Questions about blood tests

[Christy85]

Hello, I’m so glad I found this group. I’ve got lots of questions and would love some in site. Backstory: about a year ago my son who 7/8 had been having serve stomach pains, went to the doctor he thought appendix we did the scans and nope he was constipated. My son has to see a urologist for overactive bladder so we did bowel clean outs with her and further X-rays to make sure that was taken care of. When the stomach pains continues after that she got him an appt with a peds gi doctor. She also suggested limiting or taking out milk. We set the appt up but also take out cows milk and it helped a ton! No more tummy pains!! I was advised to keep his appt and I could just say stomach pains stopped after we took milk out. Gi doc ordered blood tests to just get an idea and make sure it wasn’t anything more. I’m going to post numbers because this is where I start to get overwhelmed. 
Ttg:240.2 Ttg: positive 

after this his doc scheduled an endo for biopsy’s to be taken. We are still waiting on those to get back, should be middle of this coming week. She also ordered another blood test: Endomysial antibody titer lgA: which came back at 1:80.  I’m just curious what these numbers mean. Thanks for the help in advance! Since he’s had his biopsy we’ve started the gluten free route  

 

[cristiana]

Hi Christy and welcome!
 

Would you be able to forward the lab's "normal" ranges with the figures you've sent us.  They should appear with the printout.  Labs ranges vary enormously.

Many thanks.

Cristiana

[Christy85]

3 minutes ago, cristiana said:

Hi Christy and welcome!
 

Would you be able to forward the lab's "normal" ranges with the figures you've sent us.  They should appear with the printout.  Labs ranges vary enormously.

Many thanks.

Cristiana

Yes so for his endo it says normal range is 1:10 his was 1:80 and for his ttg it says standard range is 0.0-15 U/mL his was 240.2 

[cristiana]

Thank you for sending those ranges.

Re: blood tests, put simply, the doctors are looking at the antibodies that the body makes in response to eating gluten.  Once numbers are above the upper normal ranges, doctors suspect coeliac disease.  I hope this explanation helps, but there are people better placed to answer that on the forum who can chime in if you need further detail in this regard - do ask if that is the case.

In the meantime here is a great post which I think will help you prepare for a formal diagnosis.  "Going gluten free" can sound quite simple but there are lots of things that you will need to think about to help your son.  It may feel a little overwhelming at first but in time it becomes second-nature.  Feeling well is so worth it!   

All the very best, and do come back if we can help further.

Cristiana.

 

[trents]

Was the endomysial antibody titer stated to be positive? I'm not familiar with how they gauge that since it uses a ratio rather than a raw number. I think the 80 might be the threshold number at which the antibodies were still detected as they increase the dilution in the titer process but I'm not sure about that.

I do know that the endomysial antibody test is considered to be a less sensitive test so if it is negative then it will still miss a lot of celiac cases.

But the tTG-IGA is very strongly positive and that particular antibody test is considered the centerpiece of celiac antibody testing, combining good sensitivity with good specificity: https://celiac.org/about-celiac-disease/screening-and-diagnosis/screening/ It is unusual for a doctor to run the endomysial out of the box since it is a less sensitive test and also an expensive one.

[RMJ]

The endomysial antigen test is very specific for celiac disease.  They make serial two-fold dilutions of serum - 1:5, 1:10, 1:20, 1:40, 1:80, etc. Then they apply the serum to a microscope slide that has a type of tissue on it that includes the endomysial antigen.  Celiac antibodies bind to the antigen. They then wash and add another solution that enables antibodies to be visualized, and look under a microscope.

The more the serum can be diluted and antibodies still be detected, the more positive the result is. 1:80 is a moderately strong positive.

The endomysial antigen is now thought to be TTG (tissue transglutaminase), so the test looks for anti-TTG.