chtronic inflammation

Chronic inflammation Professor Dr. Wahda M.T. Al-Naeimy Pathology Department Faculty of Medicine University of Mosul


Chronic Inflammation A prolonged process in which inflammation and attempt of healing proceed at the same time. It is less uniform & productive ( fibrosis ),& the main cells are mononuclear cells.

The dominant cell in chronic inflammation is the tissue macrophage

It is joined by lymphocytes and plasma cells, however mast cells and eosinophils are as well involved in chronic allergic diseases
Blood monocyte
Tissue macrophage (RES)
migrate into tissue within 48 hours after injury
and differentiate
Kupffer cell (liver) Microglia (CNS) Histiocytes (spleen) Alveolar macs (lung)
Lymphocyte
Plasma cell

Types of cells in Chronic Inflammation

Lymphocytes: are the main cells in chronic inflammation T.&B. lymphocytes .They are the cells of immune system T-lymphocytes responsible for cell mediated immunity. B-lymphocytes: responsible for humeral immunity i.e. produce immunoglobulin.



Macrophages: Derived from circulating monocytes activated by IL , TNF, endotoxin, and become actively phagocytic as free tissue histiocytes in pleura, peritoneum, and loose tissue . Or as fixed tissue histiocytes in sinusoids of liver spleen , bone marrow, osteoclast in the bone.


Chronic Inflammation Inflammation of long duration, characterized by predominance of lymphocytes, plasma cells & Mac. productive (fibrous tissue) rather than exudates through formation of granulation tissue. It may arise in 3 ways 1-Progression from acute inflammation persistent inflammation & suppuration due to inadequate drainage. presence of indigestible endogenous (e.g dead bone), or exogenous (e.g suture). 2-Repeated episodes of acute inflammation (e.g. Chronic Cholecystitis ). 3-Primary chronic inflammation.


Causes of chronic inflammation : 1. Persistent infection by certain micro- organisms. 2. Prolonged exposure to potentially toxic agents-( exogenous or endogenous agents ) e.g. silica, asbestose ect. 3. Autoimmunity e.g. rheumatoid arthritis.

Morphologic features of chronic inflammation. 1. Infiltration with -lymphocytes -plasma cells  -eosinophils -mast cells -macrophage, activated to epitheliod cells ,or fused together forming giant cell. 2. Tissue destruction. 3. Attempts of healing (healing with scar formation and fibrosis)..

Macroscopic appearance of chronic inflammation Chronic ulcer e.g. chronic peptic ulcer. Chronic abscess cavity. Induration & fibrosis. Caseous necrosis. Discharging sinus e.g. chronic osteomyelitis. Diffuse thickening of the wall of an organ e.g. chronic cholecystitis.

Primary chronic inflammation No initial phase of acute inflammation e.g., Certain infections e.g. T.B, leprosy, brucellosis, viral Prolonged exposure to potential toxic agents e.g. silica, lipids. Foreign body reactions. Some autoimmune diseases e.g. Rheumatoid fever. Specific diseases of unknown etiology e.g. ulcerative colitis. Primary granulomatous diseases e.g. sarcoidosis.


What’s the functions of macrophages?? Phagocytosis Secretion of biologically active substances as lysozymes, vascular permeability factor, chemotactic factor,endogenous pyrogen causes fever,factors which modulate fibroblastic proliferation, lymphokines,antibiotic and interferon.


Granulomatous inflammationSpecial type of chronic inflammation in which the predominant cell type is an epitheloid macrophage.Epitheloid macrophages: Activated macrophage, so called because of its similarity to epithelial cells. has vesicular nuclei and abundant cytoplasm . They have secretory rather than phagocytic activity.Macrophage giant cell: A large cell having numerous nuclei. 2 main types:Foreign body GC.Langhan’s GC.

Types of granuloma

1. Foreign body granuloma: formed as a reaction to foreign body e.g suture, talk…… etc.2.Immune granuloma: formed as aresult of immune reaction to certain antigenic particles.

Granuloma: A localized focus of granulomatous inflammation. An aggregate of epitheloid macrophages. +/- surrounding rim of mononuclear infl cells. +/- surrounding rim of fibroblast & fibrosis. +/- giant cells. +/- central necrosis e.g., caseating necrosis in T.B.


What’s the causes of granulomatous inflammation?Specific infectionsMycobacteria (T.B, leprosy, atypical mycrobacteria ).Parasites (larvae, eggs & worms).Fungi, Brucellosis, Syphilis, & cat-scratch disease & Yersina.Foreign bodiesEndogenous (keratin, necrotic bone, sodium ureate crystals).Exogenous (talk, silica, suture material, oil, silicon).ChemicalsBerrylosisDrugsUnknownCrohn’s disease, sarcoidosis, Wegener’s granulomatosis.

How can diagnosis the causes of granuloma??? I- History,II- Clinical examination & III- investigation which include: Histological appearance. Certain technique e.g. special stain as Z-N stain for AFB. Serological tests as in syphilis. PCR: polymerize Chain Reaction.


What’s the systemic Effects Of Inflammation?? (acute phase response or systemic inflammatory response syndrome); mediated by IL-1, IL-6, & TNF. 1. Fever (pyrogens), a. exogenous (bacterial products) b. endogenous (cytokines) 2. Acute phase proteins are increased which include; a. C-Reactive Protein (CRP). b. fibrinogen. c. serum amyloid - A protein (SAA). 3. Leukocytosis, a two – to three fold increase in the peripheral blood leucocytes count.

*neutrophilia in bacterial infection, or *lymphocytosis in viral infection, or *eosinophilia in parasitic infection and allergic reactions. decrease appetite. increase slow wave sleep. hypotension & tachycardia.