[carbocation]

Tissue biopsy is the gold standard for Celiac diagnosis; the blood tests are used to help determine who needs a biopsy (although it is true that some people think the biopsy is unnecessary). A normal biopsy procedure actually involves multiple biopsy specimens from nearby parts of the duodenum to be taken, so if they followed protocol it is unlikely that they missed the more-or-less pathognomonic signs of Celiac.

That said, if you do have Celiac and the biopsy was wrong (it happens), then your symptoms should actually take quite awhile to resolve. This is because part of the symptomatology comes from the derangement of the duodenum (villous atrophy, etc). Only by allowing it to heal over weeks to months would you expect to see real improvement.

I doubt that you have Celiac, given the biopsy results, but there is truly no harm in trying the diet.

Also, the genetic test is definitely less sensitive and less specific than the biopsy; I'm not sure why your doctor recommended this afterwards.

[savemylife]

The doctor wants to run the genetic test because if that's negative, we can rule out Celiac. A positive result would only indicate that it's still a possibility. If the bloodwork had come back negative she wouldn't have bothered, and just rule out Celiac then and there, but it was "strongly positive".

[carbocation]

This is not how the diagnostic chain for Celiac is designed to work. Optimally, you would proceed like so: (a) patient has symptoms consistent with Celiac; (b) patient gets tested for either antibodies (e.g., antiendomysial IgA) or genetics; (c) if 'b' is positive (or sometimes if it is negative and clinical suspicion is strong) then biopsy is performed.

Since the biopsy is both more sensitive and specific than the genetic test, one should not side with the genetic test over the biopsy in most circumstances. The genetic test cannot rule out Celiac. Why? The genetic test looks for specific common variants. It cannot discover anything that is not already in the database; therefore, it cannot rule out Celiac for you - it can only make it more likely or less so. (As an aside, this is why treating 23andme as a medical tool can be dangerous. Let's say you have common genetic variants protective for breast cancer -- but, lo and behold, you also have a rare variant previously undescribed in the literature and not captured by the 23andme chip. You actually have a high risk of cancer, but would think just the opposite based on the common variants examined by 23andme. Sorry for the lengthy aside.)

Let's say that Celiac is 100% determined by your genetic variation. It's still possible that there are common variants that cause Celiac, and rare ones. The tests that we have right now only look for relatively common variants, which is why they have varying accuracy in people of different genetic backgrounds but generally are positive in 95% of people with biopsy-proven disease... which gets me back to my main point, which is that you have a biopsy; the genetic test is nothing more than a waste of your money from a biological standpoint. From a peace-of-mind standpoint, I can appreciate why you want this.

[savemylife]

Thanks for the explanation. I hear you on the genetic testing. The whole process is frustrating. I do realize that I sound like that patient who wants to have "disease X" at any cost, and is looking for loopholes in the diagnostics.

But I want to know what's wrong with me, and what I can do to get better. This whole Celiac thing is really starting to feel like yet another dead end for me (Lyme Disease, Fibromyalgia, Sleep Apnea, Psychiatric, etc; just add it to the list.)

Still, I want to give it a good shot, and that seems to mean staying on the diet for a few months and see if I improve. If I feel better, who cares what the tests say? Though it would be nice to have confirmation, I just want to feel better.

[carbocation]

Yes, as I suggested in another post in this thread, there is absolutely no risk in doing the no-gluten diet (except maybe higher cost of food), so there is basically no downside. Your expected benefit is greater than or equal to zero, so keep it up!