Decrease Interleukin 6 and 17

[irishgirl]

I have Mannose Binding Lectin Deficiency Disease and IgA Deficiency. I also have decreased Interleukin 6 and 17. When I get an infection my bloods don't really show that I have an infection (only happened 3 times - twice with septicaemia and one other time). My CRP and ESR never go up and my white count doesn't really change. My neutrophils are always up but I am on Prednisolone so that is the cause. Also though it is probably due to being on the steroids I don't get fevers when I get an infection. I am wondering if there is anyone here knows what means having decreased Interleukin 6 and 17? and can it affect blood results?


Emma

[s162216]

Hi Emma,

Whilst I'm in no way a doctor, or even someone who did an immunology focused degree I do have a good understanding of the immune system via my pharmacology degree and hope that I may be able to help.

The interleukins are a series of cytokines, which act as signalling molecules in the immune system, and looking up what IL-6 does in "Janeway's Immunobiology" (an excellent immunology textbook - see here for a free online version showing the information I'm referring to) it appears to be associated with IgA production and the inducement of the "acute phase" of infection (e.g inflammation, fever etc) which likely explains why you have an IgA deficiency and lack showing certain inflammatory responses. Similarly, IL-17 is  also associated with the the inflammatory response (see here as the online edition of Janeway's Immunobiology is quite old and doesn't have hardly anything about it) via inducing other pro-inflammatory cytokines, but their actual biological role is still unclear. 

C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) are both markers of inflammation in the body, and hence if they are raised then an inflammatory response from infection could be a cause. The point is though that they are only indirect markers of infection, and are open to interpretation (i.e if they are raised it could be for many other reasons than infection) which is why ideally culturing of a suspected infection is needed to properly identify if there is one. Obviously if the inflammatory response is compromised in some way like with you then its reasonable to assume that the CRP and/or ESR may not go up. 

Septicemia is a special case as the blood is normally free of bacteria etc, and if they do manage to get into the bloodstream and cause a systemic infection then an intense inflammatory response is induced as the body essentially over-reacts and intensely induces the systemic release of TNF-alpha (a pro-inflammatory cytokine which in normal non-systemic infections is released to help control infections locally). Systemic release of TNF-alpha subsequently leads to systemic inflammation throughout the body (so called "septic shock") which is usually life-threatening unless promptly treated (this diagram from Janeway's Immunobiology illustrates it quite well).

Does that answer your question Emma? Next time you see your immunologist ask them as I'm certain they'll be able to give a much easier and probably more accurate explanation than I can! I'll try and help though if you have any more questions about it.

Sam.

[irishgirl]

Thanks Sam. It definitely helps. Am wondering if you know what would happen to my white cells with having a decreased IL-6.

Emma

[s162216]

Sept 14, 2014 20:05:03 GMT irishgirl said:

Thanks Sam. It definitely helps. Am wondering if you know what would happen to my white cells with having a decreased IL-6.

Emma

The question is a bit too broad to give an answer to unfortunately as "white cells" refer to many different types and classes of immune system cells, including amongst others neutrophils and leucocytes. Really to have any idea of what is actually going on you would need to know the levels of the individual components; it probably doesn't help that IL-6 is also involved in many different areas. I feel that I would be going beyond the scope of my knowledge to speculate on your question, and suggest that you ask your immunologist the next time you see them as I'm certain they'll be able to help.

Sam.

[irishgirl]

Thanks Sam