09.17.18 Primary Immunodeficiency Flashcards
(29 cards)
Genetic mutation that may occur at any phase of the immune response (maternal IgG can mask this)
Primary Immunodeficiencies
What is the majority of primary immune deficiencies?
Humoral defects
What are signs/symptoms of humoral/antibody defects?
- Pyogenic/encapsulated bacteria infections
- Recurrent sinus/respiratory infection
- Frequent viral infections
- Chronic diarrhea
- Caused by defects in B cell development
- Defective germinal center
- underdeveloped tonsils/lymphoid tissues
Agammaglobulinemias
- Defect in B cell tyrosine kinase (BTK)
- Majority of agammaglobulinemias
- Aka Bruton’s agammaglobulinemia
X-linked agammaglobulinemia (XLA)
What are the lab values to pay attention to with XLA?
- 50% with positive family history
- IgG <100 mg/dl
- B cells <2% of lymphocytes
- Normal T cell number and function
- Defects in B cell isotype switching
- Normal numbers of B cells but elevated levels of IgM and low levels of IgG, IgE, and IgA
Hyper-IgM Syndromes
Most common primary immunodeficiency
IgA deficiency
Second most frequent PID
Common Variable immunodeficiency (CVID)
- IgA <5-7 mg/dl
- asymptopmatic
IgA Deficiency
Characterized by:
- recurrent infections
- reduced IgG, IgA and/or IgM
- impaired/absent antibody response to previous infection/vaccine
- Cause unknown
CVID
Characterized by:
- recurrent sinopulmonary infections
- Normal IgG, igA, IgM
- Normal B cell and normal T cell number and function
- Impaired vaccine response (polysaccharide)
- Impaired antibody response to natural infection with encapsulated bacteria
Specific Antibody Deficiency
What are the encapsulated organisms?
SAY SOME KILLERS HAVE PRETTY NICE CAPSULES
Streptococcus pneumoniae/pyogenes
Staph aureus
Klebsiella
Haemophilius Influenzae
Pseudomonas aeruginosa
Neisseria meningitidis
Cryptococcus neoformans
Characterized by:
- Recurrent sinopulmonary infections
- Low IgG but normal specific antibodies
- Normal lymphocyte number and function
- Possible delay in maturation for T helper cells
Transient Hypogammaglobulinemia of Infancy
How would you evaluate the humoral immune system?
- CBC with diff
- Age adjusted quantitative Ig
- Specific Antibody Titers
- Complement pathway functional assays
- Lymphocyte markers
What kind of infections are common with T cell dysfunction
Infections with intracellular microorganisms
- Problem impacting B, T an NK cells
- Most common is X linked
- RAG deficiency
Severe Combined Immunodeficiency (SCID)
- Leaky SCID
- Low T cell
- Exudative eczema
- Large spleen
- Elevated IgE and Eosinophilia
Omenn Syndrome
- Defect in embryogenesis
- Deletion of chromosome 22q11.2
- Hypocalcemia
- Low T cell
- Congenital heart disease
- Dysmorphic face
- Diagnosed by chest x ray (absence of thymus)
- Can be partial or complete
DiGeorge Syndrome
- Thrombocytopenia with small platelets (look for min. platelet volume)
- Eczema
- WASP involved with actin polymerization- lymphocyte function
Wiskott Aldrich Syndrome
What types of diseases are associated with defects in innate immunity?
- Chronic Granulomatous Disease
- Leukocyte Adhesion Deficiency
- Hyper IgE Syndrome
- Complement Disorders
- Recurrent bacterial infection with catalase positive organisms (Staph)
- Granulomas because phagocytes can ingest but do not kill because they can’t form oxygen radicals
Chronic Granulomatous Disease
How can you diagnose CGD?
- Flow cytometry
- NBT
- Superoxide radical formation
- Absent CD18 on cell surface
- Neutrophil can’t migrate to inflammatory response
- No pus formation
Leukocyte Adhesion Deficiency
