Publications (2)6.59 Total impact
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Article: Interferon-alpha-induced hyperthyroidism: a three-stage evolution from silent thyroiditis towards Graves' disease.
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ABSTRACT: Autoimmune thyroid disease is a common side-effect of interferon-alpha (IFN-alpha) treatment of viral hepatitis C. We have described three patients with hepatitis C for whom IFN-alpha and ribavirin were prescribed and who developed two successive phases of silent thyroiditis followed by hyperthryroidism relapse due to Graves' disease. These three men had no known history of familial or personal thyroid disease. Destructive thyrotoxicosis appeared 4-6 months after starting IFN-alpha, followed by Graves' hyperthyroidism within 8 to 11 months. The thyrotropin (TSH) level was normal before IFN-alpha was started. The diagnosis of destructive thyroiditis was confirmed by anti-TSH receptor antibody (TSHRAb) negativity and the absence of radionuclide ((123)I or (99)Tc) uptake on thyroid scintiscans. Eight to eleven months after starting treatment, TSHRAb positivity and intense scintigraphic uptake confirmed the appearance of Graves' disease. IFN-alpha was continued in only one patient. Hence, hyperthyroidism induced by IFN-alpha could correspond to the first phase of silent thyroiditis, to Graves' disease or to the succession of both. Rigorous diagnostic procedures with repeated scintiscans and TSHRAb titering are necessary to avoid a false diagnosis and inappropriate therapy.European Journal of Endocrinology 04/2006; 154(3):367-72. · 3.42 Impact Factor -
Article: Study of diurnal fluctuations of plasma methoxyamines in healthy volunteers.
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ABSTRACT: We studied the diurnal fluctuations of plasma concentrations of methoxyamines (metanephrine and normetanephrine) and of their parent amines (epinephrine and norepinephrine) in normotensive subjects. Serial blood sampling at 09.00 h, 11.00 h, 12.00 h, 14.00 h, 16.00 h, 18.00 h and 20.00 h in 28 healthy volunteers at rest. Determination of plasma concentrations of free catecholamines and total methoxyamines (free and sulpho-conjugates) was carried out by high-performance liquid chromatography with electrochemical detection. Mean (+/- SD) plasma concentrations of total metanephrine (MN) and normetanephrine (NMN) were 4.31 +/- 1.73 nmol/l (range: 0.96-9.3 nmol/l) and 8.13 +/- 2.54 nmol/l (range: 3.14-17.0 nmol/l), respectively. The NMN/MN ratio ranged between 0.8 and 7.8 (mean +/- SD 2.1 +/- 1.0). Mean plasma concentrations of free epinephrine and norepinephrine were 0.21 +/- 0.12 nmol/l (range: 0.06-1.39 nmol/l) and 1.61 +/- 0.62 nmol/l (range: 0.47-4.01 nmol/l), respectively. Despite marked intraindividual fluctuations, mean methoxyamine and catecholamine levels remained constant over the entire duration of the experiment. The absence of fluctuations of plasma levels of total methoxyamines suggests that their measurement could be carried out at any time within the diurnal time frame. Further investigations, however, remain necessary to validate these findings in patients with hypertension and/or pheochromocytoma, and to explain the ever important intraindividual variation in plasma concentrations of methoxyamines and of their parent compounds.Clinical Endocrinology 02/2002; 56(1):119-22. · 3.17 Impact Factor
