Chronic inflammation - B. Pharma 2nd Semester Pathophysiology notes pdf

Chronic inflammation


       Chronic inflammation

       Granulomatous inflammation 


At the end of this PDF, student will be able to

         Define ‘chronic inflammation’

         Explain the causes of chronic inflammation

         Describe the general features of chronic inflammation

         Describe the pathogenesis granulomatous inflammation

Chronic inflammation

Chronic inflammation is defined as prolonged process in which tissue destruction and inflammation occur at the same time

Chronic inflammation – Causes

1.  Chronic inflammation following acute inflammation:

       Prolonged acute inflammation

       Tissue destruction is extensive

       The bacteria survive & persist in small numbers at the site of acute inflammation

e.g. Osteomyelitis, pneumonia terminating in lung abscess

2. Recurrent attacks of acute inflammation:

       Repeated attacks of acute inflammation

       Culminate in chronicity of the process

e.g. - Recurrent urinary tract infection leading to chronic pyelonephritis

      Repeated acute infection of gallbladder leading to chronic cholecystitis

3. Chronic inflammation starting de novo: 

       Infection with organisms of low pathogenicity is chronic

     e.g. infection with Mycobacterium tuberculosis.

General features of chronic inflammation

Mononuclear cell infiltration

Infiltration of chronic inflammatory lesions

       Phagocytes - circulating monocytes, tissue macrophages, epithelioid cells, multinucleated giant cells

        Lymphoid cells

       Chemotactic factors and adhesion molecules for continued   infiltration of macrophages

       Local proliferation of macrophages

       Longer survival of macrophages at the site of inflammation

  Tissue destruction or necrosis

       Brought about by activated macrophages

       Release a variety of biologically active substances

E.g. protease, elastase, collagenase, lipase, reactive oxygen radicals, cytokines (IL-1, IL-8, TNF-α), nitric oxide, angiogenesis growth factor

Proliferative changes

       Result of necrosis

       Proliferation of small blood vessels and fibroblasts is

       Formation of inflammatory granulation tissue

       Healing by fibrosis and collagen laying

Systemic effects of chronic inflammation

       Fever:  mild fever, often with loss of weight and weakness



       ESR:  elevated in all cases

       Amyloidosis: Long-term cases of chronic suppurative Inflammation - secondary systemic (AA) amyloidosis

Types of chronic inflammation


       Irritant substance - nonspecific chronic inflammatory

       Formation of granulation tissue

       Healing by fibrosis (chronic osteomyelitis, chronic ulcer)


Injurious agent causes a characteristic histologic tissue response

e.g. tuberculosis, leprosy, syphilis

Granulomatous inflammation


       A tiny lesion about 1 mm in diamter

       Comprises of epitheloid cells in the centre & lymphoid in the periphery 

       Contains gaint cells

       Associated with necrosis & fibrosis

       Proliferation of fibroblast in the periphery

       Due to presence of micro organism

e.g. Mycobacterium tuberculosis

      Poorly digestible

      Cell mediated immune response

Pathogenesis of granulomatous inflammation

       Type IV hypersensitivity reaction

       Engulfment by macrophages

       Presentation of microbes to CD4+ T cells

       Activation of T-cells


Composition of Granuloma

       Epithelioid cells

       Multinucleate giant cells

       Lymphoid cells




       Chronic inflammation is defined as prolonged process in which tissue destruction and inflammation occur at the same time

       Chronic inflammation may occur due to prolonged and recurrent attack of acute inflammation or may start de novo

        Chronic inflammation is characterized by mononuclear cell infiltration, proliferation and necrosis

       Granulomatous inflammation occur by proliferation of fibroblast in the periphery due to presence of micro organism

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