Type I Hypersensitivity: IgE-mediated reactions

Immediate hypersensitivity

Type II Hypersensitivity: :Antibody-mediated Cytotoxicity

  • Results when IgG or IgM bing do cell surface Ag
    – Activating Complement
    – Binding Fc receptors on Tc cells promoting Antibody-Dependent Cell-mediated Cytotoxicity (ADCC)
  • Both processes result in lysis of the Ab-coated cell
  • Clinical examples of Type II responses include:
     – Certain autoimmune diseases

   Grave’s Disease
Myasthenia Gravis
Autoimmune hemolytic anemia

– Hemolytic Disease of the Newborn
– Hyperacute graft rejection

Blood Transfusion reactions
Graft rejection

Type III Hypersensitivity:Immune Complex-mediated cytotoxicity

  • Directed against soluble antigens caused by the deposition of
    antigen/antibody complexes in tissue and blood vessels.
  • The complexes activate complement and attract ploymorphs and
    macrophages to the site.
  • These cells may exocytose their granule contents and release reactive
    oxygen and nitrogen intermediates to cause local tissue damage.


Type IV Hypersensitivity:Delayed-type hypersensitivity

T-cell mediated

카테고리: Medical science

0개의 댓글

답글 남기기

Avatar placeholder

이메일 주소는 공개되지 않습니다. 필수 필드는 *로 표시됩니다