Immunodeficiencies Flashcards
What is the difference between a primary and secondary immunodeficiency?
primary is genetic and can be inherited wile secondary is acquired and is much more common
What is the most common form of primary immunodeficiency?
Antibody deficiencies
What are some signs of humoral immunodeficiency?
Pyogenic infections, frequent viral infections, chronic diarrhea, and susceptible to encapsulated bacteria
What is the immunodeficiency caused by defects in B cell development, defective germinal centers, or underdevelopment of lymphoid tissues?
Agammaglobulinemias
What is the major defect in X-linked agammaglobulinemia?
B cell tyrosine kinase that helps stimulate B cell maturation
Assays for XLA would show what?
- Normal T cell number
- Low B cell
- Low IgG because of no class switching
What are the characteristics of Hyper-IgM syndromes?
- Normal B cell number
- Elevated levels of IgM
- Lower levels of IgA, E, and G
What is the most common defect that leads to Hyper-IgM?
CD40L
Which is the most common primary immunodeficiency?
IgA deficiency
Which is the most common symptomatic primary immunodeficiency?
CVID (Common Variable Immunodeficiency)
What are some characteristics of IgA Deficiency?
- Usually asymptomatic
- Occasional sinopulmonary infections, diarrhea, and autoimmune disease
- Low levels of IgA
What are some characteristics of CVID?
- Reduced IgG, IgA, and/or IgM
- Absent or impaired specific antibody responses with previous vaccines or infections (vaccine to titer to confirm)
- Recurrent infections (sinusitis and pneumonia) as well as malignancies, granulomatous diseases, autoimmune diseases, etc.
What are some characteristics of Specific Antibody Deficiency?
- Recurrent sinopulmonary infections
- Normal B cell and T cell count
- Normal serum Ig levels
- Impaired vaccine response
- Impaired antibody response to encapsulated bacteria
What are the common encapsulated organisms?
Staph aureus Haemophilus influenzae Neisseria meningitidis Pseudomonas aeruginosa Cryptococcus neoformans Klebsiella Streptococcus pyogenes and pneumoniae
What are some characteristics of Transient Hypoglammaglobulinea of Infancy
- Low IgG
- Normal specific antibodies
- Recurrent sinopulmonary infections
- Usually resolves by age 4 (monitor progress)
Lack of T cells cause what type of immunodeficiencies?
Combined immunodeficiencies because helper T cells also regulate B cell antibody synthesis
What is the best way to treat X-linked SCID and RAG deficiency?
Stem cell bone marrow transplant
“Leaky” SCID is another name for what?
Omenn syndrome
What are some characteristics of “Leaky” SCID?
- Eczema
- Mutations commonly in RAG genes
- High IgE and eosinophilia
How does DiGeorge Syndrome affect the immune system?
Lowered to no T cells because of thymus hypoplasia or aplasia
What are the characteristics of Wiskott Aldrich Syndrome?
- Eczema
- Thrombcytopenia with small platelets
- Problem with WASP protein in actin polymerization
People with CGD have infections from what kind of organisms?
Catalase positive
What are some characteristics of Leukocyte Adhesion Deficiency-1?
- Neutrophils cannot migrate to toward stimuli or adhere to endothelial cells
- No pus with high WBC count
- Delayed umbilical cord separation
What are the characteristics of Hyper IgE Syndrome?
- Severe eczema
- High levels of IgE
- Eosinophilia
What is the problem in Hyper IgE Syndrome?
Neutrophils
What are seven etiologies of acquired immunodeficiency?
- Disorders of biochemical hemeostasis
- Disorders of protein loss
- Trauma/burns
- Environmental exposure to radiation or chemicals
- Splenectomy/hyposplenism
- Life events such as pregnancy or stress
- Infections
What are the characteristics of Diabetes Mellitus?
- Decreased neutrophil function
2. Poor peripheral circulation increases risk of skin ulceration
How do dialysis and uremia affect the immune system?
- Reduced T cell function
- Reduced Ig production
- Compromised dendritic and neutrophil function (due to removal of opsonic factors
How does cirrhosis affect the immune system?
Greater risk of bacterial infection due to low complement levels
How does protein loss affect the immune system?
Protein loss can lead to hypogammaglobulinemia. IgM may stay the same because it is big
How would you test for protein loss vs. low serum due to other causes?
- Urine analysis
2. Examine serum after a certain time to see if you are losing more than the general half-life of passive immunizations
What are the characteristics of Nephrotic Syndrome?
- Significant protein loss
- Low Igs
- Increased risk for encapsulated bacteria
How do trauma and burns affect the immune system?
- Increases release of inflammatory cytokines
2. Burns mess up host barriers like skin
How does radiation affect the immune system?
Damages DNA that impairs cell proliferation, which leads to decreased immune function
How does radiation affect each category of leukocytes
B cells > T cells»_space;» phagocytic (relatively immune to radiation)
Issues with the spleen primarily affect which cell of the immune system?
macrophages
Issues with the spleen increase a person’s risk of infection to which types of organisms?
encapsulated bacteria
What is important to do before a splenectomy?
Make sure a patients immunizations are up to date and then consider prophylactic antibiotics
What type of immunity is suppressed during pregnancy?
cellular immunity
How does stress influence the immune system of a person?
Reduced NK activity and lymphocyte mitogen response
Measles infects which cells in the body?
T cells and dendritic cells
How does measles effect the immune system?
Decreases the amount of T cells, diminishes T cell proliferation, and lowers antibody functioning
Herpesviruses attack which kind of immunity?
Cell-mediated immunity
Which kind of herpesvirus mostly notably affects immune functioning?
CMV (cytomegalovirus)
The immune suppression resulting from ____ infection is ____ pronounced than any other kind of microbe excluding HIV
protozoan; more
How do superantigens affect the immune system?
They cause significant immune stimulation but after a while T cell numbers drop as well as neutrophil function
