immunosuppresive antibodies
DESCRIPTION
Immunosuppresive antibodies by Dr Nikhil BansalTRANSCRIPT
Immunosuppresive Antibodies
Dr Nikhil BansalDr Nikhil Bansal
J.N.M.C.,WardhaJ.N.M.C.,Wardha
Types
Antilymphocyte & Antithymocyte antibodies
Muromonab - CD3 Immune Globulin Intravenous (IGIV) Anti-D Immunoglobulin Hyperimmune Immunoglobulins
Antilymphocyte (ALG) & Antithymocyte (ATG)
Antibodies
Polyclonal antibodies
Obtained by immunization of large animals (horses or sheep) with human lymphoid cells.
ATG binds to T-lymphocytes & depletes them.
ALG acts primarily on small long lived peripheral lymphocytes.
Destruction or inactivation of T-cells
Impairment of delayed HSR & cellular
immunity
*While humoral Ab formation remains relatively intact.
Uses
As a potent immunosuppressant To suppress acute allograft rejection
episodes. Management of solid organ or bone
marrow transplantation. In induction regimens.
Adverse effects
Local pain & erythema at the site
of inj(type3 HS)
Anaphylactic reaction
Serum sickness reactions to ALG
Muromonab-CD3
A murine monoclonal antibody against CD3 glycoprotein
Binding of Muromonab-CD3 to CD-3 Ag
Obstruction of binding of MHC 2 Ag complex to the T-cell receptor
Ag recognition is interfered
Precipitation of T-cell in immune response is prevented
T-cell rapidly disappear from circulation
IMMUNE BLOCK STAGE
Uses
As induction therapy together with corticosteroids & azathioprine with delayed use of cyclosporine in ‘sequential regimen’ for organ transplant
Also valuable for steroid resistance rejection reactions & has been use to deplete T-cells from donor bone marrow before transplant
Adverse effect
It initially may produce ‘cytokine release’ syndrome with flu like symptoms: chills, rigor, wheezing, occasionally aseptic meningitis.
* High dose of corticosteroid pretreatment reduce the reaction.
Immune Globulin Intravenous (IGIV) A quit different approach to
immunomodulation is the i.v. use of polyclonal human immunoglobulin.
This Ig (usually IgG) is prepared from pools of thousands of healthy donors & no specific Ab is targeted.
Its precise mech. of action is still controversial.
Possible Mechanism Of Action of IGIV
It includes reduction of Helper T-cells Increase of suppressor T-cells Decrease of spontaneous Ig
production Fc receptor blockade Increase Ab catabolism & Idiotypic-anti-idiotypic interactions
with “pathologic antibodies”
Uses
It is effective in: Ig deficiency Autoimmune disorder HIV Bone marrow transplants SLE & Idiopathic, thrombocytopenic
purpura.
Anti-D Immunoglobulin
Human IgG having high titre of Ab against Rh (D) antigen.
Binds to Rh Ag & does not allow them to induce antibody formation in Rh –ve individuals.
Used for prevention of post partum formation Ab in Rh-D negative.
Hyper immune Immunoglobulin
IGIV preparations made from pools of selected human or animal donors with high titre of antibody against particular agents of interest (viruses and toxins)
Intravenous administration of hyper immune globulins is passive transfer of high titre antibody that either reduces risk or severity of infection.
Uses
Various hyper immune IGIV are available for treatment of Respiratory Syncytial Virus, Cytomegalo Virus, Vericella Zoster, Hepatitis B, tetanus, rabies and digoxin overdose.
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