The prognostic value of TSH receptor binding and thyroid stimulating antibodies following antithyroid drug treatment of Graves' disease.
Following a course of medical therapy for Graves' disease approximately 50% of patients relapse. Previous studies have tried to identify these patients by measuring antibodies to the TSH receptor using a range of assay methods. Such studies have produced widely discrepant results. The aim of the present study was to compare the accuracy with which TSH receptor binding antibodies and thyroid-stimulating antibodies could identify cases of relapse and remission. Fifty-six newly diagnosed and previously untreated Graves' disease patients were recruited into the study. At presentation 4 were negative for TSH receptor antibody and 5 negative for TS-ab. The remaining 47 were positive for TSH receptor antibody and TS-ab although correlation of the degree of abnormality between methods was poor (r = 0.13 NS). After 12 months carbimazole treatment 28 patients relapsed during the following year and 19 remained in remission. TSH receptor antibody levels obtained at the end of a 12-month course of treatment correctly identified 93% who relapsed and 95% who remained in remission. TS-ab levels could only correctly identify 68% who relapsed and 53% who remained in remission. These results have shown that the accuracy with which patients likely to relapse can be identified depends on the assay method chosen which may account for some of the discrepancies found in previously published studies.
Wilson
R
R
University Department of Medicine, Royal Infirmary, Glasgow, Scotland.
Fraser
W D
WD
McKillop
J H
JH
Thomson
J A
JA
D000328:Adult; D002231:Carbimazole / Q000008:administration & dosage*; D004359:Drug Therapy, Combination; D005260:Female; D006111:Graves Disease / Q000188:drug therapy / Q000276:immunology*; D006801:Humans; D007074:Immunoglobulin G / Q000276:immunology*; D018828:Immunoglobulins, Thyroid-Stimulating; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D011989:Receptors, Thyrotropin / Q000276:immunology*; D012008:Recurrence; D012075:Remission, Spontaneous; D014284:Triiodothyronine / Q000008:administration & dosage*
D007074:Immunoglobulin G; D018828:Immunoglobulins, Thyroid-Stimulating; D011989:Receptors, Thyrotropin; D014284:Triiodothyronine; D002231:Carbimazole