Septic shock, systemic inflammatory response syndrome, and tissue repair
THE CONTEXT
Severe systemic inflammation can cause widespread abnormalities, while repair restores tissue architecture and function through regeneration and scar formation.
Septic shock and noninfectious systemic inflammation
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High circulating cytokine levels in severe bacterial infection cause disseminated intravascular coagulation, hypotension, and metabolic disturbances such as insulin resistance and hyperglycemia. This clinical triad is termed septic shock.
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A similar syndrome can complicate noninfectious disorders, including severe burns, trauma, and pancreatitis. This is called systemic inflammatory response syndrome (SIRS).
Repair and regeneration
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Repair, also called healing, restores tissue architecture and function after injury. The inflammatory response initiates repair while eliminating microbes and injured tissues.
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Repair occurs through regeneration and scar formation, which commonly contribute together in varying proportions.
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Regeneration replaces damaged components and allows tissue to return essentially to normal. It depends on proliferation of surviving cells that retain the ability to generate mature cells of that tissue.
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Regenerating cells may be mature differentiated cells or, more commonly, tissue stem cells.
Scar formation and fibrosis
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Scar formation occurs when injured tissues cannot achieve complete restitution or when their supporting structures are damaged.
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Connective tissue is deposited to provide structural stability, usually allowing the injured tissue to function.
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Scarring caused by chronic inflammation in parenchymal organs, including the lungs, liver, and kidneys, is termed fibrosis.