immuno Flashcards
What is the most common mutation that is involved in SCID?
A mutation that codes for the gamma chain of an IL2 receptor
X linked reccessive
What is another mutation that can cause a SCID? One that effects the maturation and proliferation of B and T cells
ADA deficiency
Autosomal recessive
With this deficiency there is an accumulation of adenosine and deoxyadenosine which accumulate as dATP.
this inhibits ribonucleotide reductase and impairs DNA synthesis in B and T cells
What does a mutation in the RAG gene do and how does it cause a SCID?
Cannot have any VDJ recombination and no new immunoglobulins are made. Immune system is basically absent
What are the symptoms that occur in a SCID?
RECURRENT infections specifically opportunistic infections including candida, nontuberculosis mycobacteria, and pneumocystis jirovecii
Chronic diarrhea and failure to thrive
What are some ways in which SCID can be diagnosed and what will the results show?
Newborn screening tests will show low levels of TRECs
There will be a low lymphocyte count with les than 20% T cells
Absence of thymic shadow on XRAY
Absent germinal centers
Genetic testing
What are the symptoms of ataxia telangiectasia?
Poor coordination and dilated blood vessels: can have telangiectasias in the eyes
Can have recurrent respiratory infections as well
A mutation in the _____ gene is seen in ataxia telangiectasia
ATM; cannot repair DNA
What are the lab findings in ataxia telangiectasia?
Increased alpha fetoprotein
Decreased IgA, IgG and IgE
lymphopenia: low lymphocytes count
increased risk of cancer
What is the major mutation that occurs in Hyper IgM syndrome?
CD40L deficiency which does not allow for class switching
X linked recessive
What are the symptoms that are seen in Hyper IgM syndrome?
Increased opportunistic infections
Recurrent pyogenic infections: sinusitis, pneumonia, otitis
What do the labs show in hyper IgM syndrome?
Drastically decreased IgG, IgA, IgE and high IgM
No germinal centers in lymph nodes
Genetic testing
What is the mutation that occurs in Wiskott Aldrich syndrome?
X linked mutation in the WAS gene
codes for WASp: impaired immune response and more prone to infections
What kind of infections are patients with WAS more at risk for?
Encapsulated
Opportunistic
What are the symptoms that are seen with WAS?
Eczema
Autoimmune hemolytic anemia and purpura can be seen
Thrombocytopenia: easy bleeding and petechiae, bloody diarrhea, nosebleeds
What will the labs show in WAS?
Increased IgA and IgE
Normal or decreased IgG and IgM
What are the symptoms that occur in X linked agammaglobulinemia?
Recurrent bacterial and enteroviral infections AFTER 6 months (when they run out of the mothers Igs from pregnancy)
because decreased B cells and decreased immunoglobulins
What are the common pathogens that affect patients with Bruton agammaglobulinemia?
Encapsulated: strep pneumo, neisseria, klebsiella, H flu, pseudomonas aeruginosa
SINNUSITIS OTITIS MEDIA PNEUMONIA are common
Individuals with X linked agammaglobulinemia must avoid _____ ________ vaccines
Live attenuated vaccines (polio)
What are the physical exam characteristics of some one who has X linked agammaglobulinemia?
Decreased size of lymph nodes and tonsils
Absence of B cells
Decreased levels of all Igs
What is the most common and least serious immunodeficiency?
IgA
Describe selective IgA deficiency
Decreased IgA leading to recurrent respiratory and entero infections but typically are asymptomatic
Can lead to other autoimmune diseases and allergies, rhinitis, asthma
Patients with selective IgA deficiency will be at an increased risk of ________
giardiasis
What are the symptoms that are seen in CVID>
Seen in early adulthood: recurrent infections: bronchiectasis
Increased risks of lymphomas, autoimmune anemia
What will the labs show from a patient with CVID?
Decreased plasma cells and Igs
