Immunological Factors In Disease Short And Long Essay Question And Answers

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Immunological Factors In Disease Important Notes

  1. Hypersensitivity reactionsImmunological Factors In Disease Hypersensitivity Reactions
  2. Anaphylactic reaction
    • It is a state of rapid developing immune response to an antigen mediated by IgE antibodies
    • Clinical features:
      • Systemic anaphylaxis
      • Pruritus
      • Wheel and flare lesions
      • Bronchospasm
      • Tightness of chest
      • Wheezing
      • Laryngeal edema
      • Dyspnea
      • Cyanosis
      • Shock
      • Diarrhea
      • Pulmonary edema
      • If not treated death occurs Local anaphylaxis
      • Hay fever
      • Bronchial asthma
      • Food allergies
      • Contact dermatitis
      • Angioedema

Immunological Factors In Disease Long Essays

Question 1. Classify allergic reactions. Describe clinical features and management of generalised anaphylaxis.

Answer:

Allergic reactions

  • Hyperscusillvity/allergy In defined an an exaggerated/inappropriate state of normal Immune response with the onset of adverse effects on the body.
  • Lesions of hypersensitivity are a form of antigen-antibody reaction
  • Hypersensllivlly reactions are classified into 4 types,
    • Type 1: Anaphylactic (atopic) reaction
    • Type 2: Cyloxlc (cytolytic) reaction
    • Type 3: Immune complex-mediated (arthus) reaction,
    • Type 4: Delayed hypersensitivity (cell-mediated) reaction.
  • Depending, upon the rapidity, duration, and type of immune response, they are classified into immediate type and delayed type.
    • Immediate type: On administration of antigen, reaction occurs immediately, This includes types 1, 2, and 3.
    • Delayed type: Reaction is slower in onset, develop within 24-48 hours and the effects is prolonged. Includes type 4 reaction.

Anaphylaxis:

  • Anaphylaxis or type 1 hypersensitivity is defined as a state of rapidly developing immune responses to an antigen (i.e., allergen) to which the individual is previously sensitised.
  • The reaction appears within 15 – 30 min of exposure to antigen.

Read And Learn More: General Medicine Question and Answers

Etiology:

  • Type 1 reaction is mediated by humeral antibodies of IgE type or regain antibodies in response to antigen.
  • The definite cause is not known, but the following may be responsible.
  • Environmental pollutants
  • Genetic basis
  • Concomitant factors Allergic response may be linked to the occurrence of certain viral infections of upper respiratory tract.

Anaphylaxis Effects:

  • Increased vascular permeability
  • Smooth muscle contraction
  • Vaaocontriction followed by vasodilation
  • Shock
  • Increased gastric secretion
  • Increased nasal and lacrimal secretions
  • Eosinophils and neutrophilia.

Anaphylaxis Examples:

  1. Reactions against mycobacterial infection.
    • Tuberculin reaction, the granulomatous reaction in tuberculosis, leprosy.
  2. Reaction against virally infected cells
  3. Reaction against malignant cells in the body.
  4. Reaction against organ transplantation, for example, transplant rejection, graft versus host reaction.

 

Immunological Factors In Disease Short Essays

Question 1. Anaphylaxis

Answer:

Anaphylaxis

  • Anaphylaxis or type 1 hypersensitivity is defined as a stale of rapidly developing immune response to an antigen (i.e., allergen) to which the individual is previously sensitised.
  • The reaction appears within 15 – 30 min of exposure to antigen.

Etiology:

  • Type 1 reaction is mediated by humoral antibodies of IgE type or regain antibodies in response to antigen.
  • The definite cause is not known, but the following may be responsible.
  • Environmental pollutants
  • Genetic basis
  • Concomitant factors – Allergic response may be linked to occurrence of certain viral infections of upper respiratory tract.

Anaphylaxis Effects:

  • Increased vascular permeability
  • Smooth muscle contraction
  • Vasoconstriction followed by vasodilation
  • Shock
  • Increased gastric secretion
  • Increased nasal and lacrimal secretions
  • Eosinophia and neutrophilia.

Anaphylaxis Examples:

  1. Reactions against mycobacterial infection.
    • Examples: Tuberculin reaction, granulomatous reaction in tuberculosis, leprosy.
  2. Reaction against virally infected cells
  3. Reaction against malignant cells in the body.
  4. Reaction against organ transplantation for example, transplant rejection, graft versus host reaction.

Question 2. Oedema- causes

Answer: Oedema

Oedema Causes:

  • Congestive heart failure
  • Nephrotic syndrome
  • Severe malnutrition
  • Hepatic cirrhosis
  • Acute or chronic renal failure
  • Hypothyroidism

Question 3. Diagnostic procedures for hypersensitive reactions

Answer:

Hypersensitive Reactions Diagnostic Tests:

  1. Precipitation test
    • When a soluble antigen reacts with its antibody in the presence of electrolytes at optimal temperature and pH, the antigen-antibody complex forms an insoluble precipitate called precipitation
    • Tests:
      • Ring test
        • Ring is formed at the junction of antigen and antibody
      • Flocculation test
        • When instead of sedimenting, the precipitate is suspended as floccules, the reaction is called flocculation
      • Immunodiffusion test
        • Gel is used in it
        • Types
          • Single diffusion in one dimension
          • Double diffusion in one dimension
          • Single diffusion in two dimension
          • Double diffusion in two dimension
          • Immunoelectrophoresis
          • Electroimmunodiffusion
    • Counter immune electrophoresis
    • Rocket electrophoresis
  2. Agglutination:
    • In it antigen combines with its antibody in presence of an electrolyte to form clumps of particles
    • Types:
      • Slide agglutination test
      • Tube agglutination test
      • Coombs test
      • Heterophile agglutination test
        • Weil Felix reaction
        • Paul-Bunnel test
        • Streptococcus MG agglutination test
      • Passive agglutination test
        • Latex agglutination test
        • Haemagglutination test
        • Coagglutination
  3. Complement fixation test:
    • Antigen-antibody complex formed fixes complement
  4. Neutralisation test
    • Bacterial exotoxins neutralises antibody
  5. Immunofluorescence:
    • Antigen-antibody complexes produce fluorescence

