Immunodeficiencies Flashcards
What are immunodeficiencies caused by?
Defects in one or more components of the immune system
What are the types of immunodeficiencies?
Primary (congenital)
Secondary
What do primary immunodeficiencies result from?
Genetic or developmental defects
When do primary immunodeficiencies originate and present?
There from birth but may not be clinically observed till later in life
What do secondary immunodeficiencies originate as a result of?
Malnutrition, cancer, drug treatment or infection
What’s the most common secondary immunodeficiency?
AIDS
What are clinical features of primary immunodeficiencies?
Recurrent infections
Severe infections by unusual pathogens in unusual sites
What are the causes of primary immunodeficiencies?
Defect in phagocytic or complement function
What do consequences of primary immunodeficiency depend on?
The number and type of immune system components involved
What do defects in earlier stem cells affect?
The entire immune system
What do defects in later stage haematopoietic cells show?
A more restricted pathology
What are examples of phagocytic disease?
Chronic granulomatous disease
Congenital agranulocytosis
Leukocyte-adhesion deficiency
What are examples of B cell and antibody diseases?
X-linked agammaglobulinaemia
Common variable hypogammaglobulinaemia
X-linked hyper-IgM syndrome
Selective immunoglobulin deficiency c
What is an example of a thymic epithelial cell mediated disease?
Digeorge syndrome
What are examples of combined B and T cell diseases?
Reticular dysgenesis
Severe combined immunodeficiency
Bare-lymphocyte syndrome
Wiskott-Aldrich syndrome
What is affected in primary component disorders?
Defects in lymphocyte development or activation
What causes X-linked agammaglobulinaemia?
Encodes brutons tyrosine kinase
Block in B cell development at pre-b stage
What are the clinical features of x-linked agammaglobulinaemia?
Absence of B cells and low/absent plasma cells
All IgGs absent/very low
T cells and T cell mediated response normal
How is x-linked agammaglobulinaemia treated?
IVIg at 2-3 week intervals
Or subcutaneous Ig weekly
Prompt antibiotic therapy
What is common variable immunodeficiency?
Selective IgA deficiencies
What are the symptoms of common variable immunodeficiency?
Mainly asymptomatic- some lead to respiratory, urogenital or GI infections