(PART2) OVERVIEW OF IMPORTANT IMMUNOLOGIC PRINCIPLES AS APPLIED TO BLOOD BANKING

IgM, IgG, IgA

Antibody classes most commonly encountered in the Blood Bank are: _________________

Anaphylactic Transfusion Reaction

ANTIBODIES

• Involved in __________

Fab, Fc (crystallizable fragment)

ANTIBODIES

• Fragments: ___________________

Variable, Constant

ANTIBODIES

• Regions: ______________________

bind with ANTIGEN

ANTIBODIES

• Fab, Variable regions: _________________

bind with Host’s cells (phagocytes and complement)

ANTIBODIES

• Fc , Constant regions: _______

CH1 and CH2

• Hinge region is located between __________.

• It has specific amino acid that is present (PROLINE), that is used to bend

Hypervariable Region

What is end part of region?

Amino terminal end

• The portion of the molecule that binds to the antigen is called as Fab (Fragment of Antigen Binding).

• It is located on the _________________ (gives positive charges (+) on the antibodies) because of the amino repair (NH4)

antigen

Fab (Fragment of ANTIGEN binding)- binds with

Host cell

Fc region- binds with the

Papain Digestion

• One fragment spontaneously crystallized at 4 C.

• The remaining two identical fragments were found to have antigen- binding capacity.

• From the work of PORTER

• 3 fragments

• Once papain digest the antibody, it will produce 2 identical fragments, and 1 Fc

Pepsin Digestion

• This proteolytic enzyme was found to cleave IgG at the carboxy-terminal side of the interchain disulfide bonds.

• one single fragment with a molecular weight of 100,000 d and all the antigen-binding ability, known as F(ab)2.

• 2 Fragments only

• The Fc will disintegrate into smaller pieces

below the Hinge region

Where is the digestion or cut of Pepsin digestion?

In the Hinge Region

Where is the digestion or cut of Papain digestion?

IgM

What class is the most effective in activating the complement?

Edelman

Who separated out the immunoglobulins based on the molecular weight using the analytical ultracentrifuge/ultracentrifugation?

2

• For each monomer, the number of binding sites is __

5-10

• The half life of the IgM is _______ days only, because it is the first antibody produced against immunogen

IgG

Most predominant

IgM

The first responder, 1st antibody that will be produced

IgG 2

Cannot cross the placenta

1

IN ORDER FOR IT TO ACTIVATE THE COMPLEMENT SYSTEM

• IgM requires ___ IgM molecule. In order for the classical pathway of complement to be activated

2

IN ORDER FOR IT TO ACTIVATE THE COMPLEMENT SYSTEM

• IgG requires at least __ IgG molecules

C3b

COMPLEMENT SYSTEM

• Opsonin: _____→ they facilitate phagocytosis

C5a

COMPLEMENT SYSTEM

• Chemotaxin: ___ → important during the migration of the neutrophils

Chemotaxis

• migration of phagocytes toward the site of infection or inflammation.

C3a, C4a, C5a

COMPLEMENT SYSTEM

• Anaphylatoxins: ________________

• Mediators of Inflammation

• Inflammation – overall reaction of the body against a tissue injury or

  infection

C5b6789

COMPLEMENT SYSTEM

• Membrane Attack Complex: _______________

Complement System

• It is a complex series of interaction of different proteins in a very specific way to enhance the post defense mechanism against foreign cells

• It completes/complement the action of antibodies

Antigen Antibody Reaction (Immune complexes)

• In the classical pathway, in order for it to be activated → it requires __________________________________

C1qrs

Classical pathway starts with a ______

Classical Pathway

• Pillemer and colleagues discovered an antibody-DEPENDENT pathway in

  the 1950s, and this plays a major role as a natural defense system.

Alternative Pathway

• was originally named as Properdin system

• Antibody INDEPENDENT pathway

• can be activated through the presence of microbial components

Properdin

• is a normal protein/constituent of serum. It is known before that properdin causes the activation of the pathway

• But now, ____ does NOT initiate the pathway but rather it’s just stabilizes the C3 convertase

Lectin pathway

• Its major constituent, mannose- (or mannan-) binding lectin (MBL).

Mannose binding lectin

• is an acute phase reactant. It increases during an initial inflammatory response

• requires mannose residues on the surface of the microorganisms

• It is associated with the mannose binding lectin SERINE PROTEASES

COMPLETE HEMOLYSIS

Clear red supernatant no cell button

PARTIAL HEMOLYSIS

Pink to red supernatant with cell button

NO HEMOLYSIS

Clear supernatant with cell button

Law of MASS ACTION

• All antigen-antibody reactions are governed by the ________________ which states that Ag-AB reactions are REVERSIBLE.

Affinity

• Initial force of attraction between single binding sites on the antigen and antibody.

• REVERSIBLE

Avidity

• Sum total of all forces of attraction between multivalent antigens and multivalent antibodies.

• IRREVERSIBLE

Specificity

• Antibody will only react against an antigen that has caused its production

Ionic Bonds

• Exist between oppositely charged particles

Hydrogen Bonds

• Between 2 polar substances

• Weaker compared to the Ionic Bond

Hydrophobic Bonds

• Between 2 non-polar substances

• segragation of water

Van der Waals Forces

• Between the electron clouds of antigen and antibody

• weakest electric force that could be seen in between substances

Zeta potential

• given by a particular component of your membrane

• Force of repulsion among RBCs when placed in NSS/physiologic saline solution.

Sialic acid

• Component of the Red cell which gives the ionic cloud to your RBC

Sensitization

• Initial binding of antibodies to red cell antigens; deposition of complement fragments on rbc surface

• REVERSIBLE

• Not yet visible

Lattice Formation

• Formation of networks of antigen-antibody complex/immune complex

• IRREVERSIBLE

• Visibile agglutination

22% Bovine Serum Albumin

Enhancement/Reaction Media:

• ____________________- Neutralize the negative charges on rbc (30 minutes)

• Affects the Lattice Formation (2nd stage)

Low Ionic Strength Saline (LISS)

Enhancement/Reaction Media:

• Decreasing the incubation time (10-15 minutes)

• Affects the 1st stage by enhancing the Ab update

Polyethylene glycol (PEG)

Enhancement/Reaction Media:

• Remove water to concentrate the antibody

• More effective than LISS & Albumin

• Detection of Weak Ab

Enzymes (Papain, Ficin, Bromelin)

Enhancement/Reaction Media:

• Enhance or destroy certain RBC antigens

• Alter the reactive condition of the Antibodies