Seroprevalencia del SARS-CoV-2 en los pacientes con enfermedades inmunomediadas en tratamiento con terapias biológicas y sintéticos dirigidos / Seroprevalence of SARS-CoV-2 antibodies in patients with immune-mediated inflammatory diseases treated with biological and synthetic targeted therapies

INTRODUCCIÓN: La seroprevalencia del SARS-CoV-2 en las enfermedades inflamatorias inmunomediadas (IMID) sigue siendo fuente de controversia. OBJETIVO: Comparar la seroprevalencia de anticuerpos (Ac) anti SARS-CoV-2 en pacientes con IMID en tratamientos con fármacos antirreumáticos modificadores de la enfermedad biológicos (FAMEb) o sintéticos dirigidos (FAMEsd) frente a un grupo de personas sin IMID. MÉTODOS: Estudio de pacientes con IMID y tratamientos con FAMEb y FAMEsd y de individuos sin IMID. Mediante la técnica de inmunoensayo por quimioluminiscencia indirecta, se determinaron las serologías IgG frente al SARS-CoV-2 entre octubre/2020 y mayo/2021. RESULTADOS: Se estudiaron 1.100 sujetos, 550 pacientes con IMID y 550 personas sin IMID. Se observó una seroprevalencia de 16% (88/550) en los pacientes frente a 19,3% (106/550) en el grupo de personas sin IMID, sin significación estadística (OR 0,790 [IC 95% 0,558-1,118]). Comparando los tratamientos con FAMEb o FAMEsd, se observó una tendencia a una menor seroprevalencia con rituximab, en relación con los individuos sin IMID (OR 0,296 [IC 95% 0,0871,007]). Asimismo, se encontró menor seroprevalencia en los pacientes que además de su FAMEb recibían tratamiento con metotrexato, en comparación con el grupo de personas sin IMID (OR 0,432 [IC 95% 0,223-0,835]). CONCLUSIONES: Las IMID en tratamiento con FAMEb o FAMEsd no influyen en la seroprevalencia frente al SARS-CoV-2 de los pacientes. El tratamiento concomitante con metotrexato disminuye de forma significativa la seroprevalencia en estos pacientes.

BACKGROUND: The seroprevalence of SARS-CoV-2 in immunemediated inflammatory diseases (IMID) remains controversial. AIM: To compare the seroprevalence of antibodies (Ab) to SARS-CoV-2 in patients with IMID receiving treatment with biological diseasemodifying antirheumatic drugs (bDMARD) or targeted synthetic (tsDMARD) versus a group of people without IMID. METHODS: Study of patients with IMID and treatments with bDMARD and tsDMARD and individuals without IMID. IgG serology against SARS-CoV-2 was measured using the two-step sandwich immunoassay technique by indirect chemiluminescence between October 2020 and May 2021. RESULTS: A total of 1100 subjects were studied, 550 patients with IMID and 550 persons without IMID. A seroprevalence of 16% (88/550) was observed in patients versus 19.3% (106/550) in the group of people without IMID, without statistical significance (OR 0.790 [95% CI 0.558-1.118]). Comparing the treatments with bD- MARD or tsDMARD, there was a tendency to lower seroprevalence with rituximab, in relation to individuals without IMID (OR 0.296 [95% CI 0.087-1.007]). In addition, lower seroprevalence was found in patients who received methotrexate treatment in addition to their bDMARD, compared to the group of individuals without IMID (OR 0.432 [95% CI 0.223-0.835]). CONCLUSIONS: IMIDs in treatment with bDMARDs or tsDMARDs do not influence the seroprevalence against SARS-CoV-2 in patients. Concomitant treatment with methotrexate significantly decreased seroprevalence in these patients.

COVID-19 Serological Study in Non-infected Vaccinated Subjects: Differences among Age, Sex, and Vaccine Brand.

