Non-Suppressed Thyroidal Radioactive Iodine Uptake(RAIU) in Thyrotoxic phase in a Case of Subacute Thyroiditis with Thyroid-Stimulating Antibodies(TSAb).

Abstract

Abstract. In this paper, we report a 49-year-old female with subacute thyroiditis who had thyroidstimulating antibodies (TSAb) and thyroid-stimulation-blocking antibodies (TSBAb) in serum. Although she was in the thyrotoxic phase and TSH was suppressed in May, 1990, her radioactive iodine uptake (RAIU) was not suppressed (35.5%) and a thyroid scan disclosed a diffuse goiter with no defect. Serum assays revealed the presence of TSAb, but TSBAb were negative. In August, 1990, the right lobe became undetectable by thyroid scan when the RAIU was 20.7% with the TSH level remaining suppressed. At that time, TSAb were negative, while TSBAb were positive. When the RAIU was 31.1% in October, 1990, both thyroid lobes became visible and the TSH level was normalized. TSBAb became negative, and although TSAb reappeared it later became undetectable. These results indicate that the changes in the patient's thyroid scan and RAIU were attributable to the presence of TSAb.

TSH receptor antibody‐associated thyroid dysfunction following subacute thyroiditis

“…A few patients who developed Graves' disease following subacute thyroiditis (equivalent To our type 1a and 2a patients) have been reported (Sheets, 1955;Perloff, 1956;Werner, 1979;Wartofsky & Schaaf, 1987;Fukata et al, 1992). Others (Strakosch et al, 1978;Wall et al, 1982;Wägar & Mäkinen, 1983;Tamai et al, 1991;Nakamura et al, 1992) have reported cases identical to our type 1c patients who had transiently positive TBIAb without prominent thyroid dysfunction. These patients may have some genetic background of autoimmune thyroid disease as indicated by the significantly higher incidence of positive McAb and a family history of thyroid disease.…”

Graves’ Disease Presented as Painful Goiter

“…In these cases, an elevated ESR and a nonsuppressed or a decreased uptake of radioiodine could be observed during the thyrotoxic phase. The histological thyroid examinations showed follicular hyperplasia and granulomatous inflammation [10, 11]. In our patient, the painful thyroid, the high ESR values, and the dramatic response to prednisolone therapy, all provided the clinical clues for diagnosing subacute thyroiditis.…”

“…In the English literature, very few cases of coexisting Graves’ disease and subacute thyroiditis have been reported [10, 11]. In these cases, an elevated ESR and a nonsuppressed or a decreased uptake of radioiodine could be observed during the thyrotoxic phase.…”

Utility of TSH Receptor Antibodies in the Differential Diagnosis of Hyperthyroidism in Clinical Practice

“…[ 3 18 ] Similarly, subjects with subacute thyroiditis are also known to have positive TRAb in studies. [ 20 21 22 ] In some of these cases, the presence of increased radioactive iodine uptake suggests the presence of concomitant GD. [ 22 ] TRAb was found to be positive in people with painless thyroiditis.…”

“…[ 20 21 22 ] In some of these cases, the presence of increased radioactive iodine uptake suggests the presence of concomitant GD. [ 22 ] TRAb was found to be positive in people with painless thyroiditis. [ 23 24 25 26 27 ] In a study from India on 67 subjects with hyperthyroidism, 22.3% of the subjects with painless thyroiditis were positive for TRAb.…”