How specific are antistreptococcal antibodies?
ASO is relatively nonspecific, whereas ADB is somewhat more specific. High ASO titers or other antistreptococcal antibodies can also be found in patients (particularly children) with other rheumatic diseases and no associated ARF. This is usually a result of nonspecific immune stimulation resulting in a polyclonal gammopathy, and past streptococcal exposure. The streptozyme test is a hemagglutination test which reacts with five or more streptococcal antigens; however, these are not well characterized, and the overall performance of this test makes it inferior to antigen-specific tests; streptozyme should not be used to confirm the diagnosis of ARF.
