So if you look at the bottom "negative serum" you see we have nothing. With 0073 and 5044 we have faint smudges. 0073 might be reported HCV RNA < 15 (quantitative) HCV RNA detected, and 5044 HCV RNA 42, HCV RNA detected.
If you look at the positive serum, to the left you see 1:100 positive serum - this is where the "soup" was diluted 1 part soup to 100 parts water to dilute it - as you can see it still shows up, but is much fainter. Dilution lets us quantify differences between the large solid smudges.
When we get to really low levels of RNA all we see really faint smudges. At some point the smudge is there "detected" but to faint to count. The <12, <15, <20 and <25 results we see relate to the minimum sensitivity of the test in use. The lowest we used to be able to get to was <25, but is now typically <15 and recently I have seen <12 in some results from Spain.
Although it is obviously great to have nothing at all seen ie <15 and undetected this does not map as well to SVR as you would expect. No, I don't understand that either!
Thanks for that. Interesting attached article (analysing 358 drug users in an HIV study that began in 1985 and then finding 19 of them who became infected with HCV. Just trying to imagine the logistics involved with paperwork and specimen collection and storage with that amount of people, especially considering that the paper itself was published in 1999.)
G4, F4, cirrhosis.
Thank you to Gilead, Michael Sofia, and the terrific folk at FixHepC for making this adventure possible.