Understanding of CD19 levels?

[Galaxy2]

Hi All

Well I'm feeling a little miserable after receiving my covid antibody test result with a reading of just 4 u/ml after 3 vaccines.

Further more a recent blood test showed very suppressed CD19 levels, I've been researching this online to understand the significance and believe the low levels are the result of rituximab infusions and B cell depletion but would be really interested if anyone has had this explained to them in simple terms by their specialist.

I have been having rituximab throughout the pandemic but having half doses every 6 months because of covid and was due to have my next dose soon but have been told it won't go ahead now due to the low CD19 levels.

My main concern is that it means my immune system is very depleted at the moment or is it good that the level is low and it shows that rituximab is working. I would welcome anyone's understanding of the significance of this particular blood result.

Thanks All

[Grizzly-bear]

Hi Jenny

Sorry to hear about your antibody results - hopefully you’ve got a T cell response. Antibodies are only part of the picture.

Low CD19 from my understanding is both good and bad. Good in the sense that he’s the rituximab is working and this is likely a cumulative effect, but the flip side is you will be more prone to infection given your low immune system at the moment.

From my reading everyone responds differently to rituximab. Some people have their immune systems start to recover just 3 months later but for others it can stay depleted for 12 months. They do the blood tests to make sure that they’re not giving you rituximab again too soon when it’s actually still working and your B cells are still depleted. They’d likely only schedule another one if you showed signs of your B cells repopulating (with CD19 being a bio marker for B cells).

Hope you can stay safe. Things have got trickier for us immune suppressed folk with Omicron and rituximab does put us at increased risk, but it’s also very good for most at keeping vasculitis in check.

[Galaxy2 in reply to Grizzly-bear]

Thanks so much for your reply, yes I only my antibody result today so can only hope I’ve got a good T cell response, it’s a pity that can’t be measured too.So, good and bad news on the cd19 levels I suppose.

Keep safe and let’s hope we can all avoid the dreaded covid

[AmyS1]

Speak to your specialist nurse they will be able to help you.

[Mooka]

Hi jenny14. Rituximab wiped out my B cells leaving me severely immune suppressed. When they started to rise again my vasculitis flared. If your B cells are low it maybe your vasculitis is under control at the moment. If you start to get symptoms you should inform your vasculitis team quickly.

[Galaxy2 in reply to Mooka]

Thanks Mooka, it's an odd one as I've never been told before I'm due rituximab that my B cells are too low to have it and I've been on it for years. I had my last ritux in July and half my normal dose so it's strange. My main concern is how suppressed my immune system is now with covid on the increase again

[Mooka]

My B cells don’t come back and I understand that rituximab affects about 5% of us in this way. The result is I have secondary immune deficiency and have to have immunoglobulin replacement therapy. You should be having your immunoglobulin levels checked via blood tests regularly . I think they are still looking at how many antibodies people on rituximab can produce but initial findings weren’t good. Haven’t had rituximab for nearly 5 years as I haven’t needed it. If you are well enough your doctors are probably thinking it’s best to defer.

[Galaxy2 in reply to Mooka]

Hi Mooka, so sorry for the delay in replying.

Thanks so much for the information and link, my immunoglobulin are ok at the moment apparently. I didn't know that for some B cells don't come back after rituximab, that's bad luck and just another problem for you unfortunately.

I'm not in any rush for my next rituximab, all the time covid is around I think its just so worrying being on medication that affects the vaccine's response so badly.

Thanks again and have a lovely Christmas

[Mooka]

vasculitis.org.uk/news/octa... this helps.

[ZiggyDiego]

I have rituximab every 5 months: my consultant said it was essential to keep going with it as my vasculitis is always flaring. I joined research into antibodies. Was told I had not made a good response to first two vaccines and advised to be very careful & act as if I haven’t had any vaccines at all. Doctor didn’t give me results: she said no one knows what levels offer protection. But essential to keep going with rituximab for me. Consultant has emphasised to me that with new treatments for COVID being approved all the time, it looks more and more hopeful for us. But meanwhile the options for controlling vasculitis like mine are still limited, and it can be equally life threatening. So I’m glad the rituximab is still working for me.