Immune Responses and Transplantation

These flashcards cover key concepts related to the immune response, immunology, and transplantation, designed to aid in exam preparation.

What is the primary function of the immune response in the body?

To defend against foreign substances and pathogens.

What are the three main functions of the immune system?

Defense, Homeostasis, and Surveillance.

What type of immunity is present at birth and offers first-line defense?

Innate immunity.

What is the role of active acquired immunity?

To develop antibodies and sensitized lymphocytes after exposure to foreign substances.

How does passive acquired immunity differ from active immunity?

In passive immunity, the host receives antibodies, while in active immunity, the host produces antibodies.

What is an antigen?

A substance that elicits an immune response, often proteins or polysaccharides.

What is the difference between B lymphocytes and T lymphocytes?

B lymphocytes produce antibodies, while T lymphocytes are involved in directly attacking infected cells or coordinating immune responses.

What are cytokines?

Soluble factors secreted by immune cells that act as messengers to regulate immune responses.

What are the five types of immunoglobulins?

IgG, IgA, IgM, IgD, and IgE.

What does humoral immunity primarily involve?

The production of antibodies by plasma cells (B cells).

Which immunoglobulin is responsible for the primary immune response?

IgM.

What is the role of T-helper cells in the immune response?

To help regulate both cell-mediated and humoral immunity.

What does anaphylaxis involve?

A severe, systemic allergic reaction requiring immediate medical attention.

What triggers hypersensitivity reactions?

An overactive immune response to antigens.

What is the main characteristic of autoimmune diseases?

The immune system attacks the body's own tissues.

What does the term 'anergy' refer to?

A lack or diminished immune response.

What can cause secondary immunodeficiency disorders?

Illness or medical treatment, such as chemotherapy.

How does the human leukocyte antigen (HLA) system relate to transplantation?

It is used to match organs and tissues for transplantation based on immune compatibility.

What is graft-versus-host disease (GVHD)?

A condition where donor immune cells attack the recipient's tissues.

What does the immune response to viruses usually involve?

Cell-mediated immunity, primarily through T lymphocytes.

What happens during an acute rejection episode of a transplanted organ?

Recipient's immune response targets the transplanted tissue as foreign.

What is the purpose of immunosuppressive therapy?

To prevent organ rejection in transplant patients.

Why might older adults have a decreased immune response?

Due to the shrinking of the thymus gland and lower T-cell production.

What is the primary risk associated with immunosuppressive therapy?

Increased susceptibility to infections.

What are the common causes of anaphylactic shock?

Reactions to drugs, foods, or insect stings.

Why are some people more prone to allergic diseases?

Due to a genetic predisposition to become sensitive to allergens.

What is the significance of memory B and T cells?

They enable a quicker and more robust immune response upon subsequent exposures to the same antigen.

How do peripheral lymphoid organs contribute to the immune response?

They filter foreign material and circulate lymphocytes for immune activation.

What is the relationship between cytokines and immune response regulation?

Cytokines provide communication between immune cells to enhance or inhibit activities.

What is the main goal of immunotherapy in allergic conditions?

To desensitize patients to specific allergens.

What does the term 'immunocompetence' mean?

The ability of the immune system to identify and destroy foreign invaders effectively.

What is the role of macrophages in the immune response?

They capture and present antigens to lymphocytes.

What type of hypersensitivity reaction is mediated by IgE antibodies?

Type I hypersensitivity.

What laboratory test may indicate a type I hypersensitivity reaction?

High serum IgE levels.

What does 'crossmatch' refer to in transplantation?

A test to determine if a recipient has pre-existing antibodies against a potential donor's tissue.

What factors are considered in organ allocation for transplant recipients?

ABO blood type, HLA matching, medical urgency, and waiting time.

What is the result of hyperacute rejection?

Immediate rejection of the transplanted organ due to recipient pre-existing antibodies.

What can be a long-term effect of chronic rejection of a transplanted organ?

Irreversible tissue damage and organ failure.

What are immunotherapy options for allergic reactions?

Subcutaneous immunotherapy (allergy shots) and sublingual immunotherapy.

What is the importance of HLA typing prior to transplantation?

To ensure compatibility and decrease the risk of rejection.

What effect does aging have on the production of antibodies?

It generally decreases, leading to a suppressed humoral immune response.

What characterizes type II hypersensitivity reactions?

The binding of IgG or IgM antibodies to antigens on cell surfaces.

What clinical action is most effective during anaphylactic shock?

Prompt administration of epinephrine.

What is the importance of continuous monitoring in patients receiving immunosuppressive therapy?

To detect complications such as infections or organ rejection early.

How do cytokines differ from hormones?

Cytokines are produced by immune cells and act locally in the immune response, while hormones are systemic and produced by various glands.

What is plasmapheresis and its use in autoimmunity?

A process that removes harmful antibodies from the blood in certain autoimmune conditions.

What role do antibodies play in the humoral immune response?

They bind to specific antigens to neutralize pathogens or mark them for destruction.

What is the significance of the T-cell receptor on T lymphocytes?

It is responsible for recognizing and binding to specific antigens presented by other cells.