medication causing low immunoglobulins - help

[u/Strict_Bear_5122]

hi there, i’ve been diagnosed with MS for about 6 years now, (i caught it early i was 14) & im on rituximab for infusions. i started off at every 6 months & i’ve progressed to yearly & now every 18 months (yay!) i’ve noticed that this medication lowers my immunoglobulins A LOT & the last time i was infused was dec 2024 & the entire spring of 2025 i was constantly sick, it’s been 18+ months & my immunoglobulins are still low & my neurologist said it was okay for another infusion on a lower dose, but in my labs my immunoglobulins are still scarily low (for the average person i guess?) i am worried about getting constant infections again & was wondering if anyone else is experiencing this? what do you do to make sure you don’t get sick with such low levels. i know that’s what rituximab does, but i can’t help but have a little PTSD from my last infusion of being constantly sick after, honestly anything helps im just annoyed & having a lot of anxiety :(

[u/merlynne01]

It is definitely your gammaglobulins that are low

• not just your B cells (lymphocytes)?
  

Could you share the specific immunoglobulin and the figure? For example IgG levels and IgM? They’re not all created equal when it comes to immunoprotection.

Also your CD-19 b cell counts.

I’m sorry, I have a sneaking feeling you might possibly be confusing the two. Apologies if I’m wrong.

I’ve been on Ocrevus - a derivative of Rituximab - for four years and I work in hospital medicine surrounded by infection. So far my immunoglobulins are holding steady but naturally my CD19 counts are zero because that’s what the medicine does.

[u/Strict_Bear_5122 → u/merlynne01]

sure, i appreciate you asking! my results as of today (which are the lowest they’ve been, they’ve been declining since 2020) were: IgA 25.3 MG/DL, IgG 415 MG/DL, & IgM 31.1 MG/DL

all my cbc results came back in the “normal” range if that’s what you are referring to (i might be confused though lmk) my WBC was 7.3 thousand/uL & RBC was 4.49 million/uL for specifics

for some reason i feel the opposite with rituximab & idk why

[u/merlynne01 → u/Strict_Bear_5122]

Alright! You are quite right. You are suffering from something called prolonged hypogammaglobulinaemia. They’re all low but the IgG is the most concerning in terms of infections.
The way I see it - and this should be discussed with your neurologist and will depend on the country you’re in and insurance, etc. you’ve got a few options.

1. Continue with the rituximab but ask your neurologist if you’re eligible for an infusion of IVIG (immunoglobulin). Emphasise your persistently low ig and your recurrent infections.

2. Discontinue your rituximab until your IGs recover. Can take years in some cases. There’s some evidence b cell depleters go on protecting you for quite some time but you could discuss an interim DMD in the meantime while your b cells recover.

3. Continue with rituximab regardless. I don’t love this option but your neurologist must be suggesting it for a reason - MRI changes, recovering CD19s (these won’t show on a cbc as they’re in the lymphocyte differential). It could be your neuro is seeing these recover so he is extrapolating that some of these recovering lymphocytes will naturally mature into plasma cells and antibodies but that to reduce MS risk, he needs to start rituximab again soon.

I’d chat to your neurologist or nurse and express your concerns, ask the above questions and ask them to help you risk assess rituximab versus another DMD.

[u/Ladydi-bds]

Being stressed is understandable and you know doesn't help. With my DMT and also low in that area, I steer clear of crowds, any sniffles/coughs, and hand sanitize often any time I touch something outside of my home and car. The one with aloe is the best. Have one in my car and my purse.

I did get sick once since starting and did it to myself kissing my fathers forehead before he knew he had Covid.

ETA - Can't hurt to Lysol everything as well in home/car to have a clean area to return home to.

[u/CupOfMS]

I also have low immunoglobulin and was sick during the month after my first infusion 1.5 years ago. About a month and a half ago, my neurologist started me on immunoglobulin infusions that I have every two months for 6 months, then we re-evaluate.

I’d definitely see about getting something to increase your levels or change your DMT. Because of my low immunity, I developed chronic sinusitis—which my neurologist confirmed is because of my infusions—and I had to have sinus surgery two days ago to treat it.

Not to scare you, but being sick all the time is not acceptable. I go to a really good MS clinic at a university hospital, and they said about 1 in 5 who get the infusions need immunoglobulin infusions as well, and to space out their infusions additionally.