Chronic Inflammation

Dr. Raid Jastania

Chronic Inflammation:• Chronic inflammation is a prolonged inflammation

with continuous:1. Cell injury2. Active inflammation3. Ongoing healing (repair) process

• It is characterized by:1. Mononulcear cells (lymphocytes, macrophages, plasma

cells)2. Tissue destruction3. Repair process (including new vessel formation and

fibrosis)

Cellular Events in Chronic Inflammation:

• Monocyte – histiocyte – macrophage – giant mutincleated cell

• Tissue macrophages: eg. Kupffer cell in liver, alveolar macrophage in lung…

• Macrophage is responsible for:1.Mononuclear phagocytic system, and hence2.Alert the Immune system.

Cellular Events in Chronic Inflammation:

• Macrophages also produce:1.Acid and neutral proteases to break down

extracellular components2.Complement components and coagulation

factors.3.Oxygen-free radicals and NO4.AA metabolites5.Cytokines (eg. IL-1, TNF)

Cellular Events in Chronic Inflammation:

• Lymphocytes and Plasma cells:• Other cells:

– Mast cells – Eosinophils

Granulomatous Inflammation

• Collection of activated macrophages with or without giant cells

• Rimmed by lymphocytes• May be surrounded by fibrosis

Granulomatous Inflammation

• Granuloma can be divided (morphologically) into Necrotizing granuloma and Non-necrotizing granuloma.

• Necrotizing granuloma is seen in infections.• In tuberculosis the granuloma shows central

necrosis “Caseating Necrosis”

Granulomatous Inflammation

• Causes:– The causes of granuloma can be divided in:

a. Infectious a. mycobacterium (like tuberculosis), and syphilis. b. Fungal infections commonly result in granuloma

(candida, aspergillous, mucor, histoplasma, blastomycosis….)

c. Parasitic infections may result in granuloma (Schistosomiasis).

b. Non-infectiousa. immune mediated (like sarcoidosis) b. foreign body granuloma ( like suture material,

pigments….)

Lymphatic and Lymph Nodes

What are the Causes of Acute Inflammation? And,

What are the Causes of Chronic Inflammation?