Miscellaneous Flashcards
Acute-phase reactants (enumerate)
1- Positive (upregulated) - C-reactive protein - Ferritin - Fibrinogen - Hepcidin - Serum amyloid A 2- Negative (downregulated) - Albumin - Transferrin
Type I hypersensitivity reaction mechanism and examples
- Free antigen cross-links IgE on presensitized mast cells and basophils triggering immediate release of vasoactive amines
- Allergic rhinitis (hay fever), Systemic anaphylaxis, food allergies, wheal and flare, and asthma
Type II hypersensitivity reaction mechanism and examples
- IgM or IgG bind to fixed antigens on “enemy” cell leading to cell destruction by MAC formed by antibody and complement. 1) opsonization and phagocytosis 2) complement and Fc-receptor mediated inflammation 3) Antibody mediated cellular dysfunction
- Cytotoxic (autoimmune hemolytic anemia [HDNB], acute rheumatic fever, Goodpasture syndrome, transfusion reaction, autoimmune thrombocytopenic purpura, erythroblastosis fetalis, bullous pemphigoid, pemphigus vulgaris, Guillain-Barre syndrome), Non-cytotoxic (Myasthenia gravis, Graves disease, Type II dibetes, pernicious anemia)
Type III hypersensitivity reaction mechanism and examples
- Antigen-antibody (IgG) complexes activate complement, which attracts neutrophils which release lysosomal enzymes
- SLE, PSGN, Arthus reaction, serum sickness, Polyarteritis nodosa
Type IV hypersensitivity reaction mechanism and examples
- Sensitized T cells encounter antigen and then release cytokines (leads to macrophage activation)
- Tuberculin test, contact dermatitis, Hashimoto thyroiditis, multiple sclerosis, rheumatoid arthritis, type I diabetes, Guillain-Barre syndrome, Celiac disease, Crohn disease
Blood transfusion reactions (enumerate)
- Allergic reaction (Type I)
- Anaphylactic reaction
- Febrile non-hemolytic transfusion reaction (Type II)
- Acute hemolytic transfusion reaction (Type II)
After blood transfusion; urticaria, pruritis, wheezing and fever (Diagnosis?!!)
Allergic reaction
After blood transfusion; dyspnea, bronchospasm, hypotension, respiratory arrest and shock (Diagnosis?!!)
Anaphylactic reaction
After blood transfusion; fever, headaches, chills and flushing (Diagnosis?!!)
Febrile non-hemolytic transfusion reaction
After blood transfusion; fever, hypotension, tachycardia, flank pain, hemoglobinuria and jaundice (Diagnosis?!!)
Acute hemolytic transfusion reaction
Bacterial infections in individuals with decreased T cells
Sepsis
Bacterial infections in individuals with decreased B cells
Encapsulated bacteria
Bacterial infections in individuals with decreased granulocytes
- Staphylococcus
- Burkholderia cepacia
- P. aeruginosa
- Serratia
- Nocardia
Bacterial infections in individuals with decreased complement
- Encapsulated species with early component deficiencies
- Neisseria with late component (MAC) deficiencies
Viral infections in individuals with decreased T cells
- CMV, EBV, JCV, VZV
- Chronic infection with respiratory/GI viruses
Viral infections in individuals with decreased B cells
- Enteroviral encephalitis
- Polio (live vaccine contraindicated)
Viral infections in individuals with decreased granulocytes
None
Viral infections in individuals with decreased complement
None
Fungi/parasites infections in individuals with decreased T cells
- Candida (local)
- PCP
Fungi/parasites infections in individuals with decreased B cells
GI giardiasis (no IgA)
Fungi/parasites infections in individuals with decreased granulocytes
- Candida (systemic)
- Aspergillus
Fungi/parasite infections in individuals with decreased complement
None
Wide-spread thrombosis of graft vessels leading to ischemia and necrosis (Diagnosis and pathogenesis?!!)
- Hyperacute transplant rejection
- Pre-existing recipient Abs that react to donor Ags (Type II), activate complement
Vasculitis of graft vessels with dense interstitial lymphocytic infiltrate (Diagnosis and pathogenesis?!!)
- Acute transplant rejection
- Cellular: CD8+ T cells activated against MHCs (type IV). Humeral: recipient Abs that react to donor Ags (formed after transplant)
Lymphocytic infiltration of graft with proliferation of vascular smooth muscle, parenchymal atrophy, interstitial fibrosis. dominated by arteriosclerosis (Diagnosis and pathogenesis?!!)
- Chronic transplant rejection
- CD4+ T cells respond to recipient APCs presenting donor peptides, including allogeneic MHC. both cellular and hymoral component (Type II and IV)
- Examples are bronchiolitis obliterans, accelerated atherosclerosis, chronic graft nephropathy, vanishing bile duct syndrome
After graft maculopapular rash, jaundice, diarrhea, and hepatosplenomegaly (Diagnosis and pathogenesis?!!)
- Graft-versus-host disease
- Grafted immunocompetent T cells proliferate in the immunocompromised host and reject host cells with “foreign” proteins resulting in severe organ dysfunction (Type IV)
- Potentially beneficial in bone marrow transplant for leukemia (graft-versus-tumor effect)
