Kekkaku : [Tuberculosis]
-
Granuloma formation is a chronic inflammatory reaction where macrophage system and other inflammatory cells are involved. After some antigen exposure and processing, T cells, macrophages, epithelioid cells, and giant cell are activated, and granulomas are formed. Granuloma is considered as a defense mechanism against antigens, which stay in the organs without inactivation. ⋯ Whether this disease represents true infection or hypersensitivity pneumonitis is contoroversial. Recent reports support the theory that this disease represents a hypersensitivity pneumonitis rather than infection. The physicians should suspect a hypersensitivity pneumonitis reaction to MAC in the investigation of patients with hypersensitivity pneumonitis of unknown cause.