Autoimmune Diseases Overview Quiz

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Questions and Answers

What characterizes autoimmune diseases?

They only affect males.

They involve an immune response against self-antigens. (correct)

They only affect specific organs.

They have a single underlying cause.

Which type of autoimmune disease is primarily mediated by antibodies?

Type I autoimmune disease

Type II autoimmune disease (correct)

Type IV autoimmune disease

Type III autoimmune disease

What is the primary mechanism thought to lead to the development of autoimmune diseases?

Failure of self-tolerance mechanisms (correct)

Excessive physical exercise

Environmental exposure to pathogens

Increased production of immune cells

Which autoimmune condition is characterized by excessive secretion of thyroid hormone?

Graves' disease Signup and view all the answers

Which gender is more commonly affected by autoimmune diseases?

Females Signup and view all the answers

Autoimmune reactions can resemble which types of hypersensitivity reactions?

Types II, III, and IV Signup and view all the answers

What role do effector T cells and B cells play in autoimmunity?

They are involved in developing the immune response against self-antigens. Signup and view all the answers

What is a significant challenge in understanding the causes of autoimmune diseases?

Mechanisms breaking self-tolerance are largely unknown. Signup and view all the answers

What role does thyroid-stimulating hormone (TSH) play in hormone regulation?

It binds to TSH receptors to stimulate thyroid hormone release. Signup and view all the answers

What characterizes Graves' disease in relation to TSH?

Autoantibodies mimic TSH and stimulate thyroid hormone production. Signup and view all the answers

Which autoimmune disease is characterized by a reaction following a throat infection with Streptococcus pyogenes?

Rheumatic fever Signup and view all the answers

What type of autoimmune disease is rheumatic fever classified as?

Type II autoimmune disease Signup and view all the answers

What type of autoimmune disease is Type I diabetes Mellitus associated with?

Type IV autoimmune disease Signup and view all the answers

How do antibodies contribute to the inflammation seen in rheumatic fever?

They cross-react with the body's tissues, leading to inflammation. Signup and view all the answers

Which type of cells mediate the destruction of insulin-producing cells in the pancreas in Type I diabetes?

Autoreactive CD8 T cells Signup and view all the answers

Which blood group can serve as a universal donor?

Group O Signup and view all the answers

What is a common physiological consequence of the lymphocytes infiltrating islets in Type I diabetes?

Decreased β-cell count Signup and view all the answers

In systemic lupus erythematosus (SLE), what do people produce autoantibodies against?

Soluble cellular components Signup and view all the answers

What is one of the main challenges in organ or tissue transplantation?

Preventing recipient's immune response to the transplant Signup and view all the answers

What is the main limitation when transfusing RhD positive blood to an RhD negative recipient?

It can cause the formation of anti-RhD antibodies. Signup and view all the answers

What complication can result from immune complexes in systemic lupus erythematosus (SLE)?

Kidney glomerulonephritis Signup and view all the answers

Which blood group can receive blood from any donor?

Group AB Signup and view all the answers

What is a common skin manifestation of systemic lupus erythematosus (SLE)?

Butterfly rash Signup and view all the answers

Which of the following is typically not a requirement for blood transfusions?

Inherited blood conditions Signup and view all the answers

During the ABO and RhD group testing, which result indicates a negative reaction for RhD?

Negative for Anti-RhD Signup and view all the answers

Which group does not have A or B antigens on its red blood cells?

Type O Signup and view all the answers

What component is responsible for the determination of blood group types?

ABO antigens Signup and view all the answers

What is the purpose of administering hematopoietic stem cells in a bone marrow transplant?

To reconstitute a healthy hematopoietic system. Signup and view all the answers

Which of the following diseases can hematopoietic cell transplantation treat?

Leukemia Signup and view all the answers

Which of the following is NOT a component commonly transfused?

White Blood Cells Signup and view all the answers

What must be ensured when matching donors and recipients for bone marrow transplants?

HLA matching. Signup and view all the answers

What might happen after an RhD- individual receives RhD+ blood?

Production of anti-RhD antibodies occurs. Signup and view all the answers

What is a key characteristic of chronic rejection in transplanted organs?

It primarily attacks the graft's vasculature. Signup and view all the answers

What triggers chronic rejection in a transplant?

IgG antibodies against the graft's HLA. Signup and view all the answers

Why are immunosuppressive drugs given to transplant patients?

To non-specifically suppress the immune system before and after transplantation. Signup and view all the answers

What happens to blood supply during chronic rejection?

It gradually decreases leading to ischemia. Signup and view all the answers

Which type of T cells do immunosuppressive drugs inhibit after transplantation?

Naive alloreactive T cells. Signup and view all the answers

What is an autograft?

Tissue transplanted from one site to another in the same person Signup and view all the answers

What type of reaction occurs when the recipient's T cells attack the transplanted organ?

Transplant rejection Signup and view all the answers

What is required for a successful organ transplant in relation to HLA?

The donor and recipient must have similar tissue types Signup and view all the answers

What distinguishes an allograft from an autograft?

Transplanted tissue is from genetically different individuals Signup and view all the answers

Which type of rejection occurs rapidly due to pre-existing antibodies?

Hyperacute rejection Signup and view all the answers

What is graft-versus-host disease?

Donor's T cells attacking the recipient's tissues Signup and view all the answers

What triggers the activation of the recipient’s T cells in acute rejection?

