First of all, how's your patient feeling? Is he feeling hypothyroid? What other symptoms does he have?
Without knowing that:
I used these references:
For some reason your patient is not making enough thyroid hormone. It can't be the iodine, because he's taking more then enough for the thyroid. So maybe it's one of the other building blocks of the thyroid hormones.
For instance tyrosine: does your patient eat enough good quality protein? And does he absorb it (stomach acidity etc).
Second possible reason:
The TPO antibodies are up, this could mean that there's not enough glutathione present (to mop up excess hydrogen peroxide). Again this could be a protein deficiency, but there are more building blocks to glutathione. He is getting selenium so that won't be it probably. Except when has mercury because mercury binds to selenium rendering it useless. There is a supplement for glutathione production which contains:
Recipee for glutathione building blocks (take 1/2 of it twice daily):
Does he have a deficiency in any one of these?:
L-glutamine 50 mg
L-glycine 50 mg
N acetylcysteine (NAC) 900 mg
Selenium as seleno-l-methionine 200 mcg
Vitamin C 8 mg
Q10 (ubiquinon) 10 mg
B6 as p5p 13 mg
B2 20 mg
Found it, it's Dutch: http://www.degezondheidslijn.nl/913-glutathioncomplex-aov-30cap
I have low glutathione myself and use whey protein to boost my protein intake. I don't take NAC. Although it works a treat, it lowers both my copper (good thing in my case) and zinc (bad thing).
Is he perhaps a vegetarian? That will make it more difficult for the body to get easily absorbable protein and also vitamins and minerals.
Third reason could be that too much T4 is being converted to RT3 on a daily basis. Too little T4 will lead to too little T3. From: http://www.stopthethyroidmadness.com/reverse-t3/.
For instance because of the high stress or a glutathione deficiency or protein deficiency which will make life hard for the liver.
The Thyroglobulin is high (5-25 ng/ml) from http://www.globalrph.com/labs_t.htm#Thyroxine
It says: "Thyroglobulin: nonspecific test that is elevated when the thyroid gland is inflamed or enlarged."
Or 3-40 ng/ml in http://emedicine.medscape.com/article/2089532-overview
Or is "Thyroglobulin" actually a test for TgAb? I couldn't find a consistent reference range for that.
Anyway, since I'm not sure which one it is, I can't use it in my reasoning.
Hope this helps