chapter 12: disorders of the immune response

immunodeficiency

abnormality in one of more partts of the immune systems that results in an increase suspectibility

primary vs secondary immunodeficiency

primary are either congenital or inherited, secondary develop later in life

humoral immunodeficiences

B cell dysfunction and decreased Ig production—high risk for frequent and recurrent infections—pseudomonas, giardia, streptococcus pneumoniae, staph, haemophilus influ

selective IgA deficiency (SIGAD)

most common primary immunodeficiency disorder

ataxia-telangiectasis

concerns for blood reactions

cell mediated immunodeficiencies (T-cell)

heterogeneous group of disorders that arise from defects in one or more components of the cell mediated immune response

wide spread (fungal, protozoan, viral, inracellular bacterial)—herpes virus, salmonella, candida, etc

SCID—severe combined immunodeficiency disorder

rarely survive beyond infancy/childhood—so prone to opportunistic and nonopportunistic infections

-tx: bone marrow / treat like AIDS

hypersensitivity disorder types

abnormal and excessive response of the activated immune system that causes injury to host tissues

1. type I (IgE mediated

2. type II (antibody mediated

3. type III complement mediated

4. type IV t cell

type 1 hypersensitivy reactions (IgE)

rapidly upon exposure to antigen

-dependent on IgE mediated activation of mast cells and basophils

-classic allergic response

-primary / initial phase (5-30min onset, 60min subsides—vasodilation)

-secondary / late phase (occurs 2-8hr later-can last for several days)

anaphylatic (systemic) reaction

life-threatening reaction w/ widespread release of histamine—massive vasodilation, hypotension, airway edema

-I-IV, I least, IV is cardiac arrest.

type II (antibody-mediated) disorders

IgG or IgM antibodies directed against target antigens on specific host cell surfaces or tissues—results in complement-mediated phagocytosis and cellular injury

-antigens can be intrinsic (part of host cell) or extrinsic (incorporated into cell surface

type III, immune complex mediated disorders

formation of antigen-antibody immunes complex in bloodstream, which are subsequently deposited in vascular tissues and activate complement systems and massive inflammatory response

-vasculitis response

type IV, cell-mediated hypersensitivity disorders

involves tissue damage in which cell mediated immune responses w/ sensitized T lymphocytes cause injury

-ex: allergic contact dermatitis

transplantation

taking cells, tissues or organs (graft) from one and placing to another

complications come from self vs. non self rejection

GVHD graft versus host disease

major complication—usually after stem cell

GVHD criteria

1. graft cells must contain cells that are immunologically competent

2. receipts cells must express antigens that are not on donor cells

3. receipt must be immunologically compromised and incapable of mounting an effective immune response

autoimmune disease

heterogenous group when body’s immune system fails to differentiate self vs. nonself