Immunodeficiencies Flashcards
Severe Combined Immune Deficiency (SCID)
Caused By?
Lymphocytes impacted?
Immunoglobins?
Characterizations
ADA Deficiency | ARTEMIS Deficiency
Converting deoxyadenosine to deoxyinosine | repairing double strand breaks in VDJ recomb
ADA: T-B-NK-
ARTEMIS: T-B-NK+
Low IgG, IgA, IgM
Severe Lymphopenia, severe opportunistic infections, chronic diarrhea, FTT
Avoid Live Viral Vaccines
ADA Deficiency
Lymphocytes impacted?
Immunoglobins?
Characterizations
Autosomal Recessive
T-, B-, NK-
Low IgG, IgA, IgM
Accumulation of deoxyadenosine
HSCT
Avoid Live Viral Vacccines
Purine Nucleoside Phosphorylase (PNP) Deficiency
Lymphocytes impacted?
Immunoglobins?
Characterizations?
Treatment?
Autosomal Recessive
T-, B+, NK+/-
Normal IgG, IgA, IgM
Accumulation of intracellular dGTP
Decrease in peripheral T-cells
Early Onset Neurological Abnormalities
Autoimmune Disorders
HSCT Treatment
Avoid Live Viral Vacccines
ARTEMIS Deficiency
Lymphocytes impacted?
Immunoglobins?
Characterizations
Treatment?
Autosomal Recessive Radiosensitive
T-, B-, NK+
Low IgG, IgA, IgM
Diarrhea, candidiasis, pneumonia
T/B cell decreased
HSCT
Avoid Live Viral Vaccines
RAG1/RAG2 Def
Lymphocytes impacted?
Immunoglobins?
Characterizations
Treatment?
Autosomal Recessive
T-, B-, NK+
Low IgG, IgA, IgM
Causes impaired VDJ Recombination, defective pre-TCR/BCR
Diarrhea, candidiasis, pneumonia
Leaky RAGs = Omenn Syndrome
HSCT
Avoid live viral vaccines
Omenn Syndrome
Similar to Rag1/Rag2 Def.
Characterized by:
severe erythroderma, splenomegaly, eosinophilia, high IgE
Avoid live viral vaccines
Jak3 Deficiency
Lymphocytes impacted?
Immunoglobins?
Characterizations
Treatment?
Autosomal Recessive
T-, B+, NK+
Very low IgG, IgA, IgM
Caused by mutation in Jak3 gene
Causes defect in IL-2 signalling
HSCT Possible treatment
Avoid Live Viral Vaccines
Agammaglobulinemia
Characterizations
Mostly X-linked trait, but Autosomal Recessive also exists
Early B-cell development arrested
Pre-B cells are normally absent or in very low numbers
X-Linked Btk Kinase Deficiency
Lymphocytes impacted?
Immunoglobins?
Characterizations
Treatment?
X-linked disorder
B-, T+, NK+
No IgG, IgA, IgM
Mutation in tyrosine kinase
Caused by defect in rearrangement of Ig heavy chain genes
Presents in 5-6 month infants
HSCT
Isolated IgG Subclass Deficiencies
Lymphocytes impacted?
Immunoglobins?
Characterizations
Treatment?
B+, T+, NK+
Low IgG, normal IgM, IgA, IgE
Decrease of one or more IgG subclasses
Caused by defects in several genes
Normally asympotmatic, sometimes recurrent infections in respiratory tract
Low IgG2, varying IgG4
IgA Deficiency
Lymphocytes impacted?
Immunoglobins?
Characterizations
Treatment?
B+, T+, NK+
No IgA, normal IgG, IgM
Higher prevalence in males, diagnosed by recurrent infections w/ encapsulated bacteria
Mostly asymptomatic
Development of autoimmune diseases
May have anti-IgA IgG in response to anaphylaxis
Digeorge Syndrome (DGS)
Lymphocytes impacted?
Immunoglobins?
Characterizations
Treatment?
T-, B+, NK+
Normal IgG, IgA, IgM
Results from microdeletion of 22q11.2 region (35 genes)
Classic triad: Cardiac anomaly, hypocalcemia, hypoplastic thymus
Humoral Immunity intact
Live Viral Vaccines given to CD > 300
Hyper IgM Syndromes (HIGM)
Lymphocytes impacted?
Immunoglobins?
Characterizations
Treatment?
B+, T+, NK+
High TgM, low IgG, IgA
Impaired class switching & somatic hypermutation
Normal peripheral B cells, but low CD27 positive memory cells
Increased bacterial infections
X-linked HIGM: Mutations in CD40L gene
HSCT
CD40L/CD40 Deficiency
X-Linked: Happens only in males, 2/3 of all HIGM cases
Autosomal CD40 def: Male and Female, 1/3 of all HIGM
Transient Hypogammaglobulinemia of Infancy
Lymphocytes impacted?
Immunoglobins?
Characterizations
Treatment?
B+, T+, NK+
Low IgG, IgA, Normal or Low IgM
Maternal IgG disappears 6 months after birth
Ig production delayed for up to 36 months
Increased susceptibility to sinopulmonary infections
Normalizes between 2-4 years