serologisiin

Serology is a branch of laboratory medicine that studies immune responses in blood serum, typically focusing on antibodies and antigens. Serologic tests detect either antibodies produced in response to infection or vaccination, or antigens from pathogens, allowing indirect identification of current or past infection, immune status, or exposure to a specific antigen.

Historically, serology developed in the late 19th and early 20th centuries, with key contributions from Karl Landsteiner and colleagues who mapped blood groups and pioneered antibody testing.

Laboratory methods include enzyme-linked immunosorbent assay (ELISA), Western blot, immunofluorescence assays, agglutination tests, and rapid lateral flow immunoassays. Modern serology often uses automated platforms and multiplex assays, and results may be qualitative or quantitative. Some tests detect antibodies, others detect pathogen antigens.

Applications include infectious disease diagnosis (HIV, hepatitis B and C, syphilis), vaccination monitoring, seroprevalence studies, autoimmune disease testing (antinuclear antibodies, rheumatoid factor), and transfusion medicine to screen donor blood.

Interpretation: A positive antibody test may reflect past infection or vaccination; a negative result does not always rule out recent exposure due to the serologic window. Cross-reactivity can cause false positives; assay selection, timing of sampling, and clinical context are important. Confirmatory testing is common.

Quality and safety: Serologic testing relies on validated assays, proper specimen handling, and quality controls. Laboratories follow standards such as ISO 15189 and participate in external quality assessment to ensure accuracy.