Primary immunodeficiency Flashcards
what is the major consequence of immunodeficiency?
increased susceptibility to infection and cancer
also increased incidence of autoimmunity
in primary immunodeficiency, where might the abnormality be?
component of the innate immune system
stages of lymphocyte development
responses of mature lymphocytes to antigenic stimulation
what immune cell is defective if there are reduced serum Ig levels?
B cell deficiency
what immune cell is defective if a patient has reduced delayed hypersensitivity reactions to common antigens?
T cell deficiency
a patient with deficiency in what immune cell will have increased susceptibility to atypical mycobacterium infection such as TB?
T cell deficiency
a patient with deficiency in what immune cell will have increased susceptibility to pnuemocystitis jiroveci infection?
T cell deficiency
a patient with defciency in what immune cell will have increased susceptibility to pyogenic bacteria such as otitis, pneumonia, meningitis, osteomyelitis?
B cell deficiency
a patient with deficiency in what immune cell will have an increased susceptibility to parasitic infections?
B cell deficiency
a patient with a defect in phagocytes will have an increased susceptibility to what type of pathogens?
bacteria - staph - gram negative fungi - aspergillus - candida
a patient with a defect in the complement system will have an increased susceptibility to what type of pathogens?
pyogenic bacteria
neisseria
a patient with a defect in the antibodies will have an increased susceptibility to what type of pathogens?
pyogenic bacteria
- staphylococci
- strep pneumoniae
- haemophillus influenzar
some viruses
a patient with a defect in the cellular immunity will have an increased susceptibility to what type of pathogens?
viruses - CMV - HSV fungi - candida - aspiergillus - pnuemocystitis bacteria - mycobacteria protozoal - cryptospirodum
recurrent respiratory infections by pnuemoccous or haemophillus spp is due to what defect in the immune system?
antibody production
recurrent candida infections is suggestive of defects in what T cell pathway?
Th17 pathway
what part of the immune system does polygenic disorders affect?
Antibodies
what are the 3 main causes of primary immunodeficiency and what severity of disease do they cause?
polymorphs - minor changes
polygenic disorders
mutations - severe disease
what is SCID and what part of the immune system does it affect?
severe combined immunodeficiency (SCID)
gene mutation that affects both T and B cells
what is the treatment for SCID?
stem cell transplant
very soon after birth
+/- gene therapy
what are polymorphs and what effect do they have in the immune system?
polymorphs involves one of 2 or more variants of a particular DNA sequence
in the immune system they cause increased risk of infection
what is CVID?
common variable immunodeficiency
polygenic disorder
in CVID, what immunoglobulin is deficient?
IgG
what is the inheritance of CVID?
autosomal recessive
what are some primary immunodeficiencies caused by?
autoimmunity
what is the clinical presentation of a child with severe combined immunodeficiency (SCID) ?
develop infection within the first few weeks of life
unusual or recurrent infections
diarrhoea
unusual rashes
how is SCID diagnosed?
flow cytometry to measure lymphocyte count
at what lymphocyte count is diagnostic of SCID?
< 1 x 10 (9)/L
when does common viral immunodeficiency (CVID) present ?
present later on in life due to the presence of maternal antibodies
how is CVID diagnoseD?
IgA, IgM and IgG levels measured
if low - you have to consider secondary immunodeficiency before CVID
if normal test specific antibodies against haemophillus and pneumococcus
if both tests are normal then check that the problems aren’t due to complement or neutrophil function
