Oral Pathology Chapter 3 Immunity

Objectives 1. Define each of the words in the vocabulary list (please learn on your own) 2. Describe the primary difference between the immune response and the inflammatory response.

primary difference between the immune response and the inflammatory response Although both defend the body against injury they differ in that the immune response has the capacity to “remember” and respond more quickly to a foreign substance that enters the body a second time.

Antigens A substance, usually a protein, that is recognized as foreign by the body's immune system and stimulates formation of a specific antibody to the antigen.

Cells Involved in the Immune Response B lymphocytes ( associated plasma cells) T lymphocytes NK cells Macrophages

Lymphocytes The primary white blood cells involved in the immune response Able to recognize and respond to an antigen. Derived from a stem cell in the bone marrow Constitute 20 – 25 percent of WBC’s Are long living and mobile

Objective 3 List and describe the two main types of lymphocytes, their origins, and their activities. 1. B lymphocytes (B cells)-develops from stem cell in the bone marrow has two types. –First type is plasma cell – produces antibodies (immunoglobulins or Igs) IgG, IgM, IgA and IgD Immune complex or antigen-antibody complex –When the antibody combines with antigen –Second type is the B memory cell-retains the memory of previously encountered antigens. This cell clones or duplicates itself

Objective 3 List and describe the two main types of lymphocytes, their origins, and their activities. 2.T Lymphocytes (T-cells)- also develops in the bone marrow stem cell. Travel to the thymus and are processed to maturity. Memory cells -T-helper cells – increases function -suppressor cells -t-cytotoxic cells

Cytokines Are cell products of either B or T lymphocytes and are call lymphokines Different cytokines have different functions Activates macrophages and enhance the ability of macrophages to destroy foreign cells. Also involved in various other functions concerning leukocytes, fibroblasts, and endothelial cells. One of the first cytokines to be discovered was interferon.

Objective 4 List the activities of macrophages Phagocytosis Help B-cells and T-cells Produce cytokines called monokines Are a link between the inflammatory response and immune responses Are antigen-presenting cells Do not remember encountered antigens

Humoral Immune response In the production of antibodies B lymphocytes are the primary cells of the humoral response.

Cell-mediated response Involves lymphocytes (usually T-cells) working alone or with macrophages. Regulates both major responses

Passive Immunity Uses antibodies produced by another person to protect an individual against infectious disease –Either naturally acquired from mother –Or injection of antibodies

Active immunity Naturally after a person has already had exposure to the microorganism Acquired by vaccination of an altered pathogen –Immunization is the production of acquired immunity.

Hypersensitivity Hypersensitivity reactions are also called allergic reactions. Exaggerated response and tissue destruction

Type 1 Hypersensitivity Occurs immediately after exposure to a previously encounter antigen –Pollen –Latex –penicillin Can range from everyday hay fever to serious asthma and anaphylasis

Type 2 Hypersensitivity Antibody combines with an antigen bound to the surface of tissue cells (usually a circulating red blood cell) Occurs in RH incompatibility in different blood types

Type 3 Hypersensitivity Immune complexes are formed between microorganisms and antibody in the circulating blood. These complexes are deposited in various body tissues and initiate acute inflammatory response Occurs in autoimmune diseases such as lupus erythematous

Type 4 hypersensitivity Also known as delayed hypersensitivity Involves a cell-mediated immune response Put to use in the tuberculin test

Hypersensitivity to Drugs Drugs can act as antigens and cause an immunologically induced inflammatory response Many factors influence the risk of an allergic reaction –Route of administration –Topical may cause a greater number of reactions --Parenteral administration- may be more wide and severe

Autoimmune diseases The immune system begins to treat its own cells or organs as antigens. Genetic factors may play a role in predisposing individuals to auto immune disease Viral infection may be involved

Immunodeficiency An immunopathlogic condition that involves white blood cells and their products. When a person’s immune system is not functioning adequately, infections and tumors may develop.

