Chapter 4: Diseases of the Immune System Flashcards
These types of reactions are injurious immune reactions that are inappropriately targeted or inadequately controlled and can result in secondary tissue injury.
Hypersensitivity reactions
This general type of hypersensitivity reaction is characterized by a reaction to self antigens.
Autoimmunity hypersensitivity reactions
This general type of hypersensitivity reaction is characterized by an excessive reaction or persistent infection (viral hepatitis, tuberculosis).
Microbial hypersensitivity reactions
This general type of hypersensitivity reaction is characterized by reactions to harmless stimuli (allergies).
Environmental hypersensitivity reactions
This type of hypersensitivity is known as an “allergy” and is immediate. It is characterized by the activation of T helper cells, an increase in IgE antibody production, and mast cell degranulation.
Type I hypersensitivity
This type of hypersensitivity is “cytotoxic” and antibody-mediated (IgG, IgM). It is characterized by opsonization, inflammation, and various non-injurious forms of dysfunction.
Type II hypersensitivity
This type of hypersensitivity is known as an “immune complex”. It is characterized by antigen exposure leading to antibody production, antigen-antibody complexes, and inflammation (complement activation).
Type III hypersensitivity
This type of hypersensitivity is T cell-mediated (“delayed,” antibody independent). It is cytokine-mediated (CD4+ T cells) and has direct cytotoxicity (CD8+ T cells attack antigenic cells).
Type IV hypersensitivity
This type of disorder is characterized by an inappropriate immune reaction due to a failed tolerance of the body’s own cells. Tissue damage can be localized or multisystem.
Autoimmune disorders
What demographic is the most likely to develop autoimmune conditions?
Childbearing aged females
This autoimmune condition is characterized by a failed self-tolerance leading to massive antibody formation (anti-nuclear antibodies (ANA), IgG). It is extremely variable, has an insidious onset, and can occur in any organ.
Systemic lupus erythematosus (lupus)
What types of hypersensitivities are involved in lupus?
Type III (immune complex deposition) and Type II (autoantibodies against various cells)
What are some possible symptoms of lupus?
- Vessel injury
- Renal failure
- Fever of unknown origins
- Photosensitivity
- Serositis
- Hair loss
- Libman-Sacks endocarditis (mitral valve)
- Oral ulcers
- Arthritis
- CNS (seizures, psychosis)
- Fatigue, myalgia, pulmonary and liver fibrosis
- Pancytopenia (reduced number of blood cells)
- Anti-nuclear antibodies
This is a systemic autoimmune disease characterized by exocrine gland (lacrimal and salivary) destruction and enlargement. It is also positive for ANA and a type IV hypersensitivity.
Sjogren syndome (SS)
This condition is a part of Sjogren syndrome and characterized by dry eyes.
Keratoconjunctivitis sicca
This condition is a part of Sjogren syndrome and characterized by dry mouth.
Xerostomia
If Sjogren syndrome is affecting the body alone, what is called?
Sicca syndrome
Which other autoimmune conditions are patients with Sjogren syndrome most likely to have?
Rheumatoid arthritis, lupus, or systemic sclerosis
This systemic autoimmune disease is characterized by extensive fibrosis in multiple tissues and vascular destruction in small arteries. It most commonly occurs in the skin.
Systemic sclerosis (scleroderma)
What are some common features of systemic sclerosis?
- Raynaud phenomenon
- Malabsorption
- Dysphagia
- Renovascular hypertension
- Renal failure
- Pulmonary hypertension
- Dyspnea
- Myalgia
- Arthritis
This type of systemic sclerosis has mild skin involvement (fingers, face, late visceral involvement) and is also called CREST syndrome.
Limited systemic sclerosis
What is CREST syndrome?
- Calcinosis
- Raynaud phenomenon
- Esophageal dysmotility (fibrosis of the lower 2/3)
- Sclerodactyly (hard/ eroded skin)
- Telangiectasia (spider veins)
This type of systemic sclerosis has rapid/widespread skin involvement, early visceral involvement, and is aggressive.
