sérologii

Sérologie, or serology, is the branch of immunology that studies the serum components, especially antibodies and antigens, to understand immune responses and diagnose disease. It encompasses laboratory techniques that detect pathogen-derived molecules or host antibodies produced in response to infection or vaccination.

The central concepts include antibodies (immunoglobulins) that recognize specific antigens, antigens from pathogens or vaccines, seroconversion referring to the development of detectable antibodies, and antibody titers indicating concentration. Serological tests can indicate current infection, past exposure, or immune status.

Common methods include enzyme-linked immunosorbent assays (ELISA), Western blot, immunofluorescence assays, and agglutination or precipitation tests. Rapid diagnostic tests and lateral flow immunoassays provide point-of-care results. Neutralization assays assess functional antibodies, while nephelometry or turbidimetry quantify levels of immunoglobulins.

Applications span clinical diagnostics for infectious diseases such as HIV, hepatitis B and C, syphilis, and respiratory pathogens; autoimmune disease testing; blood bank screening; and monitoring vaccine responses. Serology also supports epidemiology and public health by estimating seroprevalence in populations.

Limitations include the window period before antibodies appear, cross-reactivity leading to false positives, and false negatives in immunocompromised individuals. Results must be interpreted with clinical and epidemiological context and appropriate quality control is essential.

Advances in multiplexing, high-throughput immunoassays, and point-of-care devices have expanded the utility of serology in routine care and outbreak surveillance.