T lymphocyte disorder after Capnocytophaga ochracea endocarditis

Capnocytophaga species are gram-negative rods which may cause disease in both non-immunocompromised and immunocompromised hosts. We describe a case of endocarditis due to Capnocytophaga ochracea in a non-immunocompromised patient with a decrease of blood CD4/CD8 ratio and lymphocyte proliferative response to ConA during infection. In vitro experiments showed that C. ochracea decreased lymphocyte proliferation to mitogens (ConA, PHA), cell surface CD4 antigen and IL2 receptor expression on peripheral blood mononuclear cells (PBMC) from normal volunteers.