Recovery of the thyroid function in patients with atrophic hypothyroidism and blocking type TSH binding inhibitor immunoglobulin.
The prognosis of atrophic hypothyroidism with blocking type TSH-binding inhibitor immunoglobulin was studied. Among 45 patients (16 males and 29 females) with overt hypothyroidism (serum TSH greater than 40 mU/l) without goitre, thyroid autoantibody to microsomal antigen was positive in 38 or 84.4%, and 4 or 8.9% had TSH-binding inhibitor immunoglobulin, which was shown to be a TSH-stimulation blocking antibody by cAMP production assay using cultured porcine thyroid cells. Thyroidal radioactive iodine uptake was low and thyroid hormone replacement therapy was required. Long-term follow up of 2 patients with strongly positive TSH-binding inhibitor immunoglobulin for 2 to 7 years, however, revealed recovery of the thyroid function after steroid therapy or spontaneously with iodide restriction, respectively, correlating with decrease in both TSH-binding inhibitor immunoglobulin and TSH-stimulation blocking antibody activities. Thyroidal radioactive iodine uptake became normal and histological examination of the thyroid in one patient revealed well-preserved thyroid follicles with lymphocytic infiltration. Recovery of thyroid function can be expected with a decrease in TSH-binding inhibitor immunoglobulin activity in atrophic hypothyroidism, which is not necessarily the end stage of chronic thyroiditis.
Okamura
K
K
Second Department of Internal Medicine, Faculty of Medicine, Kyushu University, Fukuoka, Japan.
Sato
K
K
Yoshinari
M
M
Ikenoue
H
H
Kuroda
T
T
Nakagawa
M
M
Tsuji
H
H
Washio
M
M
Fujishima
M
M
D000293:Adolescent; D000328:Adult; D000368:Aged; D001284:Atrophy / Q000473:pathology; D001323:Autoantibodies / Q000145:classification / Q000302:isolation & purification*; D005260:Female; D006801:Humans; D007037:Hypothyroidism / Q000097:blood / Q000276:immunology* / Q000473:pathology; D018828:Immunoglobulins, Thyroid-Stimulating; D008297:Male; D008875:Middle Aged; D008928:Mitochondria / Q000276:immunology; D013961:Thyroid Gland / Q000473:pathology* / Q000502:physiology; D013963:Thyroid Hormones / Q000097:blood*; D013972:Thyrotropin / Q000097:blood; D013974:Thyroxine / Q000097:blood; D014284:Triiodothyronine / Q000097:blood
D001323:Autoantibodies; D018828:Immunoglobulins, Thyroid-Stimulating; D013963:Thyroid Hormones; D014284:Triiodothyronine; D013972:Thyrotropin; D013974:Thyroxine