Prediction of neonatal hyperthyroidism in infants born to mothers with Graves disease.

OBJECTIVE: To determine whether determinations of thyrotropin-receptor antibody (TRAb) levels in newborn infants of women with Graves disease would predict which infants will have hyperthyroidism. METHODS: The TRAb levels, assayed in the sera of 14 infants born to 14 women with Graves disease, were measured sequentially in the infants with hyperthyroidism during the course of antithyroid medication therapy. RESULTS: Seven infants had TRAb values less than 0.15 and remained euthyroid. In seven infants whose initial TRAb values were more than 0.25 (range, 0.48 to 0.88), clinical and biochemical signs of hyperthyroidism developed. The infants were treated with antithyroid medication until day 57 to day 123 of life. Therapy was discontinued when the infants were free of symptoms and when serum thyroxine and triiodothyronine and free thyroxine levels remained normal during therapy with decreasing doses of antithyroid medication. When the medication was discontinued, TRAb values were less than 0.20. CONCLUSIONS: Infants born to mothers with Graves disease with initial TRAb values less than 0.15 remained euthyroid. The TRAb values greater than 0.25 were associated with the development of neonatal hyperthyroidism. During treatment of neonatal hyperthyroidism, TRAb values less than 0.20 may be helpful in deciding when to withdraw antithyroid medication.

Relationship of growth hormone deficiency and leukemia.

The use of growth hormone (GH) has been implicated as a possible risk factor for leukemia. We present data from six patients that support a working hypothesis that an increased risk of leukemia may exist in patients with GH deficiency not related to exogenous use of GH.

Inappropriate suppression of thyrotropin during medical treatment of Graves disease in childhood.

Twenty-nine patients (22 female) aged 2 to 17 years were followed with serial measurements of serum triiodothyronine, thyroxine, and thyrotropin during medical therapy for Graves disease. Fourteen patients had 17 instances of hypothalamic-pituitary-thyroid suppression with inappropriately low thyrotropin levels. Five patients had six episodes of low thyroxine and triiodothyronine levels with normal levels of thyrotropin, and 10 patients had 11 episodes of normal thyroxine and triiodothyronine levels with subnormal levels of thyrotropin. We conclude that thyrotropin values may not be reliable for diagnosing either mild hypothyroidism or persistent hyperthyroidism during the medical treatment of Graves disease.

Suppression of immune function in growth hormone-deficient children during treatment with human growth hormone.

Inasmuch as growth hormone is known to interact with the immune system, we studied immune functions including immunoglobulins, cell surface markers, mitogen responses, and polymorphonuclear cell function in eight children with growth hormone deficiency, ages 1 to 17 years, before and during treatment with human growth hormone for 12 to 16 months. Before treatment immune functions were normal in all children. Treatment with human growth hormone did not significantly affect serum immunoglobulins, polymorphonuclear cell function, or percent T cells. However, percent B cells decreased to subnormal levels in seven of seven patients. T helper/suppressor ratios decreased in all patients, to subnormal values in seven of eight patients; and mitogen responses decreased to below normal in all. The decline of percent B cells was transient in all patients, of T helper/suppressor ratios in seven of eight, and mitogen responses in five of eight patients. In vitro incubation of lymphocytes with growth hormone resulted in no changes in cell surface markers or mitogen responses. Although the depression of immune functions resulted in no increased rate of infections during the observation period, we do not know the possible effects of prolonged treatment and therefore caution against the indiscriminate use of human growth hormone. The effects of biosynthetically obtained growth hormone on immune function remain to be determined.