Help Decoding Blood Test and Unserstanding

[MissMegan]

Hello! I was hoping someone would be able to explain a little more to me about the recent blood results I have received. 

Long story short, I am a female in my mid twenties, I lost 30 pounds in the span of three months with no explanation (5'6" 128lbs in February of 2020, down to 98lbs in April of 2020). I have since gained a few pounds over the last year, but not much, I now rest around 101/102lbs. I was tiny before, and now I am extremely underweight. I am eating normally and have been, no changes in exercise, no explanation. I noticed I started having typical GI issues related to Celiac, went to four different doctors who kept telling me I had an eating disorder (which I am eating the exact same as I always have and have not changed any exercise patterns) which was very frustrating because I knew something was wrong, but no one was taking me seriously. Finally one doctor decided to test me for Celiac and we got a positive result back on one of the tests and I now have to get an EGD and colonoscopy done (they want to look for multiple things at the same time for a biopsy from what I understand). However, no one has really explained anything to me so I have been trying to do my own research. (They tested me for other things such as diabetes, thyroid, etc. and nothing was positive except the celiac panel). 

These were the tests run and the results (picture of test and result numbers listed below):

• Antigliadin Abs, IgA; Antigliadin Abs, IgG; t-Transglutaminase (tTG) IgA; t-Transglutaminase (tTG) IgG; Immunoglobulin A, Qn, Serum
• 

The only thing that came back positive was the t-Transglutaminase (tTG) IgG at a score of (7) which is scored as a weak positive. What does this mean? Is this also affected also by the amount of gluten that is consumed (I do not eat much to begin with because I picked up that it was gluten that was giving me issues and I have been reading that you have to eat a good amount of gluten to be able to get a solid positive test).

What does it mean that the TTG-IGG came back positive, but the TTG-IGA came back negative? And that none of the other ones came back positive? I've also been reading about sensitivities and specificities of the blood tests, but don't entirely understand what that means if someone can help explain that as well. 

Thank you all so much ahead of time, I really appreciate your help to help me understand the beginning of this journey!

[trents]

The TTG is the most specific for celiac disease but it is not the most sensitive of the test battery you had run. Given that, if the TTG is positive I would think that is a strong indicator that you have celiac disease. The guideline for daily gluten consumption in order to get valid blood antibody tests is eating 1-2 slices of wheat bread (or the equivalent) for 8 weeks and for the endosocopy/biopsy, that amount of gluten for at least two weeks up to the day of testing. Since your consumption of gluten has been minimal I would suspect that it resulted in lower values than it would have if you had been consuming normal amounts of gluten prior to.

[Scott Adams]

Welcome to the forum @MissMegan! I agree with @trents that your results would likely have been higher had you followed the testing protocol and eaten gluten daily before the test. It's astounding how many doctors, and now computer systems like the one Kaiser has and I use, that don't properly inform you of the requirements necessary to avoid false negative results with these blood tests. It seems like much of this could be programmed into computer systems that won't allow the appointment to be scheduled unless the patient has complied, or would at least send out an automated email when such an appointment is scheduled.

In any case, you need to eat gluten daily for at least two weeks before the biopsy, and I would not worry about it, it is routine and no big deal:

 Perhaps ask your gastro if they will be taking at least 4 samples, which is the current recommendation. 

[MissMegan]

18 hours ago, trents said:

The TTG is the most specific for celiac disease but it is not the most sensitive of the test battery you had run. Given that, if the TTG is positive I would think that is a strong indicator that you have celiac disease. The guideline for daily gluten consumption in order to get valid blood antibody tests is eating 1-2 slices of wheat bread (or the equivalent) for 8 weeks and for the endosocopy/biopsy, that amount of gluten for at least two weeks up to the day of testing. Since your consumption of gluten has been minimal I would suspect that it resulted in lower values than it would have if you had been consuming normal amounts of gluten prior to.

Thank you!

