Immunodeficiencies Flashcards
X Linked SCID
Common gamma chain deficiency
T cell growth factor receptor defect
Causes nonfunctional B cells, absent T and NK cells
Severe Combined Immunodeficiency Presentation
Severe opportunistic infections, chronic diarrhea and failure to thrive
At risk of abortion
ADA Deficiency
Autosomal recessive SCID
Accumulations of toxic metabolites stops development at progenitor level (no T, B or NK cells)
Jak3
Defective IL2 receptor signaling
Nonfunctional B cells
DiGeorge Syndrome
Classic T cell deficiency via 22q11 chromosome deletion
Causes hypocalcaemia which leads to parathyroid/thymic hypoplasia and heart defects
X Linked Agammaglobulinemia
BTK gene mutation causes decreased IgA, IgG and IgM via HC rearrangement defect
pre-B cell arrest lowers B cell and plasma cell count
RAG1/RAG2/Artemis gene Defect
Causes absent T and B cells but NK cells present
X Linked Hyper IgM
Mutation in CD40L gene causes defective class switching (only IgM present)
Autosomal HIGM caused by CD40 deficiency
Common Variable Immunodeficiency
Variable hypogammaglobulinemia
Defects in B cell formation are inherited
Abs against B cells are acquired
IgA deficiency common, but asymptomatic
Bare Lymphocyte Syndrome
No MHC II on APCs
Causes CD4+ cell deficiency
Leads to variable hypogammaglobulinemia
X Linked Lymphoproliferative Syndrome
Uncontrolled T cell proliferation via SH2D1A mutation
IL12-IFNgamma Defects
Non-TB mycobacteria susceptibility
Causes issues with Th1 differentiation and phagocytic cell defects
Chediak-Higashi Syndrome
Abnormally giant granules in neutrophils
Defects in chemotaxis and degranulation
Pyogenic infections followed by lymphproliferative syndrome and partial albinism
Complement Deficiencies
C1, C4, C2: systemic lupus erythematosus
C3: similar to Ab defects
C8: susceptible to neisseria infections
