Clinical Evaluation of Serum Levels of SARS-CoV-2 Anti-Spike Protein IgG Antibodies in Infected Patients and Vaccinated Subjects.

BACKGROUND: The aim was clinical evaluation of immune response against SARS-CoV-2, analyzing serum levels of IgG antibodies against the SARS-CoV-2 protein S in infected and vaccinated patients, as well as in subjects with and without frequent comorbidities (arterial hypertension, diabetes mellitus, heart disease, and chronic respiratory disease). METHODS: Patients infected by SARS-CoV-2 confirmed by RT-PCR and subjects vaccinated with vaccines based on the mRNA encoding the SARS-CoV-2 protein S were studied. SARS-CoV-2 anti-S IgG serum levels were quantified by chemiluminescent microparticle immunoassay. RESULTS: There were 79 infected patients with a median age of 53.0 years; 35 women and 44 men; 42 patients with any comorbidities and 37 without comorbidities. The median of SARS-CoV-2 anti-S IgG serum level was 203.4 BAU/mL (11.6 - 5,620.6). The median antibody level in the infected patients with any comorbidities was higher than those without comorbidities. The group of vaccinated subjects included 96 subjects with a median age of 49.5 years; 77 women and 19 men; 31 subjects with any comorbidities and 65 without comorbidities. The median of SARS-CoV-2 anti-S IgG serum levels was 1,145.6 BAU/mL (138.3 - 4,828.1). No significant differences were found in terms of specific or global comorbidities in the vaccinated subjects. CONCLUSIONS: SARS-CoV-2 anti-S IgG serum levels were 5.6 times higher in vaccinated subjects than infected patients. The vaccination produces higher serum antibody levels than SARS-CoV-2 infection. This reinforces the indication for the vaccine in infected patients. These antibodies did not decrease significantly in patients with frequent comorbidities such as hypertension, diabetes, heart disease or chronic respiratory disease.

Utilidad del estudio de la actividad antibiótica por bioensayo en el manejo de los derrames pleurales / Usefulness of the measurement of antibiotic activity by bioassay in the management of pleural effusions

Objetivo. El objetivo de este estudio fue determinar la presencia de actividad antibiótica en las muestras de líquido pleural remitidas para estudio y valorar su posible influencia en el manejo clínico de los pacientes. Material y métodos. Estudio observacional y prospectivo que incluyó 81 muestras de líquidos pleurales remitidas al Servicio de Bioquímica del Hospital Universitario de Valme. El estudio de la actividad antibiótica se realizó por bioensayo con base en las recomendaciones del proyecto Pneumonia Etiology Research for Child Health. A todas las muestras se les realizó estudio bioquímico, citológico y bacteriológico con base en técnicas convencionales. Adicionalmente, el uso previo de antibióticos fue evaluado a partir de lo registrado en la historia clínica. Resultados. De los 81 líquidos estudiados, en 26 (32,1%) se constató uso previo de antibióticos a la toma de la muestra según lo registrado en la historia clínica y en 23 (28,4%) existía actividad antibiótica por bioensayo. La actividad antibiótica fue detectada en 15 (62,5%) de los exudados y en 8 (19%) de los trasudados, con una mediana de halos de inhibición de 17mm (rango: 11-22mm). Los 23 líquidos en los que se detectó actividad antibiótica dieron todos cultivo negativo. Conclusiones. Los resultados de este estudio demuestran un alto porcentaje de uso de antibióticos previo al cultivo (32,1%). La evaluación de la actividad antibacteriana del líquido pleural mediante bioensayo paralelamente al cultivo podría ayudar a enfocar el tratamiento y, con base en los parámetros bioquímicos y citológicos, su adecuación (AU)

Objective. The aim of this study was to determine the presence of antibiotic activity in the pleural fluid samples submitted to the laboratory for study, and to assess its possible influence on the clinical management of patients. Material and methods. An observational and prognostic study that included 81 samples of pleural fluid sent to the Biochemistry Department of Valme University Hospital, Seville, Spain. The study of antibiotic activity was performed by bioassay based on the recommendations of the Pneumonia Aetiology Research for Child Health project. All samples were subjected to a biochemical, cytological, and bacteriological study based on conventional techniques. In addition, previous use of antibiotics was evaluated based on what was recorded in the medical records. Results. Based on the medical records, it was observed that 26 (32.1%) of the 81 fluids studied had previous use of antibiotics, with 23 (28.4%) showing antibiotic activity by bioassay. Antibiotic activity was detected in 15 (62.5%) of the exudates and in 8 (19%) of the transudates, with a median inhibition zone of 17mm (range: 11-22mm). In the 23 fluids in which antibiotic activity was detected, all had negative cultures. Conclusions. The results of this study demonstrate a high percentage of previous use of antibiotics prior to culture (32.1%). The evaluation of the antibacterial activity by bioassay in the pleural fluid parallel to bacteriological culture could help in the treatment approach, using the biochemical and cytological parameters to assess its suitability (AU)