title: [Hypothyroidism Associated to TSH Hormone-Receptor Autoantibodies with Blocking Activity Assessed In Vitro].
abstract: Thyroid-stimulating hormone-receptor autoantibodies normally causes hyperthyroidism. However, they might have blocking activity causing hypothyroidism. A 11-year-old girl followed due to type 1 diabetes mellitus, celiac disease and euthyroid lymphocytic thyroiditis at diagnosis. Two years after the initial evaluation, thyroid-stimulating hormone was suppressed with normal free T4; nine months later, a biochemical evolution to hypothyroidism with thyroid-stimulating hormone-receptor autoantibodies elevation was seen; the patient remained always asymptomatic. Chinese hamster ovary cells were transfected with the recombinant human thyroid-stimulating hormone -receptor, and then exposed to the patient's serum; it was estimated a 'moderate' blocking activity of these thyroid-stimulating hormone-receptor autoantibodies, and concomitantly excluded stimulating action. In this case, the acknowledgment of the blocking activity of the serum thyroid-stimulating hormone-receptor autoantibodies, supported the hypothesis of a multifactorial aetiology of the hypothyroidism, which in the absence of the in vitro tests, we would consider only as a consequence of the destructive process associated to lymphocytic thyroiditis.
authors.affiliation: Serviço de Endocrinologia. Instituto Português de Oncologia Dr. Francisco Gentil. Lisboa. Portugal.
authors.forename: Pedro
authors.initials: P
authors.lastname: Marques
authors.affiliation: Departamento de Bioquímica. CARMEN Laboratory. University Claude Bernard Lyon. Lyon Sud Hospital. Hospices Civils de Lyon. Lyon. França.
authors.forename: Karim
authors.initials: K
authors.lastname: Chikh
authors.affiliation: Departamento de Bioquímica. CARMEN Laboratory. University Claude Bernard Lyon. Lyon Sud Hospital. Hospices Civils de Lyon. Lyon. França.
authors.forename: Anne
authors.initials: A
authors.lastname: Charrié
authors.affiliation: Serviço de Endocrinologia Pediátrica. Hospital Dona Estefânia. Centro Hospitalar de Lisboa Central. Lisboa. Portugal.
authors.forename: Rosa
authors.initials: R
authors.lastname: Pina
authors.affiliation: Serviço de Endocrinologia. Instituto Português de Oncologia Dr. Francisco Gentil. Lisboa. Portugal.
authors.forename: Maria João
authors.initials: MJ
authors.lastname: Bugalho
authors.affiliation: Serviço de Endocrinologia Pediátrica. Hospital Dona Estefânia. Centro Hospitalar de Lisboa Central. Lisboa. Portugal.
authors.forename: Lurdes
authors.initials: L
authors.lastname: Lopes
mesh_terms: D000818:Animals; D001323:Autoantibodies; D016466:CHO Cells; D002648:Child; D006224:Cricetinae; D003412:Cricetulus; D005260:Female; D006801:Humans; D007037:Hypothyroidism / Q000276:immunology*; D011989:Receptors, Thyrotropin / Q000276:immunology*; D013972:Thyrotropin
chemical_list: D001323:Autoantibodies; D011989:Receptors, Thyrotropin; D013972:Thyrotropin