OBJECTIVE: To evaluate IgG antibody levels against SARS-CoV-2 in non-infected vaccinated subjects among vaccine brand, sex, and age. METHODS: Abbott's AdviseDx SARS-CoV-2 IgG II immunoassay was used to measure IgG levels within 6-9 months after the second dose vaccination; level >50 AU/mL was classified as a positive test. RESULTS: Data of 183 non-infected vaccinated subjects was analyzed according to the vaccine brand, time after second vaccination, sex, and age. Bivariate analysis showed that receiving the Moderna brand vaccine, being female, and younger were associated with higher antibody levels, p<.001. Conversely, no differences were observed between the IgG antibody levels against SARS-CoV-2 and time after second vaccination (6-7 months as compared to 8-9 months), p=.49. CONCLUSION: After six to nine months post-vaccination, receiving the Moderna vaccine, being female, and being younger were significantly associated to higher IgG antibody levels to SARS-CoV-2 in non-infected vaccinated subjects.

A higher number of SARS-COV-2 infections in quilombola communities than in the local population in Brazil.

The historical and social vulnerability of quilombola communities in Brazil can make them especially fragile in the face of COVID-19, considering that several individuals have precarious health systems and inadequate access to water. This work aimed to characterize the frequency of SARS-COV-2 infections and the presence of IgM and IgG SARS-CoV-2 antibodies in quilombola populations and their relationship with the presence of risk factors or preexisting chronic diseases in the quilombola communities. We analyzed the sociodemographic and clinical characteristics, serological status, comorbidities, and symptoms of 1,994 individuals (478 males and 1,536 females) from 18 Brazilian municipalities in the State of Sergipe of quilombola communities, which were evaluated at different epidemiological weeks, starting at the 32nd (August 6th) and ending at the 40th (October 3rd) epidemiological week. More than 70% of studied families live in rural areas and they have an extreme poverty social status. Although we found a higher number of SARS-COV-2 infections in quilombola communities than in the local population, their SARS-CoV-2 reactivity and IgM and IgG positivity varied across the communities investigated. Arterial hypertension was the most risk factor, being found in 27.8% of the individuals (9.5% in stage 1, 10.8% in stage 2, and 7.5% in stage 3). The most common COVID-19 symptoms and comorbidities were headache, runny nose, flu, and dyslipidemia. However, most individuals were asymptomatic (79.9%). Our data indicate that mass testing must be incorporated into public policy to improve the health care system available to quilombola populations during a future pandemic or epidemic.

Clinical risk factors for predicting anti-Sars-Cov-2 antibody immunoreactivity duration after mild COVID-19 infection / Fatores de risco clínicos para predizer a duração da imunoresatividade do anticorpo anti-Sars-Cov-2 após infecção leve por COVID-19

Introduction: coronavirus disease 2019 (COVID-19) is a complex multisystem disorder. It is not yet well known whether symptoms in the acute phase correlate with the duration of the immune response and the persistence of chronic symptoms.Objective: this study aimed to assess and monitor the clinical symptoms of COVID-19 and correlate them with the production of neutralizing antibodies.Methods: a cohort of 69 health workers at the University Hospital of the Federal University of Espírito Santo (HUCAM-UFES/EBSERH) diagnosed with SARS-CoV-2 infection confirmed via RT-PCR (Real-Time Reverse Transcription­Polymerase Chain Reaction) were evaluated from the onset of symptoms up to six months. SARS-CoV-2 IgG and IgM assays were used to detect the presence of IgG and IgM against the nucleocapsid protein of SARS-CoV-2 in serum samples. IgG and IgM antibody serology, pulmonary function via spirometry, and the clinical evolution of patients were performed at 15, 30, 45, 60, 90, and 180 days after the onset of COVID-19 symptoms.Results: sixty-nine health workers (age, 40 ± 10 years; 74% women) were evaluated for six months. All subjects showed mild to moderate COVID-19. The mean number of symptoms was 5.1 (± 2.3). The most common initial symptoms were muscle pain (77%), headache (75%), anosmia (70%), ageusia (64%), runny nose (59%), fever (52%), and coughing (52%). After 30 days, the patients had anosmia (18%), asthenia (18%), adynamia (14%), muscle pain (7%), and ageusia (7%). Regarding lung function, 9.25% presented with an obstructive pattern, and all recovered after six months. Of all analyzed participants, 18/69 (26%) did not have any reactive IgG or IgM values in any of the assessments. The IgG serology curve showed a peak, whereas IgM had the highest mean value on the 15th day. There was a progressive decrease and levels similar to those at baseline after 90 days, and 15/53 (28%) remained with reactive IgG after six months. Sore throat and shortness of breath were found to be independent risk factors, and patients with these symptoms were 5.9 times more likely to have reactive IgG on the 180th day. Patients with diarrhea were four times more likely to have reactive IgM.Conclusion: our findings showed that 26% of patients did not produce a humoral response post-mild COVID-19. Their antibody titers dropped significantly after 90 days, and only 28% maintained reactive IgG antibodies after six months. Sore throat and shortness of breath are predictors of a longer duration of the humoral immune response.

