Week 7 - Adaptive Immunity and Disorders - Part 2 Disorders Flashcards
(36 cards)
What are primary disorders of the adaptive system
due to deficiencies in T cells, B cells, both T and B cells
What is Di George syndrome
- Abnormal development of the thymus resulting in low T cell numbers
- Can cause underdeveloped chin
- Increased susceptibility to viral, fungal and bacterial infections
What is hyper IgM syndrome
- Lack CD40 ligand on T cells – affects maturation of B cells, activation of macrophages
- Inability to switch from IgM production resulting in low levels of IgG, IgE and IgA
- Defective cellular immunity, opportunistic infections, cancer
What is selective IgA disorder and what could it cause the development of
Selective IgA deficiency is a primary immunodeficiency disorder where the body fails to produce enough or any IgA which is the main antibody found in mucosal secretions like saliva, tears and the lining of the respiratory and GI tract.
can cause development of
- celiac disease
- systemic lupus erythematous (SLE)
- rheumatoid arthritis
What is severe combined immune deficiency (SCID)
- genetic disorder which impacts bone marrow resulting in severely impaired or lack of production of T and B cells
- has no immune defense
- Highly susceptible to infection
- Usually die within a year unless
- they have a stem cell transplant
- chicken pox (varicella) , herpes , measles, rota virus, cytomega virus - dangerous infections to SCID patients
What is wiskott aldrich syndrome
- Abnormal function of T and B cells, also platelets
- Recurrent infections, bleeding disorder
What are secondary immune deficiencies normally associated with
tumours
What are examples of tumours that can cause immune deficiencies
- Leukemia – cancer of cells in bone marrow
- Multiple myeloma – cancer of plasma cells
- Hodgkin’s disease – cancer in the lymph nodes
What is Acquired immunodeficiency syndrome (AIDS)
- Caused by human immunodeficiency virus (HIV-1) or HIV-2
- Most advanced stage of HIV
- The Virus invades and destroys CD4+ cells (helper T cells)
- Causes severely weakened immune response (antibodies, cytoktoxic T cells)
AIDS is applied to the full blown phase of HIV disease – individuals often die from cncer or overwhelming infection with an opportunistic infection
AIDS defining disease
- Tocoplasmic encephalitis
- Systemic candidiasis
- Cyptococcal meingitis
- Tuberculosis
- Ect
What is hypersensitivity
An inappropriate reaction by the immune system to an antigen it would normally ignore (termed allergen) causing damage to tissue
aka allergic reaction
What is a type 1 hypersensitivity reaction
aka allergic reaction
- sensitization process where plasma cells produce IgE in response to an allergen on the initial encounter
- the IgE attached to mast cells, priming then
- Allergy enters body again
- Allergen bind to IgE antibodies that are bound to mast cells
- Mast cells degranulate and release contents e.g. histamine
- results in allergic response - sneezing, itching, swelling, anaphylaxis
*has a delayed initial reaction as it takes time to produce the antibodies
What are common dental allergies
- Analgesics – NSAIDs and paracetamol
- Antibacterials
- Some local anaesthetics
- Chlorhexidine
- Latex
What is a type 2 hypersensitivity reaction
Occurs when antibodies binds to antigens on the surface of the body’s own cell, destroying the cell
e.g. incorrect blood type being transfused
What is a type 3 hypersensitivity reaction
When antibodies bind to free antigens in the blood or tissues (rather than antigen present on a cell). These complexes get stuck in small blood vessels or organs leading to inflammation and tissue damage
occurs when antigen-antibody complexes deposit in tissues, leading to inflammation and tissue damage.
What is type 4 hypersensitivity reaction
- aka delayed type hypersensitivity
- takes 24-72 hours to develop after exposure to an antigen
- Doesn’t involve antibodies it’s driven by T cells instead
- First exposure (sensitisation)
- Next exposure T cells recognize the substance and release chemicals like cytokines
- These cause inflammation, bringing more immune cells to the area
- This leads to redness, swelling and damage in the tissue
Common type 4 hypersensitivity dental allergens
- Metals – nickel, titanium
- Acrylic resins
- Epoxy resins
- Latex
- Chlorhexidine
- Some local anaesthetics
What is tolerance
the immune system’s ability to distinguish between self and non self and to avoid mounting an immune response against the body’s own cells and tissues
What is autoimmunity
a condition where the body’s immune system which normally protects against foreign invaders mistakenly attacks its own healthy tissues and cells leading to a variety of diseases
- Occurs when tolerance fails producing self-reactive lymphocytes (mostly B cells), responsive to self antigens, type 2 or 3 hypersensitivity reactions
- T lymphocytes do not/weakly recognize self-antigen (tolerance)
Examples of autoimmune diseases
- Coeliac disease
- Insulin dependent diabetes mellitus (type 1)
- Rheumatoid Arthritis
What is coeliac disease
- Autoimmune disease
- Presence of HLA_DQ2 or DQ8
- Involves the body making autoantibodies to gluten and TG2 (transaminase)
- Inflammatory response when gluten is eaten (chronic diarrhea, abdominal pain, anemia, weight loss, osteoporosis)
- Requires a gluten free diet
What is Insulin-dependent diabetes mellitus (type 1)
- Autoimmune disease
- Where autoantibody attacks beta cells of pancreas
- Destroys insulin production
- Causes cell to not be able to take up glucose from blood
- Upsets the electrolyte balance in the blood – excessive urination leading to dehydration
- Causes loss of consciousness, kidney failure, death
- Type 2 hypersensitivity
What is rheumatoid arthritis
- Autoimmune disease when the immune system mistakenly attacks the synovium (lining of the joints) leading to joint damage over time
- Affects the TMJ making maintaining oral hygiene dificult
- can cause sjogren syndrome
What is immunisation
process of inducing or providing immunity artificially – releasing an antigen from specific microbe.
- Involves the exposure to antigenic but not pathogenic material
- Provides memory so there’s a faster, stronger response
What are the components of a vaccine
Vaccines are material derived from a pathogen may include either:
- A live, attenuated pathogens
- Killed who bacterial cells or inactivated viruses
- Inactivated bacterial toxins
- Parts of a pathogen (subunit)
Additional components of a vaccine
- Adjuvant
- Additives (diluents, stabilisers, preservatives, remnants from manufacturing)
