When a mother and her unborn baby carry different Rh protein factors. It is specifically caused when a mother is Rh-negative and her baby is Rh-positive. If a woman is Rh-negative and her baby is Rh-positive, then her body will determine the Rh-positive protein to be foreign. if blood cells from the baby cross into the mother’s bloodstream, the mothers immune system will make antibodies against the baby’s red blood cells. Once an Rh-negative mother’s body has made these antibodies her body will send these antibodies across the placenta to attack the baby’s red blood cells
Type III - Immune Complex
How does it develop: Ag-Ab complexes deposited in organs. Cause inflammatory damage
Examples: Glomerulonephritis, inflammatory damage to kidney glomeruli (site of blood filtration). Serum sickness. Lupus.
Type III – Immune Complex
Symptoms: Chronic inflammation.
Treatments: Steroids, prednisolone.
Type IV - Cell Mediated, Delayed Hypersensitivity
How does it develop: caused by T cells
Examples: transplant rejection mediated by CTLs. TB test
Type IV – Cell Mediated, Delayed Hypersensitivity
•Symptoms: hypersensitivity of skin
•Treatments: immunosuppressive agents,
Type IV hypersensitivity
HLA = human leukocyte antigen
It’s a histocompatibility antigen the major histocompatibility antigen = MHC
human version of MHC
proteins classified as antigen
body recognizes self or nonself
HLA Reactions 2
•T cells recognize Ag + MHC
–1-10% of T cells will recognize a foreign MHC molecule
•Important for transplant rejection
Tissue moved to different location within same individual
Transplant between two identical individuals.
Transplant from one person to another. Account for many human transplants: from cadavers, living related & unrelated donors.
Surgical graft of tissue from one species to an unlike species.
ie. Graft from baboon to human.
Immune response that regards graft as foreign.
How is graft rejection prevented?
Cyclosporin, Tacrolimus – block T cell activation
Sirolimus, mycophenolate mofetil – block proliferation of T & B cells
Basiliximab & daclizumab – Abs that block IL-2
•Affects 5% of the developed world
•Disproportionately affects women
•Loss of self tolerance
•Patients can have auto reactive T cells
Autoimmune reactions can be mediated by
–Cell mediated hypersensitivities
Type II (Cytotoxic) Hypersensitivity
–Ab attach to thyroid stimulating to overproduced thyroid hormones. results in enlarged thyroid (goiter), bulging eyes.
Ab coat acetylcholine receptors at nerve impulse/muscle junction. results in muscle weakness, respiratory arrest, death
Type III (Immune Complex-Mediated) Hypersensitivity
Systemic lupus erythematosus
–How does it develop: Present at time of birth. Result of genetic defect.