(4.5) TRANSPLANTATION & IMMUNE PHARMACOTHERAPY

Tissue grafts transplanted from one part of an individual to another on the same individual.

Tissue grafts between genetically identical or nearly identical individuals (e.g., twins).

Tissue grafts between two genetically different individuals of the same species (e.g., siblings).

Describes two individuals with the same or near-identical HLA (human leukocyte antigen) types. They won't have a strong immune rejection reaction.

Blood groups determined by specific antigens (A, B, O) on red blood cells. Incompatible blood types can cause serious reactions.

A rapid rejection of a graft that happens within the first few weeks, often due to mismatched MHC genes, especially MHC class I.

A gradual rejection of a graft occurring over months or years. It involves fibrosis and scarring of the graft tissue, often a result of continued immune response.

The fastest rejection, happening within days of transplantation, often due to pre-existing antibodies, NK cells, or complement activation.

A skin graft that appears pale and lifeless due to lack of vascular connection. It's a sign of rejection.

A faster and more intense rejection of a graft that has been rejected before. Due to memory T and B cells primed by the initial exposure.

Difference in human leukocyte antigen (HLA) types between the donor and recipient, increasing the risk of rejection.

The more mismatched the HLA types between donor and recipient, the lower the survival rate of the kidney graft. The survival rate decreases significantly with an increasing number of HLA mismatches.

The graph demonstrates the correlation between HLA mismatch and kidney transplant survival. Transplants with no HLA mismatches have the highest survival rate compared to those with multiple mismatches.

HLA matching reduces the chance of rejection by ensuring the donor's tissue is recognized as 'self' by the recipient's immune system.

A graft previously rejected chronically can be rejected acutely if re-transplanted. This is because memory T and B cells from the initial rejection respond faster and more intensely the second time.

HIV rapidly mutates, creating different strains and developing resistance to antiretroviral drugs. This allows it to evade the body's immune response.

An undetectable viral load means HIV replication is suppressed to a level where it's not actively spreading in the body. This doesn't mean the virus is gone, but it significantly reduces infectivity.

Using multiple antiretroviral drugs targets different stages of the virus's life cycle, making it harder for HIV to develop resistance and ensuring a better chance of control.

Antiretroviral therapy reduces the levels of HIV in the blood, making it undetectable and preventing the virus from replicating actively. It does not eradicate the virus, but it effectively controls the infection.

Long-term antiretroviral therapy can lead to drug resistance as HIV mutates. This necessitates adjustments in the therapy regimen to maintain effectiveness.

A period in HIV infection where the virus is still present but the immune system is producing enough CD4 T-cells to prevent symptoms.

A measure of the number of CD4 T-cells in a person's blood, which are essential for immune function. A low count indicates a weakened immune system, making it harder to fight off infections.

Medicines that suppress the HIV virus, preventing it from replicating and damaging the immune system. They help control the infection and prolong life.

They interfere with the HIV virus's ability to replicate, preventing new copies from being made and allowing the immune system to recover.

It refers to a situation where the HIV virus is still present in the body, but is not being actively replicated. This is often a result of successful antiretroviral therapy.

Because even though the virus is still present, the drugs help to keep its levels stable and low enough that the immune system can handle it. It's a balanced state.

It's crucial for fighting off the virus, producing CD4 T-cells to combat infection. However, HIV weakens the immune system, making it harder to fight off other infections.

To slow down the virus's ability to develop resistance to medications. By using a combination of drugs, it becomes harder for the virus to 'adapt' and survive.

It means maintaining a low level of the virus in the blood through medication and a strong immune response, preventing the virus from causing severe damage.

To suppress the virus, prevent its replication, and preserve the immune system's strength to ensure a long and healthy life for individuals living with HIV.

Matching the Human Leukocyte Antigen (HLA) types between a donor and recipient to minimize the risk of tissue rejection. HLA proteins are crucial for immune recognition, and a mismatch can trigger a strong immune response.

The process where only T cells that recognize self HLA and can communicate with antigen-presenting cells are allowed to survive and mature in the thymus. This ensures that the immune system attacks foreign invaders.

HLA matching is critical because it reduces the chance of the recipient's immune system rejecting the donated tissue. When HLA types are mismatched, the recipient's immune system may identify the transplanted tissue as foreign, leading to rejection.

T cells communicate using HLA proteins on their surface. They recognize antigens presented by antigen-presenting cells (APCs) through their HLA receptors. If the HLA doesn't match, the T cells can't properly recognize and respond to the antigen.

T cells won't recognize the donor HLA and won't interact with the host antigen-presenting cells. This can lead to transplant rejection or a weakened immune response against true foreign invaders.

HLA matching helps prevent rejection by ensuring the donor's tissue is recognized as 'self' by the recipient's immune system.

A mismatch in HLA types between donor and recipient increases the risk of rejection. The immune system will see the transplant as foreign and attack it.

The more HLA mismatches there are, the lower the chance of a successful transplant. More mismatches = stronger immune response = higher risk of rejection.

Positive selection ensures T cells recognize 'self'. Negative selection removes T cells that attack 'self', preventing autoimmune reactions.

Knowing self allows our immune system to not attack our own cells, even after a transplant. It also enables communication between immune cells, preventing foreign threats from going unnoticed.

A skin graft that appears pale and lifeless due to lack of blood supply, indicating rejection.

A faster and more intense rejection of a graft that has been rejected before. Memory T and B cells from the initial rejection respond faster the second time.

HIV quickly mutates, constantly changing its appearance. This makes it harder for the immune system to target and destroy it.

ARTs suppress HIV replication, preventing its destructive effects on immune system. It doesn't cure, but it effectively controls the infection.