Publication year: 2010
Theses and dissertations in Portugués presented to the Universidade de São Paulo. Faculdade de Medicina to obtain the academic title of Doutor. Leader: Marui, Suemi
INTRODUÇÃO:
Manifestações auto-imunes são frequentes na infecção pelo vírus da hepatite C (VHC). Apesar da associação com doenças auto-imunes de tireóide (DAIT) ser controversa, sabe-se que distúrbios tireoidianos podem surgir ou piorar com tratamento com IFN e ribavirina. Os objetivos deste estudo foram avaliar a função tireoidiana em pacientes infectados pelo VHC, caracterizar distúrbios tireoidianos antes, durante e após tratamento com IFN e estudar as frequências dos genótipos dos polimorfismos do gene CTLA4, correlacionando-os com características clínicas e laboratoriais, presença de disfunção tireoidiana e evolução durante tratamento com IFN. MÉTODOS:
Avaliação prospectiva de 112 indivíduos com infecção crônica pelo VHC, 30 tratados com IFN, e 183 controles. Realizaram-se avaliações clínica, hormonal e de auto-imunidade tireoidiana e ultra-sonografia de tireóide no início e durante tratamento. Avaliações de globulina transportadora de hormônios tireoidianos (TBG), de CXCL10 e de biópsia hepática foram feitas pré-tratamento. Análises dos polimorfismos do gene CTLA4 -318C>T, A49G e CT60 foram realizadas por PCR-RFLP e de AT(n) por análise de fragmento através de eletroforese capilar. RESULTADOS:
A frequência de DAIT entre infectados por VHC não diferiu dos controles (10,7 vs 13,5%, p=0,585). Os limites de distribuição dos níveis de T3 (T3T) e T4 (T4T) totais foram superiores aos de referência (T3T 112-246 ng/dL; T4T 7,8-15,2 g/dL), assim como de TBG (17-47 mg/L). TBG correlacionou-se com T3T (r=0,654, p<0,001) e T4T (r=0,741, p<0,001). Heterogeneidade (p=0,027) e hipoecogenicidade de parênquima (p=0,002) foram mais frequentes nos pacientes com DAIT. Aumento de vascularização esteve presente em 49,2% dos infectados sem distúrbio tireoidiano. CXCL10 esteve aumentada nos infectados (p=0,006), mas não se relacionou com disfunção tireoidiana. Sua elevação correspondeu ao grau de atividade necro-inflamatória na biópsia hepática...
INTRODUCTION:
Autoimmune disorders are frequent in patients infected by the hepatitis C virus (HCV). Although the association with autoimmune thyroid diseases (AITD) is controversial, thyroid disturbance could occur or worsen with IFN and ribavirin treatment. The aims of the study were evaluate thyroid function in HCV-infected patients, characterize thyroid disturbance prior and after IFN treatment and analyze the frequency of the genotypes of the polymorphisms of CTLA4 gene, and their relation to clinical and laboratorial features, presence of thyroid dysfunction and disturbance along IFN treatment. METHODS:
Prospective evaluation of 112 chronically HCV-infected subjects, 30 treated with IFN, and 183 controls. Clinical, hormonal, thyroid autoimmunity and ultrasound exams were performed before and during treatment. Thyroxine-binding globulin (TBG), CXCL10 and hepatic biopsies were also evaluated before treatment. Analysis of polymorphisms of CTLA4 gene -318C>T, A49G and CT60 were made by PCR-RFLP and AT(n) polymorphism analysis by capillary electrophoresis in automatic sequencer. RESULTS:
The frequency of AITD among HCV-infected subjects was similar to the rate among controls (10.7 vs 13.5%, p=0.585). Total T3 (T3T) and T4 (T4T) distributions were right shifted (T3T 112-246 ng/dL; T4T 7.8-15.2 g/dL), as was TBG (17-47 mg/L). TBG correlated to both T3T (r=0.654, p<0.001) and T4T (r=0.741, p<0.001). Thyroid heterogeneity (p=0.027) and hipoechogenicity (p=0.002) were associated with AITD and, most notably, increased vascularization was present in 49.2% of HCV-infected patients without thyroid disturbance. CXCL10 was higher in HCV-infected group (p=0.006) but was not related to thyroid dysfunction. Increase in CXCL10 levels were consistent with hepatic necroinflammatory activity (p=0.006) and correlated to T3T (r=0.388, p=0.003), T4T (r=0.444, p=0.001) and TBG (r=0.551, p<0.001). Nineteen percent of subjects treated with IFN presented autoimmune thyroiditis and...