Presence of donor DCs with donor HLA molecules Signup and view all the answers

Why is it important to ensure compatible ABO/RhD groups in organ transplants?

To avoid hyperacute rejection Signup and view all the answers

Study Notes

Autoimmunity and Transplantation

Autoimmunity involves the immune system mistakenly attacking healthy cells and tissues.
There are over 80 different clinically described autoimmune diseases.
Autoimmune diseases can affect specific organs or be systemic.
Females are more prone to autoimmune diseases than males.
Autoimmune diseases involve dysregulation of self-tolerance, the mechanisms are still unknown.

How Autoimmunity Happens

Autoimmunity occurs when the immune system identifies self-antigens (self-Ag) as a threat.
Effector T cells and B cells play a role in autoimmunity.
Autoimmune reactions resemble hypersensitivity reactions (type II, III, and IV).
Autoimmunity is triggered by a collective failure of self-tolerance.
The mechanisms responsible for breaking self-tolerance leading to autoimmune diseases are still not fully understood.

Mechanisms of Immunological Self-Tolerance

Negative selection of B cells in the bone marrow.
Negative selection of T cells in the thymus.
Lymphatic exclusion from brain, eye, and testes.
Expression of tissue-specific proteins in the thymus.
Induction of anergy in autoreactive B and T cells.
Treg cell suppression of autoimmune responses.

Type II Autoimmune Diseases

These diseases resemble type II hypersensitivity reactions.
Antibodies attack components of cell surfaces or extracellular matrices.
Examples include hemolytic anemia, thrombocytopenia, pemphigus, rheumatic fever, Graves' disease, myasthenia gravis, and type 2 diabetes.

Graves' Disease

Graves' disease is an autoimmune disorder caused by excessive thyroid hormone secretion.
It involves antibodies mimicking TSH (thyroid stimulating hormone), stimulating thyroid cells to produce excessive thyroid hormones.
Symptoms include bulging eyes, goiter, sweating, palpitations, skin lesions, weight loss, and agitation.

Rheumatoid Fever

Rheumatoid fever is an autoimmune disease caused by an immune response to infection, usually a Streptococcus pyogenes throat infection.
The symptoms often develop 2-3 weeks after the infection.
The disease specifically attacks heart tissues.

Type III Autoimmune Diseases

These diseases involve the deposition of immune complexes in blood vessels.
Examples include bacterial endocarditis, bacterial antigen-mediated glomerulonephritis, and systemic lupus erythematosus (SLE).

Systemic Lupus Erythematosus (SLE)

SLE is an autoimmune disease where antibodies attack a broad range of soluble cellular components (“autoantigens”).
Symptoms include fatigue, headaches, ulcers, butterfly rash, joint pain, hair loss, pleurisy (inflammation of lining of lungs), photosensitivity, and possible Raynaud’s disease, weight loss, or weight gain.
Immune complexes deposit in various tissues leading to inflammatory reactions.
Kidney glomerulonephritis, arthritis, and purpura (small blood vessels) can be symptoms.

Type IV Autoimmune Diseases

These diseases are caused by autoreactive effector T cells.
Examples include type 1 diabetes, rheumatoid arthritis, and multiple sclerosis.

Type 1 Diabetes Mellitus

Type I diabetes is an autoimmune disease that damages insulin-producing beta cells within islets of Langerhans in the pancreas.
Autoreactive CD8 T cells destroy beta cells.
The disease leads to reduced insulin production resulting in difficulties in blood glucose regulation and requiring insulin injections to manage blood sugar.

Transplantation

Transplantation can be a vital treatment option.
Transplantation involves introducing transplanted tissue to maintain normal physiological function and recipient health.
Recipient immune response needs to be managed to prevent rejection.
Common types of transplants include blood, tissue, and organs.

Blood Transfusion Considerations

ABO blood group system is critical in blood transfusions.
Antigens A and B are similar to carbohydrates that exist on the surface of commensal bacteria.
Group O individuals are universal donors, while AB individuals are universal recipients.
Rh factor (D antigen) is another key element, as individuals with Rh-negative blood can't receive Rh-positive blood without risk.
Blood typing is essential to identify compatible blood for transfusion.

Transplantation Terminology

Autograft: transplantation within the same person.
Isograft: transplantation between genetically identical individuals.
Allograft: transplantation between genetically different individuals.
Alloantigen: antigens that differ between donor and recipient.
Alloantibody: antibodies made against alloantigens.
Histocompatibility: similar tissue types between donor and recipient.

Rejection

Rejection of transplanted organs occurs due to allogenic immune responses against foreign antigens.
Hyperacute rejection: rapid response due to pre-existing antibodies towards donor antigens.
Acute rejection: T cells attack the transplant shortly after transplantation.
Chronic rejection: longer-term, gradual immune response that damages the organ over time.
Immunosuppressant drugs are crucial for reducing or eliminating rejection processes.

Immunosuppressive Drugs

Immunosuppressants inhibit T-cell activation, reducing the chances of rejection.
Patients receive immunosuppressants prior to and after transplantation.

Other key terms/concepts

BM transplant (bone marrow transplant)
HLA (human leukocyte antigen) matching for transplants

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Description

Test your knowledge on the characteristics and mechanisms of autoimmune diseases. This quiz covers various types of autoimmune conditions, their effects, and the roles of different immune cells. Understand the complexities behind autoimmune disease development and their impact on health.