Sarcoidosis : Pathogenesis

Comments:
Pathogenesis: Sarcoidosis is thought be the result of a dysfunctional cell-mediated immune response to unknown environmental antigens in genetically susceptible individuals.

The process is driven by increased secretion of cytokines such as IL-2 (which lead to oligoclonal expansion of CD4+ helper T-cells) and IFN-gamma (which causes macrophage activation). Additional cytokines such as IL-8, TNF, and macrophage inflammatory protein 1-alpha attract additional lymphocytes and macrophages and lead to the formation of granulomas.

The image shows numerous non-necrotizing granulomas effacing the nodal architecture.