Monocyte CD169 expression as a biomarker in the early diagnosis of COVID-19
Authors: Bedin et al.
Tags: Clinical, Diagnostics
Monocytic CD169 (mCD169) was overexpressed in COVID-19 patients, making it a potential early biomarker
mCD169 correlated with viral replication rate and IFNa levels
Authors of this study assessed 53 adult patients (32 COVID-19 positive, 21 with another infection) and the expression of CD169 on their monocytes, which was overexpressed in COVID-19 positive patients. Expression of mCD169 correlated with thrombocytopenia and IFNα levels in the plasma, as well as with the proxy of viral replication (cycle time detection in SARS-CoV-2 PCR). Furthermore, they reported that mCD169 seemed to be linked to active infection before seroconversion. They suggest that mcD169 expression may serve as a useful biomarker, however due to low numbers of patients its usefulness as severity prognosis could not be assessed.
Impact for SARS-CoV2/COVID19 research efforts
Develop diagnostic tools for SARS-CoV2/COVID19: Identification of mCD169 as a potential biomarker for SARS-CoV-2 diagnosis
Patient Case study
Strengths and limitations of the paper
Novelty: First evaluation of CD169 expression on monocytes in the context of COVID-19.
Standing in the field: Not controversial. Overexpression of CD169 on monocytes has been previously detected in other viral infections e.g. influenza. CD169 expression itself is enhanced by type I IFN, thus, its overexpression in viral infections with high prevalence of IFN is logical.
Appropriate statistics: Mostly appropriate, however not clearly stated in figure legends. For correlation analysis, full statistics was not shown (e.g. p-value missing). No statistics in Figure 2 as it shows individual patients, however, it might be beneficial to group the data together and perform statistical analysis of the results.
Viral model used: SARS-CoV-2
Translatability: Potential of using for viral infection testing in combination with another biomarker or a complementary method.
Small sample size.
CD169 increased in other viral infections, therefore, CD169 might be useful only as one biomarker complementing another method.
Insufficient number to make predictions about disease outcome based on expression level of CD169
What happens to the negative qPCR diagnosis that turns out to be infected with SARS-CoV2? Do they not present CD169 at the outset?
Further investigation of mechanical/functional role of mCD169.
Not clear how this method improves the current qPCR for diagnostic.