Hypersensitivity

Type l hypersensitivity

(Immediate hypersensitivity)

1. Atopic dermatitis 

2. Asthma

3. Anaphylaxis (may be cause by bee sting,

drugs, food)

4. Allergic rhinitis 

Type ll hypersensitivity

(Antibody mediated hypersensitivity)

Ab of recipient attack the donor RBC, leading to

their destruction (hemolysis)-

1. Blood transfusion reaction

Ab cross the placenta and attack the fetal RBC,

leading to hemolysis- 

1. Rh incompatibility (Erythroblastosis fetalis)

Ab produce against the drug- 

1. Drug induced hemolytic anemia (eg. Quinine

therapy, penicillin therapy)

Ab produce to individuals own membrane antigen

of RBC or Granulocytes or Platelet- 

1. RBC : Autoimmune hemolytic anemia

2. Granulocyte : Agranulocytosis

3. Platelet : Thrombocytopenia

Ab produce against type lV collagen- 

1. Goodpasture syndrome 

Ab against desmosaomal protein that lead to disruption

of epidermal intra cellular junction- 

1. Pemphigus vulgaris 

Ab direct against intrinsic factor

1. Pernicious anemia 

Antibody against streptococcal Ag cross react with heart-

1. Rheumatic fever 

Type lll hypersensitivity 

(Immune complex mediated hypersensitivity)

Connective tissue disorders: Result due to autoantibodies

forming immune complexes with self-antigens

1. SLE (systemic lupus erythematosus): Anti-DNA Ab
2. Rheumatoid arthritis: Ab against human immunoglobulin

3. PAN (polyarteritis nodosa)

Parasitic diseases: Resulting from immune complex deposition

1. Nephrotic syndrome in plasmodium malariae

2. Katayama fever in schistosomiasis

3. African trypanosomiasis

Bacterial diseases: Resulting from immune complex deposition

1. Streptococcus pyogenes: Post-streptococcal glomerulonephritis (PSGN)

2. Mycobacterium leprae (Lepra reaction type 2)

Viral diseases: With immune complex deposition

1. Hepatitis B (arthritis)

2. Hepatitis C (arthritis)

3. Infectious mononucleosis (Epstein-Barr virus)

4. Dengue (arthritis)

Others:

1. Hyperacute graft rejection

2. Subacute bacterial endocarditis

3. Serum sickness

Type lV

(Cell mediated hypersensitivity)

• Lepra reattached type 1

• Contact dermatitis