Allergy, Allergen & Antibody

PREPARED BY
RASHIDUL HASAN ROBEL
B. PHARM (RU), M. PHARM (RU)
REG. NO. A4968
PGD-HRM (BIM)
EMBA (ULAB)

1. ALLERGY ALLERGEN ANTIBODY PREPARED BY RASHIDUL HASAN ROBEL B. PHARM ( RU ) , M. PHARM ( RU ) REG. NO. A4968 PGD-HRM ( BIM ) EMBA ( ULAB )

2. What is Allergy? Definition-1 Allergy is allergen-antibody reaction. Definition-2 An immune-response to foreign antigen (allergen) that results in inflammation and organ dysfunction .

3. What is Allergy ? Definition-3 Allergies are an overreaction of the body’s immune system to specific substances that it misidentifies as harmful. This overreaction of the body’s immune system is known as an allergic reaction and the substances that cause it are called allergens. Definition-4 An allergy is a hypersensitivity disorder of the immune system. Allergic reactions occur when a person's immune system reacts to normally harmless substances in the environment. A substance that causes allergic reaction is called an allergen.

4. What is Allergen ? Foreign particle that causes allergic reaction is called an allergen . Pollens Dust Plants Foods Smell Smoke Mold spores Animal dander Down feather Bee sting Insect bites Medication/Drugs Chemicals Hot & Cold etc . Common Sources

5. Types of Allergen Indoor Allergen Foods Household dust Pet dander Outdoor Allergen Pollens in spring Cold in winter Soy dust

6. What is Antibody ? Antibody is a large Y-shaped protein. Antibodies are produced & released by B-lymphocyte/B-cell. It kills germs or fight against foreign particles. It is expressed by ‘Ab ’ . It is also known as an Immunoglobulin expressed by ‘Ig ’.

7. Types of Antibody IgA : Immuno-globulin A IgD : Immuno-globulin D IgE : Immuno-globulin E IgG : Immuno-globulin G IgM : Immuno-globulin M

8. IgA % of total serum antibody – 13% Half life – 6 days. Structure – Dimer Antigen binding site – 4 Heavy chain – α (alpha) 2 sub-classes are IgA1 & IgA2 . Can not cross placenta. Mainly found in saliva, tears, mucous, milk & colostrum. Functions of IgA Secretory antibody Provides local immunity. IgA binds to surface antigen of microbes & prevents its attachment & invasion to the mucosal surface of respiratory & digestive tract. Present in colostrum & protects newborn during 1 st month.

9. IgD % of total serum antibody – 1% Half life – 3 days. Structure – Monomer Antigen binding site – 2 Heavy chain – δ (delta) Can not cross placenta. Functions of IgD B-cell receptor for antigen recognition.

10. IgE % of total serum antibody – 0.002% Half life – 6 days. Structure – Monomer Antigen binding site – 2 Heavy chain – ε (epsilon) Can not cross placenta. Functions of IgE Responsible for immediate hypersensitivity & allergic reaction. Immunity against helminthic parasites. Binds to Fc receptor on mast cell & basophils. Helps to release histamine, bradykinin, prostaglandin, leukotrienes etc. from mast cell. Fc (fragment crystallization) receptor involved in antigen recognition which is located at the membrane of certain immune cells including B lymphocytes, natural killer cells, macrophages, neutrophils, and mast cells.

11. IgM % of total serum antibody – 6% Half life – 5 days. Structure – Pentamer Antigen binding site – 10 Heavy chain – β (beta) Can not cross placenta. Functions of IgM 1 st immuno-globulin that gives primary response. Presence of IgM in newborn indicates congenital infection. Effective against multivalent antigen. Monomeric form of IgM serves as B-cell receptor.

12. IgG % of total serum antibody – 80% Half life – 23 days. Structure – Monomer Antigen binding site – 2 Heavy chain – γ (gamma) 4 sub-classes are IgG1, IgG2, IgG3 & IgG4. Can cross placenta (except IgG2). Functions of IgG Main blood antibody that provides secondary responses to germs. Cross the placenta and provide immunity to fetus & neonate at birth. Neutralize the toxins.

13. Mast Cells Location GIT Respiratory tract Nerve ending Skin Eye Around blood vessels etc. Components in mast cell Histamine Bradykinin Prostaglandin Leukotriene ACE (angiotensin converting enzyme) Heparin Trypatse IL, TNF- α etc.

14. Mechanism of Allergy/Allergic Reaction Allergens enters into the body via different routes. Allergens are processed by APC & carried by helper T-cell to the B-cell. Then B-cell are differentiated into numerous plasma cell which produces IgE antibodies.

15. 4. Next antibodies bind to the antibody over the mast cell. 5. On further expose, allergens bind to the antibody of mast cell that leads to allergen-antibody reaction . 6. This allergen-antibody reaction causes mast cell to release Histamine, Bradykinin, Prostaglandin, Leukotriene, NCF (neutrophil chemo-tactic factor), ECF (eosinophil chemo-tactic factor) etc. Mechanism of Allergy/Allergic Reaction

16. 7. Histamine & Bradykinin bind to each receptors on blood vessels & dilate blood vessels. It also increases the permeability of blood vessels. So, plasma transfuses to periphery & ultimately causes swelling which is called edema. 8. Prostaglandin causes pain & heat to the swelling site. 9. Histamine & Substance-P cause itching to the swelling site. 10. Leukotrienes causes Broncho-constriction & also stimulate the release of excess mucin. Mechanism of Allergy/Allergic Reaction

17. Allergic Rhinitis Inflammation of nose due to allergic reaction. Symptoms Rhinorrhea/runny nose. Watery eyes. Sneezing & Nasal congestion. Rhinorrhea Watery eyes Sneezing Nasal congestion

18. 1 . SAR (seasonal allergic rhinitis) Occurs at certain season such as spring, winter, summer etc. Caused by outdoor allergens such as pollens in spring, cold in winter etc. 2. PAR (perennial allergic rhinitis) Occurs at any time Caused by indoor allergens such as foods, smoke, smell etc. Types of AR

19. It is a severe, potentially life-threatening allergic reaction. It is rapid in onset and may cause death . It can occur within seconds or minutes of exposure to allergen. Common causes include venom from insect bites or stings, foods, and medication. Symptoms On skin (80-90%): Urticaria , itching, swelling or angioedema etc. Respiratory (70%): Shortness of breath, wheezing etc. GI symptoms (30-45%): Abdominal pain, diarrhea, vomiting etc. CV & vasculature (10-15%): Low blood pressure CNS symptoms (10-15%): Headache, anxiety etc. Anaphylaxis/Anaphylactic Reaction

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