Immunodeficiencies / Autoimmune processes Flashcards
Asplenia
Encapsulated extracellular bacteria (not removed from blood)
C3 deficiency
Recurrent G-, encapsulated bacterial infection (for all alternative complement pathway disruptions)
Asplenia
Encapsulated extracellular bacteria
C3 deficiency
Recurrent G- bacterial infection
Factor I deficiency
Absence of factor I –> depletion of C3
Encapsulated bacteria
Hereditary angioneurotic edema
Deficiency of C1 inhibitors –> depletion of C4, C2
Recurrent episodes of edema skin, larynx, GI, & UG tracts
Paroxysmal nocturnal hemoglobinuria
Deficient expression of DAF & CD59 –> intravascular hemolysis
(X-linked)
Autoimmune hemolytic anemia
Rh blood group antigens, I antigen; Destruction of RBCs via complement, phagocytosis –> anemia (2)
Autoimmune thrombocytopenia purpura
Platelet integrins gpIIb:IIIa –> abnormal bleeding (2)
Goodpasture’s syndrome
Basement membrane, collagen type IV –> Glomerulonephritis, pulmonary hemorrhage (2)
Pemphigus vulgaris
Epidermal cadherin –> Skin blisters (2)
Pemphigus foliaceus
Desmoglein –> mild skin blistering (2)
Acute rheumatic fever
Group A Streptococcal cell wall antigens (Abs cross react with endocardium) –> Arthritis, myocarditis, heart valve scarring (2)
Grave’s disease
TSH receptor (agonist) –> hyperthyroidism (2); IgGs may be transmitted to fetus through placenta
Myasthenia gravis
ACh receptors –> Progressive weakness (2)
T2 diabetes
Insulin receptor (antagonist) –> hyperglycemia, ketoacidosis (2)
Hypoglycemia
Insulin receptor (agonist) –> Hypoglycemia (2)
Subacute bacterial endocarditis
Bacterial antigens –> soluble immune complexes –> glomerulonephritis (3)
Cryoglobulinemia
RF IgG complexes –> Vasculitis (3)
Systemic lupus erythemaosus
DNA, histones, ribosomes –> Glomerulonephritis, vasculitis, arthritis (3)
T1 diabetes
Pancreatic beta-cell Ag –> beta-cell destruction (4)
Coxsackie A&B virus may trigger
RA
Unknown synovial joint Ag –> Joint inflammation, destruction (4)
MS
Myelin basic protein –> Brain degeneration, paralysis (4)
APECED (Autoimmune PolyEndocrinology Candidiasis Ectodermal Dystrophy)
Mutations in AIRE (AutoImmune REgulator) –> defective thymic deletion of autoreactive T cells (TECs can’t express peripheral Ags) –> wide ranging autoimmune rxns
IPEX (Immune dysregulation, Polyendocrinopathy, Enteropathy, X-linked syndrome)
Mutations in transcription regulator of FOXP3 –> Treg cells aren’t produced –> High, autoreactive B, T IRs
HLA allotypes:
B27, A29, DQ6
Associated w/:
B27 - Ankylosing spondylitis
A29 - Birdshot chorioretinopathy
DQ6 - Narcolepsy, MS, (diminished risk of T1 diabetes)
Ciliac’s
Wheat flour gluten modifies tissue transglutaminase –> Anti-transglutaminase CD4+/B cells
Borrelia burgdorferi
Associated with chronic autoimmune arthritis
Campylobacter jejuni
Associated with reactive arthritis, GBS
Chlamydia trachomatis
Associated with Reiter’s syndrome (arthritis)
Hashimoto’s thyroiditis
Hypothyroidism, autoimmune destruction, antagonists of TSH receptors
Crohn’s disease
Abnormal mucosal T cell regulation –> Granulomatous rxn
Pernicious anemia
Anti-parietal cell/anti-intrinsic factor Abs –> impaired vit B12 absorption from lack of intrinsic factor in gastric secretions
Autoimmune chronic active hepatitis
Liver cells express MHC II –> Anti-liver cell Abs
