Endocrine (1995) 3, 91-94 9 1995 StocktonPress All rights reserved0969-71 lX/95 $9.00 Follow-up study of thyroid function in polytransfused thalassemic patients M. MaggiolinP, G. De Luca ~, M. Bria 2, D. Sisci ~, S. Aquila ~, V. Pezzi 1, M. Lanzino ~, A. Giorno ~, O. TamburrinP, M. Della Sala 3, E. CorcionP, C. Brancad 2 and S. Ando I 1Health Centre and Department of Cellular Biology, University of Calabria; 2 CNR, Cosenza; 3 Department of Radiology, University of Reggio Calabria; 4Hospital of Rogliano, Cosenza, Italy The aim of our investigation was to evaluate thyroid function by a follow-up study in 45 polytransfused thalassemic patients, since endocrine abnormalities are frequent consequences of iron overload in thalassemia major. Significant changes of thyroid function have been revealed in the time elapsing the observation, despite unchanged haematological parameters; at the end of the present study five patients were affected by overt hypothyroidism and 15 patients by subclinical hypo- thyroidism. Ultrasound thyroid volume in 13 randomly selected patients was greatly reduced, while thyroid Magnetic Resonance Imaging (MRil was not able to detect tissue alterations. Inversely, liver MRI was markedly reduced in 14 patients and negatively related to furritine levels (P<0.01). We conclude that polytransfused thalas- semics are frequently affected by thyroid disfunction; haepatic haemosiderosis due to iron overload seems in- fluence hormonal peripheral metabolism, although the patients display a moderate compliance with iron chela- tion therapy. Therefore, periodic thyroid investigation should be carried out in thalassemic subjects in order to detect patients who need hormone replacement therapy. Keywords: thyroid function; thalassemia major; ultrasound, magnetic resonance imaging Introduction Thyroid is one of the endocrine parenchyma most affected by the iron body overload in polytransfused thalassemic patients (Landau et al., 1978; Madeddu et al., 1978; Costin et al., 1979; De Sanctis et al., 1990; De Sanctis et al., 1992) and in the last years various degrees of thyroid hypofunction have been reported (Cavallo et al., 1981; Sabato et al., 1983; Livadas et al., 1984; Phenekos et al., 1984; Bisbocci et al., 1987; Mar- tino et al., 1990). However the patients studied by the different authors are not often comparable for age, duration of chelation therapy and treatment compli- ance. Thus so far the main matter to be clarified in thalassemics concerns the evolutive trend of thyroid function with the elapsing of time and its relationship to chelation therapy. This prompted us to carry out a follow up study on thyroid function in 45 polytrans- fused thalassemic patients tested in 1988 and again in 1993. Correspondence: And6 Sebastiano Results When we grouped thalassemic patients according to sex and/or age as well, no significant differences in hormonal-metabolic values were found. Thus, we grouped individual data and we expressed each hor- monal-metabolic parameter as mean value. Hormonal mean levels are shown in Table 1. In 1988 individual values revealed that out of the 45 thalassemic subjects studied, one male patient (2.2%) exhibited an overt hypothyroidism (TSH basal value: 55mUI/l, T3: 0.6ng/ml, T4: 27ng/ml) and one female patients (2.2%) displayed an increase of TSH release to TRH consistent with subclinical hypothyroidism condition, according to the criteria reported in material and methods section. No significant changes in haematoiogical-metabolic parameters were revealed in the time elapsing between the two tests (Table 2), while significant changes in thyroid function have been observed. Indeed out of the 44 patients tested again in 1993, four (9%, two females and two males) developed an overt hypothyroidism and 14 patients (31.8%, eight females and six males) displayed a subclinical hypothyroidism with a signi- ficant decrease of FT3 levels (14 Thalassemics in '93: 3.3 _+0.7 pg/ml vs Controls: 5.3 _+ 0.3, P<0.01), result- ing in a lower FT3/FT4 molar ratio with respect to previous investigation of the same patients (14 Tha- lassemies in '93:0.38 + 0.1 vs '88:07 _+ 0.27) and with respect to controls (14 Thalassemics in '93:0.38 _+ 0.1 vs Controls 0.8-+ 0.16, P<0.01). Thus, at the end of the present study five patients (11.1%) were affected by overt hypothyroidism and 15 (33.3%) by subclinical hypothyroidism. It is worthy to remark that the group of patients developing subclinical hypothyroidism during the follow-up study, displayed in both periods of investiga- tion an increase of ALT transaminase activity with respect to the remaining patients (88:62.8 +_ 13.7 UI/I vs 30.5 _+ 6.16, P<0.01; 93:45 +_ 9.2 UI/1 vs 26 _+ 3.6, P=0.02) and in 1993 an increase of ferritine levels (3282 _+ 585 ng/ml vs 2096 _+ 266, P = 0.03) which appeared positively related to AST and ALT concen- trations (r=0.7, P<0.01; r=0.8, P<0.01, respec- tively). In 1988 as well as in 1993 thyroglobulin and microsomal antibodies although augmented were below the positivity limit in all patients (Table 1). Any thalassemie subject presented thyroid enlarge- ment by palpation at both times of investigation. Thyroid volume randomly evaluated by ultrasound in 8 euthyroid thalassemic patients (five females and three males), in three with subclinical hypothyroidism (two