MENSA, a Media Enriched with Newly Synthesized Antibodies, to Identify SARS-CoV-2 Persistence ... Viral Reactivation in Long-COVID, 2024, Haddad+

MENSA, a Media Enriched with Newly Synthesized Antibodies, to Identify SARS-CoV-2 Persistence and Latent Viral Reactivation in Long-COVID.

ABSTRACT

Post-acute sequelae of SARS-CoV-2 (SARS2) infection (PASC) is a heterogeneous condition, but the main viral drivers are unknown. Here, we use MENSA, Media Enriched with Newly Synthesized Antibodies, secreted exclusively from circulating human plasmablasts, to provide an immune snapshot that defines the underlying viral triggers.

We provide proof-of-concept testing that the MENSA technology can capture the new host immune response to accurately diagnose acute primary and breakthrough infections when known SARS2 virus or proteins are present. It is also positive after vaccination when spike proteins elicit an acute immune response.

Applying the same principles for long-COVID patients, MENSA is positive for SARS2 in 40% of PASC vs none of the COVID recovered (CR) patients without any sequelae demonstrating ongoing SARS2 viral inflammation only in PASC. Additionally, in PASC patients, MENSAs are also positive for Epstein-Barr Virus (EBV) in 37%, Human Cytomegalovirus (CMV) in 23%, and herpes simplex virus 2 (HSV2) in 15% compared to 17%, 4%, and 4% in CR controls respectively. Combined, a total of 60% of PASC patients have a positive MENSA for SARS2, EBV, CMV, and/or HSV2.

MENSA offers a unique antibody snapshot to reveal the underlying viral drivers in long-COVID thus demonstrating the persistence of SARS2 and reactivation of viral herpes in 60% of PASC patients.

https://www.medrxiv.org/content/10.1101/2024.07.05.24310017v1.full.pdf

 

The authors claim that this test capture antibodies secreted from plasmablasts or newly-minted antibody secreted cells that appear in the circulation right after infection or vaccination. I have no idea how this selectively only selects antibodies of these cells and whether this would include cells that are created during an ongoing chronic infection (for example in Post-Ebola replicating in testes this might not work). Supposedly this allows you to capture a response from the new illness rather than capturing the whole patient history (i.e. whether someone was once infected with something).

I tried having a look at the PASC patients but I cannot find any of the necessary details on them. Supposedly the authors claim there is ongoing viral persistence in these patients that the test measures, however the authors provide no details on duration of PASC and whether these patients knowingly had a reinfection. In Figure 5 they mention that it's been "60-279 DPSO since initial COVID-19 Wild Type infection from patients who completely recovered from their acute illness (CR; n=19) and patients who suffer PASC (n=39)." However they don't mention whether there are differences between these groups which seems like necessary information. Looking at the graphs in Figure 5 there does seem to be a difference between what the MENSA test detects and what a conventional Serum test detects. However that difference could also be driven by something like a more recent acute infection, since no details on this are provided (only 3 PASC patients look different in the Nucleocapsid snapshot, the RBD snapshot is more significant).

Figure 6 is a subset analysis without provided details on why this subset was selected or which subset of people from Figure 5 these people represent. I have no idea why authors keep on doing this.

Figure 7 shows the strongest difference between MENSA and Serum and seems to be performed on a reasonable sample size. However, it cannot differentiate between ongoing infection and recent acute infection. I wish something like PCR would have been used to show there hasn't been a recent reinfection as that could have been a strong sign for viral persistence in those patients.

Very surprisingly this is the first study that looks at more African American PASC patients than Caucasian PASC patients, i.e. it also looks at a group that is usually underrepresented in PASC research.

 

Not sure how the conclusions about herpes simplex are arrived at!

The story as told looks unconvincing and over interpreted but it might be that they are showing that PASC is associated with a different and broad anamnestic antibody response. That would fit with an idea Jo Cambridge and I were considering which is that the problem is not specific antibody species to specific antigens but a poor regulation of some aspect of antibody specificity. In crude terms that the problem is not that you are making antibodies to the wrong thing but making 'messy' antibodies that trigger various non-specific tidy up pathways, without any inflammation as such.

The idea that circulating plasmablasts would give a reliable guide to recent antibody repertoire seems simplistic but it might be roughly true, at least as an indicator sample. It may be that this is a clever way to study ongoing immune responses and that it might be ideal for picking up the sort of aberration we were wondering about.

 

What is different for HSV2, in their claims that antibodies from circulating plasmablasts indicate recent or current infections?

 

I think that is a reasonable assumption. The problem is that the cells picked up may not be representative of the current response. Moreover, the test requires each antibody species, from a separate cell, to be given a yes/no attribution of 'anti x-virus' or 'anti-y virus' and antibody stereochemistry is more complicated than that. I don't think this is going to be a reliable way to track exactly what is going on but it might pick up a functional skewing of antibody production that might be very important.

 

This for me is a key concern. I have had Covid 4 or 5 times based on my own lateral flow tests and those of my daughter who usually gives us the Covid from her school. My 'Long Covid' has been a series of phases each triggered by a new infection. I think there is a very big question mark over LC studies in this respect in that people being selected as having 'LC' may well be more likely to have had a recent re-infection. Judging by our experience people in London get re-infected about every six months with a new variant.

