What is the difference between an immune granuloma and a foreign body granuloma?

Immune granuloma formation is a local tissue response to a poorly soluble substance that is capable of inducing a cellmediated immune response (e.g., cutaneous tuberculosis). The persistent presence of a poorly soluble substance in the skin causes the activation of T cells, which secrete cytokines such as interleukin-2 (Il-2) to activate additional T cells and interferon-2 (IFN-2), which transform macrophages into epithelioid macrophages and multinucleated giant cells. In contrast, foreign body granulomas, typically are the result of larger aggregates of inert foreign material that cannot be phagocytized by a single macrophage (e.g., wood splinter). In general, granulomas are produced by infectious agents, foreign bodies, or alterations in the host immune system.