Immunodeficiency Flashcards
What is secondary immunodeficiency?
Immune defect is secondary to another disease process
Primary immunodeficiency?
Immune defect is intrinsic to immune system itself
Defects in B cells?
Antibody- so more bacterial infection in respiratory tract
T cell immunodeficiency?
Predominantly viral fungal and mycobacterial infections
What is immunodeficiency syndromes when it affects both antibody production and T cells?
Combined immunodeficiencies
Immunosenscence?
A combination of age related changes in the immune system that result in greater susceptibility to infection and reduced response to vaccination
What happens in immunosenescence?
Thymus involution Reduced T and B cell receptor diversity Telomere shortening in stem cells Reduced vaccine responses Reduced self tolerance Reduced neutrophil function Expansion of T cell pool responding to cytomegalovirus
Antibody deficiencies present with?
Recurrent upper and lower respiratory tract infections
What is the levels of antibody in immunodeficiency?
Low igG, but low igA/M with normal igG is rarely significant
If untreated?
Irreversible lung damage, bronchiectasis
Causes of antibody deficiency?
Physiological- transient hypogammaglobulinemia
Secondary- igG loss, due to nephrotic syndrome, extensive burns
Immunosuppressive drugs
Primary-
X-linked agammaglubulinemia
X linked hyper igM syndrome
Transient hypogaamaglobulinemia infancy?
6 months of age when mother igG is depleting and child’s has not yet begun properly
Infants with antibody deficiency usually present?
3-6 months
XLA? X linked agammaglobulinaemia?
Signalling via bruton’s tyrosine kinase required for signal transduction at pro-B stage
Maturation arrest occurs if absent- no heavy chain arrangement, no B cells leave marrow, no immunoglobulin production
X linked hyperigM syndrome?
Failure of B cell maturation
Raised igM, low igG and igA,
CD40L deficiency
3-6 months at age
