Immunopathology is the study of diseases caused by dysfunctions in the immune system, focusing on how immune responses contribute to the development and progression of diseases. It integrates concepts from immunology and pathology to understand how immune mechanisms can cause tissue damage, inflammation, and organ dysfunction.
Key Aspects of Immunopathology:
Autoimmune Diseases:
In autoimmune diseases, the immune system mistakenly attacks the body’s own tissues.
Examples include:
Rheumatoid arthritis (attacking joints)
Systemic lupus erythematosus (SLE) (affecting multiple organs)
Type 1 diabetes (destruction of pancreatic cells)
Hypersensitivity Reactions:
These occur when the immune system overreacts to normally harmless substances or responds excessively to pathogens, leading to tissue damage. Types of hypersensitivity include:
Type I (Immediate): Allergic reactions (e.g., hay fever, asthma, anaphylaxis)
Type II (Antibody-mediated): Autoimmune hemolytic anemia, Goodpasture’s syndrome
Type III (Immune complex-mediated): Serum sickness, lupus nephritis
Type IV (Delayed-type): Tuberculosis, contact dermatitis
Immunodeficiency Disorders:
These are conditions where the immune system is either partially or completely non-functional, making the body more susceptible to infections.
Examples include:
Primary immunodeficiencies: Genetic conditions like Severe Combined Immunodeficiency (SCID)
Acquired immunodeficiencies: Conditions like HIV/AIDS, where the immune system becomes compromised over time.
Transplant Immunopathology: This area focuses on immune responses to transplanted organs or tissues, which can lead to graft rejection.
Pathologists study the mechanisms behind acute, chronic, and hyperacute rejection to improve transplantation success.
Tumor Immunology:
The immune system can sometimes fail to recognize or destroy cancer cells. Immunopathologists investigate how immune cells interact with cancer, aiding in the development of immunotherapy treatments, like checkpoint inhibitors or CAR-T cell therapy.
Infectious Diseases:
Immunopathology also explores how the immune system fights infections (e.g., bacterial, viral, fungal) and how immune responses can contribute to the pathology of infections (such as inflammation caused by overactive responses).
Diagnostic Role of Immunopathologists:
Immunopathologists play a key role in diagnosing immune-related diseases through techniques like:
Immunohistochemistry (IHC): Identifying specific immune markers in tissue samples.
Serology: Detecting antibodies and antigens in blood for diseases like lupus or HIV.
Flow cytometry: Analyzing immune cells in blood to diagnose immunodeficiencies and leukemias.
