16) Immunocompressed Host Flashcards
(31 cards)
Why is immunodeficiency a clinical problem?
Large spectrum of primary immunodeficiencies
Failure to recognise and diagnose PID
What is immunosuppression?
State in which the immune system is unable to respond appropriately and effectively to infectious microorganisms
What immune components may be defected causing immunodeficiency?
B cells
T cells
Neutrophils
Macrophages
What is primary immunodeficiency due to?
Congenital - due to intrinsic gene defect causing missing protein, cell or non-functional components
What is secondary immunodeficiency due to?
Acquired - due to underlying disease/treatment causing decreased production, function or loss of immune components
What characteristics do infections suggesting underlying immune deficiency have?
SPUR: Severe - need IV antibiotics Persistent - under standard regime Unusual Recurrent
What are some of the 10 warning signs of PIDs?
Recurrent infections Failure to thrive (grow) Deep skin abscesses IV antibiotics Family history (70%)
What are the limitations of the 10 warning signs?
Lack of population-based evidence
PID patients with different defects/presentations
PID patients with non-infectious manifestations
What non-infectious manifestations of PID are there?
Autoimmunity
Malignancy
Inflammatory response
What is common variable ID (CVID)?
Low level of IgG and either IgM or IgA
Can occur at later age
What is severe combined ID (SCID)?
Inhibition of T cell development, leads to B cell deficiency/no function
What is XLA or Bruton’s disease?
Defect in B cell maturation, deficiency in all immunoglobulins
What is chronic granulomatous disease?
No respiratory burst due to defect in NADPH oxidase
Present with pulmonary aspergillosis (halo sign on CT) and skin infection
What defect is likely if onset is before 6 months?
T cell or phagocyte defect
What defect is likely if onset is between 6 months and 5 years?
B cell/antibody or phagocyte defect
What defect is likely if onset is after 5 years?
B cell/antibody/complement defect or secondary immunodeficiency
How would a complement deficiency present?
Infection by encapsulated bacteria
How would a phagocytic defect present?
Skin/mucous infections, invasive fungal
What micro-organisms are likely to affect someone with an antibody deficiency?
Bacteria, enteroviruses, giardia
What infections may occur with T cell defects?
Opportunistic infections
What supportive treatment is there for those with PIDs?
Infection prevention (prophylactic antimicrobials) Passive immunization Nutritional support (Vitamins A/D) Avoid live vaccines
What specific treatment is there for those with PIDs?
Regular immunoglobulin therapy
Haematopoietic stem cell therapy
What is the goal of immunoglobulin replacement therapy?
Get serum IgG > 8g/L
What can immunoglobulin therapy treat?
CVID, XLA, Hyper IgM