Introdução: a doença causada pelo coronavírus (COVID-19) é complexa e multissistêmica. Ainda não se sabe se os sintomas da fase aguda estão correlacionados com a duração da resposta imune e com a persistência dos sintomas crônicos.Objetivo: o presente estudo visa acessar e monitorar os sintomas clínicos do COVID-19, correlacionando-os com a produção de anticorpos neutralizantes.Método: uma coorte de 69 profissionais da saúde da Universidade Federal do Espírito Santo (HUCAM-UFES/EBSERH) diagnosticados com infecção por SARS-CoV-2 confirmada via RT-PCR (Real-Time Reverse Transcription-Polymerase Chain Reaction) foram avaliados do início dos sintomas até seis meses depois. Exames laboratoriais de IgG e IgM foram utilizados para detectar a presença de IgG e IgM contra a proteína do nucleocapsídeo do vírus SARS-CoV-2 nas amostras de plasma sanguíneo. Sorologia de anticorpos IgG e IgM, função pulmonar via espirometria e avaliação clínica dos pacientes foram realizadas nos dias 15, 30, 45, 60, 90 e 180 após o início dos sintomas da doença.Resultados: sessenta e nove profissionais da saúde (idade, 40 ± 10 anos; 74% mulheres) foram avaliados por seis meses. Todos apresentaram a forma leve a moderada do COVID-19. O número médio de sintomas foi 5.1 (± 2.3). O sintoma inicial mais comum foi dor muscular (77%), cefaleia (75%), anosmia (70%), ageusia (64%), coriza (59%), febre (52%), e tosse (52%). Após 30 dias, os pacientes mantiveram anosmia (18%), astenia (18%), adinamia (14%), dor muscular (7%), e ageusia (7%). Em relação à função pulmonar, 9.25% apresentaram padrão obstrutivo e todos recuperaram ao final dos seis meses. Dentre todos os participantes analisados, 18/69 (26%) não obtiveram nenhum valor de IgG e IgM considerados reagentes nos exames realizados. A curva sorológica de IgG mostrou um pico enquanto a de IgM apresentou seu maior valor médio no 15º dia. Houve um declínio progressivo e níveis similares aos basais aos 90. 15/53 (28%) permaneceram com IgG reagente após seis meses. Dor de garganta e dispneia foram considerados fatores de risco independentes, e os pacientes com esses sintomas tiveram 5,9 vezes mais chances de apresentar IgG reativa no 180º dia. Pacientes com diarreia tiveram quatro vezes mais chances de apresentar IgM reagente.Conclusão: nossos achados mostraram que 26% dos pacientes não produziram uma resposta humoral pós-COVID-19 leve. Seus títulos de anticorpos caíram significativamente após 90 dias e apenas 28% mantiveram anticorpos IgG reativos após seis meses. Dor de garganta e dispneia foram preditores de maior duração da resposta imune humoral

Cross-sectional analysis of students and school workers reveals a high number of asymptomatic SARS-CoV-2 infections during school reopening in Brazilian cities.

Brazil experienced one of the most prolonged periods of school closures, and reopening could have exposed students to high rates of SARS-CoV-2 infection. However, the infection status of students and school workers at the time of the reopening of schools located in Brazilian cities is unknown. Here we evaluated viral carriage by RT-PCR and seroprevalence of anti-SARS-CoV-2 antibodies (IgM and IgG) by immunochromatography in 2259 individuals (1139 students and 1120 school workers) from 28 schools in 28 Brazilian cities. We collected the samples within 30 days after public schools reopened and before the start of vaccination campaigns. Most students (n = 421) and school workers (n = 446) had active (qRT-PCR + IgM- IgG- or qRT-PCR + IgM + IgG-/+) SARS-CoV-2 infection. Regression analysis indicated a strong association between the infection status of students and school workers. Furthermore, while 45% (n = 515) of the students and 37% (n = 415) of the school workers were neither antigen nor antibody positive in laboratory tests, 16% of the participants (169 students and 193 school workers) were oligosymptomatic, including those reinfected. These individuals presented mild symptoms such as headache, sore throat, and cough. Notably, most of the individuals were asymptomatic (83.9%). These results indicate that many SARS-CoV-2 infections in Brazilian cities during school reopening were asymptomatic. Thus, our study highlights the need to promote a coordinated public health effort to guarantee a safe educational environment while avoiding exacerbating pre-existent social inequalities in Brazil, reducing social, mental, and economic losses for students, school workers, and their families.

