Immunotherapy and Immunosuppressants

Overview of Immunotherapy and Immunosuppressants

  • Discusses the use of immunotherapy and immunosuppressive drugs in relation to organ transplants and autoimmune diseases.

Key Topics to Cover

  • Review session planned for the upcoming Monday to clarify key points and cover objectives.

  • Role of immunotherapy in organ transplants and treatment of autoimmune diseases.

  • Importance of immunity and related pathophysiology.

Immunization Focus

  • Overview of vaccines relevant to pediatric patients.

  • Protocols to be provided for pediatric patients receiving immunizations.

Immunity Basics

  • Definition of Immunity: Protection the body has to distinguish between self and non-self (foreign substances).

  • Antigens: Substances that provoke an immune response because they are recognized as foreign.

Types of Immunity

  1. Cell-Mediated Immunity
       - Involves T-lymphocytes (T-cells).
       - Produced in the thymus.

  2. Humoral Immunity
       - Involves B-lymphocytes (B-cells).
       - Produced in bone marrow.
       - Responsible for producing antibodies that target antigens.

Role of Immunosuppressants

Purpose of Immunosuppressants

  • Used primarily in organ transplant recipients to prevent organ rejection.

  • Inhibit the immune system’s ability to attack the transplanted organ.

  • Essential for treating autoimmune diseases, where the immune system attacks the body.

  • Common conditions treated include:
      - Rheumatoid Arthritis
      - Psoriasis
      - Inflammatory Bowel Diseases (IBD) e.g., Crohn's disease, Ulcerative Colitis

Major Classes of Immunosuppressants

  1. Corticosteroids
       - Used to suppress inflammation and immune response.

  2. Antimetabolites
       - Block T-cell activity and immune responses.

  3. Biologics
       - Target specific components of the immune system.

Immunosuppressive Drugs and Their Effect

  • Patients must stay on immunosuppressants long-term (often for life).

  • Risk for opportunistic infections due to compromised immune systems.

Risks and Adverse Effects

  • Increased risk for new malignancies (e.g., skin cancer).

  • Hepatotoxicity, kidney damage, and more.

  • Severe adverse reactions to vaccines in immunosuppressed individuals.

Medication Management in Organ Transplantation

Administration Guidelines

  • Immunosuppressants must be taken consistently at the same time daily.

  • Patients should avoid grapefruit juice which affects metabolism and increases toxicity.

  • Specific interaction with herbal supplements (e.g., St. John’s Wort).

Monitoring and Dosage

  • Narrow therapeutic range crucial to monitor via laboratory tests (e.g., peak and trough levels).

  • Adjustments made based on blood work results to maintain therapeutic levels.

  • Discuss missed doses: take as soon as remembered or call prescriber if close to the next dose.

Specific Drugs Discussed

1. Azathioprine

  • Mechanism: Suppresses T-cell activity.

  • Indications: Used for prophylactic treatment of organ rejection and for rheumatoid arthritis.

  • Side Effects: Risk for malignancies due to bone marrow suppression; requires close monitoring of blood counts.

2. Cyclosporine

  • Mechanism: Inhibits production of interleukins that stimulate T-cell response.

  • Usage: Organ rejection, autoimmune diseases.

  • Adverse Effects: Nephrotoxicity, hepatotoxicity; requires monitoring of kidney function and blood pressure.

  • Considerations: Administer with food, and specific handling guidelines for administration.

Understanding Immunization Mechanisms

Types of Immunization

Active Immunity

  • Natural Active Immunity: Body develops antibodies from exposure to pathogens (getting sick).

  • Artificial Active Immunity: Body forms antibodies from vaccination (administering a harmless form of the antigen).

Passive Immunity

  • Natural Passive Immunity: Transfer of antibodies from mother to infant (breastfeeding, placental transfer).

  • Artificial Passive Immunity: Direct injection of antibodies (e.g., immunoglobulins).

Vaccines and Antibodies

  • Vaccines stimulate humoral immunity; promote long-term antigen response by activating B-cells to form memory cells.

  • Types of Vaccines:
      - Live/attenuated: Contains weakened forms of pathogens.
      - Inactivated: Killed pathogens for immune response.

Booster Shots

  • Administered to increase immunity levels after initial vaccination, ensuring long-term protection.

Antibody Titer Testing: Used to measure antibody levels and determine immunity status.

Understanding Immunization Adverse Effects

Common Reactions

  • Mild pain, swelling at the injection site, low fever as typical side effects.

  • Serious adverse effects (e.g., anaphylaxis, serum sickness) are rare but need immediate reporting and management.

Vaccine Goals

  • Achieve herd immunity where a high percentage of immunized individuals protect those unable to receive vaccines due to health conditions or allergies.

  • Optimal immunization coverage (approximately 95%) is essential for effective herd immunity.

Summary of Immunotherapy

  • Key Concepts: Preventative (via vaccines) vs. therapeutic (immunoglobulins).

  • Immunosuppression requires careful management to mitigate risks while ensuring effectiveness of treatment.