need help interpreting thyroid lab tests

[klo2011]

Hello - I am a 35 yr old female who has always felt fatigued and now even more so as I get older.  I am desperate to end my constant fatigue so on Aug '10 I had some blood work done which showed HIGH Anti TPO Ab and high T4 but seemingly normal TSH, which I listed below. I need help interpreting these results and my general doctor seemed nonchalant and gave me some low dose thyroid medication but feel I should see an endocronologist for a 2nd opinion.  Your help and feedback are greatly appreciated!  Thank you....

Thyroglobulin Ab   <less than 20.0 I/mL   normal range is 0.0-39.0
Anti TPO Ab   high 78.1 IU/mL normal range is 0.0-34.9
Thyroxine or T4 high 11.8ug/dL normal range is 5.7-11.4
T3 Uptake 24.7% normal range is 22.5-37.0
TSH    2.45mU/L  normal range is 0.38-5.50
Free Thyroxine or T4 1.2ng/dL normal range is 0.7-1.7

[goolarra]

I've never had a B-12 test.  As far as diagnosing a thyroid problem is concerned, it's not crucial or even useful.  However, once we have one autoimmune disease, we are more likely than the general population to develop a second.  Pernicious anemia (inability to metabolize B-12 through the gut) is another autoimmune.  It could explain your fatigue...  

[klo2011]

Thank you so much for your quick response!   Although I was prescribed 0.5 of levo medication, I haven't taken it because I want to get a 2nd opinion. I will follow your advice and ask for a FT3 level test as well as VitB12 (is this crucial or a nice to have?)

I will certainly follow up and thanks again.

KLo

[goolarra]

High TPOab indicates autoimmune thyroid disease, Hashimoto's thyroiditis, the most prevalent cause of hypo in the developed world.  With Hashi's, your immune system attacks your thyroid, eventually destroying function.  There are a couple of different schools of thought on antibodies.  Some feel that if you don't have an autoimmune disease, they ought to be zero period.  The range of 0.0-39.0 indicates that some think a few antibodies are considered "normal".  We often see antibody numbers in the hundreds or even thousands, so your 78.1 could be considered "borderline".  In my opinion, I think you fall nto the borderline group and would want to have the test repeated to confirm.

T4 and T3 uptake are considered obsolete tests and of limited usefulness.  

Several years ago, AACE recommended TSH range be adjusted to 0.3-3.0.  Most labs and doctors still use old ranges.  Your 2.45 is fairly close to the top of the new range, which indicates hypo.

Your FT4 was right in the middle of the range, and this is a target level for FT4.  The other important lab is FT3, and your doctor did not order that.

What thyroid meds do you take?  Was there any improvement in symptoms at all with meds?  Have you had any follow-up since starting meds?

The tests your doctor ordered indicate that he may not be the best thyroid doctor in the world.  I think a second opinion would be an excellent idea.