There isn't much, as non-celiac gluten sensitivity is just beginning to be recognized as a real phenomenon by scholars in the field. I doubt it will be very long though. This study states:

Patients with [gluten sensitivity] do not present significant autoimmune or allergic comorbidities, and, as we also have shown here, the serology for common autoantibodies, including anti-tTG IgA, is negative.

There is a need for more research here as the anecdotal evidence (like Dr. Wahl's recovery) seems to point to a link.

Also, keep an eye on Dr. Alessio Fasano. He's one of the leading researchers in this area, and has published research linking celiac and other autoimmune diseases.

And that's only considering gluten...

Also look at the work of Seignalet a French Physician http://paleozonenutrition.wordpress.com/2011/04/01/dr-jean-seignalet-ancestral-diet-and-auto-immune-disease-trials/

He carefully documented the number of people who showed 50% or more improvement in auto-immune conditions following a paleo style diet. His work is not well known but deserves a bigger audience.

A 2010 paper in gut microbes showed a decrease in inflammation in non-celiac patients in response to a gluten free diet. It's unclear what caused this reduction: the authors posit this was caused be a reduction in bacterial load, but it would need a follow-up study to test that idea. Another possibility could be that the lack of gluten is what reduced the inflammation.

From the paper:

Cytokine production by peripheral blood mononuclear cells (PBMCs) stimulated with fecal samples of healthy individuals before and after the GFD was also evaluated to establish the possible relationships between the stimulus of the gut microbiota and the host immune function under this dietary practice.11 PBMC cultures were considered a good in vitro model for such studies since monocytes of the intestinal mucosa are known to be constantly replenished by blood monocytes.14 Immunostimulatory properties of feces, which up to 50% can be represented by bacteria, were remarkably reduced as a consequence of the GFD, inducing a significantly lower production of pro-inflammatory cytokines and chemokines (TNFα, IFNγ and IL-8) and anti-inflammatory cytokines (IL-10) in PBMCs than those collected before the GFD. It seems that GFD led to a generalized reduction of bacterial-induced cytokine production as a result of the generalized reduction of the total large intestinal bacterial load, as detected in patients under a gluten-free diet.8 The fact that the GFD led to reductions in total Bifidobacterium and B. longum numbers could also explain the reductions in the ability of fecal samples to stimulate IL-10 production, since strains of this genus and species might preferentially stimulate IL-10 secretion.15,16

The Paleo Diet by Cordain mentions Sjogren's in the list of diseases reported to improve. I haven't seen it on the forums. I asked about it on the Neuromyotonia forums and a few said they tried but without success. My suspicion is that many of these will be helped but not cured by diet. As frequently discussed here, adrenal exhaustion (aka HPA axis dysfunctionis probably also a big contributor, though sadly there is little to any research to that effect right now. Hormones control Homeostatis and are the difference between a tolerant immune system and one that goes bonkers. It's also not clear if these lifestyle changes only prevent disease or can also cure them, as once the process has started it may feed upon itself.