The main injury caused by hepatitis C virus is the hepatic fibrosis, as a result of a chronic inflammatory process in the liver characterized by the deposit of components from the extracellular matrix. The fibrosis development leads to the modification of the hepatic architecture, of the hepatocellular function and to irregularities in the microcirculation. The tissue remodeling process observed in fibrosis has stellate cells, located at the space of Disse, as main acting agents. These cells, in response to a harmful stimulus, undergo phenotypic changes from non-proliferating cells to proliferating cells that express a- smooth-muscle actin (a-SMA), a process called as transdifferentiation. There are evidences that the oxidative stress is involved in the chronic liver disease and serves as bond between the injury and the hepatic fibrosis. A number of studies suggest that the estrogen, at physiological levels, presents an antifibrogenic action probably through an antioxidant effect, decreasing the levels of lipid peroxidation products in the liver and blood, thus inhibiting the myofibroblastic transformation of stellate cells and contributing for gender-associated differences in relation to the fibrosis development. The aim of this paper was to describe data from literature concerning the interaction between chronic hepatitis C and estrogens, pregnancy, use of oral contraceptives, menopause and hormone reposition therapy.

Hepatites agudas ou crônicas de causas não definidas constituem um problema na prática de médicos clínicos e gastroenterologistas. Apesar do desenvolvimento de sofisticados testes laboratoriais, uma proporção significativa das hepatites ainda permanece com causa não-determinada. São as chamadas hepatites criptogênicas ou hepatites não A-E. Possíveis etiologias são sugeridas: vírus desconhecido, doenças metabólicas ou hepatite auto-imune de apresentação atípica. Recentemente, nosso grupo demonstrou que, num centro de referência no Brasil, 17% dos casos de hepatites agudas são criptogênicos, com alguns aspectos sugerindo etiologia viral. Nós relatamos quatro casos de hepatite aguda criptogênica, demonstrando a heterogeneidade dessa condição clínica associada à possibilidade de complicações, o que justifica uma criteriosa investigação epidemiológica, clínica e laboratorial, assim como o acompanhamento desses pacientes.

Acute or chronic hepatitis with no defined causes constitute a problem for clinical and gastroenterologists. In spite of sophisticated tests, a substantial proportion of hepatitis remains with no certain cause. They are cryptogenic hepatitis or hepatitis no A-E. Possible aetiologies are suggested: unknown virus, metabolic diseases or auto-immune hepatitis with atypical presentation. Recently, our group demonstrated that, in a reference center for hepatic diseases in Brazil, 17% of cases of acute hepatitis are cryptogenic, with some aspects suggesting viral aetiology. We described four clinical cases of acute cryptogenic hepatitis, demonstrating the heterogeneity of this condition that may be associated with possible complications. This justifies a careful epidemiological and laboratorial investigation, as well as a follow-up of those patients.