PID Flashcards
ADA deficiency?
SCID
T- B- and NK- phenotype, as well as absent or low IgG IgA and IgM.
Tx Hematopoietic stem cell transplant avoid all viral vaccines.
ADA is auto recessive and second most cause of SCID
(hyperactive ADA=hemolytic anemia)
Artemis deficiency?
T- B- NK+ absent or low IgG IgA and IgM
Artemis mutations can result in rare autosomal recessive RADIOSENSITIVE SCID
Classically presents with diarrhea candidiasis and pneumocystis jiroveci
HSCT is Tx and no live viral vaccines
PNP deficiency?
an autosomal recessive mutation that accounts for 4% of SCID cases.
T- B+ NK+/- normal IgG IgA and IgM
Tx HSCT no live viral vaccines
Can onset later in life or infancy.
Also common to have autoimmune disorders such as hemolytic anemia, arthritis and lupus
(PNP&A)
RAG1/2 deficiency? Omenn syndrome?
T- B- NK+ and absent or low IgGAM
RAG defects causes impaired VDJ recombination leading to defective pre TCR and BCR. This does not occur in NK cells therefore they are functioning properly.
This is autosomal recessive and presents with classical SCID symptoms
Omenn syndrome is due to Leaky Rag1/2 that allows for partial function. (Evil for Omenn and Rag dolls ) Omenn syndrome presents with severe erythroderma splenomegaly eosinophila and IgE
Treatment for SCIDS and general presentation?
HSCT and opportunistic infections such as pneumocystic jirovecii, candididias, diarrhea
What deficiency leads to Omenn syndrome and what is it?
Leaky RAG 1 RAG2 it is characteriszed by severe erythroderma splenomegaly eosinophilia and high IgE.
Jak3 deficiency?
7% of all SCIDs
T-B+ NK- very low IgG IgA and IgM.
SCIDs autosomal recessive both men and women equally affected. Defect in IL2 signaling. IL-2 is growth factor and survival signal.
HSCT treatment and avoid live viral vaccines
Cardiac anomalies, hypocalcemia and hypoplastic thymus is the classic triad for what?
DiGeorge Syndrome.
Describe DGS.
DGS from a microdeletion of 22q11.2 low T cell numbers and humoral immunity is usually intact in most patients. DGS have frequent upper respiratoy infections. Live viral vaccines can be given to patients who have CD8T cell count greater than 300.
Presents with normal IgGAM and No T cells but normal B and NK cells.
X linked Btk deficiency
No IgM IgG IgA, B- T+ NK+.
A mutation in Bruton tyrosine kinase. Defect in rearrangement of Ig heavy chain, diagnose 5-6 months old, HSCT is treatment
(X for x linked and NO Ab’s)
Some IgG subsclasses are low, but normal IgM igA IgE are there. B+ T+ NK+, what is this?
Decreased concentrations of one or more IgG subclasses in particular IgG2 associated with poor responses to polysaccharide Ag’s in children. IgG4 levels can vary in healthy people and many don’t know they have low levels.
Called Isolated IgG Subclass deficiency
IgA deficiency?
Incidence is high although most affected people are healthy. No IgA normal IgG and IgM, B+ T+ NK+. Higher in males. Diagnosed with more than 85% recurrent infections with encapusalated bacteria.
Pts often develop autoimmune diseases and allergies. Those with undetectable IgA may have serum anti-IgA IgG which can result in non IgE mediated anaphlyaxis if given IVIG. (Example of serum sickness)
Hyper IgM syndromes?
Very low levels of CD27+ cells which marks memory cells, but they have normal numbers of peripheral B cells.
High IgM, but Low IgG and IgA. B+ T+ and NK+.
Tx with HSCT
Describe X linked HIGM.
due to mutations in CD40L which binds CD40 on B cells triggering terminal differentiation with class switching and somatic hypermutation. X linked CD40L is male only and responsible for 2/3 of all HIGM cases.
CD40 is autosomal inheritance and can be both male and female responsible for 1/3 cases. (“A” in autosomal=APC)
Autosomal CD40 deficiency?
Can be male or female and deficiency is 1/3 of all cases.
“A” for APC’s
