Montleleone - Primary Immunodeficiency Flashcards
Where is each Ig most commonly found?
IgG - extra vascular spaces IgM - first Ig made by the fetus IgA - major Ig in secretions IgD - in serum, not much is known. IgE - binds to mast cells and basophils
What is the most common type of primary immunodeficiency
Antibody deficiency
What microbes are common in T cell infections?
Pneumocystis
Cryptococcosis
Herpesvirus
- you’ll see respiratory infections, diarrhea, failure to thrive
What microbes will you see in B cells immunodeficiency?
Haemophilus, streptococcus, campylobacter, parasitic infections such as Giardiasis, and enteroviruses
- going to affect the lungs and nose
What type of bacteria will you see in phagocyte immunodeficiency?
Staphylococcus, burkholderiA, serratia, norcadia, fungal infections such as aspergillus.
- patient will have recurrent infections and abscesses
Main bacteria for monocyte immunodeficiency?
Nontuburculosus mycobacteria (respiratory) Salmonella (GI)
What type of bug would you see in a complement immunodeficiency?
Neisseria
What are the main T cell deficiency diseases?
SCID
DiGeorge
Ataxia-telamgectasia
Wiskott-Aldrich syndrome
SCID
Diminished or absent T cells
May or may not have B cell and NK cell impact depending on the gene mutation.
May die in first year of life without treatment.
DiGeorge syndrome
Impacts organs derived from the 3rd and 4th pharyngeal arches
- teterology of Fallot
- low set ears and cleft palate
- hypocalcemia
- thymus is affected which leads to absent/low T cells
Ataxia telangiectasia
Gene mutation that causes a defect in CD4 T cells.
- causes A deficiency in IgA and IgE
- neurological and progressive motor loss
- telangiectasias - spider veins
Wiskott-Aldrich syndrome
T cell immune deficiency that also affects B cells.
- small palates and thrombocytopenia with petechiae, bruising, bleeding
- eczema
- upper respiratory and opportunistic infections
- high rate of autoimmunity and lymphoid malignancy
Diseases associated with B cell deficiency
Agammaglobinemia
IgA deficiency
Common variable immunodeficiency
Selective IgA deficiency
Usually no symptoms, it is the most common. May have recurrent infections, allergies, or autoimmune diseases.
What is the structure of IgA?
In the secretory form, the form found in secretions it is in polymers of 2-4 IgA monomers.
- there are 2 chains: J chain and secretory component.
J chain - joins the different IgA monomers.
Secretory component - produced by the epithelial cells and is also involved in joining the IgA monomers. It ensures that the IgA isn’t degraded in the mucosa.
Agammaglobinemia
Defect in Bruton Tyrosine Kinase, which results in pre-B cell arrest.
- absence or markedly reduced Igs
- almost no B cells
- usually X linked but can be recessive
- treated with IV or subQ Igs
Bruton tyrosine kinase
Enzyme defective in Agammaglobinemia
Common variable immunodeficiency
Serum Igs are low but B cell numbers are normal.
- unclear genetic pattern of inheritance
- usually doesn’t take hold till later in life -20-30s
- treat with IV or subQ Ig
Phagocytic disorders
Chronic granulotmatus disease
Chediak-Higashi syndrome
CGD
X linked but can be recessive
- mutations in genes that cause deficiency in phagocyte oxidase complex and leads to defect in superoxide production.
- recurrent life-threatening infections with bacteria, fungi that cause tissue granuloma formation
- usually pulmonary, cutaneous, lymphatic, and hepatic infections
Chediak-higashi syndrome
Recessive
- defect In protein that transports materials to lysosomes
- large abnormal granules in neutrophils, melanocytes, hair, Schwann cells, CNS.
- recurrent cutaneous and sino-pulmonary infections.
- albinism, mental retardation, neuropathy
What unique thing do you evaluate for in each of the different types of deficiencies?
T cells - PPD, T cell subsets, HIV serology
B cells - quantitative Igs, pre and post vaccination titers
Phagocytic - peripheral smear, neutrophil oxidative burst test
Complement - total complement level CH50, complement component levels
Primary immunodeficiency
When the immune system is unable to defend against pathogens in the environment.
- not acquired like HIV, chemo etc
- due to genetics
- immune system is hampered or absent