[MissMegan]

16 hours ago, Scott Adams said:

Welcome to the forum @MissMegan! I agree with @trents that your results would likely have been higher had you followed the testing protocol and eaten gluten daily before the test. It's astounding how many doctors, and now computer systems like the one Kaiser has and I use, that don't properly inform you of the requirements necessary to avoid false negative results with these blood tests. It seems like much of this could be programmed into computer systems that won't allow the appointment to be scheduled unless the patient has complied, or would at least send out an automated email when such an appointment is scheduled.

In any case, you need to eat gluten daily for at least two weeks before the biopsy, and I would not worry about it, it is routine and no big deal:

 Perhaps ask your gastro if they will be taking at least 4 samples, which is the current recommendation. 

Thank you so much! I will be calling and asking about the samples and to follow up on the protocol because they never told me about the gluten challenge or to purposefully continue to eat it. Would it be worthwhile to do the gluten challenge and have them redo the blood work or is that unnecessary at this point? This is all so crazy and new, but I'm glad that after a year of going back and forth with doctors, someone finally took me seriously and we are starting to get an answer!

[Scott Adams]

You should definitely ask your doctor about a possible re-do of the blood test, but personally I don't think it's necessary (but if the doctors are willing to do it, why not?). The positive result is very specific for celiac disease, so I would just be sure she's eating a slice of wheat bread daily for at least two weeks before the biopsy. Should the biopsy be negative, to me it still would mean that she's likely in the non-celiac gluten sensitivity category, and should go gluten-free.

[jkc830]

I also have similar test results, and am confused by the information I am finding online (my appt w/ my doctor isn't until next week). I did not alter my diet prior to testing, but was not specifically eliminating gluten. I definitely eat gluten daily (likely equivalent to 2 pieces of bread), if not at ever meal.

Serum Immunoglobulin A is high at 427 (so not IgA deficient)

Tissue transglutaminase IgG is very high at 34 , but tTG IgA is within normal range at 1

HLA DQ2 Positive

All other markers were within normal range:

ENDOMYSIAL ANTIBODY SCR (IGA) W/REFL TO TITER - Negative

Cultivated Wheat IgE - <0.10 (class 0)

Wheat IgE - <0.10 (class 0)

Gluten IgE - <0.10 (class 0)

Gliadin AB IgA - 7 

Gliadin AB IgG - 4 

----------------------------

From most of what I have read, tTg IgG is only relevant if you are Serum IgA deficient, which I am not.  I know my doctor will decode this for me soon, but I'd love some insight before then. 

Thank you.

[Scott Adams]

@jkc830 Welcome to the forum. This article will be helpful:

 

[MissMegan]

On 3/4/2021 at 1:33 PM, Scott Adams said:

You should definitely ask your doctor about a possible re-do of the blood test, but personally I don't think it's necessary (but if the doctors are willing to do it, why not?). The positive result is very specific for celiac disease, so I would just be sure she's eating a slice of wheat bread daily for at least two weeks before the biopsy. Should the biopsy be negative, to me it still would mean that she's likely in the non-celiac gluten sensitivity category, and should go gluten-free.

Hello again! I wanted to come back and ask a question since I had the EGD done. The biopsies were negative, and they gave me no answers other than "it's not celiac" and no further guidance. Since the blood test was positive, and the EGD was negative, would this mean there is a strong likelihood that I am non-celiac gluten sensitive? I still have issues with most anything that contains gluten, and I'm sure there is hidden gluten in many things I am eating. Is the best method to figure this out to completely go gluten-free and see if my body reacts well to it? I have gained a few more pounds over the year, I sit around 105 now, but I am still severely underweight and it seems like nothing I am doing is helping me to gain any weight back. 

Thank you so much for all of your helpful guidance, I really appreciate it!

[RMJ]

You could go strictly gluten free, see if you feel better, and see if the antibody levels go down. Celiac damage can be uneven and the surface area of the intestine is large. The doctor might have missed it.