What roles do these play?

[ronnie]

hello,

I was wondering if anyone could explain to me what each thing does in our immune system? Please try as this is making my brain tired!

What does IgA do? What does it mean if there is a deficiency?
What does IgM do? What does it mean if there is a deficiency?
How does IgG work? And the subclasses? And if they're deficient? And if only one is deficient?

I just haven't found anything that explains this in a language I can understand. I've found heaps of basic explanations of cvid but I would like to have a more in-depth, basic understanding....if this makes sense.

See just a teeny weeny question or two! Thank-you very much,
Ronnie.

[emsy]

Hi Ronnie

I'm sure you will get great answers to these from more experienced people than me but my specialist nurse was telling me on Monday when I was having my infusions that IgA tends to be responsible for sinus type symptoms, IgG was responsible for the chest infections etc, and she couldn't remember what the others were responsible for. I found this quite interesting.

Emma

[s162216]

Hi Ronnie,

Be aware that it does usually take several months before the IVIG makes you feel less tired or ill, after 3 months I certainly started to feel 'different' although I couldn't quite work out how as had always felt the same and couldn't remember anything different.

Basically with the antibodies you have three types which are important in CVID: IgG, IgA and IgM.

The IgG does most of the work protecting against infection and as so its the most common antibody. If your deficient in it then obviously your in trouble as there will difficulty creating a specific immune response to an infection. IVIG replaces these antibodies with those from donated blood plasma so you get the antibodies that the donors had. IgG antibodies only last for about 21 days in the body, hence the reason why you have to have more infusions. This also protects you against things that you will have likely been vaccinated against, but as we can't develop a secondary immune response then vaccines usually don't work (The only vaccination that worked with me was tetanus!)

IgA protects the upper respiratory tract and is present in secretions such as saliva, mucus etc. This means that if your deficient in it then you can be prone to infections in this area, unfortunately at the moment its not possible to replace them as their mostly present in secretions not serum so they would be in the 'wrong place;. There is a very small chance of developing anti-IgA antibodies if your deficient and IVIG may cause a reaction as so, but your consultant will test you for these regularly and switch you over to an IVIG preparation with very low or 0% IgA in it to limit the chance of reactions (There is usually some very small amount in IVIG) if their detected.

IgM is more important in the primary immune response i.e its unspecific and will try to bind to and mark for destruction any infection immediately, theres no lag period in production like with IgG or IgA. If its unsuccessful and the infection persists then a secondary immune response with IgG and IgA will develop (but not in us!!). At the moment its sadly not possible to replace it either but its not quite as important in the immune system as IgG so its not too much of a problem.

I hope that you might understand what I'm saying above and if not feel free to ask me any questions!

Sam

[mali42]

Hi Ronnie
Every time we have an infusion we get antibodies from about 5000 different people so we have a good defence against the usual things like tetanus colds flu etc,

its still a good idea to keep away from people who are ill but you will have a defence against them,we just need topping up every few weeks,