Cord Blood SARS-CoV-2 IgG Antibodies and Their Association With Maternal Immunity and Neonatal Outcomes.

Passive transplacental immunity is crucial for neonatal protection from infections. Data on the correlation between neonatal immunity to SARS-CoV-2 and protection from adverse outcomes is scarce. This work aimed to describe neonatal seropositivity in the context of maternal SARS-CoV-2 infection, seropositivity, and neonatal outcomes. This retrospective nested case-control study enrolled high-risk pregnant women with a SARS-CoV-2 RT-PCR positive test who gave birth at the Instituto Nacional de Perinatología in Mexico City and their term neonates. Anti-SARS-CoV-2 IgG antibodies in maternal and cord blood samples were detected using a chemiluminescent assay. In total, 63 mother-neonate dyads (mean gestational age 38.4 weeks) were included. Transplacental transfer of SARS-CoV-2 IgG occurred in 76% of neonates from seropositive mothers. A positive association between maternal IgG levels and Cycle threshold (Ct) values of RT-qPCR test for SARS-CoV-2 with neonatal IgG levels was observed. Regarding neonatal outcomes, most seropositive neonates did not require any mechanical ventilation, and none developed any respiratory morbidity (either in the COVID-19 positive or negative groups) compared to 7 seronegative neonates. Furthermore, the odds of neonatal respiratory morbidity exhibited a tendency to decrease when neonatal IgG levels increase. These results add further evidence suggesting passive IgG transfer importance.

Immunoassay platform with surface-enhanced resonance Raman scattering for detecting trace levels of SARS-CoV-2 spike protein.

The early diagnosis of Coronavirus disease (COVID-19) requires either an accurate detection of genetic material or a sensitive detection of viral proteins. In this work, we designed an immunoassay platform for detecting trace levels of SARS-CoV-2 spike (S) protein. It is based on surface-enhanced resonance Raman scattering (SERRS) of methylene blue (MB) adsorbed onto spherical gold nanoparticles (AuNPs) and coated with a 6 nm silica shell. The latter shell in the SERRS nanoprobe prevented aggregation and permitted functionalization with SARS-CoV-2 antibodies. Specificity of the immunoassay was achieved by combining this functionalization with antibody immobilization on the cover slides that served as the platform support. Different concentrations of SARS-CoV-2 antigen could be distinguished and the lack of influence of interferents was confirmed by treating SERRS data with the multidimensional projection technique Sammon's mapping. With SERRS using a laser line at 633 nm, the lowest concentration of spike protein detected was 10 pg/mL, achieving a limit of detection (LOD) of 0.046 ng/mL (0.60 pM). This value is comparable to the lowest concentrations in the plasma of COVID-19 patients at the onset of symptoms, thus indicating that the SERRS immunoassay platform may be employed for early diagnosis.

Evaluación de ensayos ultramicroanalíticos para la detección de anticuerpos contra el SARS-CoV-2 / Evaluation of ultramicroanalytic assays to detect antibodies against SARS-CoV-2

