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

Pulmonary function and exercise capacity six months after hospital discharge of patients with severe COVID-19

ABSTRACT Introduction: The long-term consequences of COVID-19, especially pulmonary impairment, are frequent but not well understood. The knowledge about sequels or long COVID-19 are necessary, considering the high prevalence and need for specific public strategies. Method: The study was conducted to evaluate symptoms (standardized questionnaire), pulmonary function (spirometry), and exercise capacity (6-minute-walk-test) at 30 (D30), 90 (D90), and 180 (D180) days after hospital discharge of patients surviving to severe COVID-19. We excluded in this follow up patients with comorbidities before COVID infection. Results: 44 patients were included and 31 (26 men) completed the 6-month follow-up (age mean 53.6 ± 9.6 years). At D180, 28% presented still at least one symptom. The most common was dyspnea (17.2%), followed by cough (13.8%), and myalgia (10.3%). All spirometric parameters showed progressive improvement from D30 to D180. However, 16% maintained a restrictive pattern on spirometry test, 44% presented desaturation on the 6-minute walk-test, and 25% walked < 75% of the predicted value. Conclusion: 6-months after hospital discharge, reduced pulmonary function and reduced exercise capacity was founded frequently and more than a quarter remained symptomatic. The persistent symptoms and functional impairment suggest that sequels and development of Long COVID-19 are very common. The identification of these patients to provide the necessary health care is a challenging task, considering the large number of patients infected and surviving to COVID-19 disease.

Anti-SARS-CoV-2 antibody immunoreactivity profiles during COVID-19 recurrence

ABSTRACT Background: This study aimed to evaluate IgG and IgM levels in COVID-19 recurrence. Methods: The serum antibody levels and clinical data from 73 healthcare workers with SARS-CoV-2 divided into seroconverted (n=51) and non-seroconverted (n=22) groups were assessed. The presence of specific anti-nucleocapsid (anti-N) IgM and IgG for SARS-CoV-2 was evaluated. IgG antibodies to the SARS-CoV-2 spike receptor-binding domain were used to confirm non-seroconversion in all negative anti-N. Results: Four recurrent cases displayed mild symptoms and were non-seroconverted until the recurrence of symptoms. Conclusions: Undetectable anti-nucleocapsid IgM and IgG levels may be correlated with symptomatic COVID-19 recurrence.