Impact of Long-Term Cryopreservation on Blood Immune Cell Markers in ME/CFS: Implications for Biomarker Discovery Gomez-Mora et al 2020

Full title:
Impact of Long-Term Cryopreservation on Blood Immune Cell Markers in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: Implications for Biomarker Discovery

https://www.frontiersin.org/articles/10.3389/fimmu.2020.582330/full

 

Merged post

If I understand correctly, this Spanish study looked at freezing cells might cause differences in immune markers compared to fresh blood.

Some of the most tested immune markers in ME/CFS remained stable when frozen, namely: CD57 in NK cells, CD8+ effector T cells, CD56 expression in T cells, and Treg frequency.

In contrast, other markers showed inconsistent expression in biobanked PBMCs when compared to their fresh counterparts: namely NKp46, CD69 and CD25 expression on NK cells.

A previous study by this research team reported upregulated NKp46 in fresh blood. The authors now argue that frozen samples from a biobank are not appropriate to replicate their results. They write:

 

This article seems to have worrying implications because, earlier this year, some ME/CFS research teams had to freeze fresh blood samples before their labs shut down due to the COVID19 pandemic (possibly still ongoing in some places). The Cornell ENID Center, who are studying immune dysfunction in ME/CFS with 2-day CPETs, have done so:


For instance, would freezing affect cytokines? I recall that the Stanford team who looked at cytokine profiles in ME/CFS (2016) went to great lengths to process their samples as quickly and as carefully as possible.

 

I know Karl Morten has concerns about the effect that storage might have on samples and results of analysis, not just with freezing but between storage mediums as well.