Chronic Inflammation and Wound Healing

When does chronic inflammation occur?

After repeated episodes of acute inflammation that fails to eliminate inciting stimulus

What types of cells will we see in chronic inflammation?

Mononuclear (plasma, lymphocytes, macrophages)

Fibroblasts

What are some causes of Chronic inflammation?

Persistant infection of microorganisms

Prolonged toxic exposures

Autoimmune rxns

Persistent inj

What kind of inflammation is this?

Acute - neutrophils and edema

What kind of inflammation is this?

Chronic - lymphocytes and macrophages

Name a few benefits of Chronic inflamation?

Wall off antigens

Can prevent exaggerated immune response

What are ways Chronic inflammation can be harmful?

Take up space, displacing tissue

affects function of tissue

What kind of inflammation is present?

Acute - fibrin

What kind of inflammation is present?

Chronic - Fiberous attachment to wall

What is this an example of?

Abscess

How does an abscess form?

Enzymes from neutrophils will liquify tissue and neutrophils to form pus

What is the enzymes neutrophils release to form an abscess?

Myeloperoxidase

What are the two forms of abscess?

Septic - bacteria

Steril - no bacteria

What can happen to an abscess that makes it need to be lanced and unable to be penetrated w/ antibiotics?

The thin CT around the abbess will form a fibrous capsule to wall it off

What types of cells will we see in a granuloma?

Lymphocytes,

multinucleated giant cells (macrophages)

epithelial macrophages

eosinophils

fibroblasts

endothelial proliferation

What cells are dictated by the arrows(full arrows) and what are their jobs?

Epithelioid macrophages

- Secrete cell mediators

What are the cells dictated by the arrow heads and what are their function?

Multinucleated giant cells

-remove/ sequester foreign material

What are the arrows pointing to? What does it do?

fibroblasts - produces collagen and ECM as well as cytokines and chemokins

How are nodular granulomas arranged and what lymphocyte is associated with them?

Arranged in discrete masses/ Nodules - well demarcated- central necrosis

-TH1

Lepromatous granulomas are arranged how? What lymphocyte is associated w/ them?

Dispersed in sheets of cells at random. - white to gray/ non caseating

-TH2

What are two common examples of nodular granulomas?

Mycobacterium

Coccidioides (valley fever)

What are the stages of nodular granulomas?

1. Immune cells flood site,

2. Thin fibers CT forms and Macrophages start walling off,

3. Dense layer of macrophages and caseated center calcified outer ring

4. capsule formation

What do we find in the inner most region of a nodular granuloma?

Macrophages

Giant multinucleated cells

Caseating necrosis

What do we find in the middle of a nodular granuloma?

macrophages

Epithelioid macrophages

Giant multinucleated cells

What do we find on the outside of a nodular granuloma?

Lymphocytes,

plasma cells

Fibroblasts

Fiberous capsule

What is an example of Lepromatous granuloma?

Johne's dz - affects lamina proprietor of ileum

What kind of granuloma is this? What is the dz?

Lepromatous granuloma

Johne's dz

What kind of granuloma is this? What is this special stain showing?

Lepromatous granuloma

acid-fast showing bacteria (pink)

What are eosinophilic granulomas?

Dense infiltrates of eosinophils that are chronic in natures

What cells will we see present in a Eosinophilic granuloma?

Eosinophils

Macrophages

Multinucleated Giant cells

Collagen

What is the pathology?

Cutaneous habronemiasis causing a eosinophilic granuloma

Identify the type of lymphocyte?

Plasma cell

Give an example of Lymphoplasmacytic inflammation?

IBD

What is this an example of?

IBD Lymphoplasmacytic inflammation

What is chronic active inflammation?

Same cellular components as chronic inflammation but also has acute inflammatory response

What is an example of chronic active inflammation?

Feline infectious peritonitis

What does FIP look like on histopathology?

Pyogranulomatous vasculitis

What does FIP look like grossly?

Multifocal grey-tan slightly raised foci that follows vascular structures

What is this an example of?

FIP

What is the pathology?

FIP

What is the infection pathway of FIP?

Fecal oral of Feline enteric coronavirus, infects enterocytes and mutates and replicates in macrophages - disseminates based on hosts immune response

If the host has a weak immune system what will we see w/ FIP?

Delayed type IV hypersensitivity dry form (no effusion)

If we see no immune system in an FIP host what will we see?

Wet form, hypersensitivity III response - effusive

What are some things chronic inflammation and neoplasia have in common?

Increased cell division, reduced immune surveillance

What is an example of Chronic inflammation leading to neoplasia?

Feline inj site sarcoma

How does Feline inj site sarcoma occur?

Neoplastic transformation of fibroblasts/ CT

What is the photo displaying?

Feline inj site sarcoma

What are the post inj stages?

Hemostasis

Acute inflammation

Proliferation - granulation tissue, angiogenesis and epithelialization

Remodeling

In the maturation of wound healing what will we see?

Collagen will switch from type 3 to type 1

What is a the most critical growth factor in wound healing?

TGF-b

What is the difference between primary intention and secondary intention healing?

Primary - quick healing, little scar tissue

Secondary - long healing, gap/ infected, disorganized, lots of scaring

What is granulation tissue?

Exposed CT forming on a healing wound that bleeds easy,

What is proud flesh?

Over growth of granulation tissue inhibiting healing (horses)

Healthy granulation tissue will be?

Pink/red

Granular/nodular surface

Bleeds easy

Poor granulation tissue will be?

Dark in color,

Indicative of poor perfusion

ischemia

infection

Granulation tissue will restore ____ integrity but not alway ___ integrity?

Structural

Functional