Does autoantibody-negative Graves' disease exist? A second evaluation of the clinical diagnosis

Advanced technical methods are essential for accurate diagnosis of Graves' or Basedow's disease (GD). Inadequate methods may lead to a false diagnostic conclusion. We have analyzed the clinical features and methodology aspects of cases diagnosed as GD with negative findings for TSH receptor autoantibodies. The initial diagnosis was based on clinical findings (patient record, hypermetabolic state, goiter palpation) and laboratory testing (fT4 and TSH). From a total of 255 newly registered patients with GD, fifty-one (20%) were negative in a conventional porcine TBII assay. All fifty-one patients were retested with 131I or 99mTc uptake tests, thyroid scintigraphy, and a second-generation TBII assay. Results disclosed twenty-one cases (8.3%) with diagnosis other than GD: ten cases of autonomous hyperthyroidism (Plummer's disease), seven cases of painless thyroiditis and four cases of euthyroid endocrine ophthalmopathy. All twenty-one patients remained negative in the second-generation TBII assay. Measurement by second-generation TBII assay was performed on the remaining thirty patients initially found negative for TBII. As a result of this reevaluation, only 234 of the original 255 patients had GD. Of those, 231 (204 according to porcine plus 27 according to human TRAb assay) had detectable TBII (98.7%). This investigation stresses the problem of correct diagnosis and the methodological limitations in the assessment of laboratory parameter validity in GD. Based on this work, TSH receptor autoantibody-negative GD is extremely rare.

Disturbances of menstruation in hypothyroidism

OBJECTIVES

Most thyroid textbooks describe hypothyroidism resulting in changes in the length of the menstrual cycle and in the amount of bleeding. Our experience at a busy thyroid clinic had given a picture which differs from that presented in the literature. The aim of this study was to determine the frequency and type of menstrual irregularities in premenopausal hypothyroid patients.

DESIGN AND PATIENTS

We investigated the menstrual history, starting 6 months before the discovery of the disease, in 171 female premenopausal hypothyroid patients and 214 normal controls, with similar age and body mass index (BMI).

MEASUREMENTS

TSH, TT4, TT3 and thyroid antibodies were measured by radioimmunoassay, while BMI was calculated from the ratio of body weight in kg to height in m2.

RESULTS

Of the 171 hypothyroid patients, 131 (76.6%) had regular cycles and 40 (23.4%) irregular periods. Oligomenorrhoea and menorrhagia were the most common features in the latter group. No difference in BMI was found between the patients with or without menstrual abnormalities, or between patients and controls. TSH, TT4 and TT3 levels did not differ between patients with normal and abnormal menstruation. Forty-six (26.9%) out of 171 patients had subclinical hypothyroidism (group A), 42 (24.6%) mild hypothyroidism (group B) and 83 (48.5%) severe hypothyroidism (group C). Thirty-seven from group A (80.4%), 32 from group B (76.2%) and 62 from group C (74.7%) had normal periods. These differences were not statistically significant. Eighty-eight (88.9%) out of 99 patients in whom thyroid antibodies were measured had positive titres. Nineteen (21.6%) of the patients with positive thyroid antibodies had menstrual irregularities. This percentage did not differ from that found in the whole group of patients (23.4%). Out of 214 normal controls, 196 (91.6%) had normal menstruation and 19 (8.4%) irregular cycles. The latter group included mainly women with oligomenorrhoea.

CONCLUSIONS

These data demonstrate that hypothyroidism in women is less frequently associated with menstrual disturbance than was previously described. Also, menstrual irregularities tend to be more frequent in sever hypothyroidism in comparison with mild cases, although this finding was not statistically significant. Oligomenorrhoea and menorrhagia are the most common menstrual disturbances.

The significant increase in incidence of Graves' disease in eastern Serbia during the civil war in the former Yugoslavia (1992 to 1995)

The incidence of Graves' disease for the last 25 years in eastern Serbia (Yugoslavia), Timok Region is reported. Registration of all Graves' disease patients was conducted in the Endocrinology-Thyroid Unit of Nuclear Medicine Service, Medical Center Zajecar. Timok Region has a population of 315,000 people in seven counties. From 1971 to 1980 an average of 16 new patients per year were registered; from 1981 to 1990 an average of 33 patients per year were registered; in 1995 the number reached 100, and in 1996 there were 148 newly registered patients. Some of the possible factors influencing this significant annual increase of autoimmune hyperthyroidism are discussed.