Cross-idiotypic specificity detection

Amyloid proteins related to immunoglobulin possess individually specific (idiotypic) antigenic determinants i.e., such amyloid proteins from different individuals possess unique primary structures. Idiotypic determinants characteristic of a given amyloid protein can sometimes be detected in the serum of the same individual. In addition, however, amyloid proteins of a given type (it or X) frequently have shared antigenic determinants (120,124,126). Antiserum directed to an amyloid protein will, in general, cross-react weakly with normal L chains of the same type. It seems likely that these cross-reactions are attributable, in the case of the smaller amyloid proteins, to shared V region sequences. 

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