Immune System Disorders Flashcards
Immunodeficiency disorders have increased…
increased susceptibility to disease states
2 classifications of immunodeficiency disorders
Primary: congenital or inherited
Secondary: develops later in life
Humoral Immunodeficiencies are associated with…
B-cell dysfunction
decreased Ig production
What are humoral immunodeficient people are at an increased risk for and why?
increased risk for recurrent infections
- do not product antibodies
- can get infected with same virus over and over again
Examples of Humoral Immunodeficiencies - transient hypogammaglobulinemia of infancy
deficiencies of antibodies at birth –> no immune system
leads to increased respiratory tract infections + allergies
Examples of Humoral Immunodeficiencies - Primary humoral immunodeficiency disorder
impaired differentiation + maturation of lymphoid stem cells
Examples of Humoral Immunodeficiencies - Secondary humoral immunodeficiency disorder
numerous causes:
- increase in Ig deficiency
- decrease in Ig production
cancer
Cell Mediated Immunodeficiency - Primary
(affected by…)
T cell: considered MOST SEVERE
affected by viral, fungal, and opportunistic infections
Secondary cell mediated immunodeficiency is frequently associated with…
acute viral infection
Primary vs. Secondary cell mediated immunodeficiency
Secondary is more prevalent
T cell is more severe
Combined B and T cell immunodeficiencies are caused by…
mutations in genes that impact lymphocyte development or response
The disruption of communication between humoral and cell mediated response can be attributed to…
a failure of adaptive immune response
Examples of Combined B and T cell immunodeficiencies
Combined: diminished T-cell function + B-cell antibody production
Severe Combined: diverse group of disorders with profound deficiencies of B and T cells
The complement system usually coordinates…
chemotaxis, opsonization, and phagocytosis
Opsonization
the coating of targeted cells or pathogens to prepare them for phagocytosis
Red flag
Disorders of Complement System - Primary
- congenital
- autosomal recessive, dominant, or codominant traits
- increase in infections with high grade (meningitis, gonorreah) pathogens
Disorders of Complement System - Secondary
(cause, commonly seen in)
cause:
- rapid activation or turnover of complement components
- poor nutrients
commonly seen in chronic liver disease
phagocytosis is activated by:
chemotactic factors
Disorders of Phagocytosis - Primary Disorders
affect
- leukocyte adhesion
- microbicidal product + activity
increased chronic and acute infections
Disorders of Phagocytosis - Secondary Disorders
associated with:
- leukemia
- bowel infections
- diabetes
Transplantation is the process of…
taking cell, tissues, or organs (grafts) from one personal and placing into another
Allografts
transplanted from another person (person –> person)
Autografts (hint: 1st grade)
one part of the body is transplanted into another part of the same person
(my hip bone –> gum transplant in 1st grade lol)
Donor vs. Host
Donor provides graft
Host receives graft
MHC function
Major Histocompatibility Complex
A set of genes that encode for molecules in the surface of most body cells
help immune system designate body cells to being specific to a body
HLA function
Human Leukocyte Antigens
Human version of MHC
- antigens that determine self vs. non-self cells
MHC molecules or HLAs expressed on cell surfaces enable…
enable T lymphocytes to respond to antigens while ignoring “self” antigens
Alloantigens
HLA molecules that are recognized as foreign on allografts
3 types of Transplant rejection (Host vs. Graft)
- T-cell mediated (most common)
- Antibody-mediated (humoral rejection)
- Chronic rejection
T-Cell mediated transplanted rejection is initiated by:
presentation of donor alloantigens to host T lymphocytes by antigen presenting cells (APCs)
- molecules of donor + host T cells don’t like each other
Direct pathway of T-cell mediated transplant rejection occurs when…
T lymphocyte activation occurs this pathway if the antigen presenting cells (APCs) originate from donor
CD8+ T cell direct cell toxicity attack
Indirect pathway of T-cell mediated transplant rejection occurs when…
T lymphocyte activation occurs this pathway if the antigen presenting cells (APCs) originate from recipient
CD4+ T cells –> cytokines –> delayed hypersensitivity reaction
Antibody mediated transplant rejection is caused by..
