Antibodies, while crucial for fighting infections, can sometimes contribute to disease development. This occurs primarily through two mechanisms: cross-reactivity and autoimmunity.
Cross-Reactivity
In cross-reactivity, an antibody produced against a specific antigen (like a food or pathogen) mistakenly reacts with a similar tissue antigen. This "friendly fire" triggers an immune response, causing inflammation and tissue damage. For instance, an antibody generated against a food antigen might also react with a protein in the body, leading to a localized allergic reaction or even a more widespread inflammatory response. [Reference: "Here the tissue antigen is either cross-reactive with an antibody formed in response to a food- or pathogen-borne antigen. Alternatively, the antigen has been altered, making it reactive to the antibody. This triggers complement activation, which causes inflammation in the tissue of deposition." (May 10, 2022)]
Autoimmunity
Autoimmune diseases arise when the immune system attacks the body's own tissues. This can involve antibodies targeting self-antigens, triggering chronic inflammation and organ damage. Examples include:
- Crohn's disease: An inflammatory bowel disease where antibodies attack the digestive tract. [Reference: Cleveland Clinic's snippet on Crohn's disease.]
- Psoriasis: A skin condition where antibodies attack skin cells. [Reference: Cleveland Clinic's snippet on Psoriasis.]
- Lupus: A systemic autoimmune disease where antibodies attack various tissues throughout the body. [Reference: WebMD snippet on Lupus stating that "When you have lupus, you develop autoimmune antibodies that can attach to tissues throughout your body."]
- Antiphospholipid syndrome (APS): This condition involves antibodies targeting phospholipids, leading to blood clot formation in arteries and veins. [Reference: Mayo Clinic's snippet on Antiphospholipid syndrome stating that "...immune system mistakenly creates antibodies that attack tissues in the body. These antibodies can cause blood clots to form in arteries and veins."]
Antibody-Induced Diseases from Treatments
Even therapeutic antibodies, like those in convalescent plasma or monoclonal antibody therapies for cancer, carry a risk of adverse effects. These can include cross-reactivity, causing unintended tissue damage, or triggering allergic reactions. [Reference: "The administration of antibodies, either therapeutic monoclonal antibodies or convalescent plasma, or B cell vaccines, could carry the risk of…" (May 10, 2022)]
Conclusion
Antibodies, while vital for immunity, can cause disease through cross-reactivity with self-antigens or by directly attacking self-tissues in autoimmune disorders. Even therapeutic antibody treatments carry inherent risks.
