Session 9 Flashcards
(48 cards)
What is CVID?
Common variable immune deficiency - disorder that impairs the immune system (most common, needs treatment)
- Low level of all antibodies
What is the spectrum for primary immunodeficiencies?
- Different clinical phenotypes
- Knowledge needs to constantly be updated
- Need for better diagnostic criteria
When is primary immunodeficiency diagnosed?
8-12.4 years from diagnosis ( >60 % patients are 18+ when diagnosed (some can have permanent organ damage)
What is an immunocompromised host?
The state in which the immune system is unable to respond appropriately and effectively to infectious microorganisms due to a defect in one or more components of the immune system
What is primary immunodeficiency?
Congenital immunodeficiency due to an intrinsic gene defect
- Missing protein
- Missing cell
- Non-functional components
How do you treat CVID?
Intravenous immunoglobulin (IVIG)
What is secondary immunodeficiency?
Acquired immunodeficiency due to an underlying disease or treatment
- Less production or function of immune components
- More loss and catabolism of immune components
Defects in which components can cause immunodeficiency?*
- T and B lymphocytes
- Antibodies
- Macrophages
- Dendritic cells
- NK cells
- Complement system
- Granulocytes
When to suspect immunodeficiency?
- Severe
- Persistent
- Unusual
- Recurrent
(SPUR)
What are the 10 warning signs of PID in adults and children?* (just list some)
- 2 (a)/ 4 (c) or more ear infections in a year
- Failure to put on weight or weight loss
- Recurrent deep organ or skin abscesses
- 2 or more serious sinus infections within a year
- one (a) / two (c) pneumonias per year for more than one year
What are the main limitations of the 10 warning signs?
- Lack of population-based evidence for diagnosis (family history and failure to thrive)
- PID patients all present differently and some present with subtle infections
- There are PID patients with non-infectious manifestations (autoimmunity, malignancy, inflammatory response)
What can cause secondary immunodeficiency?
- Chemotherapy
- Infection
- Immunosuppression
What other manifestations of PID are recorded?*
Malignancy (adenocarcinomas, Hodkin’s disease, leukaemia, LYMPHOMA MOST COMMON)
What causes 65% of all PIDs?
Antibody defects
What is Bruton’s disease? (Remember!)
- Defect in B cell development
- X-linked agammaglobulinaemia (results in very little or no B cells so cannot produce antibodies)
What are the defects in antibody production?
- Common variable immunodeficiency
- Selective IgA deficiency
- IgG subclass deficiency
- Hyper-IgM syndrome
What is selective IgA deficiency? (Remember!)
Not enough IgA produced
- Most patients are asymptomatic
- Most prevalent
- Some patients can develop anti-IgA antibodies
What is IgG subclass deficiency? (Remember!)
The decrease of one or more IgG with other antibodies being normal
- Caused by defective CD40 ligand that can’t initiate antibody switching
What is hyper-IgM syndrome?
A condition caused by defective CD40 ligand signalling and inability to produce antibodies
What causes 15% of all PIDs?
T cell defects
What are combined T and B cell defects?
Prevent normal development and maturation
- Severe combined immunodeficiency (SCID)*
- Wiskott-Aldrich syndrome
- Ataxia telangectasia
What is SCID?
A disease caused by genetic defects that affect the function of T cells and B cells (development and function of immune fighting cells)
What are the T cell defects?
- DiGeorge syndrome (no thymus - less T cells)*
- CD3 deficiency
- MHC class II deficiency
- TAP-1 or 2 deficiency
What are 10% to immunodeficiencies caused by?
Phagocytic defects
