Acute and Chronic Inflammation in Histopathological Specimens

Definition and Pathophysiology of Acute Inflammation

Inflammation is the body's complex biological response to harmful stimuli, such as pathogens, damaged cells, or irritants. It serves as a protective mechanism, initiating tissue repair and immune defense.

Acute Inflammation

Acute inflammation is a rapid, localized response characterized by classic signs: redness, heat, swelling, pain, and loss of function. The process involves vascular changes, recruitment of leukocytes, and release of inflammatory mediators.

Pathophysiology

• Vascular Response: Increased vascular permeability and vasodilation enhance the delivery of immune cells.
• Cellular Events: Neutrophils dominate the early phase, releasing cytokines and enzymes.
• Chemical Mediators: Histamine, prostaglandins, and cytokines regulate the inflammatory process.

Chronic Inflammation

Unlike acute inflammation, chronic inflammation persists due to prolonged exposure to irritants, autoimmune dysfunction, or unresolved infections. Macrophages, lymphocytes, and fibroblasts play central roles.

Histopathological Features

• Granuloma formation in cases like tuberculosis.
• Fibrosis and tissue remodeling.
• Persistent cytokine activation.

Clinical Significance

Understanding inflammatory processes is critical for diagnosing conditions such as rheumatoid arthritis, atherosclerosis, and inflammatory bowel disease.