of IgM and a lower likelihood in patients with lymphocutaneous sporotrichosis regarding the detection of IgG3. Patients with hypersensitivity manifestations had a 3.71 odds ratio to yield negative results in total IgG detection. In conclusion, we identified specific patient groups in which antibody detection may lack sensitivity, thus contributing to a better understanding of the diagnostic challenges associated with this condition.
Assuntos
Anticorpos Antifúngicos , Ensaio de Imunoadsorção Enzimática , Sensibilidade e Especificidade , Sporothrix , Esporotricose , Humanos , Esporotricose/imunologia , Esporotricose/diagnóstico , Anticorpos Antifúngicos/sangue , Sporothrix/imunologia , Sporothrix/classificação , Masculino , Feminino , Adulto , Pessoa de Meia-Idade , Isotipos de Imunoglobulinas/sangue , Isotipos de Imunoglobulinas/imunologia , Imunoglobulina G/sangue , Idoso , Adulto Jovem , Antígenos de Fungos/imunologia , Antígenos de Fungos/sangue , Imunoglobulina A/sangue , Imunoglobulina M/sangueRESUMO
The Advisory Committee on Immunization Practices (ACIP) recommended that dengue pre-vaccination screening tests for Dengvaxia administration have at least 98% specificity and 75% sensitivity. This study evaluates the performance of commercial anti-DENV IgG tests to identify tests that could be used for pre-vaccination screening. First, for seven tests, we evaluated sensitivity and specificity in early convalescent dengue virus (DENV) infection, using 44 samples collected 7-30 days after symptom onset and confirmed by RT-PCR. Next, for the five best-performing tests and two additional tests (with and without an external test reader) that became available later, we evaluated performance to detect past dengue infection among a panel of 44 specimens collected in 2018-2019 from healthy 9- to 16-year-old children from Puerto Rico. Finally, a full-scale evaluation was done with the four best-performing tests using 400 specimens from the same population. We used virus focus reduction neutralization test and an in-house DENV IgG ELISA as reference standards. Of seven tests, five showed ≥75% sensitivity in detecting anti-DENV IgG in early convalescent specimens with low cross-reactivity to the Zika virus. For the detection of previous DENV infections, the tests with the highest performance were the Euroimmun NS1 IgG ELISA (sensitivity 84.5%, specificity 97.1%) and CTK Dengue IgG rapid test R0065C with the test reader (sensitivity 76.2% specificity 98.1%). There are IgG tests available that can be used to accurately classify individuals with previous DENV infection as eligible for dengue vaccination to support safe vaccine implementation. IMPORTANCE: The Advisory Committee on Immunization Practices (ACIP) has set forth recommendations that dengue pre-vaccination screening tests must exhibit at least 98% specificity and 75% sensitivity. Our research rigorously assesses the performance of various commercial tests against these benchmarks using well-characterized specimens from Puerto Rico. The findings from our study are particularly relevant given FDA approval and ACIP recommendation of Sanofi Pasteur's Dengvaxia vaccine, highlighting the need for accurate pre-vaccination screening tools.
Assuntos
Anticorpos Antivirais , Vacinas contra Dengue , Vírus da Dengue , Dengue , Imunoglobulina G , Sensibilidade e Especificidade , Humanos , Dengue/diagnóstico , Dengue/prevenção & controle , Dengue/imunologia , Imunoglobulina G/sangue , Vírus da Dengue/imunologia , Criança , Anticorpos Antivirais/sangue , Adolescente , Vacinas contra Dengue/imunologia , Porto Rico , Ensaio de Imunoadsorção Enzimática/métodos , Masculino , Feminino , Vacinação , Testes de Neutralização/métodosRESUMO
Humoral response to SARS-CoV-2 has been studied, predominantly the classical IgG and its subclasses. Although IgE antibodies are typically specific to allergens or parasites, a few reports describe their production in response to SARS-CoV-2 and other viruses. Here, we investigated IgE specific to receptor binding domain (RBD) of SARS-CoV-2 in a Brazilian cohort following natural infection and vaccination. Samples from 59 volunteers were assessed after infection (COVID-19), primary immunization with vectored (ChAdOx1) or inactivated (CoronaVac) vaccines, and booster immunization with mRNA (BNT162b2) vaccine. Natural COVID-19 induced IgE, but vaccination increased its levels. Subjects vaccinated with two doses of ChAdOx1 exhibited a more robust response than those immunized with two doses of CoronaVac; however, after boosting with BNT162b2, all groups presented similar IgE levels. IgE showed intermediate-to-high avidity, especially after the booster vaccine. We also found IgG4 antibodies, mainly after the booster, and they moderately correlated with IgE. ELISA results were confirmed by control assays, using IgG depletion by protein G and lack of reactivity with heterologous antigen. In our cohort, no clinical data could be associated with the IgE response. We advocate for further research on IgE and its role in viral immunity, extending beyond allergies and parasitic infections.