What are antibody titers?
Antibody titers: Bacteria are not measured directly, but rather are determined by measuring “antibodies” that are targeted to a specific “antigen.” Any substance that causes the immune system to produce antibodies against it. The substance may be from the environment or formed within the body.
What is a good critical titer for antibody titration?
The titration endpoint is reported as a reciprocal of the titer (i.e. 1:16 is reported as 16). The critical titer varies between laboratories, but most institutions use 8 to 32 for anti-D. Critical titers for other antibody specificities remain unclear.
What does a titer of 1 256 mean?
Titers are usually expressed as ratios, such as 1:256, meaning that one part serum to 256 parts saline solution (dilutant) results in no antibodies remaining detectable in the sample. A titer of 1:8 is, therefore, an indication of lower numbers of bacteria antibodies than a 1:256 titer.
Are antistreptococcal antibody titers useful in the diagnosis of GAS pharyngitis?
Antistreptococcal antibody titers have no value in the diagnosis of acute GAS pharyngitis, but are useful in prospective epidemiologic studies to differentiate true GAS infections from GAS carriage.
What is CSF antibody titer used to measure?
The CSF antibody titer can be measured for a number of diseases (Dubey, 1990b; Greene, 1990). Interpretation of the results is confounded by the need to differentiate among titers caused by vaccination, exposure to the antigen without development of the disease, and actual disease.
What happens if you dilute antibody titer?
If there are detectable antibodies present in the dilution, fluorescent green spots will appear on a slide prepared with antigens from a target pathogen. The highest dilution where reactivity, or fluorescence, can still be observed is the resulting antibody titer for the patient.