6 ms·

The post refers to an alternative method of testing for COVID-19 based on surface plasmon resonance that would have significant advantages, but unfortunately i

by zmmmmm 7y ago

The post refers to an alternative method of testing for COVID-19 based on surface plasmon resonance that would have significant advantages, but unfortunately it provides absolutely no real substantiation that the test exists or works. The link about surface plasmon resonance goes to a generic Wikipedia page, the link about saliva is a small scale study that was conducted on RT-PCR not surface plasmon resonance, and the actual link to the team goes to a nothing more than splash screen with the company logo on it. If there is substance to this then it would be massively in Paul's (and the company's) interest to better link to that in both the post and the company web site. At the moment, it looks like at worst vaporware or at best, something so early stage it's years out from viability.

dekhn 7y ago
He should also disclose any personal interest in it more clearly at the top of the article.
- m3kw9 7y ago
  Yeah he def have skin in there
- kordlessagain 7y ago
  At this point all our personal interests are to stay virus free as long as possible, given what we don't know might kill us. I really don't care why he's speculating about the things he is. Many of the things we postulate may be proven wrong simply by waiting long enough to get more data - i.e. it's not always necessary to formulate a test for disproving an idea, sometimes they evaporate on their own. (Software features for example frequently meet their ends this way). I just found out about Covid Toes. What will come tomorrow? And now, a shameless plug for a next-day delivered PPE from Amazon built from a full faced snorkel, a vacuum filter and a 3D printed adapter I designed: https://3dprint.nih.gov/discover/3dpx-013899 https://3dprint.nih.gov/discover/3dpx-013899. There's a video too, which shows a bit cheaper version's assembly: https://www.youtube.com/watch?v=wydRpFpQD4I https://www.youtube.com/watch?v=wydRpFpQD4I I haven't been into an indoor shared space without it on for almost 3 weeks. You probably shouldn't use Gorilla Tape on it, because it might off gas something. Try surgical tape.
tptacek 7y ago
According to my biochem-undergrad kid, surface plasmon resonance is a thing; it had come up in classes. "It's like doing an ELISA with no secondary antibody". Someone here will know what that means. I don't!
- IdoRA 7y ago
  If one is clever, one can use SPR to interrogate a surface: monitor the surface and you can “see” the surface changing when stuff is sticking to it. If you have something with specific binding properties on that surface, like an antibody (as is used in an ELISA), with some additional effort you can maybe have an assay that detects something binding to that antibody.
- johncolanduoni 7y ago
  It’s a thing, but doing a saliva test with limited sample prep (which you need to be beat PCR, otherwise you might as well just make more known to work qPCR machines) is not something anyone has accomplished with it for any virus. It’s a promising technology; but not for having a widely deployable test before we have boring old ELISA antigen tests. Which we have developed for plenty of viruses, and which some individual companies alone can manufacture at a rate of several per second with existing production capacity. I’m glad more money is being put towards research in this tech (I used to study plasmonics from the physics side), I don’t think it’ll make a difference for COVID specifically before it’s too late to matter.
  - predxionbio 7y ago
    Test complexity (sample prep, test workflow) is a real challenge to achieving testing scales at orders of magnitude above what is presently available. We should hopefully have boring old ELISA antigen tests shortly, thanks to Abbott and many of the other folks we've all heard from. The real challenge is scaling testing beyond what can be reasonably implemented from central lab facilities.
    - johncolanduoni 7y ago
      ELISA tests don’t need to be done at central lab facilities; there are plenty of machines on the market with varying levels of automation (and many already in hospitals, even in ones that aren’t particularly outstanding). I’m curious what barrier to scaling those with COVID (either by making more of these machines, or repurposing other test capacity) you’ve identified that makes bringing a totally new machine to market more attractive, from a scaling perspective.
predxionbio 7y ago
Hi, Walker here, one of the PreDxion Bio co-founders. Heres a some more information on the technology underlying the test we are developing: https://pubmed.ncbi.nlm.nih.gov/25790830/ https://pubmed.ncbi.nlm.nih.gov/25790830/. Unfortunately, up until about a month ago us like many folks, were blissfully minding our business developing a rapid point of care cytokine detection platform for use in monitoring patients experiencing certain immune responses following cancer immunothereapies, you can read more here: https://pubmed.ncbi.nlm.nih.gov/31597044/ https://pubmed.ncbi.nlm.nih.gov/31597044/. Currently, we are very much focused on techical/clinical validation. We will have many more details to share on our approach, the technology, as we continue to move things forward.
- klipt 7y ago
  What do you think of the article's claim that eliminating the cold virus would be a good thing? I think I read somewhere that early exposure to cold viruses reduces the chance of acute lymphoblastic leukemia, which makes me wary of trying to eliminate them completely...
  - predxionbio 7y ago
    There’s a lot of really interesting work left to be done in this area. In our company’s other life we’re involved in CAR-T research, which involves exploiting natural pathways in our immune systems to target them at cancer cells. It’s a super exciting area of research and is bleeding edge in terms of breakthrough therapies coming into the clinic. These therapies[0][1] cure upwards of 90% of what would otherwise be incurable cancers, but they also induce severe inflammatory responses (cytokine storm) which results in respiratory failure and neurological adverse events (that’s a nice clean clinical way of saying putting them in a coma). The holy grail would be real-time targeted therapeutics to modulate our immune systems up and down in response to various cues. We’re a long way off from that but it’s an idea that’s beginning to get wider acceptance in the medical community. [0] - https://www.novartis.us/sites/www.novartis.us/files/kymriah.pdf https://www.novartis.us/sites/www.novartis.us/files/kymriah.... [1] - https://www.gilead.com/-/media/files/pdfs/medicines/oncology/yescarta/yescarta-pi.pdf https://www.gilead.com/-/media/files/pdfs/medicines/oncology...
Igelau 7y ago
And it's a public kiosk that you spit in? I'm not so sure about this!
TenJack 7y ago
I gathered the same thing. Basically the gist is, if we can develop a cheap, fast, and effective test for COVID-19 then we can test everywhere and re-open everything.
- mikepurvis 7y ago
  Hasn't that always been everyone's argument? That's the crux of Pueyo's "dance" [1], that as long as you've contained the initial outbreak, you can pretty much go back to normal if you track movement and have the capacity to test everyone who comes in contact with an infected person. [1]: https://medium.com/@tomaspueyo/coronavirus-learning-how-to-dance-b8420170203e https://medium.com/@tomaspueyo/coronavirus-learning-how-to-d...
  - obeattie 7y ago
    That post, which was very popular, immediately came to my mind too. It also feels like the logical next step to the very widespread testing found in countries like South Korea.
  - joe_the_user 7y ago
    This has been one major argument. The others have been: "flatten the curve - just extend the time until everyone gets it" (obvious problem, exponential growth can't work that way), "shelter in place 'till a vaccine appears" (not very practical) and "it's really not that bad, there are so many asymptomatic carriers that in the end it's not actually worse than the flu after all or at least there's nothing we can do." (not that plausible, not appealing, non-fatal cases still much worse than the flu). I think this is the best position, however but it still needs to be argued for since it's not the only position. Edit: Also, it looks like the US has plateaued at this point but in a situation with a fairly dysfunctional testing arrangement. It is going to be hard to argue for people to sit tight until tests are in place so I'm not terribly optimistic.
    - hcknwscommenter 7y ago
      ""flatten the curve - just extend the time until everyone gets it" (obvious problem, exponential growth can't work that way)" Huh? One goal is to flatten the curve so that we don't have exponential growth. Another is to flatten the curve so much that, even if might still be exponential growth, the growth is slow enough for our health care systems to absorb the peak.

