1. © 2008, YCMOU. All Rights Reserved.1 Online Counseling Resource YCMOU ELearning Drive… School of Architecture, Science and Technology Yashwantrao Chavan Maharashtra Open University, Nashik – 422222, India

2. © 2008, YCMOU. All Rights Reserved. 2 OC-SBT052-CP3-02 Introduction Programmes and Courses  SEP–SBT052–Unit-03

3. School of Science and Technology, Online Counseling Resource… © 2008, YCMOU. All Rights Reserved.3 Credits  Academic Inputs by Arun Punaji More. M.Sc. (Microbiology) ‏ Experience: 11 Years arunmesh@hotmail.com

4. School of Science and Technology, Online Counseling Resource… © 2008, YCMOU. All Rights Reserved.4 How to Use This Resource  Counselor at each study center should use this presentation to deliver lecture of 40-60 minutes during Face-To-Face counseling.  Discussion about students difficulties or tutorial with assignments should follow the lecture for about 40-60 minutes.  Handouts (with 6 slides on each A4 size page) of this presentation should be provided to each student.  Each student should discuss on the discussion forum all the terms which could not be understood. This will improve his writing skills and enhance knowledge level about topics, which shall be immensely useful for end exam.  Appear several times, for all the Self-Tests, available for this course.  Student can use handouts for last minutes preparation just before end exam.

5. School of Science and Technology, Online Counseling Resource… © 2008, YCMOU. All Rights Reserved.5 Learning Objectives  After studying this module, you should be able to: Describe the type II hypersensitive reactions. Describe the mechanism of type II hypersensitive reactions. Describe the diseases caused due to type II hypersensitive reactions.

6. School of Science and Technology, Online Counseling Resource… © 2008, YCMOU. All Rights Reserved.6 Introduction  The prime and important functions of immune system are to remove the foreign antigens from the body and to neutralize their toxic effects.  However if the foreign antigens are not removed within a short period of time and accumulate on the tissue surfaces, the reactions between such antigens and antibodies on the tissue surface activate complement factors causing some collateral damages to such tissue.  In this module you will learn the mechanism behind such damages.

7. School of Science and Technology, Online Counseling Resource… © 2008, YCMOU. All Rights Reserved.7 Type II Hypersensitive Reactions-1  The type II hypersensitive reactions are exaggerated immunological reactions mediated by antibodies such as IgG and IgM and complement factors on tissue surfaces.  Therefore the type II hypersensitive reactions are also called as antibody- mediated cytotoxic hypersensitive reactions.  The tissues damages in type II hypersensitive reactions are mediated by complement factors activated by antigens antibodies reactions at the tissue surface.

8. School of Science and Technology, Online Counseling Resource… © 2008, YCMOU. All Rights Reserved.8 Type II Hypersensitive Reactions-2  The tissue damages in the type II hypersensitive reactions are also caused by the cytotoxic T cells.  The tissue damages by the cytotoxic T cells is called as antibody dependent cell mediated cytotoxicity.

9. School of Science and Technology, Online Counseling Resource… © 2008, YCMOU. All Rights Reserved.9 Type II Hypersensitive Reactions-3  Components of type II hypersensitive reactions:  Antibodies :- IgG, IgA and IgM  Cytotoxic T cells  Complements factors

10. School of Science and Technology, Online Counseling Resource… © 2008, YCMOU. All Rights Reserved.10 Type II Hypersensitive Reactions-4  Mechanism:- 1)the tissue damage in type II hypersensitive reaction occurs on the tissue surface by two components of the immune system: a) Antibody dependent cytotoxic cells (ADCC) ‏ b) Activated complement factors

11. School of Science and Technology, Online Counseling Resource… © 2008, YCMOU. All Rights Reserved.11 Type II Hypersensitive Reactions-5  The examples of type II hypersensitive reactions are  Transfusion reactions  Haemolytic diseases of newborn Erythroblastosis fetalis  Drug induced anemia  Antibody mediated hyperactive rejection of tissue graft

12. School of Science and Technology, Online Counseling Resource… © 2008, YCMOU. All Rights Reserved.12 Type II Hypersensitive Reactions-6  Transfusion reaction:- Occurs due to ABO blood group incompatibilities  Depending upon the presence of surface receptors on the red blood cells there are three blood groups: blood group A, blood group B and blood group O.  The persons with blood group A possess antigen A on the red blood cell and anti-antigen B antibodies in their blood while the persons with blood group B posses antigen B on the red blood cell surface and anti-antigen A antibodies in their blood.  The persons with blood group O possess neither A antigen nor B antigen on the red blood cell surface but possess anti-A and anti-B antibodies in their blood.

13. School of Science and Technology, Online Counseling Resource… © 2008, YCMOU. All Rights Reserved.13 Type II Hypersensitive Reactions-7  Transfusion reaction:- When a person with blood group A is transfused with blood with B group, anti-B antibodies react with antigen B on the red blood cells from the donor activating complements factors leading to destruction of red blood cells from the donor. The blood transfusion reaction is characterized with massive intravascular hemolysis of the transfused red blood cells. The antibodies involved in the transfusion reaction is mainly IgM. The signs and symptoms of transfusion reaction is fever, chills, nausea, pain in lower back, hemoglobinuria.

