Celiac Disease and Psoriatic Arthritis

I was trolling around PubMed today and came across this topic... frankly, I'm surprised at myself for not looking at it before, considering my history.

A study was published in the Journal Rheumatology in 2002 linking psoriatic arthritis to celiac disease. The researchers found that there was a higher rate of celiac disease in their PsA patients. They state:

An increased prevalence of coeliac disease in patients with PsoA has not been reported previously. Among our patients, 4.4% had coeliac disease (ascertained by the presence of villous atrophy) compared with 0.4% in a large Swedish adult population of blood donors.

also:

Patients with PsoA have an increased prevalence of raised serum IgA AGA and of coeliac disease. Patients with raised IgA AGA seem to have more pronounced inflammation than those with a low IgA AGA concentration.

Celiac Disease (or coeliac disease, if you live in Europe), is an autoimmune disease in which the body confuses gluten (a protein found in wheat, barley and rye, as well as some other grains) with toxins. If a "celiac" ingests gluten, the body produces antibodies to break down the intestinal wall, destroying the villi which are used to digest food, in a flawed effort to save itself from toxins. When you lose those villi, you get super sick - anemic, weak, skinny. The only known treatment is complete adherence to a gluten free diet.

What this study is saying is that people with psoriatic arthritis are more likely to have celiac disease, and that patients with more acute inflammation in their psoriatic arthritis could possible also have worse celiac disease.

I have had celiac disease and have been on a gluten-free diet for 16 years. I continually struggle with the autoimmune diet (no dairy, alcohol, sugar, etc - boring!) but the gluten-free part of the autoimmune diet has been easy. Gluten makes me very, very ill, and I'm never tempted to cheat. Its not worth it. When we're better friends I'll describe what happens to my gut when I eat wheat. But not yet. I don't know you well enough.

The researchers state, at the end of their article:

Studies of the gastrointestinal mucosa in PsoA patients are therefore needed. Controlled studies of the effects of a gluten-free diet on the severity of PsoA are also required.

In short, more psoriatic arthritics should go on gluten-free diets to see if they get better. In a research setting, with control subjects eating gluten, etc. etc.

Of course, the plot thickens. Here in the U.S.A, another study was conducted which looked at the prevalence of IgA antibodies to gliadin (in other words, celiac disease) in folks with psoriasis and psoriatic arthritis. Their results found no increase in these antibodies in psoriasis and psoriatic arthritis patients. They state:

We found no support for the results of prior studies showing that elevated AGAs occur with increased frequency in patients with psoriasis.

I'm not convinced. Look at this abstract if you want to have your mind blown. It lists many, many skin manifestations in auto-immune diseases - from Grave's to Crohn's to celiac disease. It is apparent our skin, as one of the organs of our bodies, is greatly affected by our immune system, especially when it is in havoc. I'm continually astounded by the links between all of these autoimmune diseases, and by how so much of this science is still in its infancy. And it appears that our skin disease, and our joint disease, may be related to a gut disease.

Hm. I meant for this to be a short blog post. But isn't this stuff fascinating? And here's another piece in my puzzle:

I have no idea if a gluten-free diet would work on my PsA, because guess what... the year I developed celiac disease was the year my knees first showed signs of arthritis. Autoimmune diseases can be triggered by something in the environment, and in 2003 I had just come back from Tonga with a bad case of giardia, a parasite. We think it triggered the celiac disease, and I know now what I didn't realize then - I was developing two diseases back in 2003 instead of one. At the time I had some physical therapy, but ended up ignoring my knees in order to focus on my gut. After a while, the knee pain was pretty manageable.

So here's my question: Did the giardia trigger two diseases, and did the new gluten free diet slow the disease process in my knees?

A final note: I've not had a single bout of ... um... unmentionable gastrointestinal troubles ... since I went on Humira for my arthritis. Go figure.