Comparative studies of a monoclonal IgG lambda and two IgE kappa components from an individual patient: evidence for...

An IgG lambda and two IgE kappa proteins were isolated from the serum of a patient (DB) with anaemia associated with myelofibrosis. Idiotype-specific antisera produced against the three proteins were studied by precipitation in double immunodiffusion and by enzyme-linked immunosorbent assay (ELISA) and indicated that the two IgE kappa components shared idiotypic determinants while the IgG lambda protein did not show any cross-idiotypic reaction. The idiotypic determinants of the three proteins were not present in pooled normal serum, normal IgG, normal IgE or IgE from a patient with multiple myeloma.