What day to test?

[jelise]

I just read an old post that said blood tests should be taken right before the weekly shot (it didn't say why - is it to check for the virus at lowest inf?).  My doctor wants to test soon after the shot to make sure and see all of the bad effects on blood counts.  

Which should it be?  

Thanks :)

[Marcia2202]

For Viral Load it DOES matter when you test. The most accurate would be on shot day, but BEFORE taking your shot. But the day before is also fine.

For the other blood tests it is wise to do it as your doctor suggests, for exactly the reason he suggests doing it.

Good luck with tx.

[JennyPenny]

In 2000 Dr Teresa Wright, hepatologist, discussed a study of viral kinetics and the comparison of pegasys and peg-intron on the peaks and trough of interferon. This talk was given at Digestive Diseases Week in San Diego.She stated that "Peg Intron had a maximal blood serum (no cells) concentration approximately 24 hours after a dose." And, "Pegasys has a half-life ("terminal elimination") of 50-80 hours. Whereas, due to it's shorter and linear-chain, Peg Intron has a half-life of 30-50 hours." She also discussed that after the first couple of injections the serum blood levels are high enough that the medication stays pretty much even as time goes by. This makes it likely that it will have no bearing on how much virus is showing the day before the injection.

[newleaf09]

I really never thought it made any difference when you took the blood sample.  It doesn't really matter to have a picture of a particular day; it's about the big picture.

The Neulasta (filgrastim, same as neupogen but pegylated) induces increased neutrophils overnight (maybe even in a few hours).  I was not allowed to use it and the peginterferon on the same day and was required to have a white count the day after the Neupogen shot, before they would allow me to take my peg shot.  Certainly worked well on me; I'd get neutrophil counts up to 12 or 13 and could hold normal or above for up to 2 weeks.

Do you happen to know when the next liver specialist meeting is?  Is it the AASLD meeting around the 1st of November?  I look forward to all the new info that gets reported at those.

[Isobella]

In my study, they did the PCR's before I took my shot.  If it made sense for them, it made sense for me.

I was under the impression that because the Peg had a half life of aprox 72 hours that was why we felt so much better the day or so before giving our shots.  That held true for me, especially at EOT.

[Marcia2202]

I think that one of the main reasons for taking the PCR as close as possible to the next shot is because of determining RVR, EVR etc.

After all it is called a 4 weeks PCR and not a 3 1/2 week PCR.... etc.

[ladybug52]

I know! I thought the same way, but it seems that the peg has a half life only during the first week and after that the serum levels remain constant. I was sure that JmJm was right about this, as he's the one who advised me and others to get the viral load test right before the next shot. I started reading up on it last night, and everything that JennyPenny says is consistent with the published data I read.

I had my first pcr on a Moday and my shot day was Friday and I was und 3/12 weeks after starting tx. Jim said that it would be a "3 week" pcr since it was before my 4th shot.

Old Jim....(sigh) I sure do miss him!

Take care,
Bug