Studies on monoclonal anti-isotypic and anti-idiotypic antibodies against leukemia and myeloma: I. Study on monoclonal anti-idiotypic antibodies against lambda chain protein of myeloma.

We used lambda chain extracted from urine of patient with myeloma (IgD lambda) as antigen for immunizing BALB/C mice, and 86 hybridoma cell clones secreting monoclonal antibodies (McAb) were obtained after fusing twice and cloning 3-4 times. 15 of these clones secreted monoclonal anti-idiotypic antibodies (anti-Id McAb). The results showed that 12 of 15 anti-Id antibodies reacted only with homologous lambda chain and IgD, not with lambda chain, kappa chain, IgG, IgA, IgM, IgD, IgE, albumin and paraglobulin from normal subjects. Indirect immunofluorescent assay demonstrated that positive reaction rate between anti-Id McAbs and peripheral blood lymphocytes or bone marrow cells of the patient with myeloma was up to 23%. No reaction was observed between anti-Id McAb and peripheral blood lymphocytes or bone marrow cells from normal subjects. Some of these McAbs presented positive reaction with plasmacytoma cell lines cultured in our laboratory.