RESUMO
The tragic COVID-19 pandemic, which has seen a total of 655 million cases worldwide and a death toll of over 6.6 million seems finally tailing off. Even so, new variants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) continue to arise, the severity of which cannot be predicted in advance. This is concerning for the maintenance and stability of public health, since immune evasion and increased transmissibility may arise. Therefore, it is crucial to continue monitoring antibody responses to SARS-CoV-2 in the general population. As a complement to polymerase chain reaction tests, multiplex immunoassays are elegant tools that use individual protein or peptide antigens simultaneously to provide a high level of sensitivity and specificity. To further improve these aspects of SARS-CoV-2 antibody detection, as well as accuracy, we have developed an advanced serological peptide-based multiplex assay using antigen-fused peptide epitopes derived from both the spike and the nucleocapsid proteins. The significance of the epitopes selected for antibody detection has been verified by in silico molecular docking simulations between the peptide epitopes and reported SARS-CoV-2 antibodies. Peptides can be more easily and quickly modified and synthesized than full length proteins and can, therefore, be used in a more cost-effective manner. Three different fusion-epitope peptides (FEPs) were synthesized and tested by enzyme-linked immunosorbent assay (ELISA). A total of 145 blood serum samples were used, compromising 110 COVID-19 serum samples from COVID-19 patients and 35 negative control serum samples taken from COVID-19-free individuals before the outbreak. Interestingly, our data demonstrate that the sensitivity, specificity, and accuracy of the results for the FEP antigens are higher than for single peptide epitopes or mixtures of single peptide epitopes. Our FEP concept can be applied to different multiplex immunoassays testing not only for SARS-CoV-2 but also for various other pathogens. A significantly improved peptide-based serological assay may support the development of commercial point-of-care tests, such as lateral-flow-assays.
RESUMO
Isolated congenital anosmia (ICA) is a rare entity worldwide with poorly understood genetic variation. The diagnosis of ICA is made by exclusion of acquired causes of anosmia. Additionally, magnetic resonance imaging in ICA is essential for diagnosis, as it shows reduced or absent development of olfactory bulbs and shallow olfactory sulci. Here, we present the case of a 21-year-old man who presented to our clinic with complete anosmia since birth. The patient's history was negative for acquired causes of anosmia, and the physical examinations of the ears, nose, throat, head, and neck were all not remarkable. Smell testing revealed complete anosmia. The CT imaging was unremarkable; however, magnetic resonance imaging of the anterior brain and olfactory region showed bilaterally absent olfactory bulbs and olfactory tracts, with a shallow olfactory groove. The patient was then subjected to whole exome sequencing. Bioinformatics analysis was performed on the 37 genes associated with olfactory dysfunction, in which a missense variant was identified in the HS6ST1(NM_004807.3) gene was identified, which insilico tools predicted to be likely pathogenic. The results of this patient's genetic analysis add to the possible genetic culprits reported in ICA cases. Additional genetic analyses are required to validate mutations and understand the heterogeneity of disease representation.
