ABSTRACT
BACKGROUND: A prompt set of suitable biomarkers is needed in suspected COVID-19 patients. This study aims to assess patients positive for one or more gene associated with the C reactive protein (CRP) and procalcitonin (PCT) as non-specific pro-inflammatory markers and IgG and IgM kinetic as specific diagnostic and prognostic tools in SARS-CoV-2 RT-PCR positive patients. METHODS: We enrolled 101 patients within a two month time span (March 26, 2020 to May 31, 2020). A reverse transcription-Real-Time PCR assay on nasopharyngeal/oropharyngeal swabs was used for SARS-CoV-2 identification. Serum anti-SARS-COV-2 IgM and IgG were measured by enzyme immunoassay , PCT levels by Enzyme linked fluorescent assay (ELFA)and CRP by nephelometry. RESULTS: We found that older patients were significantly associated with a worse prognosis. Serum IgM levels were significantly lower during the late stage of the disease, regardless of the presence of one or three genes and patients' outcome. On the contrary, IgG levels exhibited a higher concentration in the late phases of the illness, regardless of the gene found or patients' prognosis. With the exception of the very first sample tested, an increase in CRP in surviving patients (both one and three genes) and a time-dependent decrease of deceased patients CRP was found. PCT levels were always within the normal reference range. The difference between one gene and three genes patients was significant during late disease stages regarding IgG levels and also between three genes survivors vs. three genesdeceased , where the IgG levels were progressively increasing over time. CONCLUSIONS: The relevant finding of the present study is the significant and consistent increase of IgG and IgM in deceased patients. The associated evaluation of antibody kinetics and non specific inflammatory markers (CRP and PCT) in positive patients stratified according to the presence of one gene or three genes could help the clinician in both the diagnosis and prognosis of COVID-19 patients.
ABSTRACT
Reverse Transcription Polymerase Chain Reaction (RT-PCR) conducted on nasopharyngeal swabs is the gold standard in the diagnosis of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). In Italy, recent guidelines indicate that rapid antigen tests (RATs) can be used for the isolation of positive patients or for the interruption of quarantine, but they are often less sensitive to detect positive subjects. Indeed, the performance of these RATs depends on the timing and the population on which they are evaluated. Herein, we evaluated the performance of BIOCREDIT COVID-19 Ag and Fluorecare® SARS-CoV-2 Spike Protein Test during a population screening in the Calabria Region, Southern Italy. We report that both antigen test shows low sensitivity in contrast to the high sensitivity declared by manufacturer (90% and 92%, respectively) and that the area under the curve (AUC) was good for Fluorecare® SARS-CoV- 2 Spike Protein Test but very poor for BIOCREDIT COVID-19 Ag. We suggest that these RATs should be re-evaluated in the current pandemic era.
ABSTRACT
In this study, we report on the results of SARS-CoV-2 surveillance performed in an area of Southern Italy for 12 months (from March 2021 to February 2022). To this study, we have sequenced RNA from 609 isolates. We have identified circulating VOCs by Sanger sequencing of the S gene and defined their genotypes by whole-genome NGS sequencing of 157 representative isolates. Our results indicated that B.1 and Alpha were the only circulating lineages in Calabria in March 2021;while Alpha remained the most common variant between April 2021 and May 2021 (90 and 73%, respectively), we observed a concomitant decrease in B.1 cases and appearance of Gamma cases (6 and 21%, respectively);C.36.3 and Delta appeared in June 2021 (6 and 3%, respectively);Delta became dominant in July 2021 while Alpha continued to reduce (46 and 48%, respectively). In August 2021, Delta became the only circulating variant until the end of December 2021. As of January 2022, Omicron emerged and took over Delta (72 and 28%, respectively). No patient carrying Beta, Iota, Mu, or Eta variants was identified in this survey. Among the genomes identified in this study, some were distributed all over Europe (B1_S477N, Alpha_L5F, Delta_T95, Delta_G181V, and Delta_A222V), some were distributed in the majority of Italian regions (B1_S477N, B1_Q675H, Delta_T95I and Delta_A222V), and some were present mainly in Calabria (B1_S477N_T29I, B1_S477N_T29I_E484Q, Alpha_A67S, Alpha_A701S, and Alpha_T724I). Prediction analysis of the effects of mutations on the immune response (i.e., binding to class I MHC and/or recognition of T cells) indicated that T29I in B.1 variant;A701S in Alpha variant;and T19R in Delta variant were predicted to impair binding to class I MHC whereas the mutations A67S identified in Alpha;E484K identified in Gamma;and E156G and ΔF157/R158 identified in Delta were predicted to impair recognition by T cells. In conclusion, we report on the results of SARS-CoV-2 surveillance in Regione Calabria in the period between March 2021 and February 2022, identified variants that were enriched mainly in Calabria, and predicted the effects of identified mutations on host immune response.
ABSTRACT
The purpose of this review is to address some of the latest aspects regarding molecular features, pathogenic mechanisms, and immune system response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), based on recent publications in this field from March 2020 to May 2021. Interpretation keys for periodic re-emergence of coronavirus infections and other lethal viral pandemics are suggested. Antibody-dependent enhancement (ADE) and other potential mechanisms of immune system deception are put forward. Therefore, vaccine development must take into account ADE and other unwanted side effects of immune-based medical intervention. Features reported in our review will allow both clinicians and basic science researchers to take home ideas to improve their knowledge about SARS-CoV-2.