Serología

Serología is a branch of immunology that studies serum, the clear liquid that separates from blood when it is clotted. More specifically, it focuses on the reactions between antigens and antibodies within the serum. These reactions are the basis for many diagnostic tests used in medicine. When a foreign substance, such as a virus or bacterium, enters the body, the immune system produces antibodies to neutralize it. Serological tests detect the presence of these antibodies or the antigens themselves in a patient's blood sample.

The principles behind serological testing are relatively straightforward. If a specific antibody is present in the serum, it will bind to its corresponding antigen. This binding can be detected through various methods, such as agglutination (clumping), precipitation, complement fixation, or enzyme-linked immunosorbent assays (ELISA). The presence and quantity of these antigen-antibody complexes provide valuable information about past or current infections, autoimmune diseases, or the effectiveness of vaccinations. For example, a positive test for antibodies against a particular virus can indicate a past infection, even if the individual is no longer symptomatic.

Serological tests are crucial for diagnosing a wide range of infectious diseases, including HIV, hepatitis, syphilis, and Lyme disease. They are also used to monitor immune status, such as checking for immunity to measles or rubella after vaccination. Furthermore, serology plays a role in blood banking, where it is used to screen donated blood for infectious agents and to determine blood types. The continuous development of more sensitive and specific serological techniques enhances diagnostic accuracy and contributes to better patient care and public health surveillance.