Pertechnetate thyroid uptake is not always suppressed in patients with subacute thyroiditis.
The authors studied the clinical courses and immunologic aspects in 15 patients (age range, 32-69 years old; 14 women) with clinical features that were similar to subacute thyroiditis (SAT). In 2 patients (group A) whose thyrotropin-binding inhibitory immunoglobulins (TBII) and thyroid stimulating antibody (TSAb) showed strongly positive activity at the initial visit, Tc-99m pertechnetate thyroid uptake (Tc-99m uptake) was elevated (5.6% and 3.8%, respectively, normal; 0.7-3.0%). In 6 (group B) of 13 other patients, Tc-99m uptake was not completely suppressed (2 normal, 4 near normal) and imaging showed uptake in one lobe. In 7 (group C), however, there was no evidence of uptake in either lobe. Inflammatory process was localized in one lobe in all group B patients, and was in both lobes in all group C patients but one. Serum TSH levels were detectable in at least 4 patients (2 group B, 2 group C) low in all. There were no patients in both groups B and C in whom TBII and/or TSAb were detected at the initial visit. In SAT, marked suppression of Tc-99m uptake may be ascribed mainly to inflammatory follicular cell damage, but it is not always suppressed, owing to an association similar to Graves' disease and other unknown mechanism(s).
Shigemasa
C
C
First Department of Internal Medicine, Faculty of Medicine, Tottori University, Yonago, Japan.
Teshima
S
S
Taniguchi
S
S
Ueta
Y
Y
Mitani
Y
Y
Yoshida
A
A
D000328:Adult; D000368:Aged; D001323:Autoantibodies / Q000097:blood; D005260:Female; D006111:Graves Disease / Q000000981:diagnostic imaging; D006801:Humans; D018828:Immunoglobulins, Thyroid-Stimulating / Q000097:blood; D008297:Male; D008875:Middle Aged; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D011989:Receptors, Thyrotropin / Q000097:blood; D013670:Sodium Pertechnetate Tc 99m / Q000493:pharmacokinetics; D013961:Thyroid Gland / Q000000981:diagnostic imaging* / Q000276:immunology / Q000378:metabolism; D013968:Thyroiditis, Subacute / Q000000981:diagnostic imaging* / Q000276:immunology / Q000378:metabolism; D013971:Thyrotoxicosis / Q000000981:diagnostic imaging / Q000276:immunology / Q000378:metabolism; D013972:Thyrotropin / Q000097:blood
D001323:Autoantibodies; D018828:Immunoglobulins, Thyroid-Stimulating; D019275:Radiopharmaceuticals; D011989:Receptors, Thyrotropin; C094372:thyrotropin-binding inhibitory immunoglobulin; D013972:Thyrotropin; D013670:Sodium Pertechnetate Tc 99m