Immunodeficiency Syndromes Flashcards
x linked immunodeficiency disease
x linked agammaglobulinemeia
hyper-Igm
SCIDS
Wiskott Aldrich
x linked agammaglobulinemia
failure of b cell precursors to develop into mature B cells
caused by mutation in Btk- required for Ig chain rearrangement in maturation
manifests around 6 months
normal t cell mediated reactions
common variable immunodeficiency
hypogammaglobulinemias
normal number of b cells but cannot differentate into plasma cells
presentation normal to Brutons, but development is later and equal in both genders
isolated IgA deficiency
1:600 european descent
low levels of serum and secretory IgA
increased risk of respiratory, GI, and urogenital tracts
hyper IgM syndrome
defect in ability of helper T cells to deliver activating signals to B cells
IgM present but deficiency of G, A, and E\
majority are x linked w/ mutatino encoding CD40L
treatment for humoral immunodeficiency
IVIg
100-400 mg/kg of body weight every 3/4 weeks
adjust dose to achieve rate of infection that is comparable to general population
digeorge syndrome
failure of development of 3rd and 4th pharyngeal pouches- defect in thymus
loss of t cell mediated immunity
tetany d/t abnormal calcium, congenital heart defects
caused by 22q11 deletion
severe combined immunodeficiency
inability of common lymphoid progenitors to differentiate into proB or proT cells
low or absent T and B cells
death occurs w/o bone transplantation
cauesd by x linked recessive deficiency in cytokine receptors (most common cause). can also be caused autosomal recessive adenosine deficiency
wiskott-aldrich syndrome
low platelets, exema, and immune deficiency
low IgM, normal IgG, and elevated IgA and E
do not make Abs to polysaccharide Ags
progressive T cell depletion
bone marrow transplant curative
complement deficiencies
C2 deficiency- no increased risk of infection, but increased autoimmune disease
c3- increased risk of bacterial infection
C5-9- increased susceptibility to neisseria infection
C1 inhibitor- hereditary angioedema- episodic edema of skin or mucosal surfaces d/t stress or trauma
viral core of AIDS
capsid protein p24, 2 copies of genomic RNA, 3 viral enzymes (protease, reverse transcriptase, and integrase)
p17
matrix protein surrounding core of HIV
viral envelop of HIV
host derived studded w/ gp120 and gp41, critical for infectivity
HIV genome
flanked by LTR regions required for initiation of transcription.
contains control regions that bind host transcription factors
gene products: gag, pol, env
gag- p24 capsid protein and p17 matrix
pol- reverse transcriptase
env- gp160, 120 (CD4 binding), and 41 (fusion)
genes that are unique to HIV
vif- promotes replication
vpr- increases replication and infection of macrophages
vpu- promotes CD degradation and release of virions
tat- transcription activator
rev- regulator of viral gene expression
nef- negative effector- down regulates CD4 and MHC expressoin to protect cells from CD8
HIV infection
infects CD4, DC, and macrophages
becomes established in lymphoid tissues
not detectable in
mechanisms of immunodeficiency in HIV
direct cytopathic effect
colonization of lymphoid tissue leading to progressive destruction
chronic activation of uninfected cells leading to activation induced cell death
killing of infected cell by cytotoxic T cells
seroconversion to HIV
detectable in 3-7 weeks
HIV evading the host
mutations are frequent
virus has a glycan shield to prevent Abs
category C conditions
CMV infection mycobacterium avium toxoplasmosis in brain pneumocystis- p/ jirovecii kaposis sarcoma- HHV8