Immunological Factors In Disease Short Answers

Question 1. T cells

Answer:

T cells

  • T cells are lymphocytes
  • They are thymus-dependent

T cells Types:

  1. Regulatory T cells
    • T helper cells
      • Facilitates B cell response to produce immunglobulin
      • Balance between T helper cell and T suppressor cells produces optimum immune response
      • Overactivity of helper cells leads to autoimmunity
      • Decreased activity of helper cells causes an immunodeficiency state
    • T suppressor cells
      • They block immune reaction
      • Overactivity of suppressor cells leads to an immunodeficiency state
      • Decreased activity of suppressor cells causes an autoimmunity state
    • Effector cells
      • Cytotoxic T cells
        • It can lyse specific target cells
      • Delayed-type hypersensitivity cells
        • Responsible for delayed hypersensitivity reaction

Question 2. Penicillin anaphylaxis

Answer:

Penicillin anaphylaxis

  • Penicillin allergy develops within minutes and is called an immediate hypersensitivity reaction
  • It can induce both type of reactions
  1. Humoral-mediated immunity- causes
    • Type 1- Anaphylaxis
    • Type 2-Cytolytic reaction
    • Type 3- Arthus reaction
  2. Cell-mediated immunity- causes
    • Delayed hypersensitivity reaction
    • Induces synthesis of IgE antibodies
    • Formation of antigen-antibody complexes
    • Degranulation of mast cells
    • Release of inflammatory mediators
    • Bronchospasm
    • Laryngeal edema
    • Hypotension

Question 3. Serum sickness

Answer:

Serum sickness Causes:

  • After the administration of foreign serum
  • Tetanus antitoxin
  • Rabies antiserum

Serum sickness Mechanism:

  • Antibodies form immune complexes in blood vessels with administered antigens
  • These complexes fix complement which attract the leukocytes to the area causing direct tissue injury

Serum sickness Features:

  • Fever
  • Swelling
  • Lymphadenopathy
  • Joint and muscle pain
  • Rash
  • Peripheral neuritis
  • Kidney disease
  • Myocardial ischemia

Question 4. Pemphigus Vulgaris

Answer:

Pemphigus Vulgaris

  • It is the most common type of pemphigus

Pemphigus Vulgaris Features:

  • Age: 40-70 years
  • Sex: Common in females

Pemphigus Vulgaris Presentation:

  • Development of vesicles and bullae over skin and mucous membrane
  • Rupture of vesicles or bullae
  • Formation of painful ulcers that bleed profusely
  • Oblique pressure on the unaffected aeas around the lesion causes the stripping of the normal skin or mucous membrane called “Nikolsky’s sign”
  • Areas affected:
    • Skin lesions- over scalp, trunk, and umbilical areas
    • Orallesions- cheek, palate, and gingiva
      • Leads to excessive pain, excessive salivation, difficulty in intake of food, halitosis

Question 5. Allergy

Answer:

Allergy

  • Allergy is a state of hypersensitivity induced by exposure to a particular antigen
  • This antigenic substance capable of inducing type 1 IgE-mediated immune response
  • The first dose of allergenic exposure sensitizes B lymphocytes
  • The subsequent exposure results in harmful immunologic activation resulting in expression of an allergic reaction

Question 6. Urticaria

Answer:

Urticaria Types:

  • IgE dependent urticaria
  • Complement mediated urticaria
  • Nonimmunologic urticaria
  • Idiopathic urticaria

Urticaria Features:

  • Formation of wheal and flare cutaneous lesions involving only superficial portions of the dermis
  • This results in circumscribed wheals with erythematous raised borders with blanched centers

Question 7. Angioedema

Answer:

Etiology:

  • Food or drug allergy
  • Biochemical abnormality
  • Absence of inhibitor of Cl esterase enzyme from serum
  • Formation of kinin-like substances

Angioedema Clinical Features:

  • Exhibits as smooth, diffused, edematous swelling involving face, lips, chin, eyes, tongue, and extremities
  • Leads to edema of glottis resulting in suffocation

Angioedema Treatment:

Immunological Factors In Disease Angioedema

Question 8. Steven Johnson syndrome

Answer:

Steven Johnson syndrome

  • It is a severe form of erythema multiforme with widespread involvement, typically involving the skin, oral cavity, eyes, and genitalia

Steven Johnson syndrome Clinical Features:

  1. Symptoms:
    • Fever
    • Malaysia
    • Photophobia
    • Eruptions on oral mucosa, genital mucosa, and skin
  2. Skin Lesions:
    • Flemorrhagic
    • Vesicle and bullae are present
  3. Eye Lesions:
    • Photophobia
    • Conjunctivitis
    • Corneal ulceration
    • Keratoconjunctivitis
  4. Genital Lesions:
    • Non-specific urethritis
    • Balanitis
    • Vaginal ulcers
  5. Complications:
    • Trachea-bronchial ulceration
    • Pneumonia

Steven Johnson syndrome Treatment:

  • ACTH
  • Cortisone
  • Chlortetracycline

VIVA VOCE

  1. Adrenaline is drug of choice in anaphylaxis

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