B-lymphocyte proliferation and differentiation –> donor specific antibodies
Antibody mediated transplant rejection - Hyperacute (when does tit occur?)
occurs immediately after vascular reperfusion to graft tissue
- right after blood flow restoration
Antibody mediated transplant rejection - Acute (when does tit occur?)
occurs within days to weeks after transplantation
antibodies don’t float around - -> slow antibody build
Chronic Transplant Rejection
- body attacks transplanted organ
- immune mediated inflammatory injury
- occurs over a prolonged period
Graft vs. Host disease occurs..
- most frequently after allogenic stem cell transplant
- when DONOR T-cells react to HLAs on HOST cells
graft recognizes Host as foreign and attack body
3 conditions required at Graft vs. Host
- graft contains cells that are immunologically competent
- recipient cells must express antigens not present on donor cells
- recipient must be immunologically compromised and incapable of mounting a defense
3 step process of donor t-cells reacting to host HLAs
- activation of recipient APCs
- activation, proliferation, differentiation, and migration of donor T-cells
- target tissue destruction
What is an Autoimmune Disease?
immune system fails to differentiate itself in adaptive immunity
- self vs. non-self fails
What is impacted in an autoimmune disorder?
any cell type, tissue, or organ
Causes/mechanisms of Autoimmune Diseases
- heredity
- susceptibility genes
- first-degree relatives - environmental
- viral infection, smoking, chemical exposure, non-breastfed infants
Immunologic Tolerance - Self tolerance
(definition, common location, 2 types)
- immune system ability to differentiate self vs. non-self
- usually done through the lymph system: where B and T-cells are produced
- central - systemic in central locations
- peripheral - specific, localized peripheral areas
Immunologic Tolerance - Autoreactivity
organism acts against its own tissue
Immunologic Tolerance - B cell Tolerance
immune system’s production of autoantibodies
- immune proteins that mistakenly target and react with a person’s own tissues or organs
ex: graves disease
Immunologic Tolerance - T Cell Tolerance (2 types)
- positive selection
- based on maturation of T-cells
- when they become mature lymphocytes, become CD4 or CD8
- does not react strongly to MCH or HLA molecules - negative selection
- T cells never mature into CD4 or CD8 lymphocytes
- programmed cell death
- respond MCH complexes
Systemic Lupus Erythematosus
- multisystemic
- inflammatory
- chronic
Systemic Lupus Erythematosus - causes
- autoantibodies are produced against almost every blood cell type, protein, DNA
- autoantibody/antigen complexes are deposited in tissue, bones, joints, blood vessels and cause significant damage
Systemic Lupus Erythematosus - manifestations
- arthralgias/arthritis
- vasculitis (joints)
- butterfly rash (embedded in blood vessels + epithelial cells)
- anemia (due to SLE ability to destroy red blood cells)
- cardiovascular disease
- renal damage
- kidney failure
Systemic Lupus Erythematosus - treatments
- NSAIDs
- corticosteroids
- immunosuppressants
Rheumatoid Arthritis - manifestations
systemic
- fatigue
- anorexia/weight loss
- generalized aching and stiffness
- articular and extra-articular manifestations: nodules under knuckles + joints
Rheumatoid Arthritis is characterized by…
- exacerbations and remissions
- may only involve a few joints for a brief or become relentlessly progressive + debilitating
- symmetrical joint deformity: if left, will spread to right
- autoantibodies that attack cartilage
Criteria for Rheumatoid Arthritis
- morning stiffness for at least 1 hour for at least 6 weeks
- swelling of 3 or more joints for at least 6 weeks
- wrist, knuckles, metacarpophalangeal, or proximal interphalangeal joints - systemic joint swelling
- hand XR changes typical with the disorder
- Serum rheumatoid factor
- nodules
If Rheumatoid Arthritis does not receive proper treatment, it may lead to…
- subluxation: dislocation of the joint –> misalignment to bond ends
- “swan neck” deformity
- joint instability
- limitation of movement
Rheumatoid Arthritis - treatment
steroids and immunosuppressants to limit damage
