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Rituximab target question

62milestogojoe

What's a forum then?
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Hi, I'd be grateful if a member could tell me if the drug targets lymphoid progenitor cells.

More specifically, does rituximab target B-cell precursors alone or both B cell precursors and lymphoid precursors.

Thankso_O
 

Jonathan Edwards

"Gibberish"
Messages
5,256
Hi, I'd be grateful if a member could tell me if the drug targets lymphoid progenitor cells.

More specifically, does rituximab target B-cell precursors alone or both B cell precursors and lymphoid precursors.

Thankso_O

Only pre-B cells. Even the earlier pro-B cells are not targeted. Haemopoietic stem cells are not affected so there is no effect on T or NK cell production as far as we know.
 

neweimear

Senior Member
Messages
215
@Jonathan Edwards if the ritux phase 3 trials are good, I will be trying to get treatment. My consultant is very wary of ritux, he says he has seen fatal outcomes of tb reactivation as a result of rituximab. So im not sure if he will ever prescribe it to me, he calls it a big gun drug. If he does not treat me, I will have to travel for treatment, I am saving money at present should that arise. My question is, is tb a possible outcome from ritux treatment? And secondly, would it be risky travelling for treatment as one would be going thru busy airports with a depleted immune system. Thanks so much for any thoughts on that.
Also, I am interested on your thoughts on cyclophosphamide. We have nothing much to go on yet in terms of cyclo as a treatment for ME but in RA, can cyclo induce remission and how long of a remission would be standard? Would you see it as a possibility as a viable treatment for us if proved effective or too toxic and best avoided. Basically, is it a drug of last resort? Thanks.
 

Gingergrrl

Senior Member
Messages
16,171
he says he has seen fatal outcomes of tb reactivation as a result of rituximab.

Reactivation of TB and hepatitis are real risks with Ritux but if you have never had either in your lifetime (like me), then they cannot reactivate. PML can occur regardless but extremely rare. Please correct me, Dr. Edwards, if I got any of this wrong!
 

62milestogojoe

What's a forum then?
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221
Location
UK

Jonathan Edwards

"Gibberish"
Messages
5,256
My consultant is very wary of ritux, he says he has seen fatal outcomes of tb reactivation as a result of rituximab. My question is, is tb a possible outcome from ritux treatment? And secondly, would it be risky travelling for treatment as one would be going thru busy airports with a depleted immune system.

I have never heard of rituximab reactivating TB in autoimmune patients. Does your consultant actually know what they are talking about? Reactivation of TB is a significant common problem with anti-TNF drugs like enabler and humour but rituximab has nothing to do with TNF inhibition. Maybe since I retired cases of TB have been reported with rituximab but for the first twelve years I worked on it iI never heard of a case.

In general there is no risk in travelling if you have had rituximab. You might do well not to go to New Guinea but that's about it.

Also, I am interested on your thoughts on cyclophosphamide. We have nothing much to go on yet in terms of cyclo as a treatment for ME but in RA, can cyclo induce remission and how long of a remission would be standard? Would you see it as a possibility as a viable treatment for us if proved effective or too toxic and best avoided. Basically, is it a drug of last resort? Thanks.

Cyclo produces benefit in RA but it lasts about a month. So apart from dealing with life threaening crises, which are pretty much non-existent in RA now, it is useless. The toxicity is far too high. Bladder cancer is a major risk with long term repeated use. I understand the Norwegian physicians' interest in it but I would not want to use it.
 

neweimear

Senior Member
Messages
215
@Jonathan Edwards. Thanks for your replies, I cant wait to talk to my consultant! In relation to cyclo, why are Fluge and Mella using it if it does not bring long term benefit? I know they are trying it on severe patients now but if they only see benefit for a month, it seems strange. Would like to understand their reasoning for using it. Thanks again Jonathan.
 

62milestogojoe

What's a forum then?
Messages
221
Location
UK
Only pre-B cells. Even the earlier pro-B cells are not targeted. Haemopoietic stem cells are not affected so there is no effect on T or NK cell production as far as we know.
Clarification of rituximab action-differentiation between PRO and PRE cells

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Copyright 62milestogojoe 2017

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Copyright 62milestogojoe 2017 Rituximab targets CD20 protein on B cells. These are not present at the first stage of development or the last (plasma cell). Of interest perhaps---is that pre B cell receptor stage is still in the marrow. Does the B cell express CD20 at this stage in development or not until migration into the bloodstream as a naive B cell, or following progress to the secondary lymph nodes
@Hip

Resources used
Immunology-Kuby, Freeman publications
Medical immunology for students, Playfair and Lydyard, Chirchill Livingstone publications
Immunolgy series on Youtube by Armando Hasudungen
 
Last edited:

Gingergrrl

Senior Member
Messages
16,171
Copyright 62milestogojoe 2017 Rituximab

Thanks for your PM, Joe, and for posting your diagrams, which are very impressive, and I wish I had the ability to understand them!

Rituximab removes pre-B cells from marrow. It may actually have some impact on pro-B cells

What is the difference between "pre-B cells" and "pro-B cells"? (in the most basic terms for dummies)
 

62milestogojoe

What's a forum then?
Messages
221
Location
UK
Thanks for your PM, Joe, and for posting your diagrams, which are very impressive, and I wish I had the ability to understand them!



What is the difference between "pre-B cells" and "pro-B cells"? (in the most basic terms for dummies)
Hi, with regard to treatment with the drug I think Dr Edwards would be able to give you the best answer.

From what I've understood from early pro to immature phases the development is antigen independent stage. From the naive stage on it becomes antigen dependent. I guess the important thing to note is that the drug is targeting cells within the bone marrow. I am a dummie too.
Pre and pro simply means the cell hasn't matured into its final form.
 

Gingergrrl

Senior Member
Messages
16,171
I am a dummie too.

I don't think so :rolleyes:

Pre and pro simply means the cell hasn't matured into its final form

Are "pre" and "pro" B cells the same (meaning both simply have not yet matured into their final form) or do they differ? Also, which one comes first? I think from your diagram, the "pre" come first and are the precursor of everything that comes later?

Are B cells, T cells, and NK cells the three types of WBC's that make up the immune system or are there others? This fascinates me but I still lack the basics. I would love to study this some how in the future if I get better.
 

62milestogojoe

What's a forum then?
Messages
221
Location
UK
I don't think so :rolleyes:



Are "pre" and "pro" B cells the same (meaning both simply have not yet matured into their final form) or do they differ? Also, which one comes first? I think from your diagram, the "pre" come first and are the precursor of everything that comes later?

Are B cells, T cells, and NK cells the three types of WBC's that make up the immune system or are there others? This fascinates me but I still lack the basics. I would love to study this some how in the future if I get better.
Hi there are lots of others but I wanted to keep the diagram simple enough for everyone and couldn't fit much more on without it becoming a headbanger.:cry:

GG just track the origin of the B cell sequentially through to its final form-the cell that produces antibodies. Your chemo drug will target B cells within the bone marrow. Rituximab is a :devil: to your B cells