Specific cellular immune response and cytokine patterns in patients coinfected with hepatitis C virus and Schistosoma mansoni

Patients coinfected with hepatitis C virus (HCV) and Schistosoma mansoni sh ow high incidence of viral persistence and accelerated fibrosis. To determi ne whether immunological mechanisms are responsible for this alteration in the natural history of HCV, the HCV-specific peripheral CD4(+) T cell respo nses and cytokines were analyzed in patients with chronic hepatitis C mono- infection, S. mansoni monoinfection, or HCV and S. mansoni coinfection. An HCV-specific CD4(+) proliferative response to at least 1 HCV antigen was de tected in 73.3% of patients infected with HCV, compared with 8.6% of patien ts coinfected with HCV and S. mansoni. Stimulation with HCV antigens produc ed a type 1 cytokine profile in patients infected with HCV alone, compared with a type 2 predominance in patients coinfected with HCV and S. mansoni. In contrast, there was no difference in response to schistosomal antigens i n patients infected with S. mansoni alone, compared with those coinfected w ith HCV and S. mansoni. These findings suggest that the inability to genera te an HCV-specific CD4(+)/Th1 T cell response plays a role in the persisten ce and severity of HCV infection in patients with S. mansoni coinfection.