Diffuse systemic sclerosis
This general category of immune deficiency disorders are rare, genetic, and have an early onset (6-24 months).
Primary or congenital immune deficiency disorders
This primary immune deficiency disorders has an onset of 6 months and often occurs in males. It is caused by failed B cell maturation resulting in the inability to produce antibodies. It is treated by a good prognosis and IgG infusions.
X-linked agammaglobulinemia (Bruton disease)
This primary immune deficiency disorder is due to a decreased antibody response to infection. Individuals have normal B cells but no plasma cells. This results in an increase in autoimmunity.
Common variable immunodeficiency
This primary immune deficiency disorder is due to a decreased IgA production. Most cases are asymptomatic or very mild and characterized by upper GI and respiratory infections.
Isolated IgA deficiency (most common)
This primary immune deficiency disorder is due to an increase in IgM and decrease in IgG, IgA, and IgE. Most are X-linked mutations and are characterized by recurrent pyogenic bacterial infections.
Hyper-IgM syndrome
This primary immune deficiency disorder is known as the “bubble boy” disorder and is characterized by lymphopenia (no T or B cells) and lymphoid atrophy.
Severe combined immunodeficiency (SCID)
This primary immune deficiency disorder is due to a defective TH17 resultin in chronic mucocutaneous fungal infections.
Defects in lymphocyte activation
This primary immune deficiency disorder is characterized by defective complements, phagocytes, TLRs, and can result in multiple infections.
Defects in innate immunity
This general category of immune deficiency disorders are more common than primary ones and are the result of infections, malnutrition, aging, cancer, and therapy-induced immunosuppresion (most common). It is characterized by suppression of marrow and lymphocyte dysfunction.
Secondary (acquired) immune deficiency disorders
This secondary immune deficiency disorder is a result of an HIV infection through various bodily fluids (Blood, semen, vaginal fluid, breast milk). It is characterized by a decrease in CD4+ cells and macrophages and paves the way for opportunistic infections, tumors, and CNS defects.
Acquired immunodeficiency syndrome (AIDS)
What types of tests can be used to screen for HIV?
- ELISA test (gp120)
- Western blot
This stage of AIDS occurs after 3-6 weeks after infection and is characterized by pyrexia, pharyngitis, myalgia, and viremia.
Acute phase
This stage of AIDS occurs 2-10 years after infection and is characterized by generalized lymphadenopathy, a steady decrease of CD4+ cells, and gradually increase viremia. Other features may include a reemergence of shingles, extended pyrexia, fatigue, and candidiasis.
Chronic (latent) phase
This stage of AIDS occurs when you have 1 month), weight loss and CNS defects.
Crisis phase
80% of deaths from AIDS are a result of what?
Opportunistic infections
This condition is due to misfolded proteins being produced and accumulating in a variety of tissues. This can result in damage to tissues and a disruption of function.
Amyloidosis
This type of amyloid protein is strongly associated with abnormal B cells, which produce irregular plasma cells. Bence-Jones proteins are an example (multiple myeloma)
Amyloid light (AL)
This type of amyloid protein is associated with chronic inflammation (TB, rheumatoid arthritis, osteomyelitis) and serum-associated amyloid plasma proteins.
Amyloid-associated (AA)
This type of amyloid protein is associated with amyloid precursor protein leading to the production of cerebral plaques (Alzheimer’s disease). They are also associated with Down syndrome.
Beta-Amyloid
This type of amyloidosis normally affects multiple organ systems.
Systemic amyloidosis
What are the three types of systemic amyloidosis?
- Primary (most common): due to malignant plasma cells (AL proteins)
- Secondary: due to chronic inflammation (AA proteins)
- Aging
This type of amyloidosis normally affects a single organ/tissue and has a large amount of AL proteins.
Localized amyloidosis
This type of amyloidosis is rare, familial, and geographic. There are a large amount of AA proteins present and most often caused by an inflammasome mutation.
Hereditary amyloidosis (Mediterranean fever)
What is the most common tissue affected by amyloidosis?
Kidneys