 

This is also my major concern. The authors claim to be able to differentiate historic infections from chronic infections, but there is no effort to differentiate recent acute reinfections, which are extremely common and are likely to be biased towards LC patients.

This is a particular concern as it has already created fluke results that looked like viral persistence biomarkers in the past. The much hyped Simoa assay by Walt, claimed to be more sensitive and as such was able to detect viral persistence, but as it later turned out the initial cohort was likely just biased towards more recent reinfections on the LC side and not on the other, whilst a study by van Weyenbergh seemed to have the same problems.

I see 3 possibilities how to avoid this:

You have a sufficiently large and evenly chosen cohort, such that recent reinfections even out between recovered controls and LC patients. However, if your sample is somehow biased, which it will very likely be, or if there is some unknown pathological reason to why LC patients get statistically more Covid infections then this will probably not yield any better results (the real danger is here that if you use the nonsensical LC definition of "anything is LC if it happens 2 months after a Covid infection", you will naturally be biased to the LC cohort having had more recent infections, so you really have to control that).

The second possibility would require you to do extensive monitoring of controls and LC patients via something like PCR tests to pick up whether they had a reinfection in the past 6 months or so. I don't think anybody will do that, but if they can define a shorter detection limit of acute infections via their MENSA test, the timeframe might become a lot shorter and the whole thing might become feasible.

A further option, that would probably be the easiest option, would just be to repeat the MENSA test after a certain amount weeks if you know that in a recovered person the levels should go down after certain amount of weeks after an acute reinfection.

In this paper the authors didn’t even look at LC duration, respectively differences in duration of last known infection between LC and recovered controls to see if that makes a difference, so I’m sceptical that they really looked at this well enough.

 

Very interesting thanks - I wonder whether GWAS [common variant genetic study - DecodeME], or indeed a rare variant genetic study*, would provide an independent route to test this e.g. certain genes increasing severity --- likelihood of this outcome & if so then what genes?

*NIH - a rare variant/whole genome sequence study is one of the recommendations from the recent ME/CFS roadmap.

 

How is it that they are able to use the acronym MENSA? Are they associated with the famous 'high IQ' organisation Mensa? If not, isn't it illegal to use their name? Seems a bit weird.

 

Looking at figure 3, which unfortunately is only data for 1 patient, it seems that for repeated vaccinations the MENSA antibody levels are less high after subsequent vaccinations than after initial vaccinations and something similar seems to be the case for repeated infections, where the levels go down quicker than previously. There also seems to be a strange increase in the kinetics of Figure 3A (&3C) regarding the first vaccination, possibly the dates were not reported exact enough, but the authors really should have noticed this.

Unfortunately this data is only for one person, so this should be studied in detail for many people, but for this person the levels only remain elevated above the threshold for somewhere around 30 days. If something similar were to hold for the average person as well, then re-testing the levels after this timeframe should give a very strong indication of whether there is something different going on in LC patients or whether they simply had a more recent reinfection.

 

I wonder that too - I looked at the thread assuming that it related to the intelligence organisation.

 

Actually having a closer look this is slightly weird. There always seems to be an increase before vaccination and infection. That would not be problematic if there was some steady state around which the levels roughly hover, sometimes being higher sometimes being lower or if it has to do with some complicated dynamics of plasmablasts, but this increase seems to be so significant that it seems that even if the person hadn't been vaccinated or infected their levels would have still risen to that of what the MENSA test considers to be an acute infection as they had been rising close to the limit for 150 days before this persons last infection. That phenomenon is not observed amongst serum levels where there seems to be more stability around the steady state. It's still possible that MENSA test could be indicative of some dynamics at the population level, but it doesn't seem to be as stable as the authors imply.

Especially if your levels might be rising for several hundred days after an infection it will become increasingly difficult to control for levels rising post reinfection.

 

Yes, that's why I looked at the thread too! This makes it seem as if they are trying to look like they are associated with the actual Mensa. I wonder if Mensa knows about this? They should probably be told! Could be infringement of trademark, or 'passing off', or similar?

 

There's no copyright on names or titles. Trademarks can be registered and protected, but if this isn't sold commercially, it won't have one.

It would be quite hard to argue passing off, too, given the limited scope for confusion between an experimental antibody assay and a club for people with a particular sort of intelligence.

 

If rituximab kills all antibody producing B-cells then, if the "'messy' antibodies" are solely produced by B-cells, rituximab should work? Suppose the another option is plasma cells i.e. producing antibodies?
Is the regulatory mechanism (for checking antibodies) is common to both B-cells & plasma cells? If so then I guess that rituximab wouldn't necessarily work i.e. if there were enough messy antibodies produced by plasma cell? Beginning to understand your point re the regulatory mechanism (quality control) potentially being the issue!

 

Strike me that if there is a response to poor quality antibodies (which should be eliminated but aren't) then finding a biomarker for same would be Noble prize territory oh and a drug target --- squillions of £s!
Presumably the chemical raising the alarm would be coded for by a gene* and/or the receptor which interprets the signal?
*DecodeME (common variants study) or whole genome sequences (rare genetic variant study)?

 

Mensa is also a Latin word meaning table. I think it was the first one we were taught to decline.