14. School of Science and Technology, Online Counseling Resource… © 2008, YCMOU. All Rights Reserved.14 Type II Hypersensitive Reactions-8  Erythroblastosis fetalis:-- It is hemolytic disease of Rh + newborn developed in Rh - mother. During pregnancy fetal blood is separated from the mother blood circulation by a layer of trophoblast cells in the placenta. During the first delivery, when placenta separate from the uterine wall large amount of fetal blood enter the mother's circulation, thus sensitize the immune system of the mother to produce anti Rh antibodies and anti Rh memory cells. During the subsequent pregnancy, the memory cells against Rh antigens are activated producing IgG antibodies which cross the placenta ant destroy the fetal red blood cells.

15. School of Science and Technology, Online Counseling Resource… © 2008, YCMOU. All Rights Reserved.15 Type II Hypersensitive Reactions-9  Erythroblastosis fetalis:--mechanism

16. School of Science and Technology, Online Counseling Resource… © 2008, YCMOU. All Rights Reserved.16 Type II Hypersensitive Reactions-10  Type II hypersensitive reactions are also involved in number of autoimmune diseases. Autoimmune haemolytic anemia Bullous skin diseases such as  Pemphigus and pemphigoid Goodpasture's disease Idiopathic thrmbocytopenic purpura  In autoimmune diseases such as myasthenia gravis and tyrotoxicosis antibodies are secreted against the cell receptors; in the former the Ab are secreted against acetylcholin receptors and in later the Abs are secreted against the anti- thyroid stimulating hormone receptors.

17. School of Science and Technology, Online Counseling Resource… © 2008, YCMOU. All Rights Reserved.17 Type II Hypersensitive Reactions-11  Autoimmune disorders involving type II hypersensitive reactions: Autoimmune haemolytic anemia:  In this disease the auto-antibodies against the RBC membrane proteins are produced.  When this auto-antibodies bind to RBC, RBC are destroyed by complement mediated lysis and phagocytosed by antibody mediated opsonization.  The autoimmune haemolytic anemia due to Rh incompatibility is diagnosed by Coomb's test.

18. School of Science and Technology, Online Counseling Resource… © 2008, YCMOU. All Rights Reserved.18 Type II Hypersensitive Reactions-12  Pemphigus and pemphigoid:- Pemphigus is auto-immune disease of the skin characterized by massive formation of blisters on the skin surface. In pemphigus auto-antibodies are formed against the skin and mucous cells. In pemphigus auto-antibodies are produced against desmoglein which is binding substance sticking the epidermal cells in the skin. Acantholysis i. e. separation of individual epidermal karatinocytes from each other is prominent feature of pemphigus vulgaris.

19. School of Science and Technology, Online Counseling Resource… © 2008, YCMOU. All Rights Reserved.19 Type II Hypersensitive Reactions-13  Pemphigus and pemphigoid:- Pemphigoid is group of auto-immune disease of skin characterized by massive blistering but absence of acantholysis. Characteristic lesions in pemphigus vulgaris.

20. School of Science and Technology, Online Counseling Resource… © 2008, YCMOU. All Rights Reserved.20 Type II Hypersensitive Reactions-14  Goodpasture's syndrome:- In this autoimmune disease auto-antibodies against basement membrane antigens of kidney glomeruli and the alveoli are produced. The binding of these auto-antibodies to these antigens activate the complements which damage these organs. Damage to kidney result in non-functioning of the kidneys whereas the damage to basement membranes of alveoli result into pulmonary hemorrhage. The Goodpasture's syndrome is diagnosed by staining the biopsy samples from kidney and lungs by fluorescent-labeled anti-IgG and C3b.

21. School of Science and Technology, Online Counseling Resource… © 2008, YCMOU. All Rights Reserved.21 What We Learn…..  The mechanism of type II hypersensitive reactions.  Components of immune system involved in type II hypersensitive reactions.  Autoimmune diseases involving the type II hypersensitive reactions.

22. School of Science and Technology, Online Counseling Resource… © 2008, YCMOU. All Rights Reserved.22 Critical Thinking Question  Why in Rh incompatibility a fetus is not aborted in the first delivery?

23. School of Science and Technology, Online Counseling Resource… © 2008, YCMOU. All Rights Reserved.23 Hints For Critical Thinking Question  Secondary immune resposne  IgG can cross placenta  Exposure of fetus Rh antigen at the time of delivery( postpartum) ‏

24. School of Science and Technology, Online Counseling Resource… © 2008, YCMOU. All Rights Reserved.24 Study Tips  Book Title: Immunology Title: Immunology Author: Author: Richard A. Goldsby, Thomas Kindt, Barbara A. Osborne. Publication: Publication: W.H. Freeman and Company, New York.  Book Title: Textbook of Microbiology Author: Author: R. Anathanarayan & C.K.J. Paniker Publication: Publication: Orient Longman publication, Chennai.

25. © 2008, YCMOU. All Rights Reserved.25 End of the Presentation Thank You !