Session 10 - Immunodeficiency Flashcards
Define an immunocompromised host
State in which the immune system is unable to respond appropriately and effectively to infectious MOs
What form does infectious disesaes take in immunocompromised hosts?
SPUR:
S - severe
P - persistent
U - unusual
R - recurrent
How is defective immunity classified?
1) Primary Immunodeficiency (ID) - single gene disorder or HLA polymorphism
2) Secondary immunodeficiency - underlying disease affects immune components, decreases production or increases loss.
What cells can be defective in primary ID?
B cells
T cells
Phagocytes
Complement
How do patients with primary AB deficiencies present?
1) Recurrent upper and lower RTIs - can lead to lung failure and irreversible damage to lungs
2) GI complications including infetions
3) Increased incidence of autoimmune diseases
4) Increased incidence of lymphoma and gastric carcinoma
How do you manage patients with primary AB deficiencies?
1) Prophylaxis
2) Immunoglobulin replacement therapy
3) Avoid unnecessary radiation
4) Manage resp function
How do patients with phagocyte deficiences present?
1) prolonged and recurrent infections
2) skin and mucous membrane ulcers
3) Deep abscesses commonly caused by staph or fungi
4) inflammatory problems
How do you manage patients with phagocyte deficiencies?
1) prophylaxis
2) antifungals
3) stem cell transplantation
What disorder results from a lack of thymus? What other associated abnormalities are associated with this disorder?
Di George syndrome
CATCH 22 syndrome
C - Cardiac abnormalities
A - Abnormal facies
T - Thymic hypoplasia
C - Cleft palate
H - Hypocalcaemia
22 - chromosome 22 abnormalities
How is the lack of a thymus managed?
1) neonatal cardiac surgery
2) supplement to correct hypocalcaemia
3) use only irradiated vaccines, no live ones
How does SCID (severe combined immunodeficiency) present?
1) Failure to thrive
2) long term antibiotic therapy
3) Deep skin and organ abscesses
4) low lymphocyte count
How is SCID managed in the short term?
1) no live vaccines
2) aggressive treatment of infections
3) prevent new infections
How is SCID managed in the long term?
1) bone marrow / stem cell transplantation
2) gene therapy
How can secondary IDs result?
Malnutrition Infection e.g. HIV Liver diseases
Drug induced neutropenia
Splenectomy
How do asplenic patients present?
increased susceptibility to encapsulated bacteria e.g. H influenzae, neisseria meningitidis
