Back to Immunology ToC
Autoimmunity
Autoimmunity refers to a condition where the immune system mistakenly recognizes and attacks the body’s own tissues and cells as if they were foreign invaders. Normally, the immune system is designed to distinguish between self and non-self, targeting and eliminating pathogens while sparing the body’s own cells. However, in autoimmune disorders, this self-tolerance breaks down, leading to immune responses against healthy tissues. Examples of autoimmune diseases include rheumatoid arthritis, systemic lupus erythematosus (SLE), type 1 diabetes, and multiple sclerosis.
Key Features of Autoimmunity
Loss of Self-Tolerance: Autoimmune disorders are characterized by a failure of the immune system to recognize and tolerate the body’s own antigens, leading to the attack on self-tissues.
Inflammatory Responses: Autoimmune reactions often result in chronic inflammation, tissue damage, and, in some cases, the formation of autoantibodies targeting specific self-antigens.
Multifactorial Etiology: Autoimmune disorders arise from a combination of genetic predisposition, environmental factors, and dysregulation of immune checkpoints and signaling pathways.
Immunodeficiencies
Immunodeficiencies, on the other hand, are conditions characterized by a weakened or compromised immune system, leading to an increased susceptibility to infections. Immunodeficiencies can be congenital (present from birth) or acquired later in life. Congenital immunodeficiencies are typically genetic, resulting from mutations in genes responsible for immune system function. Acquired immunodeficiencies can be caused by factors such as infections (e.g., HIV), certain medications, or medical treatments like chemotherapy.
Key Features of Immunodeficiencies
Impaired Immune Responses: Immunodeficiencies result in a decreased ability of the immune system to mount effective responses against infections, making individuals more prone to recurrent or severe infections.
Heterogeneous Causes: Immunodeficiencies have diverse causes, including genetic mutations affecting immune cell development or function, infections, and iatrogenic factors like immunosuppressive therapies.
Variable Severity: The severity of immunodeficiencies can vary widely, ranging from mild susceptibility to severe and life-threatening conditions.
Next Topic: The “Big 3 Challenges” Every Immune System Needs to Get Right
Source: ChatGPT response prompted and edited by Joel Graff.
- Immunology (Table of Contents for Entire Course – FREE!)
Life and Biology 