IMMUNOPATHOLOGY

IMMUNOPATHOLOGY

HYPERSENSITIVITY

Hypersensitivity may be defined as

"An increased sensitivity to an antigen or hapten resulting from a previous specific immune response to the same or related antigen."

Types

It is usually classified into two types.

1. Immediate hypersensitivity
2. delayed hypersensitivity

1.IMMEDIATE HYPERSENSITIVITY

• Appear in sensitized individual almost immediately following the shocking dose of antigen
• Antibody mediated ( IgE )
• Most common types of reaction is rhinitis or  hay fever.
• Other types are bronchial asthma, allergic dermatitis and some food allergies.

2.DELAYED HYPERSENSITIVITY

• Appear in sensitized persons hours or days later.
• Cell mediated ( T lymphocytes )
• Example : Allergic contact dermatitis

Glossary

1.Antigen is chemical substance that specifically reacts with an antibody to form a stable complex.

2. hapten is a substance that combines specifically with antibody but fails to initate the antibody production.

TERMINOLOGIES

1. Cleaning is removal of contamination such as dirt.
2. Disinfection is the use of physical process or chemical agents to destroy vegetative pathogens, but not bacterial endospores.
3. Sterilization is a process that destroys or removes all viable microorganisms, including viruses.

any material that has been subjecred to this process is said to be sterile.

4.Sanitation is any cleansing technique that mechanically removes microorganism to reduce the level of contaminants.

5.Disinfectant is a chemical agent to destroy vegetative pathogens, but not bacterial endospores. ( Disintectant is normally used only on inanimate objects. )

6.antiseptics are chemical agents applied directly to exposed body surfaces ( skin and mucous membranes ) wound , and surgerical incisions to destroy or inhibit vegetative pathogen

7.Sanitizer is a compound such as soap or detergent that mechanically, removes microorganisms.

8.Bactericidal is a chemical destroys bacteria except for those in the endospore stage.

9.Fungicidal is a chemical that can kill fungal spores , hyphae and yeast.

10.Virucide is any chemical known to inactive viruses especially on livng tissue.

11.Sporicide is any chemical agent capable of destroying bacterial endospores.

12.Germicide is any chemical agent that kills pathogenic microorganisms.

13.Bacteriostatic agent prevents the growth of bacteria on tissues or on objects in the environment.

14.Degermation is a process, involves scrubbing the skin or immersing it in chemicals or both.

·        It emulsifies oil that lies on the outer cutaneous layer.

·        Mechanically removes potential pathogens on the outer layer of the skin

Examples

                                             i.            Surgical hand scrub

                                           ii.            Application of alcohol wipes to the skin

                                          iii.            Cleansing of wound with germicidal soap and water.