Relationship between hepatitis C virus infection and pulmonary disorders: potential mechanisms of interaction

Recently, an increasing number of reports have suggested that chronic hepatitis C virus (HCV) infection is associated with pulmonary disorders. The effects of HCV on the lung may present as worsening of lung function and impaired responses to therapy in patients with chronic obstructive pulmonary disease and asthma. Moreover, chronic HCV infection may be associated with the pathogenesis of interstitial lung disease. It is believed that chronic HCV infection may contribute to the immune responses modulating the pathogenic processes underlying pulmonary disorders and, therefore, may lead to a wide spectrum of clinical presentations. Potential candidates for a role in these immune responses are the CD8(+) T lymphocytes and inflammatory cytokines. In this review, the effects of HCV on the lung and the potential mechanisms of interaction between chronic HCV infection and pulmonary disorders will be discussed.