Deficiencies of any of C5-9
Lack of complement-mediated lysis –> Neisseria susceptibility
NEMO deficiency
Impaired NFkB activation –> Chronic bacterial/viral infections
Chronic granulomatous disease
Defective NADPH oxidase in neutrophils –> Chronic bacterial/fungal infections
MBL (mannose-binding lectin) deficiency
Neisseria meningitidis –> Meningitis
NK-cell deficiency
GATA2 gene impaired –> No NK cells –> Severe herpesvirus infections
Hyper-IgM deficiency
CD40/CD40L impaired –> No isotype switching/somatic hypermutation in B cells –> Extracellular bacterial/fungal infections
IgG2 deficiency
Susceptible to encapsulated bacteria
SCID
Various genes affected (ADA, PNP, common gamma chain in IL receptors, repair mechs.) –> B & T cell fxn absent –> All infxns
Omenn syndrome
RAG1/2 –> Impaired VDJ recombination –> Can’t form TCRs/BCRs properly –> All infxns
X-linked agammaglobulinemia
BTK doesn’t signal –> B cells blocked at pro-B stage –> Recurrent bacterial infxns
Complete DiGeorge syndrome
Absence of thymus, T cells –> All infxns
ZAP-70 deficiency
T cells cannot signal through TCRs –> All infxns
Selective IgA deficiency
No major susceptibility, most common immunodeficiency
DiGeorge’s syndrome
Thymic aplasia –> General infection susceptibility
MHC I deficiency
No CD8+ T cells –> Intracellular infection susceptibility
MHC II deficiency
No CD4+ T cells –> SCID
Graft-Vs-Host disease
Donor T cells in bone marrow grafts attack tissues of IC’d hosts –> allogenic IR, inflammatory state; Immunosuppressive drugs, deplete grafts of T cells
Interferon-G deficiency
Macrophages do not activate –> No granulomas, susceptible to intracellular pathogens
Serum sickness
Introduced proteins or drugs induce formation of Abs targeting them, esp. w/multiple exposures –> immune complexes form (Arthus rxn)
Atopic dermatitis
Eczema associated w/Type I hypersensitivity, common in young patients
Adenosine deaminase deficiency
Decreased DNA synthesis –> Low T & B cell counts –> SCID
Selective IgA deficiency
Slight susceptibility to mucosal pathogens, most common immunodeficiency
Adenosine deaminase deficiency
Decreased DNA synthesis –> Low T & B cell counts –> SCID; Need bone marrow transplant
Leukocyte adhesion deficiency
Deficient integrin B2/CD18/LFA-1/CR3 in neutrophils –> Defective migration to inflammation sites –> Chronic bacterial infxns
Toxic shock syndrome
Superantigen TSST from Staph, Strep –> Polyclonal CD4+ activation (~20% of total) –> Cytokine storm –> Organ failure
Leukocyte adhesion deficiency
Deficient integrin B2/CD18/LFA-1/CR3 in neutrophils/macrophages –> Defective migration to inflammation sites –> Chronic bacterial infxns
Toxic shock syndrome
Superantigen TSST from Staph, Strep –> Polyclonal CD4+ activation (~20% of total) –> Cytokine storm –> Organ failure
G6PD & Myeloperoxidase deficiency
Defective phagocytes can’t kill pathogens –> Chronic bacterial/fungal infxns
Chediak-Higashi syndrome
Lysosoal trafficking regulator protein defective –> Defective phagocytosis/phagolysosome formation –> Persistent bacterial infxns, granulomas
HIV
Depletion of CD4+ T cells –> IC
Opp. infxns include Toxoplasma, Mycobacterium, Cryptococcus, Pneumocystis, Candida, Herpesviruses
Radiation, chemotherapy, & metastases to bone marrow
Inhibition of leukocyte developmet –> IC