Hypersensitive Reactions

Definition:

• Hypersensitive reactions are inflammatory reactions within the humoral or cell-mediated branches of the immune system that lead to extensive tissue damage or even death.
• The four types of hypersensitive reactions (Gell and Coombs classification) generate characteristic  effector molecules and clinical manifestations

Type I Hypersensitive Reaction

• It is mediated by IgE antibodies whose Fc portion binds to receptors on mast cells or basophils.
• Cross linkage of the fixed IgE by allergen leads to a mast cell or basophil degranulation with the release of pharmacologically active mediators.
• The principle effects of these mediators are:

* Smooth muscle contraction

* Vasodilation

 * Systemic anaphylaxis

*Localized responses: Hay fever & asthma

Components of Type I Reactions

• Allergens
• Reaginic antibody(IgE)
• Mast cells and Basophils
• IgE binding Fc receptors

                * High-Affinity Receptors

                * Low-Affinity Receptors

P-K test (Skin test)

Reactivity of Atopic serum in P-K test

High and Low-affinity IgE Receptors

Principal Mediators of Type I Hypersensitivity

Type II Hypersensitive Reaction

• A type II hypersensitive reaction occurs when an antibody reacts with antigenic determinants present on the surface of cells leading to cell damage or death through complement-mediated lysis or antibody-dependent cell-mediated cytotoxicity (ADCC).
• Transfusion reactions and hemolytic disease of the newborn are type II reactions.

Structure of ABO blood group antigens

Development of Erythroblastosis Fetalis (Hemolytic Disease of a newborn)

Type III Hypersensitive Reaction

• A type III hypersensitive reaction is mediated by the formation of immune complexes and the ensuing activity of the complement system.
• Complement split products serve as immune effector molecules that elicit localized vasodilation and chemotactically attract neutrophils.
• The deposition of immune complexes near the site of antigen entry can induce Arthus reaction. This lytic enzyme released by accumulated neutrophils and the complement membrane attack complex cause localized tissue damage.

Type III hypersensitive Reaction (Arthus Reaction)

Type IV Hypersensitive Reaction

• It involves the cell-mediated branch of the immune system.
• Antigen activation of sensitized TH 1 cells induces the release of various cytokines that cause macrophages to accumulate and become activated.
• The net effect of the activation of macrophages is to release lytic enzymes that cause localized tissue damage.

• Overview of DTH response

itel P55 5G | Dimensity 6080 | 12GB* RAM+128GB ROM with Memory Fusion| 50MP AI Dual Rear Camera| 5000mAh Battery | 2 Years Warranty | Galaxy Blue

(778)

₹9,999.00 (as of November 24, 2023 06:57 GMT +00:00 - More infoProduct prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on [relevant Amazon Site(s), as applicable] at the time of purchase will apply to the purchase of this product.)

realme narzo 60 Pro (Cosmic Black,8GB+128GB) Ultra Smooth 120 Hz Super Amoled Curved Display | 100 MP OIS Camera

(1654)

₹23,999.00 (as of November 24, 2023 06:57 GMT +00:00 - More infoProduct prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on [relevant Amazon Site(s), as applicable] at the time of purchase will apply to the purchase of this product.)

iQOO Z7 Pro 5G (Blue Lagoon, 8GB RAM, 128GB Storage) | 3D Curved AMOLED Display | 4nm MediaTek Dimesity 7200 5G Processor | 64MP Aura Light OIS Camera | Segment's Slimmest & Lightest Smartphone

(4184)

₹23,999.00 (as of November 24, 2023 06:57 GMT +00:00 - More infoProduct prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on [relevant Amazon Site(s), as applicable] at the time of purchase will apply to the purchase of this product.)

realme narzo 60X 5G（Nebula Purple 4GB, 128GB Storage） Up to 2TB External Memory | 50 MP AI Primary Camera | Segments only 33W Supervooc Charge

(3180)

₹12,999.00 (as of November 24, 2023 06:57 GMT +00:00 - More infoProduct prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on [relevant Amazon Site(s), as applicable] at the time of purchase will apply to the purchase of this product.)

Redmi 12 5G Jade Black 4GB RAM 128GB ROM

(6304)

₹11,999.00 (as of November 24, 2023 06:57 GMT +00:00 - More infoProduct prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on [relevant Amazon Site(s), as applicable] at the time of purchase will apply to the purchase of this product.)

Redmi 12 5G Jade Black 6GB RAM 128GB ROM

(6304)

₹13,499.00 (as of November 24, 2023 06:57 GMT +00:00 - More infoProduct prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on [relevant Amazon Site(s), as applicable] at the time of purchase will apply to the purchase of this product.)

Samsung Galaxy M34 5G (Waterfall Blue,6GB,128GB)|120Hz sAMOLED Display|50MP Triple No Shake Cam|6000 mAh Battery|4 Gen OS Upgrade & 5 Year Security Update|12GB RAM with RAM+|Android 13|Without Charger

(7532)

₹19,999.00 (as of November 24, 2023 06:57 GMT +00:00 - More infoProduct prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on [relevant Amazon Site(s), as applicable] at the time of purchase will apply to the purchase of this product.)

