Alterations in T-lymphocyte subsets in the airways of asthmatic patients with active hepatitis C virus infection.

BACKGROUND

The interaction between hepatitis C virus (HCV) infection and certain pulmonary disorders is of considerable interest. We have previously found that active HCV infection in asthmatic patients is associated with impaired responses to inhaled corticosteroid therapy.

OBJECTIVES

To examine differences in T-lymphocyte subsets in asthmatic airways with or without HCV infection.

METHODS

12 HCV-negative and 29-HCV positive asthmatics were included in this study. All HCV-positive asthmatics received interferon (IFN) therapy (11 IFN responders and 18 IFN non-responders). T-lymphocyte subsets in induced sputum were analyzed before and 1 year after IFN therapy.

RESULTS

Before IFN therapy, percentages of lymphocytes and CD8+ T lymphocytes in induced sputum were higher in HCV-positive asthmatics than in HCV-negative asthmatics. After IFN therapy, there was no significant change in percentages of lymphocytes and T-lymphocyte subsets in IFN non-responders. However, percentage of lymphocytes and CD8+ T lymphocytes in IFN responders significantly decreased, while CD4+ T lymphocytes increased. Therefore, the CD4/CD8 ratio significantly increased following IFN therapy in IFN responders. In IFN responders, forced expiratory volume in 1 s (FEV(1)) after salbutamol administration significantly increased following IFN therapy, while it did not change in non-responders. In addition, in IFN responders, the change in the CD4/CD8 ratio after IFN therapy was significantly correlated with the increase in FEV(1) after salbutamol administration.

CONCLUSIONS

The number of CD8+ T lymphocytes increases in the airways of asthmatic patients with active HCV infection, and this may be associated with airway dysfunction in these patients.