Aphthous Ulcers AKA – canker sores or aphthous stomatitis Common ulcers occurring in about 20% of the general population First episode of these ulcers usually occurs in adolescence…..more common in females than in males. Clinical appearance and location are important in establishing the diagnosis

Aphthous Ulcers Trauma most commonly reported precipitating factor Emotional stress Certain foods with high acidity Recurrence associate with menstruation Immunologic pathogenesis Association with certain systemic diseases –Behcet syndrome, Crohn disease, Ulcerative colitis, Cyclic neutropenia, Sprue (gluten intolerance), Intestinal lymphoma

Minor Aphthous ulcers Most common Discrete, round to oval ulcers up to 1 cm Movable mucosa Occasionally extend to gingiva Labial and buccal mucosa, vestibular mucosa More common in anterior Prodromal period of 1 – 2 days –Characterized by a burning sensation Heal spontaneously in 7 – 10 days

Major Aphthous Ulcers Larger than 1 cm Deeper and last longer Have been seen in HIV pts. Differential diagnosis clinically may be squamous cell carcinoma or deep fungal infections. Biopsy is often necessary Herpetiform Aphthous Ulcers- very tiny and resemble herpes simplex virus. Are painful. May develop anywhere in the mouth.

Diagnosis Minor – based on their distinctive clinical appearance, the location, and a complete patient history. The location is important to distinguish from recurrent herpes. (Herpes when intra oral appear on mucosa fixed to bone--- palate and gingiva)

Treatment Locally applied topical steroids Most effective during the prodromal period. Occasionally systemic steroids fro major apthous ulcers Local steroids are contraindicated for viral lesions.

Urticaria= hives Angioeddema = diffuse swelling Contact mucositis & Dermatitis result from direct contact of an allergen with the skin or mucosa.

Erythema Multiforme

Diagnosis Made base on the clinical features and the exclusion of other diseases Usually systemic steriods

Lichen planus

Skin Characteristic white lace-like pattern on buccal mucosa

Lichen planus Lichen planus-This is the erosive form of lichen planus, which is characterized by an erythematous atrophic base with fine, lace-like white lines. These white lines are known as Wickham's striae. This patient exhibited erosive lichen affecting the buccal mucosa and lateral border of the tongue

Diagnosis Distinctive clinical appearance and histologic appearance of biopsy tissue. Epithelium is generally parakeratotic and either hyperplastic or atrophic.

Reiter Syndrome A syndrome is a group of signs and symptoms that occur together. A triad of arthritis, urethritis, and conjunctivitis. Can occur almost anywhere in the oral cavity Aphthouslike ulcers, erythematous lesions and geographic tonguelike lesions

Langerhans Cell disease A type of macropahge Immunologicaly competent cell which proliferates –Letterer-Siwe –Hand-Schuller-Christian –Solitary eosinophilic granuloma of bone conservative surgical excision low dose radiation

Objective name the two cells that histologically characterize Langerhans cell disease Langerhans cells eosinophils

Autoimmune Diseases that effect the oral cavity Sjögren's syndrome = xerostomia Lupus erythematosus = White, erosive lesions on mucosa Pemphigus vulgaris = mucosal ulceration, bullae Benign mucous membrane pemphigoid = mucosal ulceration, desquamative gingivitis Behcet syndrome = aphthous ulcers Pernicious anemia = mucosal atrophy, mucosal ulceration loss of filiform and fungiform papillae

Sjögren Syndrome Autoimmune diseases that affects the salivary and lacrimal glands. Resulting in xerostomia and xerophthalmia Keratoconjunctivitis sicca (dry) High risk of caries, periodontal diseases and oral candidiasis 90% have a positive reaction to rheumatoid factor

Lupus Erythematosus LE cell = A cell that is a characteristic of lupus erythematosus and other autoimmune diseases. It is a mature neutrophil that has phagocytized a spherical inclusion derived from another neutrophil. See pg 129 in your atlas

Pemphigus Vulgaris Seer and progressive autoimmune disease that affects the skin and mucous membranes Pemphigus vulgaris may affect any area of the oral cavity. Here lesions of the buccal mucosa again show the irregular shape and ragged margins typical of this disease.

Pemphigus vulgaris Acantholysis= epithelial cell separation 50% of cases the first signs appear in the oral cavity.

Cicatricial pemphigoid AKA = mucous membrane pemphigoid and benign mucous membrane pemphigoid Most common site is gingiva ( free and attached) Desquamative gingivitis Erythema to ulceration

Cicatricial pemphigoid

Bullous Pemphigoid May be a variant of Cicatricial Oral lesions are not as common

Behcet Syndrome Chronic reoccurring autoimmune disease consisting primarily of oral ulcers, genital ulcers and ocular inflammation Mean age 30 years no sex predilection Pg 158 in atlas