keresztreagivitás

Keresztireagitivitás, also known as cross-reactivity, is a phenomenon where an antibody designed to bind to a specific antigen also binds to other, structurally similar antigens. This occurs because the molecular structures of different antigens can share common epitopes, which are the specific sites on an antigen that an antibody recognizes and binds to. When these epitopes are similar enough, an antibody produced against one antigen may exhibit a degree of binding to another.

This concept is particularly important in immunology and medicine. In diagnostic tests, for example, cross-reactivity can lead to false-positive results if an antibody designed to detect one substance also reacts with a different, unrelated substance. This can be a concern in allergy testing, where a person might test positive for an allergen they are not truly allergic to due to cross-reactivity with a similar-looking substance. Conversely, cross-reactivity can sometimes be exploited, such as in vaccine development, where an attenuated or weakened form of a pathogen might elicit an immune response that also protects against a closely related, more virulent strain. Understanding the degree of cross-reactivity is crucial for accurate diagnosis, effective treatment, and the development of reliable immunological tools.