Disorders of the Immune System (P) Flashcards
What are the 3 broad categories of the disorders of IS?
1) Hypersensitivity rxns
2) Autoimmune diseases
3) Immunologic deficiency syndromes
*Amyloidosis
What are the types of hypersensitivity rxns?
1) Immediate hypersensitivity
2) Cytotoxic (Ab-mediated) hypersensitivity
A. Opsonization and complement and Fc receptor-mediated phagocytosis
B. Complement and Fc receptor mediated inflammation
C. Antibody mediated cell dysfunction
3) Immune complex mediated hypersensitivity
4) Cell mediated hypersensitivity
A. Delayed type hypersensitivity
B. T-cell mediated hypersensitivity
What is the other term for immediate hypersensitivity?
Type I hypersensitivity
What is the principle of immediate (type I) hypersensitivity?
Rapidly developing immunologic rxn occurring within mins after the combination of an Ag w/ Ab bound to mast cells in individuals previously sensitized to the Ag
What is the role of IgE Abs to type I hypersensitivity?
It is mediated by IgE Abs directed against sp Ags (allergens)
What is the mechanism of type I hypersensitivity?
Ag + Ab (IgE) bound to mast cells / basophils immediate release of vasoactive amines and other mediators from mast cells; recruitment of inflammatory cells
What is the other term for antibody-mediated hypersensitivity?
Type II hypersensitivity
What is antibody-mediated (type II) hypersensitivity?
It is mediated by Abs against intrinsic Ags or extrinsic Ags adsorbed on cell surfaces or ECM
What is the mechanism of type II hypersensitivity?
Ab (IgG or IgM) + Ag (bound to cell surface or ECM)
*What is the process (or steps) of type II hypersensitivity?
1) Opsonization and phagocytosis
2) Complement and Fc receptor-mediated inflammation
3) Antibody-mediated cellular dysfunction
*What are the diseases / disorders that causes type II hypersensitivity?
1) Autoimmune hemolytic anemia
2) Autoimmune thrombocytopenic purpura
3) Goodpasture syndrome
4) Myasthenia gravis
5) Graves disease (hyperthyroidism)
6) Insulin-resistance DM
What are the ff w/ regards to the given disorder:
1) What is/are the target Ags of the given disorder?
2) What is the mechanism of the given disorder?
Given disorder: Autoimmune hemolytic anemia
1) RBC membrane proteins
2) IIa opsonization and phagocytosis of erythrocytes
What are the ff w/ regards to the given disorder:
1) What is/are the target Ags of the given disorder?
2) What is the mechanism of the given disorder?
Given disorder: Autoimmune thrombocytopenic purpura
1) PLT membrane proteins (GpIIb:IIIa *opr GpIb/IX)
2) IIa opsonization and phagocytosis of PLTs
What are the ff w/ regards to the given disorder:
1) What is/are the target Ags of the given disorder?
2) What is the mechanism of the given disorder?
Given disorder: Goodpasture syndrome
1) Noncollagenous protein in BM of alveoli and glomeruli
2) IIb complement and Fc receptor mediated inflammation
What are the ff w/ regards to the given disorder:
1) What is/are the target Ags of the given disorder?
2) What is the mechanism of the given disorder?
Given disorder: Myasthenia gravis
1) Acetylcholine receptor
2) IIc Ab inhibits Ach binding; down regulates receptors
What are the ff w/ regards to the given disorder:
1) What is/are the target Ags of the given disorder?
2) What is the mechanism of the given disorder?
Given disorder: Graves disease
1) TSH receptor
2) IIc Ab-mediated stimulation of TSH receptors
What are the ff w/ regards to the given disorder:
1) What is/are the target Ags of the given disorder?
2) What is the mechanism of the given disorder?
Given disorder: Insulin-resistance DM
1) Insulin receptor
2) IIc Ab inhibits binding of insulin
What is the other term of immune-complex mediated hypersensitivity?
Type III hypersensitivity
What is the mechanism of immune-complex mediated (type III) hypersensitivity?
(all *)
Ag + Ab AgAb complex
(in circulation or in situ)
Activate complement
Attract neutrophils
Release lysosomal enzymes
*What are the types of type III hypersensitivity?
1) Systemic or
2) Local
*What are the diff phases of type III hypersensitivity?
1) Phase I
2) Phase II
3) Phase III
What is the action that happen in phase I?
Formation of Ag-Ab complexes in the circulation
What is the action that happen in phase II?
Deposition of the immune complexes in various tissues
What is the action that happen in phase III?
1) Inflammatory rxn at the sites of immune complex deposition
2) Clinical features appear
*What are the characteristics of type III hypersensitivity?
1) Presence of acute necrotizing vasculitis
2) Fibrinoid necrosis
*What are the diff diseases that causes type III hypersensitivity?
