patho - altered immunity

INNATE VS ADAPTIVE IMMUNITY

innate immunity

present from birth

acts quickly

nonspecific

includes barriers, inflammation and NK cells

doesn’t provide the same antigen specific memory as adaptive immunity

innate = immediate

adaptive immunity

develops in response to specific antigens

initial response may take longer

antigen specific

includes B cells and T cells

can form immune memory

adaptive = specific and remembers

IMMUNE CELLS

B cells

develop into plasma cells that produce antibodies

memory B cells help the body respond quicker ro future exposure to the same antigen

CD4 helper T cells

coordinate immune responses and helps activate other immune cells

CD8 cytotoxic T cells

destroy infected or abnormal cells

macrophages

engulf pathogens and cellular debris

can also present antigens to help activate adaptive immunity

natural killer (NK) cells

innate immune cells that can kill certain infected or abnormal cells

humoral immunity

B cells and antibodies

cell mediated immunity

primarily T cell responses

ACTIVE VS PASSIVE IMMUNITY

active immunity

your own immune system responds after infection or vaccination

it can create memory

active = I make antibodies

passive immunity

you receive antibodies from another source, such as maternal antibodies or an antibody medication

protection is temporary and does not create the same memory response

passive = I receive antibodies

TYPES OF ALTERED IMMUNITY

immunodeficiency

immune defenses are insufficient

hypersensitivity

immune response is excessive or inappropriate

autoimmunity

immune system attacks the bodys own tissues

alloimmunity

immune response against another individuals cells or tissues

FOUR TYPES OF HYPERSENSITIVITY

type 1

immediate

age-mediated response

ex: anaphylaxis

type 1 = immediate

type 2

antibodies target cell associated antigens

ex: certain transfusion reactions

Rh incompatibility

type 2 = targets cells

type 3

immune complexes deposit in tissues

ex: immune complex disease

type 3 = immune complexes

type 4

delayed

T cells mediated response

ex: TB skin test reaction

type 4 = delayed T cells

anaphylaxis

severe, life threatening systemic allergic reaction

symptoms: diffculty breathing/wheezing, swelling of the lips, tongue, throat, itching or flushing, severe drop in blood pressure

treatment: give intramuscular epinephrine promptly when anaphalyxix is suspected, activate emergency assistance, support airway, breathing and circulation.

antihistamines arent a substitute for epinephrine

Rh isoimmunization

a Rh-negative pregnant patient exposed to the Rh positive fetal blood cells may develop antibodies against the Rh antigen.

those antibodies can later affect Rh positive pregnancy by crossing the placenta and destroying fetal red blood cells

Rh immune globulin (Rhlg) helps prevent sensation in eligible Rh negative patients.

screening and appropriate prenatal care are important

HIV AND AIDS

HIV

HIV attacks CD4 helper T cells, weakening the immune function.

AIDS

an advanced stage of HIV disease involving severe immune deficiency.

CD4 count

helps assess immune status

viral load

measures the amount of HIV in the blood

antiretroviral therapy (ART)

suppresses viral replication and helps preserve or restore immune function