3 ms·

antibody tests are really hard. his could be a false negative. further, he could have had it, but without antibodies. or he might have had something else.

renewiltord 5y ago
If he didn’t have antibodies then how did he ever recover? Surely the thing doesn’t just burn itself out. Without anything to fight it, won’t it just continually infect him?
- abfan1127 5y ago
  some people are recovering through other responses, including t-cell response, etc. I don't have the academic experience, the clinic experience, or his specific medical history, so I can't speak specifically. I do recall lots of papers at the beginning of Covid talking about high t-cell responses in patients without a lingering anti-body response. That all could have been early science based on poor data as well though.
  - peter422 5y ago
    Based on the information provided it seems highly unlikely the OP had covid. It isn't impossible but the lack of antibodies is just one further data point. Most people who recover have positive antibody tests.
- nradov 5y ago
  There are two basic immune systems: innate and adaptive. In some cases the innate immune system clears the infection before the adaptive immune system produces detectible levels of antibodies. https://en.wikipedia.org/wiki/Innate_immune_system?wprov=sfla1 https://en.wikipedia.org/wiki/Innate_immune_system?wprov=sfl...
  - renewiltord 5y ago
    Sorry, I'm aware of that in general. I was wondering in this case. I suppose that's possible for people who don't fall sick (I assume that's why low viral load means you can get exposed and not get sick?) but OP was quite sick.
  - simonh 5y ago
    I think it’s unlikely that’s it for someone seriously ill for an extended period.
passivate 5y ago
>antibody tests are really hard. Are you referring to the quantitative side? You can simply buy the antibody standard and sVNT test kit from Genscript. You can get a 96 test kit for under $3k. We have it and it works quite well.
- abfan1127 5y ago
  the general concept of antibody tests. Antibodies have serious dilution. Detection is a challenging problem. Many antibody tests (ex. measles) has a pretty high (in my unqualified opinion) false negative rate. Its a tough problem to solve in general. a single paper discussing false reports - https://pubmed.ncbi.nlm.nih.gov/14574997/ https://pubmed.ncbi.nlm.nih.gov/14574997/
  - passivate 5y ago
    Well, let me first state the obvious - no test anywhere is perfect. But when it comes to antibody tests you have to be a bit more specific and discuss the underlying technology and method of detection. For e.g. there are 1129 diagnostic products for covid, and not all of them are identical. There are many reasons for false-negatives and some could be specific to the product being used. The paper you linked to is not about COVID19, its from 2003 and also its scope is not a general review of antibody tests. Its an investigation into false-positives with a specific underlying autoimmune disease possibly masking the result. I am not familiar with this study to speak in any great detail. https://www.finddx.org/covid-19/pipeline/ https://www.finddx.org/covid-19/pipeline/

renewiltord 5y ago

If he didn’t have antibodies then how did he ever recover? Surely the thing doesn’t just burn itself out. Without anything to fight it, won’t it just continually infect him?

abfan1127 5y ago
some people are recovering through other responses, including t-cell response, etc. I don't have the academic experience, the clinic experience, or his specific medical history, so I can't speak specifically. I do recall lots of papers at the beginning of Covid talking about high t-cell responses in patients without a lingering anti-body response. That all could have been early science based on poor data as well though.
- peter422 5y ago
  Based on the information provided it seems highly unlikely the OP had covid. It isn't impossible but the lack of antibodies is just one further data point. Most people who recover have positive antibody tests.
nradov 5y ago
There are two basic immune systems: innate and adaptive. In some cases the innate immune system clears the infection before the adaptive immune system produces detectible levels of antibodies. https://en.wikipedia.org/wiki/Innate_immune_system?wprov=sfla1 https://en.wikipedia.org/wiki/Innate_immune_system?wprov=sfl...
- renewiltord 5y ago
  Sorry, I'm aware of that in general. I was wondering in this case. I suppose that's possible for people who don't fall sick (I assume that's why low viral load means you can get exposed and not get sick?) but OP was quite sick.
- simonh 5y ago
  I think it’s unlikely that’s it for someone seriously ill for an extended period.

passivate 5y ago

>antibody tests are really hard. Are you referring to the quantitative side? You can simply buy the antibody standard and sVNT test kit from Genscript. You can get a 96 test kit for under $3k. We have it and it works quite well.

abfan1127 5y ago
the general concept of antibody tests. Antibodies have serious dilution. Detection is a challenging problem. Many antibody tests (ex. measles) has a pretty high (in my unqualified opinion) false negative rate. Its a tough problem to solve in general. a single paper discussing false reports - https://pubmed.ncbi.nlm.nih.gov/14574997/ https://pubmed.ncbi.nlm.nih.gov/14574997/
- passivate 5y ago
  Well, let me first state the obvious - no test anywhere is perfect. But when it comes to antibody tests you have to be a bit more specific and discuss the underlying technology and method of detection. For e.g. there are 1129 diagnostic products for covid, and not all of them are identical. There are many reasons for false-negatives and some could be specific to the product being used. The paper you linked to is not about COVID19, its from 2003 and also its scope is not a general review of antibody tests. Its an investigation into false-positives with a specific underlying autoimmune disease possibly masking the result. I am not familiar with this study to speak in any great detail. https://www.finddx.org/covid-19/pipeline/ https://www.finddx.org/covid-19/pipeline/