What is a recognized theory of the origin of autoimmunity?

The production of antibodies that cross-react with tissue components is a recognized theory of the origin of autoimmunity. This concept, often referred to as molecular mimicry, implies that certain pathogens may share structural similarities with the body's own tissues. When the immune system produces antibodies to fight these pathogens, they may inadvertently also bind to and attack similar structures in the body, leading to an autoimmune response.

This type of cross-reactivity can result in the immune system erroneously targeting its own cells, causing inflammation and damage to various tissues. Diseases such as rheumatic fever, where antibodies against streptococcal bacteria can lead to damage in heart tissues, exemplify this mechanism. Understanding this theory provides insight into how autoimmunity can develop from an immune response initially aimed at protecting the body from infection.

While genetic mutations, viral infections, and environmental toxins can also be involved in the development of autoimmunity, they are part of broader theories that often incorporate multiple factors. For example, genetic predispositions can increase susceptibility to developing autoimmune disorders, while viral infections may trigger an autoimmune response, but the specific mechanism of cross-reactivity highlights a direct interaction between the immune system and body tissues that is critical to understanding many autoimmune diseases.