Samsung Galaxy M34 5G (Prism Silver,6GB,128GB)|120Hz sAMOLED Display|50MP Triple No Shake Cam|6000 mAh Battery|4 Gen OS Upgrade & 5 Year Security Update|12GB RAM with RAM+|Android 13|Without Charger

(7532)

₹19,999.00 (as of November 24, 2023 06:57 GMT +00:00 - More infoProduct prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on [relevant Amazon Site(s), as applicable] at the time of purchase will apply to the purchase of this product.)

Lava Agni 2 5G (Glass Heather, 8GB RAM, 256GB Storage) |2.6GHz Dimensity 7050 6nm Processor | Curved Amoled Display| 13 5G Bands | Superfast 66W Charger | Clean Android (No Bloatware, No Ads)

(2508)

₹19,999.00 (as of November 24, 2023 06:57 GMT +00:00 - More infoProduct prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on [relevant Amazon Site(s), as applicable] at the time of purchase will apply to the purchase of this product.)

itel S23+| 3D Curved Amoled Display| 16GB* RAM+256GB ROM| in-Display Fingerprint| 50MP AI Dual Rear + 32MP Front Camera| 5000mAh Battery| 2 Years Warranty| Lake Cyan

(465)

₹13,999.00 (as of November 24, 2023 06:57 GMT +00:00 - More infoProduct prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on [relevant Amazon Site(s), as applicable] at the time of purchase will apply to the purchase of this product.)

Jockey 1406 Women's High Coverage Super Combed Cotton Mid Waist Hipster with Concealed Waistband and StayFresh Treatment (Pack of 3_Colors & Prints May Vary)

(33473)

₹498.00 (as of November 24, 2023 07:16 GMT +00:00 - More infoProduct prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on [relevant Amazon Site(s), as applicable] at the time of purchase will apply to the purchase of this product.)

Kraftidy Dog Collar Belt with Name tag id Customized for Small Medium Large Dogs Neck Collar with Personalized Dog Name (Orange) (with Dog Name) (Large Dogs)

(17)

₹279.00 (as of November 24, 2023 07:16 GMT +00:00 - More infoProduct prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on [relevant Amazon Site(s), as applicable] at the time of purchase will apply to the purchase of this product.)

VRPRIME Shoe Sneaker Cleaner for White Shoes | Foam Sneaker Cleaning Kit | Suitable for Nubuck, Canvas, Knit, Trainers & Sports Shoes | With Brush, Microfibre cloth & Refill Bottle

(263)

₹499.00 (as of November 24, 2023 07:16 GMT +00:00 - More infoProduct prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on [relevant Amazon Site(s), as applicable] at the time of purchase will apply to the purchase of this product.)

My First Library: Boxset of 10 Board Books for Kids

(73874)

₹399.00 (as of November 24, 2023 07:16 GMT +00:00 - More infoProduct prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on [relevant Amazon Site(s), as applicable] at the time of purchase will apply to the purchase of this product.)

Kennel Kitchen Creameroo Cat Treats, 60g, 4 Pieces | Chicken with Mackerel Flavour | Smooth Creamy Treats for Cats and Kittens | Handheld Lick-able Wet Cat Food Treats | Preservative Free

(8)

₹99.00 (as of November 24, 2023 07:16 GMT +00:00 - More infoProduct prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on [relevant Amazon Site(s), as applicable] at the time of purchase will apply to the purchase of this product.)

Campus Mens Atlantis Running

(584)

₹750.00 (as of November 24, 2023 07:16 GMT +00:00 - More infoProduct prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on [relevant Amazon Site(s), as applicable] at the time of purchase will apply to the purchase of this product.)

Amazon Basics Cat Litter Box Tray with Free Scooper | Semi Closed Design and Durable Quality | Suitable for All Adult Cats & Kittens, Pink

(6533)

₹279.00 (as of November 24, 2023 07:16 GMT +00:00 - More infoProduct prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on [relevant Amazon Site(s), as applicable] at the time of purchase will apply to the purchase of this product.)

LEOTUDE Men's Classic Loopknit Bomber Jacket with Zipper Closure and Side Pockets (Color Black)

(6)

₹449.00 (as of November 24, 2023 07:16 GMT +00:00 - More infoProduct prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on [relevant Amazon Site(s), as applicable] at the time of purchase will apply to the purchase of this product.)

COSTEM Spin Mop with Wheels and Stainless Steel Wringer, Bucket Floor Cleaning and Mopping System,2 Microfiber Refills (Blue)

(150)

₹799.00 (as of November 24, 2023 07:16 GMT +00:00 - More infoProduct prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on [relevant Amazon Site(s), as applicable] at the time of purchase will apply to the purchase of this product.)

ZANIC Kitchen Wall Stickers Wood Wallpaper DIY PVC Shelf Liner, Furniture, Almirah, Table Top, Wardrobe, Kitchen Cupboard Decal, Mahogany Brown (45 x 300 CM, Mahogany Brown)

(49)

₹199.00 (as of November 24, 2023 07:16 GMT +00:00 - More infoProduct prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on [relevant Amazon Site(s), as applicable] at the time of purchase will apply to the purchase of this product.)