Immunology Diseases Flashcards
(31 cards)
Neutropenia
Low Neutrophil Count (<1500/uL)
Common cause: Chemotherapy
Increases susceptibility to infection
X-linked agammaglobulinemia
B Cell Only Defect
Deficiency in Bruton’s tyrosine kinase (required for B Cell Development)
pre-B Cells cannot develop further!
Low B Cells, no circulating antibodies, absence of secondary lymphoid tissues (no germinal centers)
Life threatening infections occur! (Encapsulated bacteria, enterovirus, vaccine associated poliomyelitis)
IgA Deficiency
Humoral Immunodeficiency
Most common immunodeficiency
Frequently asymptomatic
Increased risk for mucosal infections (viral)
Autoimmune associations
Blood transfusion risk (will develop antibodies against IgA)
Hyper IgM Syndrome
T Cell only defect
CD40L Deficiency (on helper CD4+ T Cells)
B Cells cannot class switch (High IgM Low others)
Decreased/absent germinal centers
Severe, recurrent pyogenic bacterial infections
Hereditary Angioedema
Complement/Innate Immunity Defect
Deficiency of C1 esterase inhibitor
Overactivation of complement leads to facial swelling
Leukocyte Adhesion Deficiency (LAD)
Innate Immunity Defect
Defect with integrin (CD18 subunit)
Neutrophil cannot adhere to endothelium
Causes delayed umbilical cord separation and recurrent nonsuppurative infections
Lab tests - increased leukocytes in blood
Chronic Granulomatous Disease (CGD)
Innate Immunity Defect
Defect in NADPH Oxidase
Failure to produce H2O2 to kill bacteria
Causes recurrent infection in catalase-producing organisms
Failure to kill organisms leads to foamy macrophages and granuloma formation
Chediak-Higashi Disease
Innate Immunity Defect
Genetic Defect in vesicle formation and trafficking
Failure to form phagolysosomes
Increases susceptibility to pyogenic infections
Causes neutropenia with giant granules in neutrophils and macrophages
Causes oculocutaneous albinism
Severe Combined Immunodeficiency (SCID)
B AND T Cell Defect
Impaired/Absent Immune Response
None/very little B Cells + T Cells +/- NK Cells
Severe, life-threatening infections
Caused by many mutaitons (ADA, RAG, X-linked common gamma chain)
Therapy: Stem Cell Transplant
Common Variable Immunodeficiency (CVID)
Humoral Immunodeficiency
Multiple Etiologies and Numerous Mutations
Underlying defect in B cells or Helper CD4+ T Cells
Overall Low Ig’s (Low IgA/IgG, Low/normal IgM)
Decreased memory B Cells
Increased risk for bacterial, enteroviral, and Giardia lamblia infections
Autoimmune association and increased risk for lymphoma
DiGeorge Syndrome
Defect in T Cells OnLY
Thymic Aplasia
Developmental Defect in Third and Fourth Pharyngeal Pouches
Marked T Cell Deficiency, Hypocalcemia
Severe viral, fungal, protozoal, pyogenic infections
RAG Deficiency
B AND T Cell Defect
Mutations in RAG1/2 = SCID
No B/T Cells, Normal NK Cells
VDJ recombination cannot occur in B/T Cell Development
Ommen’s Syndrome: lower than normal RAG expression - autoimmune manifestations and immunodeficiency
Hyper IgE Syndrome (Job’s Syndrome)
Defect in effector signalling
STAT3 mutation - deficiency in TH17 CD4+ Helper T Cells
Impaired neutrophil recruitment and increased IgE
Staphylococcal abscesses without inflammation and eczema
IL-12 Receptor Deficiency
Decreased TH1 Response, Decreased IFN-gamma release, Disseminated Mycobacterial infections (can’t form granulomas)
Celiac’s Disease
IgG/IgA react to gluten - abnormal TH2 CD4+ response, creates inflammatory disease of small bowel
Food Allergies
TH2 CD4+ T Cell Dependent IgE response - mast cell degranulation, failure to suppress immune response to food
MALT Lymphoma
Inflammatory reaction from H. pylori infection, malignant transformation in B Cells
Inflammatory Bowel Disease
Defects in TH1/TH17 response to commensal microbes/antigens (cell-mediated) - defective Treg function, ab pain, vomiting, diarrhea
Chronic Rhinosinusitis (CRS)
Defect in TH2 CD4+ T Cell Dependent IgE response - mast cell degranulation - inflammation
Psoriasis
Defect in TH1/TH17 - cell-mediated response to environmental antigens - keratinocyte proliferation, red, scaly plaques
Atopic Dermatitis (Eczema)
Defect in TH2 CD4+ T Cell Dependent IgE response - mast cell degranulation - inflammation
Wiskott-Aldrich
system disease
defect in WAS protein
defect in T Cell function, impairs B Cell function, impairs phagocytosis/chemotaxis, decreased T reg function
Hyperacute Rejection
Preformed antibody-mediated (minutes)
Type II HS Rxn
antibodies against ABO blood group antigens
Acute Rejection
CD8 T Cell mediated (weeks)
CD8 T Cells recognize graft-MHC as foreign
Either bind directly to graft-MHC or to self-MHC presenting graft-MHC peptide (APC engulfed graft cell)
