2. 2
HYPERSENSITIVITY
Hypersensitivity reaction resulting from
specific interactions between antigens
(allergens) and either antibodies or sensitized
lymphocytes.
Hypersensitivity reaction resulting from specific
interactions between antigens (allergens) and either
antibodies or sensitized lymphocytes
Diffuse urticaria Anaphylactic response to bee sting
7. (A)Electron micrograph of normal mast cell illustrating large monocyte-like
nucleus and electron-dense granules.
(B) (B) Mast cell that has been triggered and is beginning to release
contents of granules, as seen by their decrease in opacity and formation
of vacuoles connecting with exterior.
ELECTRON MICROSCOPIC VIEW
8. Clinical Examples
Hay fever and Asthma----To pollen,
house dust, pets etc.
Urticaria(Hives)---Drugs,food.
Reddening and itching of skin.
Systemic anaphylaxis---Inj. of
Penicillin,Insect bites.
11. Drug-Induced Reactions:
Adherence to Blood
Components
complementcomplement
blood cell adsorbed drugblood cell adsorbed drug
or antigen drug metaboliteor antigen drug metabolite antibody to drugantibody to drug
lysis
14. Hemolytic Disease of the New Born
RhD-ve mother
RhD +ve fetus
Anti-RhD Abs
RhD +ve fetus
15. ‘A’ blood group
mother
‘B’ blood group fetus
Anti-B Abs
If mother and fetus have different blood
groups, hemolytic disease does not occur.
16. Prophylaxis (RhoGAM)
RhD-ve mother
RhD +ve fetus
Anti-RhD Abs
RhD +ve fetus
Mid-term injection of RhoGAM and a second
injection within a few days of delivery
27. Type V Hypersensitivity / Auto
immune
This is an additional type that is sometimes used
as a distinction from Type 2
Instead of binding to cell surface components, the
antibodies recognize and bind to the cell surface
receptors , which either prevents the intended
ligand binding with the receptor or mimics the
effects of the ligand, thus impairing cell signaling
28. Examples of Type V
Grave's disease
Myasthenia Gravis
Hashimoto's thyroiditis
Systemic lupus erythematosus
32. LYMPH NODE:QUANTITATIVE
ASSAY
* The basic principle is to induce proliferation of lymphocytes in the
lymph nodes draining the site of test substance application.
* This proliferation is proportional to the dose and to the potency of
the applied allergen and provides a simple means of obtaining a
quantitative measurement of sensitization.
* Proliferation is measured by comparing the mean proliferation in
each test group to the vehicle treated control (VC) group.
* The ratio of the mean proliferation in each treated group to that in
the VC group, termed the SI, is determined, and should be ≥1.8.
33. * The methods described here are based on the use of measuring ATP
content by bioluminescence to indicate an increased number of
proliferating cells in the draining auricular lymph nodes
* The bioluminescent method utilises the luciferase enzyme to catalyse
the formation of light from ATP and luciferin according to the following
reaction:
ATP+LUCIFERIN+OXYGEN
luciferase
OXYLUCIFERIN+AMP+Ppi+CO2+LIGHT
* The emitted light intensity is linearly related to the ATP concentration
and is measured using a luminometer
* The luciferin-luciferase assay is a sensitive method for ATP
35. REFERENCES
Willey drug safety evaluation (2002)by shayne c.Gad
OECD (2010), Skin Sensitization: Local Lymph Node Assay,
Test Guideline No. 429, Guidelines for the Testing of
Chemicals, OECD, Paris. Available at:
[http://www.oecd.org/env/testguidelines]
http://iccvam.niehs.nih.gov/docs/immunotox_docs/llna/llnarep.
pdf]
OECD (1992), Skin Sensitisation, Test Guideline No. 406,
Guidelines for Testing of Chemicals, OECD, Paris. Available
at: [http://www.oecd.org/env/testguidelines]
OECD (2002), Acute Dermal Irritation/Corrosion, Test
Guideline No. 404, Guidelines for Testing of Chemicals,
OECD, Paris. Available at:
[http://www.oecd.org/env/testguidelines]