Introducción: En el presente trabajo se muestran los resultados de la validación de los ensayos serológicos in vitro para la detección de anticuerpos IgM, IgG y anticuerpos totales contra el SARS-CoV-2 UMELISA SARS-CoV-2 IgM, UMELISA ANTI-SARS-CoV-2 y UMELISA SARS-CoV-2 IgG desarrollados por el Centro de Inmunoensayo (CIE). Métodos: Se utilizaron paneles de muestras de suero de individuos negativos y de casos confirmados de COVID-19 para determinar el desempeño analítico de cada ensayo. Resultados: La especificidad clínica de los ensayos UMELISA SARS-CoV-2 IgM, UMELISA ANTI-SARS-CoV-2 y UMELISA SARS-CoV-2 IgG fue del 100 por ciento en todos los ensayos y la especificidad analítica fue de 100 por ciento para los dos primeros ensayos y del 93,1 por cientopara el último. La sensibilidad clínica fue de 64,3, 80,8 y 97,5 por ciento, respectivamente. El valor predictivo positivo fue de 100 por ciento en todos los ensayos, en tanto que el negativo osciló entre 83,3 y 95,2 por ciento. La concordancia fluctuó entre 92,4 y 96,9 por ciento y el índice kappa de todos los ensayos fue muy bueno. La sensibilidad de los ensayos se incrementó a 82,76, 96,5 y 100 por ciento, respectivamente, en las muestras de suero colectadas con más de 14 días de iniciado el cuadro clínico. Conclusiones: Los ensayos demostraron una elevada sensibilidad y especificidad, lo que permite contar con herramientas basadas en una tecnología desarrollada en Cuba que posibilita la realización de estudios serológicos, vigilancia epidemiológica y de otro tipo, incluyendo los relacionados con vacunas en una plataforma con amplia distribución nacional(AU)

Introduction: This paper shows the results obtained in the validation of in vitro serological assays to detect IgM, IgG antibodies, and total antibodies against SARS-CoV-2 UMELISA SARS-CoV-2 IgM, UMELISA ANTI-SARS-CoV-2 and UMELISA SARS-CoV-2 IgG developed by the Immunoassay Center. Methods: Panels of serum samples from negative and COVID-19 confirmed patients were used to determine the analytical performance of each assay. Results: UMELISA SARS-CoV-2 IgM, UMELISA ANTI-SARS-CoV-2 and UMELISA SARS-CoV-2 IgG assays demonstrated 100 percent clinical specificity for all assays; and 100 percent analytical specificity for the first two assays, and 93.1 percent for the last one. Clinical sensitivity was 64.3 percent, 80.8 percent and 97.5 percent, respectively. The positive predictive value was 100 percent in all assays, while the negative predictive value ranged from 83.3 percent to 95.2 percent. Concordance varied from 92.4 percent to 96.9 percent, and kappa index in every assay was very good. Assays sensitivity increased to 82.7 percent, 96.5 percent and 100 percent, respectively for serum samples collected more than 14 days after onset of the symptoms. Conclusions: The assays demonstrated high sensitivity and specificity, which allows us to have Cuban technology-based tools for serological, epidemiological surveillance, and other types of studies, including those related to vaccines on a platform with wide national distribution(AU)

SARS-CoV-2 seroprevalence in healthcare workers in a high-volume ophthalmology centre in Guatemala.

PURPOSE: To determine the seroprevalence of SARS-CoV-2 antibodies in eye healthcare workers (EHCW) in the largest ophthalmology centre in Guatemala and factors associated with antibody positivity. METHODS: We conducted a cross sectional sero-survey in all the staff at the largest ophthalmology centre in Guatemala. Serum samples were collected and tested for total antibodies against SARS-CoV-2 employing Roche Elecsys Anti-SARS-CoV-2 Immunoassay. Results were reported as reactive or non-reactive. According to patient exposure the staff were divided into low risk (technicians, domestic and administrative staff) and high risk (nurses, ophthalmologists, anaesthesiologists, and optometrists). Among those with positive antibodies, they were given a survey that included demographic characteristics, COVID-19 exposure, and related symptomatology. Logistic regression was used to determine the factors associated with antibody positivity. RESULTS: On November 25th a total of 94 healthcare workers were sero-surveyed, mean age was 34.15 years (±8.41), most (57.44%) were females. Seroprevalence was 18%, the majority (77%) were in the low-risk group; while 64% at high-risk, tested negative. Those at low exposure, were five times more likely to have antibodies than those at high exposure (OR:5.69; 95% CI 1.69-19.13). Age and gender were not associated to seropositivity. CONCLUSIONS: We found a similar seroprevalence of SARS-CoV-2 antibodies in EHCW to what has been reported in other healthcare groups. Seropositivity was higher among HCW with fewer patient exposure, hence the probability of community transmission.Key messagesEven though eye healthcare workers are believed to be at higher risk of infection, the prevalence of antibodies against SARS-CoV-2 in this group is comparable to what has been reported previously in other healthcare groups.