11. Immunodeficiency Flashcards
What cases should immunodeficiency be suspected in?
Serious, persistant, unusual and recurrent infections Family history HIV risk Failure to thrive/weight loss Lymphopaenia in infants Reaction to live vaccines Associated congenital malformations eg. cleft palate Lymphoid malignancies
What features require investigation if over 2 of them are present in an adult?
4+ infections requiring antibiotics in the past year
Recurring infections or require a long course of antibiotics
2+ severe bacterial infections
2+ radiologically proven pneumonia within 3 years
Infection in an unusual location or unusual pathogen
Family history
What is physiological immunodeficiency?
Period of time between receiving mother’s IgG and making their own
Name 3 primary immunodeficiencies
X-linked agammaglobulinaemia
CVID
Specific antibody deficiencies
Give some examples of secondary immunodeficiencies
Neoplasms
Drug therapy
Splenectomy
What antibodies are typically underproduced in CVID?
IgG
IgA
IgM
What age does CVID present?
Any
In what way can the lungs be damaged in CVID?
Scarring from recurrent infections leads to bronchiectasis
Breathing is compromised
What does CVID increase the risk of?
Granulomatous disease
Auto immunity
Malignancies
What immune defect is associated with viral, protozoal and fungal infections?
T cell
What immune defect is associated with bacterial infections?
B cell
What immune defect is associated with boils and abscesses?
Neutrophils
What immune defect is associated with recurrent meningitis and lupus like disease?
Complement
How are humoral immunity defects managed?
Antibiotics and vaccination
IV or subcutaneous Ig replacement
Physio and bronchodilators
What are Howell-Jolly bodies?
Purple dots on RBCs that show they still have a nucleus
Property of an inactive spleen
What type of infection is most closely associated with post splenectomy patients?
Encapsulated bacteria
How are patients managed post-splenectomy?
Vaccination
Antibiotic prophylaxis
Advice, wear medic alert bracelet
What are the causes of primary neutrophil dysfunction?
Chronic granulomatous disease
Leukocyte adhesion defect
Hyper-IgE syndrome
What are the secondary causes of neutrophil dysfunction?
Steroids
Diabetes
Iron deficiency
How do steroids cause neutrophil dysfunction?
Affects migration
How does diabetes cause neutrophil dysfunction?
Impaired mobility due to sugar levels
How does an iron deficiency cause neutrophil dysfunction?
Impaired bacterial killing as iron is needed for respiratory burst
How is chronic granulomatous disease managed?
Antibiotics
Antifungals
Steroids for any inflammatory complications
What is the cure for chronic granulomatous disease?
Haematopoietic stem cell transplant
What is the difference between primary and secondary complement deficiency?
Primary is a genetic cause of low or dysfunctional proteins
Secondary due to the production of autoantibodies
How is a complement deficiency managed?
No cure
Vaccination and prophylactic antibiotics
Patient education
Name 3 primary T cell defects
SCID
ADA deficiency
CD40 ligand deficiency
Name 4 secondary causes of T cell defects
HIV
Chemo and radiotherapy
Transplant recipients
Treatments for severe autoimmune diseases
How is T cell function clinically assessed?
History Lymphocyte count: T cell count and subtypes Expression of TCRs, cytokine receptors Delayed hypersensitivity skin tests Vaccination with protein antigens Proliferation assays
How is SCID managed?
Irradiate all blood products to prevent GvHD
No live vaccines
Haematopoietic stem cell transplant ASAP
