Hi Inge. Glad that the diet is beginning to work for you.
I did a bit of research on the Wegener's. Dr. Sarah Myhill has an interesting snippet about it and 'autoimmune disease' in general in the following info.... http://www.drmyhill.co.uk/wiki/Autoimmune_diseases_-_the_environmental_approach_to_treating
As you will probably pick up from my posts, I avidly believe that disease is a combination of the ingestion of food and substances that take more nutrition away from the body than it provides triggering a welcome environment for pathogenic microbes and parasites to move in and proliferate (and eat our food and nutrition!)
Many products and 'food-like substances' gradually erode health and vitality, undermining the body's ability to defend itself. It doesn't happen overnight, it's a gradual process that wears away at the nutritional strength over years.
Unfortunately, things like diet coke are among the worst culprits. Contrary to popular opinion, our bodies cannot cope with everything we throw at them! Food containing 'empty' calories like sugar, unnatural chemical additives, that is denatured or fractionated or missing any of its original nutritional elements, robs the body of nutrition.
If you think of nutritional elements in food being like codes, each element fits into the digestion in different ways. So the elements in say, an orange, are like a code, telling the body what the food is, and how to metabolise it. Remove any one, or a part of one element and the code gets scrambled. The body says, oooh, something's missing! It then has to go off and 'borrow' the missng element in order to complete the process.
You imagine that happening with products that are a jumble of mixed messages or missing 'code'. The more of that type of food or drink we are ingesting, the more the body has to 'borrow' from other processes. It cannot do that indefinitely. Eventually, somethin's gotta give.....
The benefit of going low carb is that a lot of the 'empty', denatured, fractionated, and jumbled food is taken out of the equation. Highly processed wheat, meat, and sugar products are avoided, and get replaced by fresh vegetables (the more, the better), meat, fish, eggs, fats, etc. So straight away people are getting considerably more nutrition and are starting to build the supplies back up.
Healing through diet doesn't happen overnight - all the niggly symptoms we get over the years are our bodies telling us they are struggling - but healing can happen over time once the antagonistic substances are removed and replaced by the protagonistic ones.