Elevated Nucleoprotein-Induced Interferon-γ Release in COVID-19 Patients Detected in a SARS-CoV-2 Enzyme-Linked Immunosorbent Spot Assay
Authors: Steven Thisjen et al
Link to paper: https://papers.ssrn.com/sol3/papers.cfm?abstract_id=3605260
Journal/ Pre-Print: Pre-prints with The Lancet
Tags: Diagnostics, Immunology/Immunity
The authors developed an ELISpot using a mosaic structural recombinant protein and nucleoprotein with potential diagnostic utility.
The strongest T Cell response in COVID-19 Patients was against the nucleoprotein.
ELISA showing an increased IgG and IgA levels in COVID-19 patients compared to healthy controls (HC).
Steven Thisjen et al performed ELISpots on samples collected from 27 RT-PCR positive COVID-19 patients, from either the ICU or the pulmonary ward and 16 healthy controls obtained from Hospital personnel volunteers. Both the S1 domain of the nucleoprotein and a recombinant mosaic surface protein were used to investigate T-Cell responses. There was an increased T-cell response from COVID-19 patients compared to HC against the nucleoprotein while there was no difference found between the two groups against the mosaic protein. More than 10 spots after performing an ELISpot was the cut-off for positivity for COVID-19 responses and not all COVID-19 patients were found to be positive.
Impact for SARS-CoV2/COVID19 research efforts
Possible development of diagnostic tools for SARS-CoV2/COVID19
· In vitro study
Strengths and limitations of the paper
Novelty: Investigating the use of ELISpot as a diagnostic tool for SARS-CoV-2
Standing in the field: The Authors refer to several studies with similar ELISA results to their own
Appropriate statistics: The value of statistics in such a small group is limited, especially for a claim that over half the 19 COVID-19 patients showed significant T-cell response.
Viral model used: SARS-CoV-2
Translatability: The Authors propose that this could be a diagnostic tool and show if patients develop protective immunity, following infection with SARS-CoV2.
Small sample study of 27 COVID-19 Patients (19 of which are post 14 days onset of symptoms) and 16 healthy controls.
Healthy controls were not pre-pandemic samples, but from “healthy volunteers” from personnel working at the same hospital as the patient samples were obtained and no RT-PCR is described as being run on these patients to make sure they have not been infected and asymptomatic.
Large age difference between the patients and healthy controls.