by zmmmmm 7y ago

dekhn 7y ago

He should also disclose any personal interest in it more clearly at the top of the article.

m3kw9 7y ago
Yeah he def have skin in there
kordlessagain 7y ago
At this point all our personal interests are to stay virus free as long as possible, given what we don't know might kill us. I really don't care why he's speculating about the things he is. Many of the things we postulate may be proven wrong simply by waiting long enough to get more data - i.e. it's not always necessary to formulate a test for disproving an idea, sometimes they evaporate on their own. (Software features for example frequently meet their ends this way). I just found out about Covid Toes. What will come tomorrow? And now, a shameless plug for a next-day delivered PPE from Amazon built from a full faced snorkel, a vacuum filter and a 3D printed adapter I designed: https://3dprint.nih.gov/discover/3dpx-013899 https://3dprint.nih.gov/discover/3dpx-013899. There's a video too, which shows a bit cheaper version's assembly: https://www.youtube.com/watch?v=wydRpFpQD4I https://www.youtube.com/watch?v=wydRpFpQD4I I haven't been into an indoor shared space without it on for almost 3 weeks. You probably shouldn't use Gorilla Tape on it, because it might off gas something. Try surgical tape.

tptacek 7y ago

According to my biochem-undergrad kid, surface plasmon resonance is a thing; it had come up in classes. "It's like doing an ELISA with no secondary antibody". Someone here will know what that means. I don't!

