Def

Question 1

Autoimmunity

Answer 1

The reaction of the immune system against self constituents is termed as auto immunity
Also loss of self tolerance

Question 3

Self tolerance

Answer 3

Immunological unresponsiveness to self antigen

Question 4

Molecular mimicry

Answer 4

Many micro organisms have got antigenic similarity with human cell constituents and thereby are a source of cross reacting antigen.
Eg shigella chlamydia-reiters syndrome
Campylobacter- guillian barre syndrome
Wheb ab is produced against these microbial antigens they cross react with human ag producing autoimmune disease
Eg. There is antigenic similarity between m protein of strep pyogens and myosin of human cardiac muscle . Abs against m protein cross react with cardiac myosin leading to rheumatic arthritis

Question 5

Alteration of self protein

Answer 5

Some drugs bind to self proteins and makes them immunogenic wg procaineamide induced SLE
drug induced haemolytic anaemia by a methyldopa which binds with rbc

Question 6

Release of sequestered antigen

Answer 6

Certain tissues like sperm, cns, lens, and uveal tract of eye remain sequestered so that they are not exposed to immune system during embryonic life
Such ag can gain access to circulation by accident and cell gets damaged by infection or uv light giving rise to formation of auto antibodies or auto reactive t cells

Question 7

Epitope spreading

Answer 7

Exposure of sequestered autoantigens as a result of viral infection

Newly exposer autoantigens stimulate autoreactive t cells causing autoimmune disease

Failure of regulatory t cell

Question 9

Transplantation

Answer 9

Refers to the act of transferring cells tissues or organs from one site to another of the same indivisual or between indivisuals of same species or different species

Question 10

Use of clinical transplantation

Answer 10

Skin cornea
Kidney liver
Bone marrow
Blood
Heart lungs
Pancreas

Question 11

Types of transplantation

Answer 11

Autograft
Isograft
Allograft
Xenograft

Question 12

Autograft

Answer 12

Transfer of an indivisuals own tissue from one body site to another eg skin and bone etc
Artery or vein used in cardiac by pass

Question 13

Isograft

Answer 13

It is the transfer of tissue or organ between genetically identical indivisuals ie. Identical twins

Question 14

Allograft

Answer 14

It is the tissue or organ transffered between genetically different members of the same species eg. From one human to another

Question 15

Xenograft

Answer 15

Tissue transffered btw members of different species eg animal heart into human
These are vigorously rejected

Question 16

Allograft rejection

Answer 16

It occurs when antigen of the allograft specially hla antigen of donor is genetically dissimilar to the host
These ags are recognised as foreign by the immune system of the host and rejected

Question 17

Types of graft rejection

Answer 17

Hyper Acute rejection-first 24 hrs
Acute rejection- 1st few weeks
Chronic rejection- months to years

Question 18

Outcome

Answer 18

Corneas are well grafted as they are avascular and lymphatic supply of the eye prevents many antigen
2. In well matched donor and recipient in hla typing the survival rate of kidney transplant is 95%

Question 20

Lab tests

Answer 20

1. Hla typing or tissue typing to determine mhc match btw donor and recipient
2. Mixed lymphocyte culture
   To detect cytotoxic abs against donors lymphocytes in recipients blood
3. Abo blood grouping

Question 21

Clinical features

Answer 21

Fever
Pain
Swelling
Flu like symptoms
Chills and body aches
Itching
Abdomenal tenderness
Cough
Sudden weight gain