Zdenek Vrozina Profile picture
Feb 17 14 tweets 2 min read Read on X
One of the most important recent studies on post-COVID biology delivers a concerning message.
SARS-CoV-2 doesn’t just affect immune cells.
It can leave long-lasting changes directly in the immune proteins circulating in our blood.🧵
Think of the immune system in three layers.
immune cells (T, B, NK…)
signaling molecules
effector proteins - antibodies and complement
This study shows persistent changes in the deepest layer - the effector proteins themselves.
Researchers analyzed blood samples from more than 400 people after COVID-19.
They identified hundreds of chemical alterations in proteins - called ncAA modifications.
It’s about proteins becoming chemically different.
The most striking finding?
Some of these changes did not disappear after recovery.
They were still detectable up to 12 months after infection.
This suggests COVID can leave a long-lasting/persistent molecular imprint on the immune system.
The most affected systems were two core pillars of immunity.
Antibodies and the complement system.
These are the main drivers of inflammation and tissue damage during immune responses.
In antibodies, modifications appeared in the most critical regions.
The antigen-binding sites,
the Fc regions that activate immune cells and complement
In other words -
Even if antibodies recognize targets correctly, their effector strength may be altered.
The strongest signal was seen in the complement system.
Unlike coagulation changes - which mostly normalized -
many complement protein modifications persisted.
This raises concern about sustained inflammatory activation.
The study highlights one particularly important mechanism - deamidation of amino acids!
This modification is
irreversible (!)
alters protein charge
can change protein function
may create new autoantigenic epitopes
In essence, it can act as a molecular memory of inflammatory stress.
The authors describe this phenomenon as structural immune imprinting.

The immune system may not only remember pathogens.
It may also carry long-lasting chemical alterations of its own proteins.
So it is a strong biological signal that COVID-19 can leave a deep, long-lasting molecular reprogramming of immune effector systems.
These findings align with broader observations in post-COVID research
chronic low-grade inflammation
thrombo-inflammatory states
persistent immune dysregulation
Sum:
COVID-19 may leave a lasting chemical imprint on key immune proteins - particularly antibodies and complement - potentially keeping the immune system in a chronically altered state.
Further research is urgently needed to understand the clinical impact!
Liu at al., Widespread ncaas Imprints in the Serum Proteome of COVID-19 Convalescents Uncovering Immune System Sequelae. mcponline.org/article/S1535-…
Ignoring these persistent immune alterations is a major public-health failure. The long-term population burden of chronic inflammation, immune dysregulation, and post-COVID illness may ultimately rival - or exceed - the acute waves of 2020–2021. @szupraha @ZdravkoOnline @adamvojtech86 @adamkova_vera

• • •

Missing some Tweet in this thread? You can try to force a refresh
 

Keep Current with Zdenek Vrozina

Zdenek Vrozina Profile picture

Stay in touch and get notified when new unrolls are available from this author!

Read all threads

This Thread may be Removed Anytime!

PDF

Twitter may remove this content at anytime! Save it as PDF for later use!

Try unrolling a thread yourself!

how to unroll video
  1. Follow @ThreadReaderApp to mention us!

  2. From a Twitter thread mention us with a keyword "unroll"
@threadreaderapp unroll

Practice here first or read more on our help page!

More from @ZdenekVrozina

Mar 3
Two recent studies suggest that Long COVID may involve long-term neurobiological remodeling - even after mild infection.
One examined the brain under cognitive load.
The other looked at it at rest.
Together, they point to a persistent shift in network organization!🧵
In the first study (Barnden et al.), the key issue was not where the brain activates -
but how its networks coordinate under mental exertion.
The largest differences appeared during cognitive load.
The regulatory switching system began to fail.
The main systems involved were
the salience network - deciding what matters, and executive control circuits - sustaining performance.
And after repeated cognitive effort, the disruption became more pronounced.
That matches the lived experience
I can manage for a while - then it falls apart.
Read 17 tweets
Mar 2
In this group of people who self-identified as having Long COVID and were willing to complete an online survey, Long COVID is very long-lasting - around 20 months after symptom onset, only about 5% were fully back to baseline.🧵
The median duration of symptoms was about 20 months.
Only 5% of patients fully recovered.
About 59% never had a symptom-free day.
Most common course patterns
constant symptoms 45%
fluctuating ~27%
relapsing ~10%
Read 17 tweets
Mar 2
This paper is a systematic review summarizing 10 studies focused on cardiovascular findings after COVID.
The main message is - Long COVID is associated with measurable changes in the heart and blood vessels🧵
Systematic review according to PRISMA 2020
PubMed, Scopus, Web of Science
1/2020 - 3/2024 (updated 11/2025)
Out of 412 records, 10 high-quality studies were selected.
Subclinical myocardial dysfunction (eg impaired strain/GLS), arrhythmias, endothelial/vascular dysfunction, increased arterial stiffness, occasionally persistent biomarkers (troponin), and newly diagnosed hypertension.
Read 15 tweets
Feb 26
When we talk about COVID in children, we often hear - mild disease.
The real question we rarely ask is this - what if some children leave the infection with a silent, measurable cardiovascular footprint - and we simply don’t have long enough follow-up yet to see what it leads to?🧵
About a quarter of children.
In a new study, 16 out of 67 kids (24%) had subclinical cardiac contractility changes three months after mild or asymptomatic COVID - despite having no persistent symptoms.
The abnormalities were detected only with speckle-tracking strain imaging, a sensitive method that can reveal very subtle myocardial dysfunction.
Read 22 tweets
Feb 25
The interesting proof-of-concept study shows that in some severely immunocompromised people with long-lasting COVID-19, it is possible to use autologous VSTs🧵
It is possible to -
Produce SARS-CoV-2–specific T cells from their own blood (autologous VSTs),
Infuse them back into the patient,
In the 3 treated patients this was temporally associated with clinical improvement, PCR turning negative, and better CT findings - without serious side effects.
How strong is the evidence of effectiveness?
Rather weak to moderate for efficacy, but fairly solid for feasibility and short-term safety. This is an early signal, no control group.
Read 19 tweets
Feb 24
One overlooked signal of the pandemic. IL-32 - a cytokine known from HIV research as a marker of chronic immune activation - is now elevated not only in COVID patients, but across large parts of the general population🧵
Here’s an underappreciated detail. IL-32 isn’t just another inflammatory cytokine. In HIV research, it’s a well-known marker of chronic immune activation - linked to persistent low-grade inflammation and long-term viral persistence
In people with HIV, IL-32 doesn’t simply fight infection. It can also upregulate immunosuppressive pathways (PD-L1 and IDO1), creating an environment where inflammation persists - but effective viral clearance does not.
Read 8 tweets

Did Thread Reader help you today?

Support us! We are indie developers!


This site is made by just two indie developers on a laptop doing marketing, support and development! Read more about the story.

Become a Premium Member ($3/month or $30/year) and get exclusive features!

Become Premium

Don't want to be a Premium member but still want to support us?

Make a small donation by buying us coffee ($5) or help with server cost ($10)

Donate via Paypal

Or Donate anonymously using crypto!

Ethereum

0xfe58350B80634f60Fa6Dc149a72b4DFbc17D341E copy

Bitcoin

3ATGMxNzCUFzxpMCHL5sWSt4DVtS8UqXpi copy

Thank you for your support!

Follow Us!

:(