Use of immunoblot technique for detection of human IgE and IgG antibodies to individual silk proteins.

Allergenic proteins were extracted from one silk batch that was imported to be used as filling material for bed mattresses and rugs. IgE and IgG antibodies to the extracted silk proteins were measured by RAST in sera of nine silk-sensitive persons as well as in sera of healthy control donors. Silk proteins were fractionated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis into 12 polypeptides of molecular weights between 14 and 70 kilodaltons. By means of the immunoblot technique, IgE and IgG antibodies to the individual silk polypeptides could be detected. Sera of silk-sensitive persons contained high titers of IgE and low titers of IgG antibodies to the separated silk polypeptides. Sera of control donors contained low IgG antibody titers to a limited number of these polypeptides.