What characterizes chronic inflammation?

Chronic inflammation is characterized primarily by the replacement of leukocytes, which are typically the first responders to inflammation, with macrophages and lymphocytes. This shift reflects a transition from the acute phase of inflammation, which involves a rapid response to injury or infection, to a prolonged state of inflammation that often indicates an ongoing, unresolved issue.

Macrophages play a crucial role in cleaning up debris from damaged tissues and orchestrating the healing process, while lymphocytes contribute to the immune response by targeting persistent pathogens. This shift can lead to tissue changes, fibrosis, or even the development of chronic inflammatory diseases.

The other choices do not accurately reflect the nature of chronic inflammation. For instance, the accumulation of platelets and proteins characterizes the initial response in acute inflammation. Increased blood pressure and oxygen levels may occur due to various conditions but are not definitive characteristics of chronic inflammation. Lastly, rapid healing and repair are typically associated with acute inflammation rather than chronic inflammation, which usually involves ongoing tissue damage and repair mechanisms that are less efficient.