Breadth of concomitant immune responses prior to patient recovery: a case report of non-severe COVID-19

https://doi.org/10.1038/s41591-020-0819-2

SUMMARY

This article is a clinical case study of a 47-years old woman with mild-symptoms that resolved without treatment after 10 days. She was tested positive for SARS-COV2 by RT-qPCR at day 4, 5,6, time after which the virus was undetectable. Phenotyping by flow cytometry of immune cells from blood shows increased circulating TFH (CD4+CXCR5+PD1+ICOS+), antibody-secreting cells (CD19+CD27hiCD38hi) and activated CD8+ and CD4+ T cells (CD38+HLADR+) at day 7,8,9 that persist at day 20. In the serum, the presence of SARS-COV2 specific IgG and IgM was detected by immunofluorescence staining of SARS-COV2 infected Vero cells. These results suggest that primary anti-viral B and T cell response occur in this patient and might correlate with better outcome.

RESEARCH HIGHLIGHTS

• Presence of B cell response after infection with increased ASC and cTFH in blood
• SARS-COV2 specific IgM and IgG detected in plasma
• Presence of anti-viral CD8+ T cell response after infection that is still not contracted one-week post-symptoms

RESEARCH IMPACT

They suggest some parameters that could be used in a larger cohort of patients with different disease severities to test if they could predict the disease outcome.

METHODOLOGY

Case study-one patient

STRENGTHS AND WEAKNESSES OF THE PAPER

Strength:

• They provide the gating strategy
• They analyse the blood of this patient at different time-points during and after the presence of the symptoms.

Weakness:

• It remains anecdotal as it includes a single patient and it would be very interested to look at similar parameters on a bigger cohort as suggested by the authors.
• This study looks at the presence of IgG and IgM but they don’t titer the Ab response that could be important to highlight an efficient B cell response.
• Even if the authors look 20 days after the initial symptoms, it remains too early to look at the formation of memory.