Cloudy with a Chance of Autoimmunity

Sometimes everything gets screwed up and it's all for the best.

My 2yo son Dibbs was screened for celiac disease and for celiac genetic markers at the same time his big sister was in July 2013 through a free screening session by a team from the Center for Celiac Research out of Mass General Hospital for Children.

In late August, we learned in a letter that Dibbs was negative for antibodies and that Sweetie was positive. By the end of September, we had her official biopsy-confirmed diagnosis. By the end of December, we had her (and my) genetic test results, but not his. I wrote to and called the research clinic and explained my urgency to know whether or not my baby also had the gene we have. They told me that, as soon as they had more testing kits arrive, they would expedite his test results and email me since his sister was a confirmed diagnosis.

But in February, I received an email saying that the original letter stating that his celiac antibody test was negative should never have been sent. They did not have any record of actually performing the test and did not appear to have a sample on which they could perform the genetic testing either. His blood sample was just not there.

Now, this is where I should say that, while I was angry to have learned I received false results, the Center for Celiac Research has been very communicative and helpful in exploring what happened. They recommended I have my son re-screened elsewhere and sent the case to a review board.

My son's pediatrician ordered a celiac panel for us last week. A celiac panel consists of at least these 4 tests:

1. tTG (anti-tissue transglutaminase)-IgA
2. EMA (anti-endomysial antibodies)-IgA
3. IgG
4. Total serum IgA

Now, the reason you need all of them is that, if #1 alone is positive, it could be a false positive if you also have another autoimmune disease (like, say, type 1 diabetes). If #2 is negative, it could just be that you don't have enough intestinal damage for it to show as positive yet. Test #3 is kind of a backup test for a different form of antibody, but it's not nearly as specific for celiac. And if you're found in test #4 to have a deficiency in the amount of IgA antibody you're able to produce, well then, you may as well just discount the whole lot of it.

For the record, Sweetie's panel results as run by Children's Medical Center (with standard reference range they gave us in parentheses):

1. tTG IgA: >128 (normal range <10)
2. EMA IgA: 1:80 (normal range 1:10)
3. IgG: 1 (normal range <10)
4. total serum IgA: 152 (normal range 46-345)

Guess where Dibbs' problem was though. That's right. A problem with Test #4. He is apparently IgA deficient. His total serum IgA clocked in at...10.

This is from the page on celiac testing at About.com:

If you have a very low total serum IgA, that can invalidate the three blood tests that rely on your IgA levels. People with celiac disease suffer from low total IgA levels about 10 to 15 times more frequently than people in the general population.

Now, Dibbs has no symptoms for celiac, we don't have a genetic result for him to know if he's susceptible, and the other three tests came back negative/normal range. So that's good, right? Except for the whole "invalidate" part. Our pediatrician has deemed the panel "inconclusive" for this reason.

IgA deficiency also, however, according to my friend Wikipedia, has "an association with autoimmune disease" with patients having "a higher risk of developing autoimmune diseases in middle age."

Well, crap. Seems the crosshairs are on my little fella as well.

But here's the silver lining as I see it.

First of all, nothing seems wrong with the boy, and of course we're glad of that. :)

Secondly, I've since discovered, in all my communication with the research coordinator who did or did not run the original test, that their clinic tests only for tTG IgA. They would never have run the total serum IgA test for this research study to know that he was deficient.

So had they actually run his sample, I'd still have received a negative result. But I wouldn't know that I couldn't trust it.

If nothing had gone wrong with Dibbs's screening, I'd have had no reason to have him re-screened. I would not have suspected IgA deficiency. I would not have understood that the Center for Celiac Research runs only the 1st component of the panel. I would not have any of the information I currently have.

But I'd have the HLA genetic marker results...which I still intend to get.

In the meantime, like I said, he's asymptomatic. I hate to think that I'm continuing to expose someone to gluten who may be likely to present with celiac or even that I might somehow increase the odds of his developing an autoimmune disease by the choices we make now, but here's the thing...

As Hubster and I always say, you do the best you can with the information you have in the moment. We are already lightyears ahead of where were with our daughter who was a year and a half older before she was diagnosed. We are already expertly prepared to deal with diabetes and celiac. And if all Dibbs is is IgA deficient (one hopes), it's mostly harmless and there's nothing to be done about it.

As Wendy relayed from Dr. Fasano in a post that gave me comfort after my daughter's diagnosis, "you can't go back; you can only move forward."

So forward we go.