IdoRA 7y ago
If one is clever, one can use SPR to interrogate a surface: monitor the surface and you can “see” the surface changing when stuff is sticking to it. If you have something with specific binding properties on that surface, like an antibody (as is used in an ELISA), with some additional effort you can maybe have an assay that detects something binding to that antibody.
johncolanduoni 7y ago
It’s a thing, but doing a saliva test with limited sample prep (which you need to be beat PCR, otherwise you might as well just make more known to work qPCR machines) is not something anyone has accomplished with it for any virus. It’s a promising technology; but not for having a widely deployable test before we have boring old ELISA antigen tests. Which we have developed for plenty of viruses, and which some individual companies alone can manufacture at a rate of several per second with existing production capacity. I’m glad more money is being put towards research in this tech (I used to study plasmonics from the physics side), I don’t think it’ll make a difference for COVID specifically before it’s too late to matter.
- predxionbio 7y ago
  Test complexity (sample prep, test workflow) is a real challenge to achieving testing scales at orders of magnitude above what is presently available. We should hopefully have boring old ELISA antigen tests shortly, thanks to Abbott and many of the other folks we've all heard from. The real challenge is scaling testing beyond what can be reasonably implemented from central lab facilities.
  - johncolanduoni 7y ago
    ELISA tests don’t need to be done at central lab facilities; there are plenty of machines on the market with varying levels of automation (and many already in hospitals, even in ones that aren’t particularly outstanding). I’m curious what barrier to scaling those with COVID (either by making more of these machines, or repurposing other test capacity) you’ve identified that makes bringing a totally new machine to market more attractive, from a scaling perspective.

predxionbio 7y ago

Hi, Walker here, one of the PreDxion Bio co-founders. Heres a some more information on the technology underlying the test we are developing: https://pubmed.ncbi.nlm.nih.gov/25790830/ https://pubmed.ncbi.nlm.nih.gov/25790830/. Unfortunately, up until about a month ago us like many folks, were blissfully minding our business developing a rapid point of care cytokine detection platform for use in monitoring patients experiencing certain immune responses following cancer immunothereapies, you can read more here: https://pubmed.ncbi.nlm.nih.gov/31597044/ https://pubmed.ncbi.nlm.nih.gov/31597044/. Currently, we are very much focused on techical/clinical validation. We will have many more details to share on our approach, the technology, as we continue to move things forward.

klipt 7y ago
What do you think of the article's claim that eliminating the cold virus would be a good thing? I think I read somewhere that early exposure to cold viruses reduces the chance of acute lymphoblastic leukemia, which makes me wary of trying to eliminate them completely...
- predxionbio 7y ago
  There’s a lot of really interesting work left to be done in this area. In our company’s other life we’re involved in CAR-T research, which involves exploiting natural pathways in our immune systems to target them at cancer cells. It’s a super exciting area of research and is bleeding edge in terms of breakthrough therapies coming into the clinic. These therapies[0][1] cure upwards of 90% of what would otherwise be incurable cancers, but they also induce severe inflammatory responses (cytokine storm) which results in respiratory failure and neurological adverse events (that’s a nice clean clinical way of saying putting them in a coma). The holy grail would be real-time targeted therapeutics to modulate our immune systems up and down in response to various cues. We’re a long way off from that but it’s an idea that’s beginning to get wider acceptance in the medical community. [0] - https://www.novartis.us/sites/www.novartis.us/files/kymriah.pdf https://www.novartis.us/sites/www.novartis.us/files/kymriah.... [1] - https://www.gilead.com/-/media/files/pdfs/medicines/oncology/yescarta/yescarta-pi.pdf https://www.gilead.com/-/media/files/pdfs/medicines/oncology...

Igelau 7y ago

And it's a public kiosk that you spit in? I'm not so sure about this!

TenJack 7y ago

I gathered the same thing. Basically the gist is, if we can develop a cheap, fast, and effective test for COVID-19 then we can test everywhere and re-open everything.

mikepurvis 7y ago
Hasn't that always been everyone's argument? That's the crux of Pueyo's "dance" [1], that as long as you've contained the initial outbreak, you can pretty much go back to normal if you track movement and have the capacity to test everyone who comes in contact with an infected person. [1]: https://medium.com/@tomaspueyo/coronavirus-learning-how-to-dance-b8420170203e https://medium.com/@tomaspueyo/coronavirus-learning-how-to-d...
- obeattie 7y ago
  That post, which was very popular, immediately came to my mind too. It also feels like the logical next step to the very widespread testing found in countries like South Korea.
- joe_the_user 7y ago
  This has been one major argument. The others have been: "flatten the curve - just extend the time until everyone gets it" (obvious problem, exponential growth can't work that way), "shelter in place 'till a vaccine appears" (not very practical) and "it's really not that bad, there are so many asymptomatic carriers that in the end it's not actually worse than the flu after all or at least there's nothing we can do." (not that plausible, not appealing, non-fatal cases still much worse than the flu). I think this is the best position, however but it still needs to be argued for since it's not the only position. Edit: Also, it looks like the US has plateaued at this point but in a situation with a fairly dysfunctional testing arrangement. It is going to be hard to argue for people to sit tight until tests are in place so I'm not terribly optimistic.
  - hcknwscommenter 7y ago
    ""flatten the curve - just extend the time until everyone gets it" (obvious problem, exponential growth can't work that way)" Huh? One goal is to flatten the curve so that we don't have exponential growth. Another is to flatten the curve so much that, even if might still be exponential growth, the growth is slow enough for our health care systems to absorb the peak.