Table 2.

Initial laboratory and immunohistochemistry in Riedel’s thyroiditis

Case	TSH	Free T4	Free T3	TPOab	Tgab	TRAb	Calcium	PTH	CRP
1	0.01	26	8.1	Neg	Neg	Neg	Normal	Normal	142
2	Elevated	Low	NA	NA	NA	NA	Normal	Normal	Elevated
3	123	9	4.4	Neg	Neg	Neg	2.29	Normal	Normal
4	19	5	2.4	Neg	Pos	Neg	1.21*	<0.3	Elevated
5	118	<5.5	<1.5	Pos	NA	Neg	Normal	Normal	10
6	111	2	2.7	Pos	Pos	Pos	Normal	Normal	119

Normal range: TSH 0.3–4.2 mIU/L; free T4 12–22 pmol/L; free T3 3.1–6.8 pmol/L; thyroid peroxidase antibodies (TPOab) <34 kIU/L; thyreoglobulin autoantibodies (Tgab) <4.0 kIE/L; thyroid receptor antibodies (TRAb) <1.8 mIU/L; calcium 2.15–2.50 mmol/L; PTH 1.5–7.6 pmol/L; CRP <3 mg/L; * ionized calcium 1.15-1.33 mmol/L

NA not available