Thyroid Hormone and Insulin-Like Growth Factor-I in Patients with Multiple Myeloma Treated with Melphalan and Prednisone

Abstract

The relationship between endocrine regulation and immune system has recently become the subject of intense investigations. The aim of this study was the comparative assessment of serum levels of selected hormones and insulin-like growth factor-I (IGF-I) in patients with multiple myeloma (MM) during applied therapy. The levels of prolactin, hGH, TSH, fT3, fT4 and IGF-I in serum of 13 untreated patients with MM and in 16 healthy controls were determined. The patients were treated in cyclic courses with melphalan plus prednisone, and investigations were carried out in the first four courses of this therapy. The results were compared in the following manner: (1) at entry between studied MM group and healthy subjects, and (2) during the therapy intragroup-intracyclic comparisons were made in paired serum samples collected from patients before and after every therapeutic course. At entry, significantly lower levels of TSH and fT3 were obtained in MM patients. The means remained within low normal reference range. Slightly increasing levels of TSH and fT3 during treatment with lower concentrations of these hormones after every therapeutic course and a statistically significant difference of fT3 level in the fourth therapy course were revealed. The levels of fT4 were within the normal reference values and showed a tendency to decrease during therapy with significant differences in the first therapeutic course. After the third and the fourth therapy courses, concentrations of IGF-I were statistically significantly higher than initially. Euthyroid sick syndrome can exist in MM patients, and the therapy with melphalan plus prednisone is accompanied by slightly expressed serum changes of thyroid hormone concentrations and IGF-I levels.