1) SLE
2) Polyarteritis nodosa
3) Post streptococcal glomerulonephritis
4) Acute glomerulonephritis
5) Arthus reaction
6) Serum sickness
Answer the ff questions w/ regards to the given disease:
1) What is/are the Ags involved?
2) What is/are the clinical manifestations of the given disease?
Given disease: SLE
1) DNA, nucleoproteins, others
2) Nephritis, arthritis, and vasculitis
Answer the ff questions w/ regards to the given disease:
1) What is/are the Ags involved?
2) What is/are the clinical manifestations of the given disease?
Given disease: Polyarteritis nodosa
1) Hep B surface Ags
2) Vasculitis
Answer the ff questions w/ regards to the given disease:
1) What is/are the Ags involved?
2) What is/are the clinical manifestations of the given disease?
Given disease: Post streptococcal glomerulonephritis
1) Streptococcal cell wall Ag(s) may be planted in GBM
2) Nephritis
Answer the ff questions w/ regards to the given disease:
1) What is/are the Ags involved?
2) What is/are the clinical manifestations of the given disease?
Given disease: Acute glomerulonephritis
1) Bacterial, parasite, and tumor Ags
2) Nephritis
Answer the ff questions w/ regards to the given disease:
1) What is/are the Ags involved?
2) What is/are the clinical manifestations of the given disease?
Given disease: Arthus reaction
1) Various foreign proteins
2) Cutaneous vasculitis
Answer the ff questions w/ regards to the given disease:
1) What is/are the Ags involved?
2) What is/are the clinical manifestations of the given disease?
Given disease: Serum sickness
1) Various proteins (e.g. *forein serum)
2) Arthritis, vasculitis, and nephritis
What is the other term for T-cell mediated hypersensitivity?
Type IV hypersensitivity
T-cell mediated (type IV) hypersensitivity is initiated by what?
By Ag-activated (sensitized) lymphocytes
*What are the 2 types of type IV hypersensitivity?
1) Delayed type hypersensitivity
2) T-cell mediated cytotoxicity
*What cells are involved in delayed type hypersensitivity?
CD4+ T cells
*Principal pattern?
What are the cytokines released if delayed type hypersensitivity is present?
1) IFN gamma(sign)
2) IL-2
3) TNF and lymphotoxin
What is the function of IFN gamma(sign)?
For the activation of macrophages
What is the function of IL-2?
For the proliferation of T cells
What are the functions of TNF and lymphotoxin?
1) For the extravasation of lymphocytes and monocytes
2) For granuloma formation
*What cells are present if T-cell mediated cytotoxicity is present?
CD8+ T cells
What may contribute to graft rejection?
Response to:
1) Viral infections
2) Tumor cells
What are the 2 pathways that mediates T-cell mediated cytotoxicity?
1) Perforin-granzyme-dependent killing
2) Fas-fas ligand- dependent killing
- Answer the ff questions w/ regards to the given type of hypersensitivity:
1) What are the prototype disorders present?
2) What is/are the immune mechanism/s by the given hypersensitivity?
Given hypersensitivity: Immediate hypersensitivity
1) Anaphylaxis; allergies and bronchial asthma (atopic forms)
2) Production of IgE Abs; immediate release of vasoactive amines and other mediators from mast cells
- Answer the ff questions w/ regards to the given type of hypersensitivity:
1) What are the prototype disorders present?
2) What is/are the immune mechanism/s by the given hypersensitivity?
Given hypersensitivity: Ab-mediated hypersensitivity
1) AIHA (IIa), Goodpasture syndrome (IIb), graves, and myasthenia gravis (IIc)
2) Production of IgG, IgM; binds to Ag on target cells or tissue; phagocytosis or lysis of target cell by C8, C9 (IIa), or inflammation (IIb) or cellular dysfunction (IIc)
- Answer the ff questions w/ regards to the given type of hypersensitivity:
1) What are the prototype disorders present?
2) What is/are the immune mechanism/s by the given hypersensitivity?
Given hypersensitivity: Immune complex-mediated hypersensitivity
1) SLE, some forms of GN, serum sickness, and Arthus rxn
2) Deposition of Ag-Ab complexes; complement activation; recruitment of leukocytes; release of lysosomal enzymes and toxic moieties
- Answer the ff questions w/ regards to the given type of hypersensitivity:
1) What are the prototype disorders present?
2) What is/are the immune mechanism/s by the given hypersensitivity?
Given hypersensitivity: Cell-mediated hypersensitivity
1) TB (IVa), response to viral infections (IVb), and transplant rejection
2) Activated T lymphocytes; i) release of cytokines and macrophage activation; ii) T cell-mediated cytotoxicity
Autoimmune diseases result from what?
These results from tissue injury caused by T cells or Abs that react against self-Ags
What are the general features of autoimmune diseases?
1) Female predilection
2) Characterized by remissions and exacerbations
3) Increased incidence of malignancy
4) Familial prevalence of the same or other A.I.D.
5) Clinical and serologic overlaps
6) Pts often have increased Ig in the serum