Chemokines have been detected during inflammation in most organs and tissues. In immunologic diseases, chemokines cause the accumulation and activation of leukocytes in tissues. The type of inflammatory infiltrate that characterizes a specific disease is controlled, in part, by the subgroup of chemokines expressed in the diseased tissue. In addition to controlling infiltration of cells to sites of inflammation, chemokines are also involved in general lymphoid homeostasis within the body. Significant neutrophil accumulation occurs within the first 6 hours of the response.
Neutrophils also phagocytose any bacteria present.
Other cell types also migrate to the scene. See Kuby Figure 15-12. The local response is also accompanied by a systemic response - the acute phase response. See Kuby Figure 15-13. Sites of chronic inflammation have a marked accumulation of macrophages and shows formation of a type of scar tissue - fibrosis.