[Characterization of distribution of immunological competent cells in sarcoid granuloma]

Sarcoidosis is a systemic, immunological disorder that is histologically defined the presence of noncaseating granuloma in the involved tissue. Granuloma formation follows the accumulation of large numbers of T lymphocytes within the lesions. To elucidate the immunopathologic situation of granuloma-formation in sarcoidosis, the relationship between activated T lymphocyte subsets including Th-1 and Th-2 cells has been studied by using immunohistochemical, RT-TCR, and in situ hybridization techniques for functional T cell subsets and by using RT-PCR-SSCP analysis for T cell clonotypes. The results of analysis of functional T cell subsets showed that T cells in internal area (core) of granulomas were predominantly Th-2 subset. On the other hand, Th-1 cells were present in abundance in the surrounding areas(rind). The additional results showed the presence of common T-cell clones in samples from different tissues, supporting the underlying Ag-specific mechanism in pathogenesis of sarcoidosis.