Trial Report Bulk RNA sequencing for analysis of post COVID-19 condition in adolescents and young adults, 2024, Sommen

Selvkuumar has multiple times on twitter defended the notion that children have symptoms of long covid due to "long lockdown" and being scared. Explaining what stress can to do the body to the children (and their parents) they will feel empowered and complaints will reduce.

 

Not the first time BPS throws in som biomedical stuff they can then point to and say "see, we look at that too".

 

So
SARS+F+: 20 participants SARS-CoV-2 positive; high fatigue (numerical CFQ>=21); meeting WHO PCC and Fukuda criteria
SARS+F-: 20 participants SARS-CoV-2 positive; low fatigue (numerical CFQ<=11); not meeting WHO PCC and Fukuda criteria
SARS-F+: 20 participants SARS-CoV-2 negative; high fatigue (bimodal CFQ>=4)
SARS-F-: 20 participants SARS-CoV-2 negative; low fatigue ('not reporting fatigue'), not meeting WHO PCC and Fukuda criteria

That's already looking a bit odd - they used a different method to identify SARS-CoV-2-negative participants with high fatigue. Figure 1 shows that the SARS-F+ group did not all meet WHO PCC and did not all meet Fukuda criteria

They don't say how they selected the 20 participants for each group from the larger numbers qualifying.
All participants female.

 

The 13 differentially expressed genes are between the SARS+F+ group and the SARS+F- group. That's good. Although 20 people is not a big sample.

 

PCA analysis

The PCA is in Figure 2 - there's no separation of any of the groups, despite the axes accounting for a lot of the variation in gene expression. I guess there's just so much individual variation.

I guess PCA probably isn't appropriate with such a small number of samples relative to the massive number of gene expression features.

Maybe the blood sample needs to be stratified, to get smaller samples of features, to zero in on what is different? Or there could be prior decisions to only look at certain gene expressions, such as those for viral defense genes.

 

Top differentially expressed genes



Fig 4 looks a bit more exciting. The heat map is the difference between each group versus the mean of the other three groups. They say that the only significant differences were the 13 gene expressions different between the SARS+F+ and the rest.

And the upregulated gene expressions do tell a pretty coherent story about an immune response to viral infection.

We just have to remember that these are the most different gene expressions found out of about 59,000. And also , it looks as though about 4 individuals in the 20 people in the SARS+F+ group are doing the heavy lifting in terms of the upregulation. Most of the others look quite a lot like the rest of the people in the other groups. (Each individual is represented by a column in the heat map - see the red coloured columns.)