A possible role of TARC in antigen-specific Th2-dominant responses in patients with Paragonimiasis westermani.

BACKGROUND

Paragonimiasis westermani (Pw), a common parasitic zoonosis in Asia, is typically associated with eosinophilia. Th2 cytokines seem to have an important role in the clinical manifestations of this disease. Thymus and activation-regulated chemokine (TARC) is a potential key regulator of Th2-mediated inflammation. The purpose of the present study was to evaluate the antigen-specific Th2-dominant responses in patients with Pw.

METHODS

The concentrations of cytokines and chemokines in supernatants of peripheral blood mononuclear cell (PBMC) cultures with or without antigen stimulation were measured by enzyme-linked immunosorbent assay (ELISA). TARC levels in serum from Pw patients were also evaluated by ELISA. The number of Th2 cells expressing the CC-chemokine receptor 4 (CCR4) in the peripheral blood was evaluated by flow cytometry.

RESULTS

Antigen-stimulation induced production of IL-5 and IL-13, but not IFN-gamma from PBMC cultures in patients with Pw. Pw patients had elevated serum TARC levels and a higher proportion of CCR4-expressing cells among CD4+ T cells in the peripheral blood. There were also higher levels of TARC, but not IP-10, in supernatants of antigen-stimulated PBMC culture compared to unstimulated PBMC culture in patients with Pw.

CONCLUSION

Our findings clarify antigen-specific Th2-dominant responses in patients with Pw and suggest a possible role for TARC in Th2-dominant responses.