From Amigo's post [interesting by the way] I am just seeing Vicky's for the first time. Vicky are you out there? Can you tell us how this turned out?

Paula

The new view of Vitamin D has taken some getting used to. It shows the value of constantly questioning what we "know" - at least until it drives us nuts.

For those who wonder about Th1/Th2 cytokines, very briefly:

Cytokines are the hormonal messengers responsible for most of the biological effects in the immune system, such as cell mediated immunity and allergic type responses. Although they are numerous, cytokines can be functionally divided into two groups: those that are proinflammatory and those that are essentially anti-inflammatory but that promote allergic responses.

T lymphocytes are a major source of cytokines. These cells bear antigen specific receptors on their cell surface to allow recognition of foreign pathogens. They can also recognise normal tissue during episodes of autoimmune diseases. There are two main subsets of T lymphocytes, distinguished by the presence of cell surface molecules known as CD4 and CD8. T lymphocytes expressing CD4 are also known as helper T cells, and these are regarded as being the most prolific cytokine producers. This subset can be further subdivided into Th1 and Th2, and the cytokines they produce are known as Th1-type cytokines and Th2-type cytokines.

Th1-type cytokines tend to produce the proinflammatory responses responsible for killing intracellular parasites and for perpetuating autoimmune responses. Interferon gamma is the main Th1 cytokine. Excessive proinflammatory responses can lead to uncontrolled tissue damage, so there needs to be a mechanism to counteract this. The Th2-type cytokines include interleukins 4, 5, and 13, which are associated with the promotion of IgE and eosinophilic responses in atopy, and also interleukin-10, which has more of an anti-inflammatory response. In excess, Th2 responses will counteract the Th1 mediated microbicidal action. The optimal scenario would therefore seem to be that humans should produce a well balanced Th1 and Th2 response, suited to the immune challenge.

from- http://www.bmj.com/cgi/content/full/321/7258/424

so..................

I'm trying very hard but still don't feel like I have the key words to quite put this all together. Is t1 disease an over reaction to normal parasites in humans or does it mean we have parasites that we should get rid of and can't? both? none of the above?

Nothing would surprise me.
more info if you have some and thanks
paula